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authorJoerg Roedel <joerg.roedel@amd.com>2011-04-04 12:39:24 +0200
committerAvi Kivity <avi@redhat.com>2011-05-11 07:57:00 -0400
commit775fde8648ebc588d07de39457aadc7c2131df2e (patch)
tree56706d5d6eff4b5f02c911cbbbcf3b14648aee69
parentKVM: x86 emulator: add SVM intercepts (diff)
downloadlinux-dev-775fde8648ebc588d07de39457aadc7c2131df2e.tar.xz
linux-dev-775fde8648ebc588d07de39457aadc7c2131df2e.zip
KVM: x86 emulator: Don't write-back cpu-state on X86EMUL_INTERCEPTED
This patch prevents the changed CPU state to be written back when the emulator detected that the instruction was intercepted by the guest. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Avi Kivity <avi@redhat.com>
-rw-r--r--arch/x86/include/asm/kvm_emulate.h1
-rw-r--r--arch/x86/kvm/emulate.c3
-rw-r--r--arch/x86/kvm/x86.c3
3 files changed, 7 insertions, 0 deletions
diff --git a/arch/x86/include/asm/kvm_emulate.h b/arch/x86/include/asm/kvm_emulate.h
index 470ac54ca38d..1dbd0c736cd1 100644
--- a/arch/x86/include/asm/kvm_emulate.h
+++ b/arch/x86/include/asm/kvm_emulate.h
@@ -331,6 +331,7 @@ int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len);
#define EMULATION_FAILED -1
#define EMULATION_OK 0
#define EMULATION_RESTART 1
+#define EMULATION_INTERCEPTED 2
int x86_emulate_insn(struct x86_emulate_ctxt *ctxt);
int emulator_task_switch(struct x86_emulate_ctxt *ctxt,
u16 tss_selector, int reason,
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index c2260e57450a..a2c31e527a99 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -3592,6 +3592,9 @@ writeback:
done:
if (rc == X86EMUL_PROPAGATE_FAULT)
ctxt->have_exception = true;
+ if (rc == X86EMUL_INTERCEPTED)
+ return EMULATION_INTERCEPTED;
+
return (rc == X86EMUL_UNHANDLEABLE) ? EMULATION_FAILED : EMULATION_OK;
twobyte_insn:
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 36786bbb4c09..99bed74779d2 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4516,6 +4516,9 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu,
restart:
r = x86_emulate_insn(&vcpu->arch.emulate_ctxt);
+ if (r == EMULATION_INTERCEPTED)
+ return EMULATE_DONE;
+
if (r == EMULATION_FAILED) {
if (reexecute_instruction(vcpu, cr2))
return EMULATE_DONE;