KVM: x86/mmu: Grab mmu_invalidate_seq in kvm_faultin_pfn()

Grab mmu_invalidate_seq in kvm_faultin_pfn() and stash it in struct
kvm_page_fault. The eliminates duplicate code and reduces the amount of
parameters needed for is_page_fault_stale().

Preemptively split out __kvm_faultin_pfn() to a separate function for
use in subsequent commits.

No functional change intended.

Signed-off-by: David Matlack <dmatlack@google.com>
Reviewed-by: Isaku Yamahata <isaku.yamahata@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20220921173546.2674386-4-dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 31bdf93..efc540e 100644 (file)
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -4189,7 +4189,7 @@ void kvm_arch_async_page_ready(struct kvm_vcpu *vcpu, struct kvm_async_pf *work)
        kvm_mmu_do_page_fault(vcpu, work->cr2_or_gpa, 0, true);
 }
 
-static int kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
+static int __kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
 {
        struct kvm_memory_slot *slot = fault->slot;
        bool async;
@@ -4250,12 +4250,20 @@ static int kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
        return RET_PF_CONTINUE;
 }
 
+static int kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
+{
+       fault->mmu_seq = vcpu->kvm->mmu_invalidate_seq;
+       smp_rmb();
+
+       return __kvm_faultin_pfn(vcpu, fault);
+}
+
 /*
  * Returns true if the page fault is stale and needs to be retried, i.e. if the
  * root was invalidated by a memslot update or a relevant mmu_notifier fired.
  */
 static bool is_page_fault_stale(struct kvm_vcpu *vcpu,
-                               struct kvm_page_fault *fault, int mmu_seq)
+                               struct kvm_page_fault *fault)
 {
        struct kvm_mmu_page *sp = to_shadow_page(vcpu->arch.mmu->root.hpa);
 
@@ -4275,14 +4283,12 @@ static bool is_page_fault_stale(struct kvm_vcpu *vcpu,
                return true;
 
        return fault->slot &&
-              mmu_invalidate_retry_hva(vcpu->kvm, mmu_seq, fault->hva);
+              mmu_invalidate_retry_hva(vcpu->kvm, fault->mmu_seq, fault->hva);
 }
 
 static int direct_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
 {
        bool is_tdp_mmu_fault = is_tdp_mmu(vcpu->arch.mmu);
-
-       unsigned long mmu_seq;
        int r;
 
        fault->gfn = fault->addr >> PAGE_SHIFT;
@@ -4299,9 +4305,6 @@ static int direct_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault
        if (r)
                return r;
 
-       mmu_seq = vcpu->kvm->mmu_invalidate_seq;
-       smp_rmb();
-
        r = kvm_faultin_pfn(vcpu, fault);
        if (r != RET_PF_CONTINUE)
                return r;
@@ -4317,7 +4320,7 @@ static int direct_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault
        else
                write_lock(&vcpu->kvm->mmu_lock);
 
-       if (is_page_fault_stale(vcpu, fault, mmu_seq))
+       if (is_page_fault_stale(vcpu, fault))
                goto out_unlock;
 
        r = make_mmu_pages_available(vcpu);

diff --git a/arch/x86/kvm/mmu/mmu_internal.h b/arch/x86/kvm/mmu/mmu_internal.h
index dbaf675..1556f59 100644 (file)
--- a/arch/x86/kvm/mmu/mmu_internal.h
+++ b/arch/x86/kvm/mmu/mmu_internal.h
@@ -222,6 +222,7 @@ struct kvm_page_fault {
        struct kvm_memory_slot *slot;
 
        /* Outputs of kvm_faultin_pfn.  */
+       unsigned long mmu_seq;
        kvm_pfn_t pfn;
        hva_t hva;
        bool map_writable;

diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h
index 0f64550..88acf23 100644 (file)
--- a/arch/x86/kvm/mmu/paging_tmpl.h
+++ b/arch/x86/kvm/mmu/paging_tmpl.h
@@ -791,7 +791,6 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault
 {
        struct guest_walker walker;
        int r;
-       unsigned long mmu_seq;
        bool is_self_change_mapping;
 
        pgprintk("%s: addr %lx err %x\n", __func__, fault->addr, fault->error_code);
@@ -838,9 +837,6 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault
        else
                fault->max_level = walker.level;
 
-       mmu_seq = vcpu->kvm->mmu_invalidate_seq;
-       smp_rmb();
-
        r = kvm_faultin_pfn(vcpu, fault);
        if (r != RET_PF_CONTINUE)
                return r;
@@ -871,7 +867,7 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault
        r = RET_PF_RETRY;
        write_lock(&vcpu->kvm->mmu_lock);
 
-       if (is_page_fault_stale(vcpu, fault, mmu_seq))
+       if (is_page_fault_stale(vcpu, fault))
                goto out_unlock;
 
        r = make_mmu_pages_available(vcpu);