emulator_pio_in handles both the case where the data is pending in vcpu->arch.pio.count, and the case where I/O has to be done via either an in-kernel device or a userspace exit. For SEV-ES we would like to split these, to identify clearly the moment at which the sev_pio_data is consumed. To this end, create two different functions: __emulator_pio_in fills in vcpu->arch.pio.count, while complete_emulator_pio_in clears it and releases vcpu->arch.pio.data.
While at it, remove the void* argument also from emulator_pio_in_out.
No functional change intended.
Cc: stable@vger.kernel.org Fixes: 7ed9abfe8e9f ("KVM: SVM: Support string IO operations for an SEV-ES guest") Signed-off-by: Paolo Bonzini pbonzini@redhat.com --- arch/x86/kvm/x86.c | 42 +++++++++++++++++++++++------------------- 1 file changed, 23 insertions(+), 19 deletions(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 8880dc36a2b4..07d9533b471d 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -6906,7 +6906,7 @@ static int kernel_pio(struct kvm_vcpu *vcpu, void *pd) }
static int emulator_pio_in_out(struct kvm_vcpu *vcpu, int size, - unsigned short port, void *val, + unsigned short port, unsigned int count, bool in) { vcpu->arch.pio.port = port; @@ -6927,26 +6927,31 @@ static int emulator_pio_in_out(struct kvm_vcpu *vcpu, int size, return 0; }
-static int emulator_pio_in(struct kvm_vcpu *vcpu, int size, - unsigned short port, void *val, unsigned int count) +static int __emulator_pio_in(struct kvm_vcpu *vcpu, int size, + unsigned short port, unsigned int count) { - int ret; - - if (vcpu->arch.pio.count) - goto data_avail; - + WARN_ON(vcpu->arch.pio.count); memset(vcpu->arch.pio_data, 0, size * count); + return emulator_pio_in_out(vcpu, size, port, count, true); +}
- ret = emulator_pio_in_out(vcpu, size, port, val, count, true); - if (ret) { -data_avail: - memcpy(val, vcpu->arch.pio_data, size * count); - trace_kvm_pio(KVM_PIO_IN, port, size, count, vcpu->arch.pio_data); - vcpu->arch.pio.count = 0; - return 1; - } +static void complete_emulator_pio_in(struct kvm_vcpu *vcpu, int size, + unsigned short port, void *val) +{ + memcpy(val, vcpu->arch.pio_data, size * vcpu->arch.pio.count); + trace_kvm_pio(KVM_PIO_IN, port, size, vcpu->arch.pio.count, vcpu->arch.pio_data); + vcpu->arch.pio.count = 0; +}
- return 0; +static int emulator_pio_in(struct kvm_vcpu *vcpu, int size, + unsigned short port, void *val, unsigned int count) +{ + if (!vcpu->arch.pio.count && !__emulator_pio_in(vcpu, size, port, count)) + return 0; + + WARN_ON(count != vcpu->arch.pio.count); + complete_emulator_pio_in(vcpu, size, port, val); + return 1; }
static int emulator_pio_in_emulated(struct x86_emulate_ctxt *ctxt, @@ -6965,12 +6970,11 @@ static int emulator_pio_out(struct kvm_vcpu *vcpu, int size,
memcpy(vcpu->arch.pio_data, val, size * count); trace_kvm_pio(KVM_PIO_OUT, port, size, count, vcpu->arch.pio_data); - ret = emulator_pio_in_out(vcpu, size, port, (void *)val, count, false); + ret = emulator_pio_in_out(vcpu, size, port, count, false); if (ret) vcpu->arch.pio.count = 0;
return ret; - }
static int emulator_pio_out_emulated(struct x86_emulate_ctxt *ctxt,