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| author | Sean Christopherson <sean.j.christopherson@intel.com> | 2018-03-08 08:57:26 -0800 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2018-03-16 22:01:38 +0100 |
| commit | 432baf60eee3dcacac94b8781464ab566abf0183 (patch) | |
| tree | 83baadab98c52c7fd5026a9619b8983b755e32c5 /arch/x86/kvm/vmx.c | |
| parent | 2bb8cafea80bf69c0e729bf1ad1bcd1d6c53248d (diff) | |
| download | linux-0-day-432baf60eee3dcacac94b8781464ab566abf0183.tar.gz linux-0-day-432baf60eee3dcacac94b8781464ab566abf0183.tar.xz | |
KVM: VMX: use kvm_fast_pio_in for handling IN I/O
Fast emulation of processor I/O for IN was disabled on x86 (both VMX
and SVM) some years ago due to a buggy implementation. The addition
of kvm_fast_pio_in(), used by SVM, re-introduced (functional!) fast
emulation of IN. Piggyback SVM's work and use kvm_fast_pio_in() on
VMX instead of performing full emulation of IN.
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/vmx.c')
| -rw-r--r-- | arch/x86/kvm/vmx.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 5d67a15b51160..8d31e1b7cdd05 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -6270,15 +6270,15 @@ static int handle_io(struct kvm_vcpu *vcpu) exit_qualification = vmcs_readl(EXIT_QUALIFICATION); string = (exit_qualification & 16) != 0; - in = (exit_qualification & 8) != 0; ++vcpu->stat.io_exits; - if (string || in) + if (string) return emulate_instruction(vcpu, 0) == EMULATE_DONE; port = exit_qualification >> 16; size = (exit_qualification & 7) + 1; + in = (exit_qualification & 8) != 0; ret = kvm_skip_emulated_instruction(vcpu); @@ -6286,7 +6286,10 @@ static int handle_io(struct kvm_vcpu *vcpu) * TODO: we might be squashing a KVM_GUESTDBG_SINGLESTEP-triggered * KVM_EXIT_DEBUG here. */ - return kvm_fast_pio_out(vcpu, size, port) && ret; + if (in) + return kvm_fast_pio_in(vcpu, size, port) && ret; + else + return kvm_fast_pio_out(vcpu, size, port) && ret; } static void |