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-rw-r--r--arch/x86/include/asm/kvm_host.h1
-rw-r--r--arch/x86/kvm/x86.c36
2 files changed, 27 insertions, 10 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 264814f26ce0..159b5988292f 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -350,6 +350,7 @@ struct kvm_mmu_page {
};
struct kvm_pio_request {
+ unsigned long linear_rip;
unsigned long count;
int in;
int port;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 9f279bb145e5..099b851dabaf 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6535,14 +6535,27 @@ int kvm_emulate_instruction_from_buffer(struct kvm_vcpu *vcpu,
}
EXPORT_SYMBOL_GPL(kvm_emulate_instruction_from_buffer);
+static int complete_fast_pio_out(struct kvm_vcpu *vcpu)
+{
+ vcpu->arch.pio.count = 0;
+
+ if (unlikely(!kvm_is_linear_rip(vcpu, vcpu->arch.pio.linear_rip)))
+ return 1;
+
+ return kvm_skip_emulated_instruction(vcpu);
+}
+
static int kvm_fast_pio_out(struct kvm_vcpu *vcpu, int size,
unsigned short port)
{
unsigned long val = kvm_register_read(vcpu, VCPU_REGS_RAX);
int ret = emulator_pio_out_emulated(&vcpu->arch.emulate_ctxt,
size, port, &val, 1);
- /* do not return to emulator after return from userspace */
- vcpu->arch.pio.count = 0;
+
+ if (!ret) {
+ vcpu->arch.pio.linear_rip = kvm_get_linear_rip(vcpu);
+ vcpu->arch.complete_userspace_io = complete_fast_pio_out;
+ }
return ret;
}
@@ -6553,6 +6566,11 @@ static int complete_fast_pio_in(struct kvm_vcpu *vcpu)
/* We should only ever be called with arch.pio.count equal to 1 */
BUG_ON(vcpu->arch.pio.count != 1);
+ if (unlikely(!kvm_is_linear_rip(vcpu, vcpu->arch.pio.linear_rip))) {
+ vcpu->arch.pio.count = 0;
+ return 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;
@@ -6565,7 +6583,7 @@ static int complete_fast_pio_in(struct kvm_vcpu *vcpu)
vcpu->arch.pio.port, &val, 1);
kvm_register_write(vcpu, VCPU_REGS_RAX, val);
- return 1;
+ return kvm_skip_emulated_instruction(vcpu);
}
static int kvm_fast_pio_in(struct kvm_vcpu *vcpu, int size,
@@ -6584,6 +6602,7 @@ static int kvm_fast_pio_in(struct kvm_vcpu *vcpu, int size,
return ret;
}
+ vcpu->arch.pio.linear_rip = kvm_get_linear_rip(vcpu);
vcpu->arch.complete_userspace_io = complete_fast_pio_in;
return 0;
@@ -6591,16 +6610,13 @@ static int kvm_fast_pio_in(struct kvm_vcpu *vcpu, int size,
int kvm_fast_pio(struct kvm_vcpu *vcpu, int size, unsigned short port, int in)
{
- int ret = kvm_skip_emulated_instruction(vcpu);
+ int ret;
- /*
- * TODO: we might be squashing a KVM_GUESTDBG_SINGLESTEP-triggered
- * KVM_EXIT_DEBUG here.
- */
if (in)
- return kvm_fast_pio_in(vcpu, size, port) && ret;
+ ret = kvm_fast_pio_in(vcpu, size, port);
else
- return kvm_fast_pio_out(vcpu, size, port) && ret;
+ ret = kvm_fast_pio_out(vcpu, size, port);
+ return ret && kvm_skip_emulated_instruction(vcpu);
}
EXPORT_SYMBOL_GPL(kvm_fast_pio);