diff options
| author | Gleb Natapov | 2010-03-18 14:20:23 +0100 |
|---|---|---|
| committer | Avi Kivity | 2010-05-17 11:16:25 +0200 |
| commit | cf8f70bfe38b326bb80b10f76d6544f571040229 (patch) | |
| tree | d646456d773a887ca592d174b3d45a57d2779d85 /arch/x86/kvm/vmx.c | |
| parent | KVM: x86 emulator: during rep emulation decrement ECX only if emulation succe... (diff) | |
| download | kernel-qcow2-linux-cf8f70bfe38b326bb80b10f76d6544f571040229.tar.gz kernel-qcow2-linux-cf8f70bfe38b326bb80b10f76d6544f571040229.tar.xz kernel-qcow2-linux-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/vmx.c')
| -rw-r--r-- | arch/x86/kvm/vmx.c | 18 |
1 files changed, 8 insertions, 10 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 87b3c6843aac..1cceca1c59be 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -2985,22 +2985,20 @@ static int handle_io(struct kvm_vcpu *vcpu) int size, in, string; unsigned port; - ++vcpu->stat.io_exits; exit_qualification = vmcs_readl(EXIT_QUALIFICATION); string = (exit_qualification & 16) != 0; + in = (exit_qualification & 8) != 0; - if (string) { - if (emulate_instruction(vcpu, 0, 0, 0) == EMULATE_DO_MMIO) - return 0; - return 1; - } + ++vcpu->stat.io_exits; - size = (exit_qualification & 7) + 1; - in = (exit_qualification & 8) != 0; - port = exit_qualification >> 16; + if (string || in) + return !(emulate_instruction(vcpu, 0, 0, 0) == EMULATE_DO_MMIO); + port = exit_qualification >> 16; + size = (exit_qualification & 7) + 1; skip_emulated_instruction(vcpu); - return kvm_emulate_pio(vcpu, in, size, port); + + return kvm_fast_pio_out(vcpu, size, port); } static void |