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From 585df9100649b5038250e1c33cf8af019a77844c Mon Sep 17 00:00:00 2001
From: Liran Alon <liran.alon@oracle.com>
Date: Sun, 5 Nov 2017 16:56:34 +0200
Subject: [PATCH 05/33] KVM: x86: Don't re-execute instruction when not passing
CR2 value
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
[ Upstream commit 9b8ae63798cb97e785a667ff27e43fa6220cb734 ]
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: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/x86/include/asm/kvm_host.h | 3 ++-
arch/x86/kvm/vmx.c | 2 +-
2 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index bdde807..6f6ee68 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1113,7 +1113,8 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu, unsigned long cr2,
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);
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index ee766c2..8e5001d 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -6232,7 +6232,7 @@ static int handle_invalid_guest_state(struct kvm_vcpu *vcpu)
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;
--
2.7.4
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