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 <[email protected]> --- arch/x86/include/asm/kvm_emulate.h | 1 + arch/x86/kvm/emulate.c | 3 +++ arch/x86/kvm/x86.c | 3 +++ 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 277f189..7960eeb 100644 --- a/arch/x86/include/asm/kvm_emulate.h +++ b/arch/x86/include/asm/kvm_emulate.h @@ -325,6 +325,7 @@ 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 cf5f396..078acc4 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -3455,6 +3455,9 @@ 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 2338309..90a41aa 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -4458,6 +4458,9 @@ 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; -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
