KVM: MIPS/MMU: Use lockless GVA helpers for get_inst()

Use the lockless GVA helpers to implement the reading of guest
instructions for emulation. This will allow it to handle asynchronous
TLB flushes when they are implemented.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org

diff --git a/arch/mips/kvm/mmu.c b/arch/mips/kvm/mmu.c
index 32c317de6c0ae4d3298bcf0cc77d36f80c417d34..b3da473e15693318f7bfb5bb1ca35eed35cb73b7 100644 (file)
--- a/arch/mips/kvm/mmu.c
+++ b/arch/mips/kvm/mmu.c
@@ -787,11 +787,26 @@ int kvm_get_inst(u32 *opc, struct kvm_vcpu *vcpu, u32 *out)
 {
        int err;
 
+retry:
+       kvm_trap_emul_gva_lockless_begin(vcpu);
        err = get_user(*out, opc);
+       kvm_trap_emul_gva_lockless_end(vcpu);
+
        if (unlikely(err)) {
-               kvm_err("%s: illegal address: %p\n", __func__, opc);
-               return -EFAULT;
-       }
+               /*
+                * Try to handle the fault, maybe we just raced with a GVA
+                * invalidation.
+                */
+               err = kvm_trap_emul_gva_fault(vcpu, (unsigned long)opc,
+                                             false);
+               if (unlikely(err)) {
+                       kvm_err("%s: illegal address: %p\n",
+                               __func__, opc);
+                       return -EFAULT;
+               }
 
+               /* Hopefully it'll work now */
+               goto retry;
+       }
        return 0;
 }