diff options
| author | Gleb Natapov <gleb@redhat.com> | 2010-08-02 12:47:51 +0300 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2010-10-24 10:50:29 +0200 |
| commit | 4fc40f076f4fa289dd546990b597351c9cdad985 (patch) | |
| tree | 589e394aee1efb859a398438ced6326a5df3f97e | |
| parent | 9928ff608b1b6ba10fafde85f57970a83a181331 (diff) | |
KVM: x86 emulator: check io permissions only once for string pio
Do not recheck io permission on every iteration.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
| -rw-r--r-- | arch/x86/include/asm/kvm_emulate.h | 1 | ||||
| -rw-r--r-- | arch/x86/kvm/emulate.c | 6 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 1 |
3 files changed, 8 insertions, 0 deletions
diff --git a/arch/x86/include/asm/kvm_emulate.h b/arch/x86/include/asm/kvm_emulate.h index 0f901c16cf1..8762411fe9b 100644 --- a/arch/x86/include/asm/kvm_emulate.h +++ b/arch/x86/include/asm/kvm_emulate.h @@ -224,6 +224,7 @@ struct x86_emulate_ctxt { int interruptibility; bool restart; /* restart string instruction after writeback */ + bool perm_ok; /* do not check permissions if true */ int exception; /* exception that happens during emulation or -1 */ u32 error_code; /* error code for exception */ diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 4d49514a919..760e2b030e6 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -1621,9 +1621,15 @@ static bool emulator_io_permited(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops, u16 port, u16 len) { + if (ctxt->perm_ok) + return true; + if (emulator_bad_iopl(ctxt, ops)) if (!emulator_io_port_access_allowed(ctxt, ops, port, len)) return false; + + ctxt->perm_ok = true; + return true; } diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 3cbe8032394..35c0f4e4a62 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3997,6 +3997,7 @@ int emulate_instruction(struct kvm_vcpu *vcpu, memcpy(c->regs, vcpu->arch.regs, sizeof c->regs); vcpu->arch.emulate_ctxt.interruptibility = 0; vcpu->arch.emulate_ctxt.exception = -1; + vcpu->arch.emulate_ctxt.perm_ok = false; r = x86_decode_insn(&vcpu->arch.emulate_ctxt); trace_kvm_emulate_insn_start(vcpu); |