3.16.55-rc1 review patch. If anyone has any objections, please let me know.
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From: Liran Alon liran.alon@oracle.com
commit 9b8ae63798cb97e785a667ff27e43fa6220cb734 upstream.
In case of instruction-decode failure or emulation failure, x86_emulate_instruction() will call reexecute_instruction() which will attempt to use the cr2 value passed to x86_emulate_instruction(). However, when x86_emulate_instruction() is called from emulate_instruction(), cr2 is not passed (passed as 0) and therefore it doesn't make sense to execute reexecute_instruction() logic at all.
Fixes: 51d8b66199e9 ("KVM: cleanup emulate_instruction")
Signed-off-by: Liran Alon liran.alon@oracle.com Reviewed-by: Nikita Leshenko nikita.leshchenko@oracle.com Reviewed-by: Konrad Rzeszutek Wilk konrad.wilk@oracle.com Signed-off-by: Konrad Rzeszutek Wilk konrad.wilk@oracle.com Reviewed-by: Wanpeng Li wanpeng.li@hotmail.com Signed-off-by: Radim Krčmář rkrcmar@redhat.com Signed-off-by: Ben Hutchings ben@decadent.org.uk --- arch/x86/include/asm/kvm_host.h | 3 ++- arch/x86/kvm/vmx.c | 2 +- 2 files changed, 3 insertions(+), 2 deletions(-)
--- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -847,7 +847,8 @@ int x86_emulate_instruction(struct kvm_v static inline int emulate_instruction(struct kvm_vcpu *vcpu, int emulation_type) { - return x86_emulate_instruction(vcpu, 0, emulation_type, NULL, 0); + return x86_emulate_instruction(vcpu, 0, + emulation_type | EMULTYPE_NO_REEXECUTE, NULL, 0); }
void kvm_enable_efer_bits(u64); --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -5659,7 +5659,7 @@ static int handle_invalid_guest_state(st if (test_bit(KVM_REQ_EVENT, &vcpu->requests)) return 1;
- err = emulate_instruction(vcpu, EMULTYPE_NO_REEXECUTE); + err = emulate_instruction(vcpu, 0);
if (err == EMULATE_USER_EXIT) { ++vcpu->stat.mmio_exits;