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Ben Gardon [Thu, 1 Apr 2021 23:37:25 +0000 (16:37 -0700)]
KVM: x86/mmu: Move kvm_mmu_(get|put)_root to TDP MMU
The TDP MMU is almost the only user of kvm_mmu_get_root and
kvm_mmu_put_root. There is only one use of put_root in mmu.c for the
legacy / shadow MMU. Open code that one use and move the get / put
functions to the TDP MMU so they can be extended in future commits.
No functional change intended.
Signed-off-by: Ben Gardon <bgardon@google.com>
Message-Id: <
20210401233736.638171-3-bgardon@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Ben Gardon [Thu, 1 Apr 2021 23:37:24 +0000 (16:37 -0700)]
KVM: x86/mmu: Re-add const qualifier in kvm_tdp_mmu_zap_collapsible_sptes
kvm_tdp_mmu_zap_collapsible_sptes unnecessarily removes the const
qualifier from its memlsot argument, leading to a compiler warning. Add
the const annotation and pass it to subsequent functions.
Signed-off-by: Ben Gardon <bgardon@google.com>
Message-Id: <
20210401233736.638171-2-bgardon@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sean Christopherson [Fri, 2 Apr 2021 00:56:58 +0000 (17:56 -0700)]
KVM: x86/mmu: Allow yielding during MMU notifier unmap/zap, if possible
Let the TDP MMU yield when unmapping a range in response to a MMU
notification, if yielding is allowed by said notification. There is no
reason to disallow yielding in this case, and in theory the range being
invalidated could be quite large.
Cc: Ben Gardon <bgardon@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <
20210402005658.
3024832-11-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sean Christopherson [Fri, 2 Apr 2021 00:56:56 +0000 (17:56 -0700)]
KVM: Take mmu_lock when handling MMU notifier iff the hva hits a memslot
Defer acquiring mmu_lock in the MMU notifier paths until a "hit" has been
detected in the memslots, i.e. don't take the lock for notifications that
don't affect the guest.
For small VMs, spurious locking is a minor annoyance. And for "volatile"
setups where the majority of notifications _are_ relevant, this barely
qualifies as an optimization.
But, for large VMs (hundreds of threads) with static setups, e.g. no
page migration, no swapping, etc..., the vast majority of MMU notifier
callbacks will be unrelated to the guest, e.g. will often be in response
to the userspace VMM adjusting its own virtual address space. In such
large VMs, acquiring mmu_lock can be painful as it blocks vCPUs from
handling page faults. In some scenarios it can even be "fatal" in the
sense that it causes unacceptable brownouts, e.g. when rebuilding huge
pages after live migration, a significant percentage of vCPUs will be
attempting to handle page faults.
x86's TDP MMU implementation is especially susceptible to spurious
locking due it taking mmu_lock for read when handling page faults.
Because rwlock is fair, a single writer will stall future readers, while
the writer is itself stalled waiting for in-progress readers to complete.
This is exacerbated by the MMU notifiers often firing multiple times in
quick succession, e.g. moving a page will (always?) invoke three separate
notifiers: .invalidate_range_start(), invalidate_range_end(), and
.change_pte(). Unnecessarily taking mmu_lock each time means even a
single spurious sequence can be problematic.
Note, this optimizes only the unpaired callbacks. Optimizing the
.invalidate_range_{start,end}() pairs is more complex and will be done in
a future patch.
Suggested-by: Ben Gardon <bgardon@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <
20210402005658.
3024832-9-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sean Christopherson [Fri, 2 Apr 2021 00:56:55 +0000 (17:56 -0700)]
KVM: Move MMU notifier's mmu_lock acquisition into common helper
Acquire and release mmu_lock in the __kvm_handle_hva_range() helper
instead of requiring the caller to do the same. This paves the way for
future patches to take mmu_lock if and only if an overlapping memslot is
found, without also having to introduce the on_lock() shenanigans used
to manipulate the notifier count and sequence.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <
20210402005658.
3024832-8-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sean Christopherson [Fri, 2 Apr 2021 00:56:54 +0000 (17:56 -0700)]
KVM: Kill off the old hva-based MMU notifier callbacks
Yank out the hva-based MMU notifier APIs now that all architectures that
use the notifiers have moved to the gfn-based APIs.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <
20210402005658.
3024832-7-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sean Christopherson [Fri, 2 Apr 2021 00:56:53 +0000 (17:56 -0700)]
KVM: PPC: Convert to the gfn-based MMU notifier callbacks
Move PPC to the gfn-base MMU notifier APIs, and update all 15 bajillion
PPC-internal hooks to work with gfns instead of hvas.
No meaningful functional change intended, though the exact order of
operations is slightly different since the memslot lookups occur before
calling into arch code.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <
20210402005658.
3024832-6-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sean Christopherson [Fri, 2 Apr 2021 00:56:52 +0000 (17:56 -0700)]
KVM: MIPS/MMU: Convert to the gfn-based MMU notifier callbacks
Move MIPS to the gfn-based MMU notifier APIs, which do the hva->gfn
lookup in common code, and whose code is nearly identical to MIPS'
lookup.
No meaningful functional change intended, though the exact order of
operations is slightly different since the memslot lookups occur before
calling into arch code.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <
20210402005658.
3024832-5-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sean Christopherson [Fri, 2 Apr 2021 00:56:51 +0000 (17:56 -0700)]
KVM: arm64: Convert to the gfn-based MMU notifier callbacks
Move arm64 to the gfn-base MMU notifier APIs, which do the hva->gfn
lookup in common code.
No meaningful functional change intended, though the exact order of
operations is slightly different since the memslot lookups occur before
calling into arch code.
Reviewed-by: Marc Zyngier <maz@kernel.org>
Tested-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <
20210402005658.
3024832-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sean Christopherson [Fri, 2 Apr 2021 00:56:50 +0000 (17:56 -0700)]
KVM: Move x86's MMU notifier memslot walkers to generic code
Move the hva->gfn lookup for MMU notifiers into common code. Every arch
does a similar lookup, and some arch code is all but identical across
multiple architectures.
In addition to consolidating code, this will allow introducing
optimizations that will benefit all architectures without incurring
multiple walks of the memslots, e.g. by taking mmu_lock if and only if a
relevant range exists in the memslots.
The use of __always_inline to avoid indirect call retpolines, as done by
x86, may also benefit other architectures.
Consolidating the lookups also fixes a wart in x86, where the legacy MMU
and TDP MMU each do their own memslot walks.
Lastly, future enhancements to the memslot implementation, e.g. to add an
interval tree to track host address, will need to touch far less arch
specific code.
MIPS, PPC, and arm64 will be converted one at a time in future patches.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <
20210402005658.
3024832-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sean Christopherson [Fri, 2 Apr 2021 00:56:49 +0000 (02:56 +0200)]
KVM: Assert that notifier count is elevated in .change_pte()
In KVM's .change_pte() notification callback, replace the notifier
sequence bump with a WARN_ON assertion that the notifier count is
elevated. An elevated count provides stricter protections than bumping
the sequence, and the sequence is guarnateed to be bumped before the
count hits zero.
When .change_pte() was added by commit
828502d30073 ("ksm: add
mmu_notifier set_pte_at_notify()"), bumping the sequence was necessary
as .change_pte() would be invoked without any surrounding notifications.
However, since commit
6bdb913f0a70 ("mm: wrap calls to set_pte_at_notify
with invalidate_range_start and invalidate_range_end"), all calls to
.change_pte() are guaranteed to be surrounded by start() and end(), and
so are guaranteed to run with an elevated notifier count.
Note, wrapping .change_pte() with .invalidate_range_{start,end}() is a
bug of sorts, as invalidating the secondary MMU's (KVM's) PTE defeats
the purpose of .change_pte(). Every arch's kvm_set_spte_hva() assumes
.change_pte() is called when the relevant SPTE is present in KVM's MMU,
as the original goal was to accelerate Kernel Samepage Merging (KSM) by
updating KVM's SPTEs without requiring a VM-Exit (due to invalidating
the SPTE). I.e. it means that .change_pte() is effectively dead code
on _all_ architectures.
x86 and MIPS are clearcut nops if the old SPTE is not-present, and that
is guaranteed due to the prior invalidation. PPC simply unmaps the SPTE,
which again should be a nop due to the invalidation. arm64 is a bit
murky, but it's also likely a nop because kvm_pgtable_stage2_map() is
called without a cache pointer, which means it will map an entry if and
only if an existing PTE was found.
For now, take advantage of the bug to simplify future consolidation of
KVMs's MMU notifier code. Doing so will not greatly complicate fixing
.change_pte(), assuming it's even worth fixing. .change_pte() has been
broken for 8+ years and no one has complained. Even if there are
KSM+KVM users that care deeply about its performance, the benefits of
avoiding VM-Exits via .change_pte() need to be reevaluated to justify
the added complexity and testing burden. Ripping out .change_pte()
entirely would be a lot easier.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Paolo Bonzini [Wed, 31 Mar 2021 07:40:39 +0000 (09:40 +0200)]
KVM: MIPS: defer flush to generic MMU notifier code
Return 1 from kvm_unmap_hva_range and kvm_set_spte_hva if a flush is
needed, so that the generic code can coalesce the flushes.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Paolo Bonzini [Fri, 2 Apr 2021 09:44:56 +0000 (11:44 +0200)]
KVM: MIPS: let generic code call prepare_flush_shadow
Since all calls to kvm_flush_remote_tlbs must be preceded by
kvm_mips_callbacks->prepare_flush_shadow, repurpose
kvm_arch_flush_remote_tlb to invoke it. This makes it possible
to use the TLB flushing mechanism provided by the generic MMU
notifier code.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Paolo Bonzini [Wed, 31 Mar 2021 07:38:16 +0000 (09:38 +0200)]
KVM: MIPS: rework flush_shadow_* callbacks into one that prepares the flush
Both trap-and-emulate and VZ have a single implementation that covers
both .flush_shadow_all and .flush_shadow_memslot, and both of them end
with a call to kvm_flush_remote_tlbs.
Unify the callbacks into one and extract the call to kvm_flush_remote_tlbs.
The next patches will pull it further out of the the architecture-specific
MMU notifier functions kvm_unmap_hva_range and kvm_set_spte_hva.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Paolo Bonzini [Fri, 2 Apr 2021 15:53:09 +0000 (17:53 +0200)]
KVM: constify kvm_arch_flush_remote_tlbs_memslot
memslots are stored in RCU and there should be no need to
change them.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sean Christopherson [Tue, 6 Apr 2021 19:07:40 +0000 (12:07 -0700)]
KVM: Explicitly use GFP_KERNEL_ACCOUNT for 'struct kvm_vcpu' allocations
Use GFP_KERNEL_ACCOUNT when allocating vCPUs to make it more obvious that
that the allocations are accounted, to make it easier to audit KVM's
allocations in the future, and to be consistent with other cache usage in
KVM.
When using SLAB/SLUB, this is a nop as the cache itself is created with
SLAB_ACCOUNT.
When using SLOB, there are caveats within caveats. SLOB doesn't honor
SLAB_ACCOUNT, so passing GFP_KERNEL_ACCOUNT will result in vCPU
allocations now being accounted. But, even that depends on internal
SLOB details as SLOB will only go to the page allocator when its cache is
depleted. That just happens to be extremely likely for vCPUs because the
size of kvm_vcpu is larger than the a page for almost all combinations of
architecture and page size. Whether or not the SLOB behavior is by
design is unknown; it's just as likely that no SLOB users care about
accounding and so no one has bothered to implemented support in SLOB.
Regardless, accounting vCPU allocations will not break SLOB+KVM+cgroup
users, if any exist.
Reviewed-by: Wanpeng Li <kernellwp@gmail.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <
20210406190740.
4055679-1-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Paolo Bonzini [Fri, 2 Apr 2021 12:05:19 +0000 (08:05 -0400)]
KVM: MMU: protect TDP MMU pages only down to required level
When using manual protection of dirty pages, it is not necessary
to protect nested page tables down to the 4K level; instead KVM
can protect only hugepages in order to split them lazily, and
delay write protection at 4K-granularity until KVM_CLEAR_DIRTY_LOG.
This was overlooked in the TDP MMU, so do it there as well.
Fixes:
a6a0b05da9f37 ("kvm: x86/mmu: Support dirty logging for the TDP MMU")
Cc: Ben Gardon <bgardon@google.com>
Reviewed-by: Keqian Zhu <zhukeqian1@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Maxim Levitsky [Thu, 1 Apr 2021 13:54:47 +0000 (16:54 +0300)]
KVM: s390x: implement KVM_CAP_SET_GUEST_DEBUG2
Define KVM_GUESTDBG_VALID_MASK and use it to implement this capabiity.
Compile tested only.
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <
20210401135451.
1004564-6-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Maxim Levitsky [Thu, 1 Apr 2021 13:54:46 +0000 (16:54 +0300)]
KVM: aarch64: implement KVM_CAP_SET_GUEST_DEBUG2
Move KVM_GUESTDBG_VALID_MASK to kvm_host.h
and use it to return the value of this capability.
Compile tested only.
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <
20210401135451.
1004564-5-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Maxim Levitsky [Thu, 1 Apr 2021 13:54:45 +0000 (16:54 +0300)]
KVM: x86: implement KVM_CAP_SET_GUEST_DEBUG2
Store the supported bits into KVM_GUESTDBG_VALID_MASK
macro, similar to how arm does this.
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <
20210401135451.
1004564-4-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Paolo Bonzini [Tue, 6 Apr 2021 14:24:07 +0000 (10:24 -0400)]
KVM: introduce KVM_CAP_SET_GUEST_DEBUG2
This capability will allow the user to know which KVM_GUESTDBG_* bits
are supported.
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <
20210401135451.
1004564-3-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Maxim Levitsky [Thu, 1 Apr 2021 14:38:14 +0000 (17:38 +0300)]
KVM: x86: pending exceptions must not be blocked by an injected event
Injected interrupts/nmi should not block a pending exception,
but rather be either lost if nested hypervisor doesn't
intercept the pending exception (as in stock x86), or be delivered
in exitintinfo/IDT_VECTORING_INFO field, as a part of a VMexit
that corresponds to the pending exception.
The only reason for an exception to be blocked is when nested run
is pending (and that can't really happen currently
but still worth checking for).
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <
20210401143817.
1030695-2-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Yang Yingliang [Thu, 1 Apr 2021 14:25:14 +0000 (22:25 +0800)]
KVM: selftests: remove redundant semi-colon
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Message-Id: <
20210401142514.
1688199-1-yangyingliang@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Maxim Levitsky [Thu, 1 Apr 2021 14:18:10 +0000 (17:18 +0300)]
KVM: nSVM: call nested_svm_load_cr3 on nested state load
While KVM's MMU should be fully reset by loading of nested CR0/CR3/CR4
by KVM_SET_SREGS, we are not in nested mode yet when we do it and therefore
only root_mmu is reset.
On regular nested entries we call nested_svm_load_cr3 which both updates
the guest's CR3 in the MMU when it is needed, and it also initializes
the mmu again which makes it initialize the walk_mmu as well when nested
paging is enabled in both host and guest.
Since we don't call nested_svm_load_cr3 on nested state load,
the walk_mmu can be left uninitialized, which can lead to a NULL pointer
dereference while accessing it if we happen to get a nested page fault
right after entering the nested guest first time after the migration and
we decide to emulate it, which leads to the emulator trying to access
walk_mmu->gva_to_gpa which is NULL.
Therefore we should call this function on nested state load as well.
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <
20210401141814.
1029036-3-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
David Edmondson [Thu, 18 Mar 2021 12:08:41 +0000 (12:08 +0000)]
KVM: x86: dump_vmcs should include the autoload/autostore MSR lists
When dumping the current VMCS state, include the MSRs that are being
automatically loaded/stored during VM entry/exit.
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: David Edmondson <david.edmondson@oracle.com>
Message-Id: <
20210318120841.133123-6-david.edmondson@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
David Edmondson [Thu, 18 Mar 2021 12:08:40 +0000 (12:08 +0000)]
KVM: x86: dump_vmcs should show the effective EFER
If EFER is not being loaded from the VMCS, show the effective value by
reference to the MSR autoload list or calculation.
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: David Edmondson <david.edmondson@oracle.com>
Message-Id: <
20210318120841.133123-5-david.edmondson@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
David Edmondson [Thu, 18 Mar 2021 12:08:39 +0000 (12:08 +0000)]
KVM: x86: dump_vmcs should consider only the load controls of EFER/PAT
When deciding whether to dump the GUEST_IA32_EFER and GUEST_IA32_PAT
fields of the VMCS, examine only the VM entry load controls, as saving
on VM exit has no effect on whether VM entry succeeds or fails.
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: David Edmondson <david.edmondson@oracle.com>
Message-Id: <
20210318120841.133123-4-david.edmondson@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
David Edmondson [Thu, 18 Mar 2021 12:08:38 +0000 (12:08 +0000)]
KVM: x86: dump_vmcs should not conflate EFER and PAT presence in VMCS
Show EFER and PAT based on their individual entry/exit controls.
Signed-off-by: David Edmondson <david.edmondson@oracle.com>
Message-Id: <
20210318120841.133123-3-david.edmondson@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
David Edmondson [Thu, 18 Mar 2021 12:08:37 +0000 (12:08 +0000)]
KVM: x86: dump_vmcs should not assume GUEST_IA32_EFER is valid
If the VM entry/exit controls for loading/saving MSR_EFER are either
not available (an older processor or explicitly disabled) or not
used (host and guest values are the same), reading GUEST_IA32_EFER
from the VMCS returns an inaccurate value.
Because of this, in dump_vmcs() don't use GUEST_IA32_EFER to decide
whether to print the PDPTRs - always do so if the fields exist.
Fixes:
4eb64dce8d0a ("KVM: x86: dump VMCS on invalid entry")
Signed-off-by: David Edmondson <david.edmondson@oracle.com>
Message-Id: <
20210318120841.133123-2-david.edmondson@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Maxim Levitsky [Thu, 1 Apr 2021 11:19:28 +0000 (14:19 +0300)]
KVM: nSVM: improve SYSENTER emulation on AMD
Currently to support Intel->AMD migration, if CPU vendor is GenuineIntel,
we emulate the full 64 value for MSR_IA32_SYSENTER_{EIP|ESP}
msrs, and we also emulate the sysenter/sysexit instruction in long mode.
(Emulator does still refuse to emulate sysenter in 64 bit mode, on the
ground that the code for that wasn't tested and likely has no users)
However when virtual vmload/vmsave is enabled, the vmload instruction will
update these 32 bit msrs without triggering their msr intercept,
which will lead to having stale values in kvm's shadow copy of these msrs,
which relies on the intercept to be up to date.
Fix/optimize this by doing the following:
1. Enable the MSR intercepts for SYSENTER MSRs iff vendor=GenuineIntel
(This is both a tiny optimization and also ensures that in case
the guest cpu vendor is AMD, the msrs will be 32 bit wide as
AMD defined).
2. Store only high 32 bit part of these msrs on interception and combine
it with hardware msr value on intercepted read/writes
iff vendor=GenuineIntel.
3. Disable vmload/vmsave virtualization if vendor=GenuineIntel.
(It is somewhat insane to set vendor=GenuineIntel and still enable
SVM for the guest but well whatever).
Then zero the high 32 bit parts when kvm intercepts and emulates vmload.
Thanks a lot to Paulo Bonzini for helping me with fixing this in the most
correct way.
This patch fixes nested migration of 32 bit nested guests, that was
broken because incorrect cached values of SYSENTER msrs were stored in
the migration stream if L1 changed these msrs with
vmload prior to L2 entry.
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <
20210401111928.996871-3-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Maxim Levitsky [Thu, 1 Apr 2021 11:19:27 +0000 (14:19 +0300)]
KVM: x86: add guest_cpuid_is_intel
This is similar to existing 'guest_cpuid_is_amd_or_hygon'
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <
20210401111928.996871-2-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sean Christopherson [Wed, 31 Mar 2021 02:30:25 +0000 (19:30 -0700)]
KVM: x86: Account a variety of miscellaneous allocations
Switch to GFP_KERNEL_ACCOUNT for a handful of allocations that are
clearly associated with a single task/VM.
Note, there are a several SEV allocations that aren't accounted, but
those can (hopefully) be fixed by using the local stack for memory.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <
20210331023025.
2485960-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sean Christopherson [Wed, 31 Mar 2021 03:19:36 +0000 (20:19 -0700)]
KVM: SVM: Do not allow SEV/SEV-ES initialization after vCPUs are created
Reject KVM_SEV_INIT and KVM_SEV_ES_INIT if they are attempted after one
or more vCPUs have been created. KVM assumes a VM is tagged SEV/SEV-ES
prior to vCPU creation, e.g. init_vmcb() needs to mark the VMCB as SEV
enabled, and svm_create_vcpu() needs to allocate the VMSA. At best,
creating vCPUs before SEV/SEV-ES init will lead to unexpected errors
and/or behavior, and at worst it will crash the host, e.g.
sev_launch_update_vmsa() will dereference a null svm->vmsa pointer.
Fixes:
1654efcbc431 ("KVM: SVM: Add KVM_SEV_INIT command")
Fixes:
ad73109ae7ec ("KVM: SVM: Provide support to launch and run an SEV-ES guest")
Cc: stable@vger.kernel.org
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <
20210331031936.
2495277-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sean Christopherson [Wed, 31 Mar 2021 03:19:35 +0000 (20:19 -0700)]
KVM: SVM: Do not set sev->es_active until KVM_SEV_ES_INIT completes
Set sev->es_active only after the guts of KVM_SEV_ES_INIT succeeds. If
the command fails, e.g. because SEV is already active or there are no
available ASIDs, then es_active will be left set even though the VM is
not fully SEV-ES capable.
Refactor the code so that "es_active" is passed on the stack instead of
being prematurely shoved into sev_info, both to avoid having to unwind
sev_info and so that it's more obvious what actually consumes es_active
in sev_guest_init() and its helpers.
Fixes:
ad73109ae7ec ("KVM: SVM: Provide support to launch and run an SEV-ES guest")
Cc: stable@vger.kernel.org
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <
20210331031936.
2495277-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sean Christopherson [Wed, 31 Mar 2021 03:19:34 +0000 (20:19 -0700)]
KVM: SVM: Use online_vcpus, not created_vcpus, to iterate over vCPUs
Use the kvm_for_each_vcpu() helper to iterate over vCPUs when encrypting
VMSAs for SEV, which effectively switches to use online_vcpus instead of
created_vcpus. This fixes a possible null-pointer dereference as
created_vcpus does not guarantee a vCPU exists, since it is updated at
the very beginning of KVM_CREATE_VCPU. created_vcpus exists to allow the
bulk of vCPU creation to run in parallel, while still correctly
restricting the max number of max vCPUs.
Fixes:
ad73109ae7ec ("KVM: SVM: Provide support to launch and run an SEV-ES guest")
Cc: stable@vger.kernel.org
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <
20210331031936.
2495277-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sean Christopherson [Wed, 31 Mar 2021 00:49:42 +0000 (17:49 -0700)]
KVM: x86/mmu: Simplify code for aging SPTEs in TDP MMU
Use a basic NOT+AND sequence to clear the Accessed bit in TDP MMU SPTEs,
as opposed to the fancy ffs()+clear_bit() logic that was copied from the
legacy MMU. The legacy MMU uses clear_bit() because it is operating on
the SPTE itself, i.e. clearing needs to be atomic. The TDP MMU operates
on a local variable that it later writes to the SPTE, and so doesn't need
to be atomic or even resident in memory.
Opportunistically drop unnecessary initialization of new_spte, it's
guaranteed to be written before being accessed.
Using NOT+AND instead of ffs()+clear_bit() reduces the sequence from:
0x0000000000058be6 <+134>: test %rax,%rax
0x0000000000058be9 <+137>: je 0x58bf4 <age_gfn_range+148>
0x0000000000058beb <+139>: test %rax,%rdi
0x0000000000058bee <+142>: je 0x58cdc <age_gfn_range+380>
0x0000000000058bf4 <+148>: mov %rdi,0x8(%rsp)
0x0000000000058bf9 <+153>: mov $0xffffffff,%edx
0x0000000000058bfe <+158>: bsf %eax,%edx
0x0000000000058c01 <+161>: movslq %edx,%rdx
0x0000000000058c04 <+164>: lock btr %rdx,0x8(%rsp)
0x0000000000058c0b <+171>: mov 0x8(%rsp),%r15
to:
0x0000000000058bdd <+125>: test %rax,%rax
0x0000000000058be0 <+128>: je 0x58beb <age_gfn_range+139>
0x0000000000058be2 <+130>: test %rax,%r8
0x0000000000058be5 <+133>: je 0x58cc0 <age_gfn_range+352>
0x0000000000058beb <+139>: not %rax
0x0000000000058bee <+142>: and %r8,%rax
0x0000000000058bf1 <+145>: mov %rax,%r15
thus eliminating several memory accesses, including a locked access.
Cc: Ben Gardon <bgardon@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <
20210331004942.
2444916-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sean Christopherson [Wed, 31 Mar 2021 00:49:41 +0000 (17:49 -0700)]
KVM: x86/mmu: Remove spurious clearing of dirty bit from TDP MMU SPTE
Don't clear the dirty bit when aging a TDP MMU SPTE (in response to a MMU
notifier event). Prematurely clearing the dirty bit could cause spurious
PML updates if aging a page happened to coincide with dirty logging.
Note, tdp_mmu_set_spte_no_acc_track() flows into __handle_changed_spte(),
so the host PFN will be marked dirty, i.e. there is no potential for data
corruption.
Fixes:
a6a0b05da9f3 ("kvm: x86/mmu: Support dirty logging for the TDP MMU")
Cc: Ben Gardon <bgardon@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <
20210331004942.
2444916-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sean Christopherson [Fri, 26 Mar 2021 02:19:57 +0000 (19:19 -0700)]
KVM: x86/mmu: Drop trace_kvm_age_page() tracepoint
Remove x86's trace_kvm_age_page() tracepoint. It's mostly redundant with
the common trace_kvm_age_hva() tracepoint, and if there is a need for the
extra details, e.g. gfn, referenced, etc... those details should be added
to the common tracepoint so that all architectures and MMUs benefit from
the info.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <
20210326021957.
1424875-19-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sean Christopherson [Fri, 26 Mar 2021 02:19:48 +0000 (19:19 -0700)]
KVM: Move arm64's MMU notifier trace events to generic code
Move arm64's MMU notifier trace events into common code in preparation
for doing the hva->gfn lookup in common code. The alternative would be
to trace the gfn instead of hva, but that's not obviously better and
could also be done in common code. Tracing the notifiers is also quite
handy for debug regardless of architecture.
Remove a completely redundant tracepoint from PPC e500.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <
20210326021957.
1424875-10-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sean Christopherson [Fri, 26 Mar 2021 02:19:47 +0000 (19:19 -0700)]
KVM: Move prototypes for MMU notifier callbacks to generic code
Move the prototypes for the MMU notifier callbacks out of arch code and
into common code. There is no benefit to having each arch replicate the
prototypes since any deviation from the invocation in common code will
explode.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <
20210326021957.
1424875-9-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sean Christopherson [Fri, 26 Mar 2021 02:19:46 +0000 (19:19 -0700)]
KVM: x86/mmu: Use leaf-only loop for walking TDP SPTEs when changing SPTE
Use the leaf-only TDP iterator when changing the SPTE in reaction to a
MMU notifier. Practically speaking, this is a nop since the guts of the
loop explicitly looks for 4k SPTEs, which are always leaf SPTEs. Switch
the iterator to match age_gfn_range() and test_age_gfn() so that a future
patch can consolidate the core iterating logic.
No real functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <
20210326021957.
1424875-8-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sean Christopherson [Fri, 26 Mar 2021 02:19:45 +0000 (19:19 -0700)]
KVM: x86/mmu: Pass address space ID to TDP MMU root walkers
Move the address space ID check that is performed when iterating over
roots into the macro helpers to consolidate code.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <
20210326021957.
1424875-7-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sean Christopherson [Fri, 26 Mar 2021 02:19:44 +0000 (19:19 -0700)]
KVM: x86/mmu: Pass address space ID to __kvm_tdp_mmu_zap_gfn_range()
Pass the address space ID to TDP MMU's primary "zap gfn range" helper to
allow the MMU notifier paths to iterate over memslots exactly once.
Currently, both the legacy MMU and TDP MMU iterate over memslots when
looking for an overlapping hva range, which can be quite costly if there
are a large number of memslots.
Add a "flush" parameter so that iterating over multiple address spaces
in the caller will continue to do the right thing when yielding while a
flush is pending from a previous address space.
Note, this also has a functional change in the form of coalescing TLB
flushes across multiple address spaces in kvm_zap_gfn_range(), and also
optimizes the TDP MMU to utilize range-based flushing when running as L1
with Hyper-V enlightenments.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <
20210326021957.
1424875-6-seanjc@google.com>
[Keep separate for loops to prepare for other incoming patches. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sean Christopherson [Fri, 26 Mar 2021 02:19:43 +0000 (19:19 -0700)]
KVM: x86/mmu: Coalesce TLB flushes across address spaces for gfn range zap
Gather pending TLB flushes across both address spaces when zapping a
given gfn range. This requires feeding "flush" back into subsequent
calls, but on the plus side sets the stage for further batching
between the legacy MMU and TDP MMU. It also allows refactoring the
address space iteration to cover the legacy and TDP MMUs without
introducing truly ugly code.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <
20210326021957.
1424875-5-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sean Christopherson [Fri, 26 Mar 2021 02:19:42 +0000 (19:19 -0700)]
KVM: x86/mmu: Coalesce TLB flushes when zapping collapsible SPTEs
Gather pending TLB flushes across both the legacy and TDP MMUs when
zapping collapsible SPTEs to avoid multiple flushes if both the legacy
MMU (for nested guests) and TDP MMU have mappings for the memslot.
Note, this also optimizes the TDP MMU to flush only the relevant range
when running as L1 with Hyper-V enlightenments.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <
20210326021957.
1424875-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sean Christopherson [Fri, 26 Mar 2021 02:19:41 +0000 (19:19 -0700)]
KVM: x86/mmu: Move flushing for "slot" handlers to caller for legacy MMU
Place the onus on the caller of slot_handle_*() to flush the TLB, rather
than handling the flush in the helper, and rename parameters accordingly.
This will allow future patches to coalesce flushes between address spaces
and between the legacy and TDP MMUs.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <
20210326021957.
1424875-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sean Christopherson [Fri, 26 Mar 2021 02:19:40 +0000 (19:19 -0700)]
KVM: x86/mmu: Coalesce TDP MMU TLB flushes when zapping collapsible SPTEs
When zapping collapsible SPTEs across multiple roots, gather pending
flushes and perform a single remote TLB flush at the end, as opposed to
flushing after processing every root.
Note, flush may be cleared by the result of zap_collapsible_spte_range().
This is intended and correct, e.g. yielding may have serviced a prior
pending flush.
Cc: Ben Gardon <bgardon@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <
20210326021957.
1424875-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Vitaly Kuznetsov [Mon, 29 Mar 2021 12:48:04 +0000 (14:48 +0200)]
KVM: x86/vPMU: Forbid reading from MSR_F15H_PERF MSRs when guest doesn't have X86_FEATURE_PERFCTR_CORE
MSR_F15H_PERF_CTL0-5, MSR_F15H_PERF_CTR0-5 MSRs have a CPUID bit assigned
to them (X86_FEATURE_PERFCTR_CORE) and when it wasn't exposed to the guest
the correct behavior is to inject #GP an not just return zero.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <
20210329124804.170173-1-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Krish Sadhukhan [Tue, 23 Mar 2021 17:50:03 +0000 (13:50 -0400)]
KVM: nSVM: If VMRUN is single-stepped, queue the #DB intercept in nested_svm_vmexit()
According to APM, the #DB intercept for a single-stepped VMRUN must happen
after the completion of that instruction, when the guest does #VMEXIT to
the host. However, in the current implementation of KVM, the #DB intercept
for a single-stepped VMRUN happens after the completion of the instruction
that follows the VMRUN instruction. When the #DB intercept handler is
invoked, it shows the RIP of the instruction that follows VMRUN, instead of
of VMRUN itself. This is an incorrect RIP as far as single-stepping VMRUN
is concerned.
This patch fixes the problem by checking, in nested_svm_vmexit(), for the
condition that the VMRUN instruction is being single-stepped and if so,
queues the pending #DB intercept so that the #DB is accounted for before
we execute L1's next instruction.
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oraacle.com>
Message-Id: <
20210323175006.73249-2-krish.sadhukhan@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Paolo Bonzini [Thu, 8 Apr 2021 12:10:25 +0000 (08:10 -0400)]
KVM: MMU: load PDPTRs outside mmu_lock
On SVM, reading PDPTRs might access guest memory, which might fault
and thus might sleep. On the other hand, it is not possible to
release the lock after make_mmu_pages_available has been called.
Therefore, push the call to make_mmu_pages_available and the
mmu_lock critical section within mmu_alloc_direct_roots and
mmu_alloc_shadow_roots.
Reported-by: Wanpeng Li <wanpengli@tencent.com>
Co-developed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Paolo Bonzini [Sat, 17 Apr 2021 12:29:47 +0000 (08:29 -0400)]
Merge remote-tracking branch 'tip/x86/sgx' into kvm-next
Pull generic x86 SGX changes needed to support SGX in virtual machines.
Paolo Bonzini [Sat, 17 Apr 2021 12:29:41 +0000 (08:29 -0400)]
Merge tag 'kvm-s390-next-5.13-2' of git://git./linux/kernel/git/kvms390/linux into HEAD
KVM: s390: Fix potential crash in preemptible kernels
There is a potential race for preemptible kernels, where
the host kernel would get a fault when it is preempted as
the wrong point in time.
Paolo Bonzini [Thu, 15 Apr 2021 17:02:13 +0000 (13:02 -0400)]
Merge tag 'kvm-s390-next-5.13-1' of git://git./linux/kernel/git/kvms390/linux into HEAD
KVM: s390: Updates for 5.13
- properly handle MVPG in nesting KVM (vsie)
- allow to forward the yield_to hypercall (diagnose 9c)
- fixes
Heiko Carstens [Thu, 15 Apr 2021 08:01:27 +0000 (10:01 +0200)]
KVM: s390: fix guarded storage control register handling
store_regs_fmt2() has an ordering problem: first the guarded storage
facility is enabled on the local cpu, then preemption disabled, and
then the STGSC (store guarded storage controls) instruction is
executed.
If the process gets scheduled away between enabling the guarded
storage facility and before preemption is disabled, this might lead to
a special operation exception and therefore kernel crash as soon as
the process is scheduled back and the STGSC instruction is executed.
Fixes:
4e0b1ab72b8a ("KVM: s390: gs support for kvm guests")
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Cc: <stable@vger.kernel.org> # 4.12
Link: https://lore.kernel.org/r/20210415080127.1061275-1-hca@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Wei Yongjun [Mon, 12 Apr 2021 16:00:23 +0000 (16:00 +0000)]
x86/sgx: Mark sgx_vepc_vm_ops static
Fix the following sparse warning:
arch/x86/kernel/cpu/sgx/virt.c:95:35: warning:
symbol 'sgx_vepc_vm_ops' was not declared. Should it be static?
This symbol is not used outside of virt.c so mark it static.
[ bp: Massage commit message. ]
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210412160023.193850-1-weiyongjun1@huawei.com
Jarkko Sakkinen [Thu, 8 Apr 2021 09:29:24 +0000 (12:29 +0300)]
x86/sgx: Do not update sgx_nr_free_pages in sgx_setup_epc_section()
The commit in Fixes: changed the SGX EPC page sanitization to end up in
sgx_free_epc_page() which puts clean and sanitized pages on the free
list.
This was done for the reason that it is best to keep the logic to assign
available-for-use EPC pages to the correct NUMA lists in a single
location.
sgx_nr_free_pages is also incremented by sgx_free_epc_pages() but those
pages which are being added there per EPC section do not belong to the
free list yet because they haven't been sanitized yet - they land on the
dirty list first and the sanitization happens later when ksgxd starts
massaging them.
So remove that addition there and have sgx_free_epc_page() do that
solely.
[ bp: Sanitize commit message too. ]
Fixes:
51ab30eb2ad4 ("x86/sgx: Replace section->init_laundry_list with sgx_dirty_page_list")
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210408092924.7032-1-jarkko@kernel.org
Sean Christopherson [Fri, 19 Mar 2021 07:23:09 +0000 (20:23 +1300)]
x86/sgx: Move provisioning device creation out of SGX driver
And extract sgx_set_attribute() out of sgx_ioc_enclave_provision() and
export it as symbol for KVM to use.
The provisioning key is sensitive. The SGX driver only allows to create
an enclave which can access the provisioning key when the enclave
creator has permission to open /dev/sgx_provision. It should apply to
a VM as well, as the provisioning key is platform-specific, thus an
unrestricted VM can also potentially compromise the provisioning key.
Move the provisioning device creation out of sgx_drv_init() to
sgx_init() as a preparation for adding SGX virtualization support,
so that even if the SGX driver is not enabled due to flexible launch
control not being available, SGX virtualization can still be enabled,
and use it to restrict a VM's capability of being able to access the
provisioning key.
[ bp: Massage commit message. ]
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Link: https://lkml.kernel.org/r/0f4d044d621561f26d5f4ef73e8dc6cd18cc7e79.1616136308.git.kai.huang@intel.com
Sean Christopherson [Fri, 19 Mar 2021 07:23:08 +0000 (20:23 +1300)]
x86/sgx: Add helpers to expose ECREATE and EINIT to KVM
The host kernel must intercept ECREATE to impose policies on guests, and
intercept EINIT to be able to write guest's virtual SGX_LEPUBKEYHASH MSR
values to hardware before running guest's EINIT so it can run correctly
according to hardware behavior.
Provide wrappers around __ecreate() and __einit() to hide the ugliness
of overloading the ENCLS return value to encode multiple error formats
in a single int. KVM will trap-and-execute ECREATE and EINIT as part
of SGX virtualization, and reflect ENCLS execution result to guest by
setting up guest's GPRs, or on an exception, injecting the correct fault
based on return value of __ecreate() and __einit().
Use host userspace addresses (provided by KVM based on guest physical
address of ENCLS parameters) to execute ENCLS/EINIT when possible.
Accesses to both EPC and memory originating from ENCLS are subject to
segmentation and paging mechanisms. It's also possible to generate
kernel mappings for ENCLS parameters by resolving PFN but using
__uaccess_xx() is simpler.
[ bp: Return early if the __user memory accesses fail, use
cpu_feature_enabled(). ]
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Link: https://lkml.kernel.org/r/20e09daf559aa5e9e680a0b4b5fba940f1bad86e.1616136308.git.kai.huang@intel.com
Kai Huang [Fri, 19 Mar 2021 07:23:07 +0000 (20:23 +1300)]
x86/sgx: Add helper to update SGX_LEPUBKEYHASHn MSRs
Add a helper to update SGX_LEPUBKEYHASHn MSRs. SGX virtualization also
needs to update those MSRs based on guest's "virtual" SGX_LEPUBKEYHASHn
before EINIT from guest.
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Link: https://lkml.kernel.org/r/dfb7cd39d4dd62ea27703b64afdd8bccb579f623.1616136308.git.kai.huang@intel.com
Sean Christopherson [Fri, 19 Mar 2021 07:23:06 +0000 (20:23 +1300)]
x86/sgx: Add encls_faulted() helper
Add a helper to extract the fault indicator from an encoded ENCLS return
value. SGX virtualization will also need to detect ENCLS faults.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Link: https://lkml.kernel.org/r/c1f955898110de2f669da536fc6cf62e003dff88.1616136308.git.kai.huang@intel.com
Sean Christopherson [Fri, 19 Mar 2021 07:23:05 +0000 (20:23 +1300)]
x86/sgx: Add SGX2 ENCLS leaf definitions (EAUG, EMODPR and EMODT)
Define the ENCLS leafs that are available with SGX2, also referred to as
Enclave Dynamic Memory Management (EDMM). The leafs will be used by KVM
to conditionally expose SGX2 capabilities to guests.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Link: https://lkml.kernel.org/r/5f0970c251ebcc6d5add132f0d750cc753b7060f.1616136308.git.kai.huang@intel.com
Sean Christopherson [Fri, 19 Mar 2021 07:23:04 +0000 (20:23 +1300)]
x86/sgx: Move ENCLS leaf definitions to sgx.h
Move the ENCLS leaf definitions to sgx.h so that they can be used by
KVM.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Link: https://lkml.kernel.org/r/2e6cd7c5c1ced620cfcd292c3c6c382827fde6b2.1616136308.git.kai.huang@intel.com
Sean Christopherson [Fri, 19 Mar 2021 07:23:03 +0000 (20:23 +1300)]
x86/sgx: Expose SGX architectural definitions to the kernel
Expose SGX architectural structures, as KVM will use many of the
architectural constants and structs to virtualize SGX.
Name the new header file as asm/sgx.h, rather than asm/sgx_arch.h, to
have single header to provide SGX facilities to share with other kernel
componments. Also update MAINTAINERS to include asm/sgx.h.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Co-developed-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Link: https://lkml.kernel.org/r/6bf47acd91ab4d709e66ad1692c7803e4c9063a0.1616136308.git.kai.huang@intel.com
Kai Huang [Fri, 19 Mar 2021 07:23:02 +0000 (20:23 +1300)]
x86/sgx: Initialize virtual EPC driver even when SGX driver is disabled
Modify sgx_init() to always try to initialize the virtual EPC driver,
even if the SGX driver is disabled. The SGX driver might be disabled
if SGX Launch Control is in locked mode, or not supported in the
hardware at all. This allows (non-Linux) guests that support non-LC
configurations to use SGX.
[ bp: De-silli-fy the test. ]
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Link: https://lkml.kernel.org/r/d35d17a02bbf8feef83a536cec8b43746d4ea557.1616136308.git.kai.huang@intel.com
Sean Christopherson [Fri, 19 Mar 2021 07:22:58 +0000 (20:22 +1300)]
x86/cpu/intel: Allow SGX virtualization without Launch Control support
The kernel will currently disable all SGX support if the hardware does
not support launch control. Make it more permissive to allow SGX
virtualization on systems without Launch Control support. This will
allow KVM to expose SGX to guests that have less-strict requirements on
the availability of flexible launch control.
Improve error message to distinguish between three cases. There are two
cases where SGX support is completely disabled:
1) SGX has been disabled completely by the BIOS
2) SGX LC is locked by the BIOS. Bare-metal support is disabled because
of LC unavailability. SGX virtualization is unavailable (because of
Kconfig).
One where it is partially available:
3) SGX LC is locked by the BIOS. Bare-metal support is disabled because
of LC unavailability. SGX virtualization is supported.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Co-developed-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Link: https://lkml.kernel.org/r/b3329777076509b3b601550da288c8f3c406a865.1616136308.git.kai.huang@intel.com
Sean Christopherson [Fri, 19 Mar 2021 07:22:21 +0000 (20:22 +1300)]
x86/sgx: Introduce virtual EPC for use by KVM guests
Add a misc device /dev/sgx_vepc to allow userspace to allocate "raw"
Enclave Page Cache (EPC) without an associated enclave. The intended
and only known use case for raw EPC allocation is to expose EPC to a
KVM guest, hence the 'vepc' moniker, virt.{c,h} files and X86_SGX_KVM
Kconfig.
The SGX driver uses the misc device /dev/sgx_enclave to support
userspace in creating an enclave. Each file descriptor returned from
opening /dev/sgx_enclave represents an enclave. Unlike the SGX driver,
KVM doesn't control how the guest uses the EPC, therefore EPC allocated
to a KVM guest is not associated with an enclave, and /dev/sgx_enclave
is not suitable for allocating EPC for a KVM guest.
Having separate device nodes for the SGX driver and KVM virtual EPC also
allows separate permission control for running host SGX enclaves and KVM
SGX guests.
To use /dev/sgx_vepc to allocate a virtual EPC instance with particular
size, the hypervisor opens /dev/sgx_vepc, and uses mmap() with the
intended size to get an address range of virtual EPC. Then it may use
the address range to create one KVM memory slot as virtual EPC for
a guest.
Implement the "raw" EPC allocation in the x86 core-SGX subsystem via
/dev/sgx_vepc rather than in KVM. Doing so has two major advantages:
- Does not require changes to KVM's uAPI, e.g. EPC gets handled as
just another memory backend for guests.
- EPC management is wholly contained in the SGX subsystem, e.g. SGX
does not have to export any symbols, changes to reclaim flows don't
need to be routed through KVM, SGX's dirty laundry doesn't have to
get aired out for the world to see, and so on and so forth.
The virtual EPC pages allocated to guests are currently not reclaimable.
Reclaiming an EPC page used by enclave requires a special reclaim
mechanism separate from normal page reclaim, and that mechanism is not
supported for virutal EPC pages. Due to the complications of handling
reclaim conflicts between guest and host, reclaiming virtual EPC pages
is significantly more complex than basic support for SGX virtualization.
[ bp:
- Massage commit message and comments
- use cpu_feature_enabled()
- vertically align struct members init
- massage Virtual EPC clarification text
- move Kconfig prompt to Virtualization ]
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Co-developed-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Link: https://lkml.kernel.org/r/0c38ced8c8e5a69872db4d6a1c0dabd01e07cad7.1616136308.git.kai.huang@intel.com
Paolo Bonzini [Fri, 2 Apr 2021 11:25:32 +0000 (07:25 -0400)]
Merge branch 'kvm-tdp-fix-rcu' into HEAD
Paolo Bonzini [Fri, 2 Apr 2021 11:24:54 +0000 (07:24 -0400)]
Merge branch 'kvm-tdp-fix-flushes' into HEAD
Paolo Bonzini [Wed, 31 Mar 2021 11:35:52 +0000 (07:35 -0400)]
Merge branch 'kvm-fix-svm-races' into HEAD
Paolo Bonzini [Wed, 31 Mar 2021 10:28:01 +0000 (06:28 -0400)]
KVM: SVM: ensure that EFER.SVME is set when running nested guest or on nested vmexit
Fixing nested_vmcb_check_save to avoid all TOC/TOU races
is a bit harder in released kernels, so do the bare minimum
by avoiding that EFER.SVME is cleared. This is problematic
because svm_set_efer frees the data structures for nested
virtualization if EFER.SVME is cleared.
Also check that EFER.SVME remains set after a nested vmexit;
clearing it could happen if the bit is zero in the save area
that is passed to KVM_SET_NESTED_STATE (the save area of the
nested state corresponds to the nested hypervisor's state
and is restored on the next nested vmexit).
Cc: stable@vger.kernel.org
Fixes:
2fcf4876ada ("KVM: nSVM: implement on demand allocation of the nested state")
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Paolo Bonzini [Wed, 31 Mar 2021 10:24:43 +0000 (06:24 -0400)]
KVM: SVM: load control fields from VMCB12 before checking them
Avoid races between check and use of the nested VMCB controls. This
for example ensures that the VMRUN intercept is always reflected to the
nested hypervisor, instead of being processed by the host. Without this
patch, it is possible to end up with svm->nested.hsave pointing to
the MSR permission bitmap for nested guests.
This bug is CVE-2021-29657.
Reported-by: Felix Wilhelm <fwilhelm@google.com>
Cc: stable@vger.kernel.org
Fixes:
2fcf4876ada ("KVM: nSVM: implement on demand allocation of the nested state")
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sean Christopherson [Thu, 25 Mar 2021 20:01:19 +0000 (13:01 -0700)]
KVM: x86/mmu: Don't allow TDP MMU to yield when recovering NX pages
Prevent the TDP MMU from yielding when zapping a gfn range during NX
page recovery. If a flush is pending from a previous invocation of the
zapping helper, either in the TDP MMU or the legacy MMU, but the TDP MMU
has not accumulated a flush for the current invocation, then yielding
will release mmu_lock with stale TLB entries.
That being said, this isn't technically a bug fix in the current code, as
the TDP MMU will never yield in this case. tdp_mmu_iter_cond_resched()
will yield if and only if it has made forward progress, as defined by the
current gfn vs. the last yielded (or starting) gfn. Because zapping a
single shadow page is guaranteed to (a) find that page and (b) step
sideways at the level of the shadow page, the TDP iter will break its loop
before getting a chance to yield.
But that is all very, very subtle, and will break at the slightest sneeze,
e.g. zapping while holding mmu_lock for read would break as the TDP MMU
wouldn't be guaranteed to see the present shadow page, and thus could step
sideways at a lower level.
Cc: Ben Gardon <bgardon@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <
20210325200119.
1359384-4-seanjc@google.com>
[Add lockdep assertion. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sean Christopherson [Thu, 25 Mar 2021 20:01:18 +0000 (13:01 -0700)]
KVM: x86/mmu: Ensure TLBs are flushed for TDP MMU during NX zapping
Honor the "flush needed" return from kvm_tdp_mmu_zap_gfn_range(), which
does the flush itself if and only if it yields (which it will never do in
this particular scenario), and otherwise expects the caller to do the
flush. If pages are zapped from the TDP MMU but not the legacy MMU, then
no flush will occur.
Fixes:
29cf0f5007a2 ("kvm: x86/mmu: NX largepage recovery for TDP MMU")
Cc: stable@vger.kernel.org
Cc: Ben Gardon <bgardon@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <
20210325200119.
1359384-3-seanjc@google.com>
Reviewed-by: Ben Gardon <bgardon@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sean Christopherson [Thu, 25 Mar 2021 20:01:17 +0000 (13:01 -0700)]
KVM: x86/mmu: Ensure TLBs are flushed when yielding during GFN range zap
When flushing a range of GFNs across multiple roots, ensure any pending
flush from a previous root is honored before yielding while walking the
tables of the current root.
Note, kvm_tdp_mmu_zap_gfn_range() now intentionally overwrites its local
"flush" with the result to avoid redundant flushes. zap_gfn_range()
preserves and return the incoming "flush", unless of course the flush was
performed prior to yielding and no new flush was triggered.
Fixes:
1af4a96025b3 ("KVM: x86/mmu: Yield in TDU MMU iter even if no SPTES changed")
Cc: stable@vger.kernel.org
Reviewed-by: Ben Gardon <bgardon@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <
20210325200119.
1359384-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sean Christopherson [Fri, 19 Mar 2021 07:22:20 +0000 (20:22 +1300)]
x86/sgx: Add SGX_CHILD_PRESENT hardware error code
SGX driver can accurately track how enclave pages are used. This
enables SECS to be specifically targeted and EREMOVE'd only after all
child pages have been EREMOVE'd. This ensures that SGX driver will
never encounter SGX_CHILD_PRESENT in normal operation.
Virtual EPC is different. The host does not track how EPC pages are
used by the guest, so it cannot guarantee EREMOVE success. It might,
for instance, encounter a SECS with a non-zero child count.
Add a definition of SGX_CHILD_PRESENT. It will be used exclusively by
the SGX virtualization driver to handle recoverable EREMOVE errors when
saniziting EPC pages after they are freed.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Link: https://lkml.kernel.org/r/050b198e882afde7e6eba8e6a0d4da39161dbb5a.1616136308.git.kai.huang@intel.com
Kai Huang [Thu, 25 Mar 2021 09:30:57 +0000 (22:30 +1300)]
x86/sgx: Wipe out EREMOVE from sgx_free_epc_page()
EREMOVE takes a page and removes any association between that page and
an enclave. It must be run on a page before it can be added into another
enclave. Currently, EREMOVE is run as part of pages being freed into the
SGX page allocator. It is not expected to fail, as it would indicate a
use-after-free of EPC pages. Rather than add the page back to the pool
of available EPC pages, the kernel intentionally leaks the page to avoid
additional errors in the future.
However, KVM does not track how guest pages are used, which means that
SGX virtualization use of EREMOVE might fail. Specifically, it is
legitimate that EREMOVE returns SGX_CHILD_PRESENT for EPC assigned to
KVM guest, because KVM/kernel doesn't track SECS pages.
To allow SGX/KVM to introduce a more permissive EREMOVE helper and
to let the SGX virtualization code use the allocator directly, break
out the EREMOVE call from the SGX page allocator. Rename the original
sgx_free_epc_page() to sgx_encl_free_epc_page(), indicating that
it is used to free an EPC page assigned to a host enclave. Replace
sgx_free_epc_page() with sgx_encl_free_epc_page() in all call sites so
there's no functional change.
At the same time, improve the error message when EREMOVE fails, and
add documentation to explain to the user what that failure means and
to suggest to the user what to do when this bug happens in the case it
happens.
[ bp: Massage commit message, fix typos and sanitize text, simplify. ]
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Link: https://lkml.kernel.org/r/20210325093057.122834-1-kai.huang@intel.com
Sean Christopherson [Fri, 19 Mar 2021 07:22:18 +0000 (20:22 +1300)]
x86/cpufeatures: Add SGX1 and SGX2 sub-features
Add SGX1 and SGX2 feature flags, via CPUID.0x12.0x0.EAX, as scattered
features, since adding a new leaf for only two bits would be wasteful.
As part of virtualizing SGX, KVM will expose the SGX CPUID leafs to its
guest, and to do so correctly needs to query hardware and kernel support
for SGX1 and SGX2.
Suppress both SGX1 and SGX2 from /proc/cpuinfo. SGX1 basically means
SGX, and for SGX2 there is no concrete use case of using it in
/proc/cpuinfo.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Link: https://lkml.kernel.org/r/d787827dbfca6b3210ac3e432e3ac1202727e786.1616136308.git.kai.huang@intel.com
Kai Huang [Fri, 19 Mar 2021 07:22:17 +0000 (20:22 +1300)]
x86/cpufeatures: Make SGX_LC feature bit depend on SGX bit
Move SGX_LC feature bit to CPUID dependency table to make clearing all
SGX feature bits easier. Also remove clear_sgx_caps() since it is just
a wrapper of setup_clear_cpu_cap(X86_FEATURE_SGX) now.
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Link: https://lkml.kernel.org/r/5d4220fd0a39f52af024d3fa166231c1d498dd10.1616136308.git.kai.huang@intel.com
Ira Weiny [Wed, 24 Mar 2021 18:22:46 +0000 (11:22 -0700)]
x86/sgx: Remove unnecessary kmap() from sgx_ioc_enclave_init()
kmap() is inefficient and is being replaced by kmap_local_page(), if
possible. There is no readily apparent reason why initp_page needs to be
allocated and kmap'ed() except that 'sigstruct' needs to be page-aligned
and 'token' 512 byte-aligned.
Rather than change it to kmap_local_page(), use kmalloc() instead
because kmalloc() can give this alignment when allocating PAGE_SIZE
bytes.
Remove the alloc_page()/kmap() and replace with kmalloc(PAGE_SIZE, ...)
to get a page aligned kernel address.
In addition, add a comment to document the alignment requirements so that
others don't attempt to 'fix' this again.
[ bp: Massage commit message. ]
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210324182246.2484875-1-ira.weiny@intel.com
Tianjia Zhang [Sun, 14 Mar 2021 11:16:21 +0000 (19:16 +0800)]
selftests/sgx: Use getauxval() to simplify test code
Use the library function getauxval() instead of a custom function to get
the base address of the vDSO.
[ bp: Massage commit message. ]
Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Link: https://lkml.kernel.org/r/20210314111621.68428-1-tianjia.zhang@linux.alibaba.com
Claudio Imbrenda [Mon, 22 Mar 2021 14:05:59 +0000 (15:05 +0100)]
KVM: s390: VSIE: fix MVPG handling for prefixing and MSO
Prefixing needs to be applied to the guest real address to translate it
into a guest absolute address.
The value of MSO needs to be added to a guest-absolute address in order to
obtain the host-virtual.
Fixes:
bdf7509bbefa ("s390/kvm: VSIE: correctly handle MVPG when in VSIE")
Reported-by: Janosch Frank <frankja@linux.ibm.com>
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210322140559.500716-3-imbrenda@linux.ibm.com
[borntraeger@de.ibm.com simplify mso]
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Claudio Imbrenda [Mon, 22 Mar 2021 14:05:58 +0000 (15:05 +0100)]
KVM: s390: split kvm_s390_real_to_abs
A new function _kvm_s390_real_to_abs will apply prefixing to a real address
with a given prefix value.
The old kvm_s390_real_to_abs becomes now a wrapper around the new function.
This is needed to avoid code duplication in vSIE.
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210322140559.500716-2-imbrenda@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Claudio Imbrenda [Mon, 1 Feb 2021 20:54:13 +0000 (21:54 +0100)]
KVM: s390: VSIE: correctly handle MVPG when in VSIE
Correctly handle the MVPG instruction when issued by a VSIE guest.
Fixes:
a3508fbe9dc6d ("KVM: s390: vsie: initial support for nested virtualization")
Cc: stable@vger.kernel.org # f85f1baaa189: KVM: s390: split kvm_s390_logical_to_effective
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Acked-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Link: https://lore.kernel.org/r/20210302174443.514363-4-imbrenda@linux.ibm.com
[borntraeger@de.ibm.com: apply fixup from Claudio]
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Claudio Imbrenda [Mon, 1 Feb 2021 16:26:54 +0000 (17:26 +0100)]
KVM: s390: extend kvm_s390_shadow_fault to return entry pointer
Extend kvm_s390_shadow_fault to return the pointer to the valid leaf
DAT table entry, or to the invalid entry.
Also return some flags in the lower bits of the address:
PEI_DAT_PROT: indicates that DAT protection applies because of the
protection bit in the segment (or, if EDAT, region) tables.
PEI_NOT_PTE: indicates that the address of the DAT table entry returned
does not refer to a PTE, but to a segment or region table.
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: stable@vger.kernel.org
Reviewed-by: Janosch Frank <frankja@de.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Link: https://lore.kernel.org/r/20210302174443.514363-3-imbrenda@linux.ibm.com
[borntraeger@de.ibm.com: fold in a fix from Claudio]
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Dave Hansen [Thu, 18 Mar 2021 19:43:01 +0000 (12:43 -0700)]
selftests/sgx: Improve error detection and messages
The SGX device file (/dev/sgx_enclave) is unusual in that it requires
execute permissions. It has to be both "chmod +x" *and* be on a
filesystem without 'noexec'.
In the future, udev and systemd should get updates to set up systems
automatically. But, for now, nobody's systems do this automatically,
and everybody gets error messages like this when running ./test_sgx:
0x0000000000000000 0x0000000000002000 0x03
0x0000000000002000 0x0000000000001000 0x05
0x0000000000003000 0x0000000000003000 0x03
mmap() failed, errno=1.
That isn't very user friendly, even for forgetful kernel developers.
Further, the test case is rather haphazard about its use of fprintf()
versus perror().
Improve the error messages. Use perror() where possible. Lastly,
do some sanity checks on opening and mmap()ing the device file so
that we can get a decent error message out to the user.
Now, if your user doesn't have permission, you'll get the following:
$ ls -l /dev/sgx_enclave
crw------- 1 root root 10, 126 Mar 18 11:29 /dev/sgx_enclave
$ ./test_sgx
Unable to open /dev/sgx_enclave: Permission denied
If you then 'chown dave:dave /dev/sgx_enclave' (or whatever), but
you leave execute permissions off, you'll get:
$ ls -l /dev/sgx_enclave
crw------- 1 dave dave 10, 126 Mar 18 11:29 /dev/sgx_enclave
$ ./test_sgx
no execute permissions on device file
If you fix that with "chmod ug+x /dev/sgx" but you leave /dev as
noexec, you'll get this:
$ mount | grep "/dev .*noexec"
udev on /dev type devtmpfs (rw,nosuid,noexec,...)
$ ./test_sgx
ERROR: mmap for exec: Operation not permitted
mmap() succeeded for PROT_READ, but failed for PROT_EXEC
check that user has execute permissions on /dev/sgx_enclave and
that /dev does not have noexec set: 'mount | grep "/dev .*noexec"'
That can be fixed with:
mount -o remount,noexec /devESC
Hopefully, the combination of better error messages and the search
engines indexing this message will help people fix their systems
until we do this properly.
[ bp: Improve error messages more. ]
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Link: https://lore.kernel.org/r/20210318194301.11D9A984@viggo.jf.intel.com
Jarkko Sakkinen [Wed, 17 Mar 2021 23:53:31 +0000 (01:53 +0200)]
x86/sgx: Add a basic NUMA allocation scheme to sgx_alloc_epc_page()
Background
==========
SGX enclave memory is enumerated by the processor in contiguous physical
ranges called Enclave Page Cache (EPC) sections. Currently, there is a
free list per section, but allocations simply target the lowest-numbered
sections. This is functional, but has no NUMA awareness.
Fortunately, EPC sections are covered by entries in the ACPI SRAT table.
These entries allow each EPC section to be associated with a NUMA node,
just like normal RAM.
Solution
========
Implement a NUMA-aware enclave page allocator. Mirror the buddy allocator
and maintain a list of enclave pages for each NUMA node. Attempt to
allocate enclave memory first from local nodes, then fall back to other
nodes.
Note that the fallback is not as sophisticated as the buddy allocator
and is itself not aware of NUMA distances. When a node's free list is
empty, it searches for the next-highest node with enclave pages (and
will wrap if necessary). This could be improved in the future.
Other
=====
NUMA_KEEP_MEMINFO dependency is required for phys_to_target_node().
[ Kai Huang: Do not return NULL from __sgx_alloc_epc_page() because
callers do not expect that and that leads to a NULL ptr deref. ]
[ dhansen: Fix an uninitialized 'nid' variable in
__sgx_alloc_epc_page() as
Reported-by: kernel test robot <lkp@intel.com>
to avoid any potential allocations from the wrong NUMA node or even
premature allocation failures. ]
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lore.kernel.org/lkml/158188326978.894464.217282995221175417.stgit@dwillia2-desk3.amr.corp.intel.com/
Link: https://lkml.kernel.org/r/20210319040602.178558-1-kai.huang@intel.com
Link: https://lkml.kernel.org/r/20210318214933.29341-1-dave.hansen@intel.com
Link: https://lkml.kernel.org/r/20210317235332.362001-2-jarkko.sakkinen@intel.com
Jarkko Sakkinen [Wed, 17 Mar 2021 23:53:30 +0000 (01:53 +0200)]
x86/sgx: Replace section->init_laundry_list with sgx_dirty_page_list
During normal runtime, the "ksgxd" daemon behaves like a version of
kswapd just for SGX. But, before it starts acting like kswapd, its first
job is to initialize enclave memory.
Currently, the SGX boot code places each enclave page on a
epc_section->init_laundry_list. Once it starts up, the ksgxd code walks
over that list and populates the actual SGX page allocator.
However, the per-section structures are going away to make way for the
SGX NUMA allocator. There's also little need to have a per-section
structure; the enclave pages are all treated identically, and they can
be placed on the correct allocator list from metadata stored in the
enclave page (struct sgx_epc_page) itself.
Modify sgx_sanitize_section() to take a single page list instead of
taking a section and deriving the list from there.
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lkml.kernel.org/r/20210317235332.362001-1-jarkko.sakkinen@intel.com
Sean Christopherson [Mon, 15 Mar 2021 23:38:03 +0000 (16:38 -0700)]
KVM: x86/mmu: Store the address space ID in the TDP iterator
Store the address space ID in the TDP iterator so that it can be
retrieved without having to bounce through the root shadow page. This
streamlines the code and fixes a Sparse warning about not properly using
rcu_dereference() when grabbing the ID from the root on the fly.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Ben Gardon <bgardon@google.com>
Message-Id: <
20210315233803.
2706477-5-bgardon@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Ben Gardon [Mon, 15 Mar 2021 23:38:02 +0000 (16:38 -0700)]
KVM: x86/mmu: Factor out tdp_iter_return_to_root
In tdp_mmu_iter_cond_resched there is a call to tdp_iter_start which
causes the iterator to continue its walk over the paging structure from
the root. This is needed after a yield as paging structure could have
been freed in the interim.
The tdp_iter_start call is not very clear and something of a hack. It
requires exposing tdp_iter fields not used elsewhere in tdp_mmu.c and
the effect is not obvious from the function name. Factor a more aptly
named function out of tdp_iter_start and call it from
tdp_mmu_iter_cond_resched and tdp_iter_start.
No functional change intended.
Signed-off-by: Ben Gardon <bgardon@google.com>
Message-Id: <
20210315233803.
2706477-4-bgardon@google.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Ben Gardon [Mon, 15 Mar 2021 23:38:01 +0000 (16:38 -0700)]
KVM: x86/mmu: Fix RCU usage when atomically zapping SPTEs
Fix a missing rcu_dereference in tdp_mmu_zap_spte_atomic.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Ben Gardon <bgardon@google.com>
Message-Id: <
20210315233803.
2706477-3-bgardon@google.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Ben Gardon [Mon, 15 Mar 2021 23:38:00 +0000 (16:38 -0700)]
KVM: x86/mmu: Fix RCU usage in handle_removed_tdp_mmu_page
The pt passed into handle_removed_tdp_mmu_page does not need RCU
protection, as it is not at any risk of being freed by another thread at
that point. However, the implicit cast from tdp_sptep_t to u64 * dropped
the __rcu annotation without a proper rcu_derefrence. Fix this by
passing the pt as a tdp_ptep_t and then rcu_dereferencing it in
the function.
Suggested-by: Sean Christopherson <seanjc@google.com>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Ben Gardon <bgardon@google.com>
Message-Id: <
20210315233803.
2706477-2-bgardon@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sean Christopherson [Tue, 9 Mar 2021 22:42:07 +0000 (14:42 -0800)]
KVM: x86/mmu: Mark the PAE roots as decrypted for shadow paging
Set the PAE roots used as decrypted to play nice with SME when KVM is
using shadow paging. Explicitly skip setting the C-bit when loading
CR3 for PAE shadow paging, even though it's completely ignored by the
CPU. The extra documentation is nice to have.
Note, there are several subtleties at play with NPT. In addition to
legacy shadow paging, the PAE roots are used for SVM's NPT when either
KVM is 32-bit (uses PAE paging) or KVM is 64-bit and shadowing 32-bit
NPT. However, 32-bit Linux, and thus KVM, doesn't support SME. And
64-bit KVM can happily set the C-bit in CR3. This also means that
keeping __sme_set(root) for 32-bit KVM when NPT is enabled is
conceptually wrong, but functionally ok since SME is 64-bit only.
Leave it as is to avoid unnecessary pollution.
Fixes:
d0ec49d4de90 ("kvm/x86/svm: Support Secure Memory Encryption within KVM")
Cc: stable@vger.kernel.org
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <
20210309224207.
1218275-5-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sean Christopherson [Tue, 9 Mar 2021 22:42:06 +0000 (14:42 -0800)]
KVM: x86/mmu: Use '0' as the one and only value for an invalid PAE root
Use '0' to denote an invalid pae_root instead of '0' or INVALID_PAGE.
Unlike root_hpa, the pae_roots hold permission bits and thus are
guaranteed to be non-zero. Having to deal with both values leads to
bugs, e.g. failing to set back to INVALID_PAGE, warning on the wrong
value, etc...
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <
20210309224207.
1218275-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sean Christopherson [Fri, 5 Mar 2021 18:31:23 +0000 (10:31 -0800)]
KVM: VMX: Track root HPA instead of EPTP for paravirt Hyper-V TLB flush
Track the address of the top-level EPT struct, a.k.a. the root HPA,
instead of the EPTP itself for Hyper-V's paravirt TLB flush. The
paravirt API takes only the address, not the full EPTP, and in theory
tracking the EPTP could lead to false negatives, e.g. if the HPA matched
but the attributes in the EPTP do not. In practice, such a mismatch is
extremely unlikely, if not flat out impossible, given how KVM generates
the EPTP.
Opportunsitically rename the related fields to use the 'root'
nomenclature, and to prefix them with 'hv_' to connect them to Hyper-V's
paravirt TLB flushing.
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <
20210305183123.
3978098-12-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sean Christopherson [Fri, 5 Mar 2021 18:31:22 +0000 (10:31 -0800)]
KVM: VMX: Skip additional Hyper-V TLB EPTP flushes if one fails
Skip additional EPTP flushes if one fails when processing EPTPs for
Hyper-V's paravirt TLB flushing. If _any_ flush fails, KVM falls back
to a full global flush, i.e. additional flushes are unnecessary (and
will likely fail anyways).
Continue processing the loop unless a mismatch was already detected,
e.g. to handle the case where the first flush fails and there is a
yet-to-be-detected mismatch.
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <
20210305183123.
3978098-11-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sean Christopherson [Fri, 5 Mar 2021 18:31:21 +0000 (10:31 -0800)]
KVM: VMX: Define Hyper-V paravirt TLB flush fields iff Hyper-V is enabled
Ifdef away the Hyper-V specific fields in structs kvm_vmx and vcpu_vmx
as each field has only a single reference outside of the struct itself
that isn't already wrapped in ifdeffery (and both are initialization).
vcpu_vmx.ept_pointer in particular should be wrapped as it is valid if
and only if Hyper-v is active, i.e. non-Hyper-V code cannot rely on it
to actually track the current EPTP (without additional code changes).
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <
20210305183123.
3978098-10-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sean Christopherson [Fri, 5 Mar 2021 18:31:20 +0000 (10:31 -0800)]
KVM: VMX: Explicitly check for hv_remote_flush_tlb when loading pgd
Explicitly check that kvm_x86_ops.tlb_remote_flush() points at Hyper-V's
implementation for PV flushing instead of assuming that a non-NULL
implementation means running on Hyper-V. Wrap the related logic in
ifdeffery as hv_remote_flush_tlb() is defined iff CONFIG_HYPERV!=n.
Short term, the explicit check makes it more obvious why a non-NULL
tlb_remote_flush() triggers EPTP shenanigans. Long term, this will
allow TDX to define its own implementation of tlb_remote_flush() without
running afoul of Hyper-V.
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <
20210305183123.
3978098-9-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sean Christopherson [Fri, 5 Mar 2021 18:31:19 +0000 (10:31 -0800)]
KVM: VMX: Don't invalidate hv_tlb_eptp if the new EPTP matches
Don't invalidate the common EPTP, and thus trigger rechecking of EPTPs
across all vCPUs, if the new EPTP matches the old/common EPTP. In all
likelihood this is a meaningless optimization, but there are (uncommon)
scenarios where KVM can reload the same EPTP.
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <
20210305183123.
3978098-8-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sean Christopherson [Fri, 5 Mar 2021 18:31:18 +0000 (10:31 -0800)]
KVM: VMX: Invalidate hv_tlb_eptp to denote an EPTP mismatch
Drop the dedicated 'ept_pointers_match' field in favor of stuffing
'hv_tlb_eptp' with INVALID_PAGE to mark it as invalid, i.e. to denote
that there is at least one EPTP mismatch. Use a local variable to
track whether or not a mismatch is detected so that hv_tlb_eptp can be
used to skip redundant flushes.
No functional change intended.
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <
20210305183123.
3978098-7-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sean Christopherson [Fri, 5 Mar 2021 18:31:17 +0000 (10:31 -0800)]
KVM: VMX: Do Hyper-V TLB flush iff vCPU's EPTP hasn't been flushed
Combine the for-loops for Hyper-V TLB EPTP checking and flushing, and in
doing so skip flushes for vCPUs whose EPTP matches the target EPTP.
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <
20210305183123.
3978098-6-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>