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| author | Gleb Natapov <gleb@redhat.com> | 2010-03-18 15:20:23 +0200 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2010-05-17 12:16:25 +0300 |
| commit | cf8f70bfe38b326bb80b10f76d6544f571040229 (patch) | |
| tree | d646456d773a887ca592d174b3d45a57d2779d85 /arch/x86/kvm/svm.c | |
| parent | d9271123a46011af26da680baeb7fdf67b498abf (diff) | |
| download | linux-stable-cf8f70bfe38b326bb80b10f76d6544f571040229.tar.gz linux-stable-cf8f70bfe38b326bb80b10f76d6544f571040229.tar.bz2 linux-stable-cf8f70bfe38b326bb80b10f76d6544f571040229.zip | |
KVM: x86 emulator: fix in/out emulation.
in/out emulation is broken now. The breakage is different depending
on where IO device resides. If it is in userspace emulator reports
emulation failure since it incorrectly interprets kvm_emulate_pio()
return value. If IO device is in the kernel emulation of 'in' will do
nothing since kvm_emulate_pio() stores result directly into vcpu
registers, so emulator will overwrite result of emulation during
commit of shadowed register.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Diffstat (limited to 'arch/x86/kvm/svm.c')
| -rw-r--r-- | arch/x86/kvm/svm.c | 20 |
1 files changed, 7 insertions, 13 deletions
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index abbc3f9d03b2..e9f79619e185 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -1494,29 +1494,23 @@ static int shutdown_interception(struct vcpu_svm *svm) static int io_interception(struct vcpu_svm *svm) { + struct kvm_vcpu *vcpu = &svm->vcpu; u32 io_info = svm->vmcb->control.exit_info_1; /* address size bug? */ int size, in, string; unsigned port; ++svm->vcpu.stat.io_exits; - - svm->next_rip = svm->vmcb->control.exit_info_2; - string = (io_info & SVM_IOIO_STR_MASK) != 0; - - if (string) { - if (emulate_instruction(&svm->vcpu, - 0, 0, 0) == EMULATE_DO_MMIO) - return 0; - return 1; - } - in = (io_info & SVM_IOIO_TYPE_MASK) != 0; + if (string || in) + return !(emulate_instruction(vcpu, 0, 0, 0) == EMULATE_DO_MMIO); + port = io_info >> 16; size = (io_info & SVM_IOIO_SIZE_MASK) >> SVM_IOIO_SIZE_SHIFT; - + svm->next_rip = svm->vmcb->control.exit_info_2; skip_emulated_instruction(&svm->vcpu); - return kvm_emulate_pio(&svm->vcpu, in, size, port); + + return kvm_fast_pio_out(vcpu, size, port); } static int nmi_interception(struct vcpu_svm *svm) |