diff options
Diffstat (limited to 'arch/x86/kvm/x86.c')
| -rw-r--r-- | arch/x86/kvm/x86.c | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 6f9c9ad13f88..ec59301f5192 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -5615,6 +5615,49 @@ int kvm_fast_pio_out(struct kvm_vcpu *vcpu, int size, unsigned short port) } EXPORT_SYMBOL_GPL(kvm_fast_pio_out); +static int complete_fast_pio_in(struct kvm_vcpu *vcpu) +{ + unsigned long val; + + /* We should only ever be called with arch.pio.count equal to 1 */ + BUG_ON(vcpu->arch.pio.count != 1); + + /* For size less than 4 we merge, else we zero extend */ + val = (vcpu->arch.pio.size < 4) ? kvm_register_read(vcpu, VCPU_REGS_RAX) + : 0; + + /* + * Since vcpu->arch.pio.count == 1 let emulator_pio_in_emulated perform + * the copy and tracing + */ + emulator_pio_in_emulated(&vcpu->arch.emulate_ctxt, vcpu->arch.pio.size, + vcpu->arch.pio.port, &val, 1); + kvm_register_write(vcpu, VCPU_REGS_RAX, val); + + return 1; +} + +int kvm_fast_pio_in(struct kvm_vcpu *vcpu, int size, unsigned short port) +{ + unsigned long val; + int ret; + + /* For size less than 4 we merge, else we zero extend */ + val = (size < 4) ? kvm_register_read(vcpu, VCPU_REGS_RAX) : 0; + + ret = emulator_pio_in_emulated(&vcpu->arch.emulate_ctxt, size, port, + &val, 1); + if (ret) { + kvm_register_write(vcpu, VCPU_REGS_RAX, val); + return ret; + } + + vcpu->arch.complete_userspace_io = complete_fast_pio_in; + + return 0; +} +EXPORT_SYMBOL_GPL(kvm_fast_pio_in); + static int kvmclock_cpu_down_prep(unsigned int cpu) { __this_cpu_write(cpu_tsc_khz, 0); |