[PATCH v2 01/13] KVM: x86: Refactor I/O emulation helpers to provide vcpu-only variant

Sean Christopherson
2020-02-18T23:31:01Z

Add variants of the I/O helpers that take a vCPU instead of an emulation
context. This will eventually allow KVM to limit use of the emulation
context to the full emulation path.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
arch/x86/kvm/x86.c | 39 ++++++++++++++++++++++++---------------
1 file changed, 24 insertions(+), 15 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index fbabb2f06273..6554abef631f 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5959,11 +5959,9 @@ static int emulator_pio_in_out(struct kvm_vcpu *vcpu, int size,
return 0;
}

-static int emulator_pio_in_emulated(struct x86_emulate_ctxt *ctxt,
- int size, unsigned short port, void *val,
- unsigned int count)
+static int emulator_pio_in(struct kvm_vcpu *vcpu, int size,
+ unsigned short port, void *val, unsigned int count)
{
- struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
int ret;

if (vcpu->arch.pio.count)
@@ -5983,17 +5981,30 @@ static int emulator_pio_in_emulated(struct x86_emulate_ctxt *ctxt,
return 0;
}

-static int emulator_pio_out_emulated(struct x86_emulate_ctxt *ctxt,
- int size, unsigned short port,
- const void *val, unsigned int count)
+static int emulator_pio_in_emulated(struct x86_emulate_ctxt *ctxt,
+ int size, unsigned short port, void *val,
+ unsigned int count)
{
- struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
+ return emulator_pio_in(emul_to_vcpu(ctxt), size, port, val, count);

+}
+
+static int emulator_pio_out(struct kvm_vcpu *vcpu, int size,
+ unsigned short port, const void *val,
+ unsigned int count)
+{
memcpy(vcpu->arch.pio_data, val, size * count);
trace_kvm_pio(KVM_PIO_OUT, port, size, count, vcpu->arch.pio_data);
return emulator_pio_in_out(vcpu, size, port, (void *)val, count, false);
}

+static int emulator_pio_out_emulated(struct x86_emulate_ctxt *ctxt,
+ int size, unsigned short port,
+ const void *val, unsigned int count)
+{
+ return emulator_pio_out(emul_to_vcpu(ctxt), size, port, val, count);
+}
+
static unsigned long get_segment_base(struct kvm_vcpu *vcpu, int seg)
{
return kvm_x86_ops->get_segment_base(vcpu, seg);
@@ -6930,8 +6941,8 @@ static int kvm_fast_pio_out(struct kvm_vcpu *vcpu, int size,
unsigned short port)
{
unsigned long val = kvm_rax_read(vcpu);
- int ret = emulator_pio_out_emulated(&vcpu->arch.emulate_ctxt,
- size, port, &val, 1);
+ int ret = emulator_pio_out(vcpu, size, port, &val, 1);
+
if (ret)
return ret;

@@ -6967,11 +6978,10 @@ static int complete_fast_pio_in(struct kvm_vcpu *vcpu)
val = (vcpu->arch.pio.size < 4) ? kvm_rax_read(vcpu) : 0;

/*
- * Since vcpu->arch.pio.count == 1 let emulator_pio_in_emulated perform
+ * Since vcpu->arch.pio.count == 1 let emulator_pio_in perform
* the copy and tracing
*/
- emulator_pio_in_emulated(&vcpu->arch.emulate_ctxt, vcpu->arch.pio.size,
- vcpu->arch.pio.port, &val, 1);
+ emulator_pio_in(vcpu, vcpu->arch.pio.size, vcpu->arch.pio.port, &val, 1);
kvm_rax_write(vcpu, val);

return kvm_skip_emulated_instruction(vcpu);
@@ -6986,8 +6996,7 @@ static int kvm_fast_pio_in(struct kvm_vcpu *vcpu, int size,
/* For size less than 4 we merge, else we zero extend */
val = (size < 4) ? kvm_rax_read(vcpu) : 0;

- ret = emulator_pio_in_emulated(&vcpu->arch.emulate_ctxt, size, port,
- &val, 1);
+ ret = emulator_pio_in(vcpu, size, port, &val, 1);
if (ret) {
kvm_rax_write(vcpu, val);
return ret;
--
2.24.1