[PATCH 2/2] KVM: nSVM: Add helper to synthesize nested VM-Exit without collateral

Sean Christopherson
2021-03-03T07:23:43Z

Add a helper to consolidate boilerplate for nested VM-Exits that don't
provide any data in exit_info_*.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/kvm/svm/nested.c | 55 +++++----------------------------------
arch/x86/kvm/svm/svm.c | 6 +----
arch/x86/kvm/svm/svm.h | 9 +++++++
3 files changed, 16 insertions(+), 54 deletions(-)

diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index 93a61ed76e5b..307c11125391 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -797,12 +797,7 @@ int nested_svm_vmexit(struct vcpu_svm *svm)

static void nested_svm_triple_fault(struct kvm_vcpu *vcpu)
{
- struct vcpu_svm *svm = to_svm(vcpu);
-
- svm->vmcb->control.exit_code = SVM_EXIT_SHUTDOWN;
- svm->vmcb->control.exit_info_1 = 0;
- svm->vmcb->control.exit_info_2 = 0;
- nested_svm_vmexit(svm);
+ nested_svm_simple_vmexit(to_svm(vcpu), SVM_EXIT_SHUTDOWN);
}

int svm_allocate_nested(struct vcpu_svm *svm)
@@ -1027,50 +1022,11 @@ static void nested_svm_inject_exception_vmexit(struct vcpu_svm *svm)
nested_svm_vmexit(svm);
}

-static void nested_svm_smi(struct vcpu_svm *svm)
-{
- svm->vmcb->control.exit_code = SVM_EXIT_SMI;
- svm->vmcb->control.exit_info_1 = 0;
- svm->vmcb->control.exit_info_2 = 0;
-
- nested_svm_vmexit(svm);
-}
-
-static void nested_svm_nmi(struct vcpu_svm *svm)
-{
- svm->vmcb->control.exit_code = SVM_EXIT_NMI;
- svm->vmcb->control.exit_info_1 = 0;
- svm->vmcb->control.exit_info_2 = 0;
-
- nested_svm_vmexit(svm);
-}
-
-static void nested_svm_intr(struct vcpu_svm *svm)
-{
- trace_kvm_nested_intr_vmexit(svm->vmcb->save.rip);
-
- svm->vmcb->control.exit_code = SVM_EXIT_INTR;
- svm->vmcb->control.exit_info_1 = 0;
- svm->vmcb->control.exit_info_2 = 0;
-
- nested_svm_vmexit(svm);
-}
-
static inline bool nested_exit_on_init(struct vcpu_svm *svm)
{
return vmcb_is_intercept(&svm->nested.ctl, INTERCEPT_INIT);
}

-static void nested_svm_init(struct vcpu_svm *svm)
-{
- svm->vmcb->control.exit_code = SVM_EXIT_INIT;
- svm->vmcb->control.exit_info_1 = 0;
- svm->vmcb->control.exit_info_2 = 0;
-
- nested_svm_vmexit(svm);
-}
-
-
static int svm_check_nested_events(struct kvm_vcpu *vcpu)
{
struct vcpu_svm *svm = to_svm(vcpu);
@@ -1084,7 +1040,7 @@ static int svm_check_nested_events(struct kvm_vcpu *vcpu)
return -EBUSY;
if (!nested_exit_on_init(svm))
return 0;
- nested_svm_init(svm);
+ nested_svm_simple_vmexit(svm, SVM_EXIT_INIT);
return 0;
}

@@ -1102,7 +1058,7 @@ static int svm_check_nested_events(struct kvm_vcpu *vcpu)
return -EBUSY;
if (!nested_exit_on_smi(svm))
return 0;
- nested_svm_smi(svm);
+ nested_svm_simple_vmexit(svm, SVM_EXIT_SMI);
return 0;
}

@@ -1111,7 +1067,7 @@ static int svm_check_nested_events(struct kvm_vcpu *vcpu)
return -EBUSY;
if (!nested_exit_on_nmi(svm))
return 0;
- nested_svm_nmi(svm);
+ nested_svm_simple_vmexit(svm, SVM_EXIT_NMI);
return 0;
}

@@ -1120,7 +1076,8 @@ static int svm_check_nested_events(struct kvm_vcpu *vcpu)
return -EBUSY;
if (!nested_exit_on_intr(svm))
return 0;
- nested_svm_intr(svm);
+ trace_kvm_nested_intr_vmexit(svm->vmcb->save.rip);
+ nested_svm_simple_vmexit(svm, SVM_EXIT_INTR);
return 0;
}

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 54610270f66a..9fe9076d4b8b 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -2203,12 +2203,8 @@ static int emulate_svm_instr(struct kvm_vcpu *vcpu, int opcode)
int ret;

if (is_guest_mode(vcpu)) {
- svm->vmcb->control.exit_code = guest_mode_exit_codes[opcode];
- svm->vmcb->control.exit_info_1 = 0;
- svm->vmcb->control.exit_info_2 = 0;
-
/* Returns '1' or -errno on failure, '0' on success. */
- ret = nested_svm_vmexit(svm);
+ ret = nested_svm_simple_vmexit(svm, guest_mode_exit_codes[opcode]);
if (ret)
return ret;
return 1;
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index fbbb26dd0f73..c4a433c66a33 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -444,6 +444,15 @@ int svm_allocate_nested(struct vcpu_svm *svm);
int nested_svm_vmrun(struct kvm_vcpu *vcpu);
void nested_svm_vmloadsave(struct vmcb *from_vmcb, struct vmcb *to_vmcb);
int nested_svm_vmexit(struct vcpu_svm *svm);
+
+static inline int nested_svm_simple_vmexit(struct vcpu_svm *svm, u32 exit_code)
+{
+ svm->vmcb->control.exit_code = exit_code;
+ svm->vmcb->control.exit_info_1 = 0;
+ svm->vmcb->control.exit_info_2 = 0;
+ return nested_svm_vmexit(svm);
+}
+
int nested_svm_exit_handled(struct vcpu_svm *svm);
int nested_svm_check_permissions(struct kvm_vcpu *vcpu);
int nested_svm_check_exception(struct vcpu_svm *svm, unsigned nr,