| Message ID | 20240112065159.982-1-robert.hoo.linux@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: VMX: Correct *intr_info content and *info2 for EPT_VIOLATION in get_exit_info() | expand |
On Fri, Jan 12, 2024, Robert Hoo wrote: > Fill vmx::idt_vectoring_info in *intr_info, to align with > svm_get_exit_info(), where *intr_info is for complement information about > intercepts occurring during event delivery through IDT (APM 15.7.2 > Intercepts During IDT Interrupt Delivery), whose counterpart in > VMX is IDT_VECTORING_INFO_FIELD (SDM 25.9.3 Information for VM Exits > That Occur During Event Delivery), rather than VM_EXIT_INTR_INFO. > > Fill *info2 with GUEST_PHYSICAL_ADDRESS in case of EPT_VIOLATION, also > to align with SVM. It can be filled with other info for different exit > reasons, like SVM's EXITINFO2. Nothing in here says *why*. > Fixes: 235ba74f008d ("KVM: x86: Add intr/vectoring info and error code to kvm_exit tracepoint") > Signed-off-by: Robert Hoo <robert.hoo.linux@gmail.com> > --- > arch/x86/kvm/vmx/vmx.c | 20 ++++++++++++++++---- > 1 file changed, 16 insertions(+), 4 deletions(-) > > diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c > index d21f55f323ea..f1bf9f1fc561 100644 > --- a/arch/x86/kvm/vmx/vmx.c > +++ b/arch/x86/kvm/vmx/vmx.c > @@ -6141,14 +6141,26 @@ static void vmx_get_exit_info(struct kvm_vcpu *vcpu, u32 *reason, > > *reason = vmx->exit_reason.full; > *info1 = vmx_get_exit_qual(vcpu); > + > if (!(vmx->exit_reason.failed_vmentry)) { > - *info2 = vmx->idt_vectoring_info; > - *intr_info = vmx_get_intr_info(vcpu); > + *intr_info = vmx->idt_vectoring_info; > if (is_exception_with_error_code(*intr_info)) > - *error_code = vmcs_read32(VM_EXIT_INTR_ERROR_CODE); > + *error_code = vmcs_read32(IDT_VECTORING_ERROR_CODE); > else > *error_code = 0; > - } else { > + > + /* various *info2 semantics according to exit reason */ > + switch (vmx->exit_reason.basic) { > + case EXIT_REASON_EPT_VIOLATION: > + *info2 = vmcs_read64(GUEST_PHYSICAL_ADDRESS); > + break; > + /* To do: *info2 for other exit reasons */ I really, really don't want to go down this road. As I stated in a different, similar thread[*], I don't think this approach is sustainable. I would much rather people put time and effort into (a) developing BPF programs to extract info from the VM-Entry and VM-Exit paths, (b) enhancing KVM in the areas where it's painful or impossible for a BPF program to get at interesting data, and (c) start upstreaming the BPF programs, e.g. somewhere in tools/. [*] https://lore.kernel.org/all/ZRNC5IKXDq1yv0v3@google.com
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index d21f55f323ea..f1bf9f1fc561 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -6141,14 +6141,26 @@ static void vmx_get_exit_info(struct kvm_vcpu *vcpu, u32 *reason, *reason = vmx->exit_reason.full; *info1 = vmx_get_exit_qual(vcpu); + if (!(vmx->exit_reason.failed_vmentry)) { - *info2 = vmx->idt_vectoring_info; - *intr_info = vmx_get_intr_info(vcpu); + *intr_info = vmx->idt_vectoring_info; if (is_exception_with_error_code(*intr_info)) - *error_code = vmcs_read32(VM_EXIT_INTR_ERROR_CODE); + *error_code = vmcs_read32(IDT_VECTORING_ERROR_CODE); else *error_code = 0; - } else { + + /* various *info2 semantics according to exit reason */ + switch (vmx->exit_reason.basic) { + case EXIT_REASON_EPT_VIOLATION: + *info2 = vmcs_read64(GUEST_PHYSICAL_ADDRESS); + break; + /* To do: *info2 for other exit reasons */ + default: + *info2 = 0; + break; + } + + } else { *info2 = 0; *intr_info = 0; *error_code = 0;
Fill vmx::idt_vectoring_info in *intr_info, to align with svm_get_exit_info(), where *intr_info is for complement information about intercepts occurring during event delivery through IDT (APM 15.7.2 Intercepts During IDT Interrupt Delivery), whose counterpart in VMX is IDT_VECTORING_INFO_FIELD (SDM 25.9.3 Information for VM Exits That Occur During Event Delivery), rather than VM_EXIT_INTR_INFO. Fill *info2 with GUEST_PHYSICAL_ADDRESS in case of EPT_VIOLATION, also to align with SVM. It can be filled with other info for different exit reasons, like SVM's EXITINFO2. Fixes: 235ba74f008d ("KVM: x86: Add intr/vectoring info and error code to kvm_exit tracepoint") Signed-off-by: Robert Hoo <robert.hoo.linux@gmail.com> --- arch/x86/kvm/vmx/vmx.c | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-) base-commit: 1c6d984f523f67ecfad1083bb04c55d91977bb15