[PATCH 8/10] KVM: MIPS/MMU: Use lockless GVA helpers for get_inst()
From: James Hogan <hidden>
Date: 2017-01-09 20:56:47
Also in:
kvm
Subsystem:
kernel virtual machine for mips (kvm/mips), mips, the rest · Maintainers:
Huacai Chen, Thomas Bogendoerfer, Linus Torvalds
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 <redacted> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: "Radim Krčmář" <redacted> Cc: Ralf Baechle <redacted> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org --- arch/mips/kvm/mmu.c | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-)
diff --git a/arch/mips/kvm/mmu.c b/arch/mips/kvm/mmu.c
index 32c317de6c0a..b3da473e1569 100644
--- 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; }
--
git-series 0.8.10