From 4b21e8abf959ca66c27f0656bf294fe69d3f2254 Mon Sep 17 00:00:00 2001 From: James Hogan Date: Mon, 28 Nov 2016 23:13:38 +0000 Subject: [PATCH] KVM: MIPS/T&E: Use lockless GVA helpers for dyntrans MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Use the lockless GVA helpers to implement the dynamic translation of guest instructions. This will allow it to handle asynchronous TLB flushes when they are implemented. Signed-off-by: James Hogan Cc: Paolo Bonzini Cc: "Radim Krčmář" Cc: Ralf Baechle Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org --- arch/mips/kvm/dyntrans.c | 26 ++++++++++++++++++++++++-- 1 file changed, 24 insertions(+), 2 deletions(-) diff --git a/arch/mips/kvm/dyntrans.c b/arch/mips/kvm/dyntrans.c index 60ebf5862d2b..f8e772564d74 100644 --- a/arch/mips/kvm/dyntrans.c +++ b/arch/mips/kvm/dyntrans.c @@ -33,10 +33,32 @@ static int kvm_mips_trans_replace(struct kvm_vcpu *vcpu, u32 *opc, unsigned long vaddr = (unsigned long)opc; int err; +retry: + /* The GVA page table is still active so use the Linux TLB handlers */ + kvm_trap_emul_gva_lockless_begin(vcpu); err = put_user(replace.word, opc); + kvm_trap_emul_gva_lockless_end(vcpu); + if (unlikely(err)) { - kvm_err("%s: Invalid address: %p\n", __func__, opc); - return err; + /* + * We write protect clean pages in GVA page table so normal + * Linux TLB mod handler doesn't silently dirty the page. + * Its also possible we raced with a GVA invalidation. + * Try to force the page to become dirty. + */ + err = kvm_trap_emul_gva_fault(vcpu, vaddr, true); + if (unlikely(err)) { + kvm_info("%s: Address unwriteable: %p\n", + __func__, opc); + return -EFAULT; + } + + /* + * Try again. This will likely trigger a TLB refill, which will + * fetch the new dirty entry from the GVA page table, which + * should then succeed. + */ + goto retry; } __local_flush_icache_user_range(vaddr, vaddr + 4); -- 2.11.0