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@xxxxxxxxxx>
---
v1->v2:
* now propagating kvm_skip_emulated_instruction return value up the stack
arch/x86/kvm/svm.c | 59 ++++++++++++++++++++++++++++++------------------------
1 file changed, 33 insertions(+), 26 deletions(-)
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 4250f9a..09f8f43 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -2266,7 +2266,7 @@ static int io_interception(struct vcpu_svm *svm)
{
struct kvm_vcpu *vcpu = &svm->vcpu;
u32 io_info = svm->vmcb->control.exit_info_1; /* address size bug? */
- int size, in, string;
+ int size, in, string, ret;
unsigned port;
++svm->vcpu.stat.io_exits;
@@ -2278,10 +2278,16 @@ 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);
+ ret = kvm_skip_emulated_instruction(&svm->vcpu);
- return in ? kvm_fast_pio_in(vcpu, size, port)
- : kvm_fast_pio_out(vcpu, size, port);
+ /*
+ * 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;
+ else
+ return kvm_fast_pio_out(vcpu, size, port) && ret;
}
static int nmi_interception(struct vcpu_svm *svm)
@@ -3054,6 +3060,7 @@ static int vmload_interception(struct vcpu_svm *svm)
{
struct vmcb *nested_vmcb;
struct page *page;
+ int ret;
if (nested_svm_check_permissions(svm))
return 1;
@@ -3063,18 +3070,19 @@ static int vmload_interception(struct vcpu_svm *svm)
return 1;
svm->next_rip = kvm_rip_read(&svm->vcpu) + 3;
- skip_emulated_instruction(&svm->vcpu);
+ ret = kvm_skip_emulated_instruction(&svm->vcpu);
nested_svm_vmloadsave(nested_vmcb, svm->vmcb);
nested_svm_unmap(page);
- return 1;
+ return ret;
}
static int vmsave_interception(struct vcpu_svm *svm)
{
struct vmcb *nested_vmcb;
struct page *page;
+ int ret;
if (nested_svm_check_permissions(svm))
return 1;
@@ -3084,12 +3092,12 @@ static int vmsave_interception(struct vcpu_svm *svm)
return 1;
svm->next_rip = kvm_rip_read(&svm->vcpu) + 3;
- skip_emulated_instruction(&svm->vcpu);
+ ret = kvm_skip_emulated_instruction(&svm->vcpu);
nested_svm_vmloadsave(svm->vmcb, nested_vmcb);
nested_svm_unmap(page);
- return 1;
+ return ret;
}
static int vmrun_interception(struct vcpu_svm *svm)
@@ -3122,25 +3130,29 @@ static int vmrun_interception(struct vcpu_svm *svm)
static int stgi_interception(struct vcpu_svm *svm)
{
+ int ret;
+
if (nested_svm_check_permissions(svm))
return 1;
svm->next_rip = kvm_rip_read(&svm->vcpu) + 3;
- skip_emulated_instruction(&svm->vcpu);
+ ret = kvm_skip_emulated_instruction(&svm->vcpu);
kvm_make_request(KVM_REQ_EVENT, &svm->vcpu);
enable_gif(svm);
- return 1;
+ return ret;
}
static int clgi_interception(struct vcpu_svm *svm)
{
+ int ret;
+
if (nested_svm_check_permissions(svm))
return 1;
svm->next_rip = kvm_rip_read(&svm->vcpu) + 3;
- skip_emulated_instruction(&svm->vcpu);
+ ret = kvm_skip_emulated_instruction(&svm->vcpu);
disable_gif(svm);
@@ -3151,7 +3163,7 @@ static int clgi_interception(struct vcpu_svm *svm)
mark_dirty(svm->vmcb, VMCB_INTR);
}
- return 1;
+ return ret;
}
static int invlpga_interception(struct vcpu_svm *svm)
@@ -3165,8 +3177,7 @@ 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);
- return 1;
+ return kvm_skip_emulated_instruction(&svm->vcpu);
}
static int skinit_interception(struct vcpu_svm *svm)
@@ -3189,7 +3200,7 @@ 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);
+ return kvm_skip_emulated_instruction(&svm->vcpu);
}
return 1;
@@ -3285,8 +3296,7 @@ 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);
- return 1;
+ return kvm_skip_emulated_instruction(&svm->vcpu);
}
static int emulate_on_interception(struct vcpu_svm *svm)
@@ -3436,9 +3446,7 @@ static int dr_interception(struct vcpu_svm *svm)
kvm_register_write(&svm->vcpu, reg, val);
}
- skip_emulated_instruction(&svm->vcpu);
-
- return 1;
+ return kvm_skip_emulated_instruction(&svm->vcpu);
}
static int cr8_write_interception(struct vcpu_svm *svm)
@@ -3561,6 +3569,7 @@ static int rdmsr_interception(struct vcpu_svm *svm)
if (svm_get_msr(&svm->vcpu, &msr_info)) {
trace_kvm_msr_read_ex(ecx);
kvm_inject_gp(&svm->vcpu, 0);
+ return 1;
} else {
trace_kvm_msr_read(ecx, msr_info.data);
@@ -3569,9 +3578,8 @@ 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);
+ return kvm_skip_emulated_instruction(&svm->vcpu);
}
- return 1;
}
static int svm_set_vm_cr(struct kvm_vcpu *vcpu, u64 data)
@@ -3697,11 +3705,11 @@ static int wrmsr_interception(struct vcpu_svm *svm)
if (kvm_set_msr(&svm->vcpu, &msr)) {
trace_kvm_msr_write_ex(ecx, data);
kvm_inject_gp(&svm->vcpu, 0);
+ return 1;
} else {
trace_kvm_msr_write(ecx, data);
- skip_emulated_instruction(&svm->vcpu);
+ return kvm_skip_emulated_instruction(&svm->vcpu);
}
- return 1;
}
static int msr_interception(struct vcpu_svm *svm)
@@ -3730,8 +3738,7 @@ static int pause_interception(struct vcpu_svm *svm)
static int nop_interception(struct vcpu_svm *svm)
{
- skip_emulated_instruction(&(svm->vcpu));
- return 1;
+ return kvm_skip_emulated_instruction(&(svm->vcpu));
}
static int monitor_interception(struct vcpu_svm *svm)
--
2.9.3
