[PATCH v2 1/6] KVM: x86: Add function for vectoring error generation

Ivan Orlov
2024-11-11T10:28:06Z

Extract VMX code for unhandleable VM-Exit during vectoring into
vendor-agnostic function so that boiler-plate code can be shared by SVM.

Report an actual GPA for EPT misconfig or invalid GPA for any other exit
code in internal.data[3].

Signed-off-by: Ivan Orlov <iorlov@amazon.com>
---
V1 -> V2:
- Return GPA for any exit reason, using reported GPA when it is valid or
INVALID_GPA otherwise.
- Rename the error preparation function
- Fix indentation

arch/x86/include/asm/kvm_host.h | 2 ++
arch/x86/kvm/vmx/vmx.c | 16 ++++------------
arch/x86/kvm/x86.c | 22 ++++++++++++++++++++++
3 files changed, 28 insertions(+), 12 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 6d9f763a7bb9..eb413079b7c6 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -2060,6 +2060,8 @@ void __kvm_prepare_emulation_failure_exit(struct kvm_vcpu *vcpu,
u64 *data, u8 ndata);
void kvm_prepare_emulation_failure_exit(struct kvm_vcpu *vcpu);

+void kvm_prepare_event_vectoring_exit(struct kvm_vcpu *vcpu, gpa_t gpa);
+
void kvm_enable_efer_bits(u64);
bool kvm_valid_efer(struct kvm_vcpu *vcpu, u64 efer);
int kvm_get_msr_with_filter(struct kvm_vcpu *vcpu, u32 index, u64 *data);
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index f6900bec4874..f92740e7e107 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -6452,6 +6452,7 @@ static int __vmx_handle_exit(struct kvm_vcpu *vcpu, fastpath_t exit_fastpath)
union vmx_exit_reason exit_reason = vmx->exit_reason;
u32 vectoring_info = vmx->idt_vectoring_info;
u16 exit_handler_index;
+ gpa_t gpa;

/*
* Flush logged GPAs PML buffer, this will make dirty_bitmap more
@@ -6550,19 +6551,10 @@ static int __vmx_handle_exit(struct kvm_vcpu *vcpu, fastpath_t exit_fastpath)
exit_reason.basic != EXIT_REASON_APIC_ACCESS &&
exit_reason.basic != EXIT_REASON_TASK_SWITCH &&
exit_reason.basic != EXIT_REASON_NOTIFY)) {
- int ndata = 3;
+ gpa = exit_reason.basic == EXIT_REASON_EPT_MISCONFIG
+ ? vmcs_read64(GUEST_PHYSICAL_ADDRESS) : INVALID_GPA;

- vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
- vcpu->run->internal.suberror = KVM_INTERNAL_ERROR_DELIVERY_EV;
- vcpu->run->internal.data[0] = vectoring_info;
- vcpu->run->internal.data[1] = exit_reason.full;
- vcpu->run->internal.data[2] = vmx_get_exit_qual(vcpu);
- if (exit_reason.basic == EXIT_REASON_EPT_MISCONFIG) {
- vcpu->run->internal.data[ndata++] =
- vmcs_read64(GUEST_PHYSICAL_ADDRESS);
- }
- vcpu->run->internal.data[ndata++] = vcpu->arch.last_vmentry_cpu;
- vcpu->run->internal.ndata = ndata;
+ kvm_prepare_event_vectoring_exit(vcpu, gpa);
return 0;
}

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 83fe0a78146f..e338d583f48f 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -8828,6 +8828,28 @@ void kvm_prepare_emulation_failure_exit(struct kvm_vcpu *vcpu)
}
EXPORT_SYMBOL_GPL(kvm_prepare_emulation_failure_exit);

+void kvm_prepare_event_vectoring_exit(struct kvm_vcpu *vcpu, gpa_t gpa)
+{
+ u32 reason, intr_info, error_code;
+ struct kvm_run *run = vcpu->run;
+ u64 info1, info2;
+ int ndata = 0;
+
+ kvm_x86_call(get_exit_info)(vcpu, &reason, &info1, &info2,
+ &intr_info, &error_code);
+
+ run->internal.data[ndata++] = info2;
+ run->internal.data[ndata++] = reason;
+ run->internal.data[ndata++] = info1;
+ run->internal.data[ndata++] = (u64)gpa;
+ run->internal.data[ndata++] = vcpu->arch.last_vmentry_cpu;
+
+ run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+ run->internal.suberror = KVM_INTERNAL_ERROR_DELIVERY_EV;
+ run->internal.ndata = ndata;
+}
+EXPORT_SYMBOL_GPL(kvm_prepare_event_vectoring_exit);
+
static int handle_emulation_failure(struct kvm_vcpu *vcpu, int emulation_type)
{
struct kvm *kvm = vcpu->kvm;
--
2.43.0