[PATCH] KVM: SVM: handle singlestep exception when skipping emulated instructions

[Ladi Prosek <lprosek@redhat.com>]

kvm_skip_emulated_instruction handles the singlestep debug exception
which is something we almost always want. This commit (specifically
the change in rdmsr_interception) makes the debug.flat KVM unit test
pass on AMD.

Two call sites still call skip_emulated_instruction directly:

* In svm_queue_exception where it's used only for moving the rip forward

* In task_switch_interception which is analogous to handle_task_switch
  in VMX

Signed-off-by: Ladi Prosek <lprosek@redhat.com>
---
 arch/x86/kvm/svm.c | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 4250f9a..472a1c1 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -2278,7 +2278,7 @@ static int io_interception(struct vcpu_svm *svm)
 	port = io_info >> 16;
 	size = (io_info & SVM_IOIO_SIZE_MASK) >> SVM_IOIO_SIZE_SHIFT;
 	svm->next_rip = svm->vmcb->control.exit_info_2;
-	skip_emulated_instruction(&svm->vcpu);
+	kvm_skip_emulated_instruction(&svm->vcpu);
 
 	return in ? kvm_fast_pio_in(vcpu, size, port)
 		  : kvm_fast_pio_out(vcpu, size, port);
@@ -3063,7 +3063,7 @@ static int vmload_interception(struct vcpu_svm *svm)
 		return 1;
 
 	svm->next_rip = kvm_rip_read(&svm->vcpu) + 3;
-	skip_emulated_instruction(&svm->vcpu);
+	kvm_skip_emulated_instruction(&svm->vcpu);
 
 	nested_svm_vmloadsave(nested_vmcb, svm->vmcb);
 	nested_svm_unmap(page);
@@ -3084,7 +3084,7 @@ static int vmsave_interception(struct vcpu_svm *svm)
 		return 1;
 
 	svm->next_rip = kvm_rip_read(&svm->vcpu) + 3;
-	skip_emulated_instruction(&svm->vcpu);
+	kvm_skip_emulated_instruction(&svm->vcpu);
 
 	nested_svm_vmloadsave(svm->vmcb, nested_vmcb);
 	nested_svm_unmap(page);
@@ -3126,7 +3126,7 @@ static int stgi_interception(struct vcpu_svm *svm)
 		return 1;
 
 	svm->next_rip = kvm_rip_read(&svm->vcpu) + 3;
-	skip_emulated_instruction(&svm->vcpu);
+	kvm_skip_emulated_instruction(&svm->vcpu);
 	kvm_make_request(KVM_REQ_EVENT, &svm->vcpu);
 
 	enable_gif(svm);
@@ -3140,7 +3140,7 @@ static int clgi_interception(struct vcpu_svm *svm)
 		return 1;
 
 	svm->next_rip = kvm_rip_read(&svm->vcpu) + 3;
-	skip_emulated_instruction(&svm->vcpu);
+	kvm_skip_emulated_instruction(&svm->vcpu);
 
 	disable_gif(svm);
 
@@ -3165,7 +3165,7 @@ static int invlpga_interception(struct vcpu_svm *svm)
 	kvm_mmu_invlpg(vcpu, kvm_register_read(&svm->vcpu, VCPU_REGS_RAX));
 
 	svm->next_rip = kvm_rip_read(&svm->vcpu) + 3;
-	skip_emulated_instruction(&svm->vcpu);
+	kvm_skip_emulated_instruction(&svm->vcpu);
 	return 1;
 }
 
@@ -3189,7 +3189,7 @@ static int xsetbv_interception(struct vcpu_svm *svm)
 
 	if (kvm_set_xcr(&svm->vcpu, index, new_bv) == 0) {
 		svm->next_rip = kvm_rip_read(&svm->vcpu) + 3;
-		skip_emulated_instruction(&svm->vcpu);
+		kvm_skip_emulated_instruction(&svm->vcpu);
 	}
 
 	return 1;
@@ -3285,7 +3285,7 @@ static int invlpg_interception(struct vcpu_svm *svm)
 		return emulate_instruction(&svm->vcpu, 0) == EMULATE_DONE;
 
 	kvm_mmu_invlpg(&svm->vcpu, svm->vmcb->control.exit_info_1);
-	skip_emulated_instruction(&svm->vcpu);
+	kvm_skip_emulated_instruction(&svm->vcpu);
 	return 1;
 }
 
@@ -3436,7 +3436,7 @@ static int dr_interception(struct vcpu_svm *svm)
 		kvm_register_write(&svm->vcpu, reg, val);
 	}
 
-	skip_emulated_instruction(&svm->vcpu);
+	kvm_skip_emulated_instruction(&svm->vcpu);
 
 	return 1;
 }
@@ -3569,7 +3569,7 @@ static int rdmsr_interception(struct vcpu_svm *svm)
 		kvm_register_write(&svm->vcpu, VCPU_REGS_RDX,
 				   msr_info.data >> 32);
 		svm->next_rip = kvm_rip_read(&svm->vcpu) + 2;
-		skip_emulated_instruction(&svm->vcpu);
+		kvm_skip_emulated_instruction(&svm->vcpu);
 	}
 	return 1;
 }
@@ -3699,7 +3699,7 @@ static int wrmsr_interception(struct vcpu_svm *svm)
 		kvm_inject_gp(&svm->vcpu, 0);
 	} else {
 		trace_kvm_msr_write(ecx, data);
-		skip_emulated_instruction(&svm->vcpu);
+		kvm_skip_emulated_instruction(&svm->vcpu);
 	}
 	return 1;
 }
@@ -3730,7 +3730,7 @@ static int pause_interception(struct vcpu_svm *svm)
 
 static int nop_interception(struct vcpu_svm *svm)
 {
-	skip_emulated_instruction(&(svm->vcpu));
+	kvm_skip_emulated_instruction(&(svm->vcpu));
 	return 1;
 }
 
-- 
2.9.3