| Message ID | 20210729133931.1129696-2-david.edmondson@oracle.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | kvm: x86: Convey the exit reason, etc. to user-space on emulation failure | expand |
Shortlog is a bit odd, "should" is subjective and makes this sound like a bug fix. KVM: x86: Get exit_reason as part of kvm_x86_ops.get_exit_info On Thu, Jul 29, 2021, David Edmondson wrote: > Extend the get_exit_info static call to provide the reason for the VM > exit. Modify relevant trace points to use this rather than extracting > the reason in the caller. > > Signed-off-by: David Edmondson <david.edmondson@oracle.com> > --- > -static void svm_get_exit_info(struct kvm_vcpu *vcpu, u64 *info1, u64 *info2, > +static void svm_get_exit_info(struct kvm_vcpu *vcpu, u64 *reason, > + u64 *info1, u64 *info2, > u32 *intr_info, u32 *error_code) > { > struct vmcb_control_area *control = &to_svm(vcpu)->vmcb->control; > > + *reason = control->exit_code; > *info1 = control->exit_info_1; > *info2 = control->exit_info_2; > *intr_info = control->exit_int_info; ... > diff --git a/arch/x86/kvm/trace.h b/arch/x86/kvm/trace.h > index b484141ea15b..2228565beda2 100644 > --- a/arch/x86/kvm/trace.h > +++ b/arch/x86/kvm/trace.h > @@ -273,11 +273,11 @@ TRACE_EVENT(kvm_apic, > > #define TRACE_EVENT_KVM_EXIT(name) \ > TRACE_EVENT(name, \ > - TP_PROTO(unsigned int exit_reason, struct kvm_vcpu *vcpu, u32 isa), \ > - TP_ARGS(exit_reason, vcpu, isa), \ > + TP_PROTO(struct kvm_vcpu *vcpu, u32 isa), \ > + TP_ARGS(vcpu, isa), \ > \ > TP_STRUCT__entry( \ > - __field( unsigned int, exit_reason ) \ > + __field( u64, exit_reason ) \ Converting to a u64 is unnecessary and misleading. vmcs.EXIT_REASON and vmcb.EXIT_CODE are both u32s, a.k.a. unsigned ints. There is vmcb.EXIT_CODE_HI, but that's not being included, and AFAICT isn't even sanity checked by KVM. > __field( unsigned long, guest_rip ) \ > __field( u32, isa ) \ > __field( u64, info1 ) \
On Thursday, 2021-07-29 at 22:27:28 GMT, Sean Christopherson wrote: > Shortlog is a bit odd, "should" is subjective and makes this sound like a bug fix. > > KVM: x86: Get exit_reason as part of kvm_x86_ops.get_exit_info Okay. > On Thu, Jul 29, 2021, David Edmondson wrote: >> Extend the get_exit_info static call to provide the reason for the VM >> exit. Modify relevant trace points to use this rather than extracting >> the reason in the caller. >> >> Signed-off-by: David Edmondson <david.edmondson@oracle.com> >> --- >> -static void svm_get_exit_info(struct kvm_vcpu *vcpu, u64 *info1, u64 *info2, >> +static void svm_get_exit_info(struct kvm_vcpu *vcpu, u64 *reason, >> + u64 *info1, u64 *info2, >> u32 *intr_info, u32 *error_code) >> { >> struct vmcb_control_area *control = &to_svm(vcpu)->vmcb->control; >> >> + *reason = control->exit_code; >> *info1 = control->exit_info_1; >> *info2 = control->exit_info_2; >> *intr_info = control->exit_int_info; > > ... > >> diff --git a/arch/x86/kvm/trace.h b/arch/x86/kvm/trace.h >> index b484141ea15b..2228565beda2 100644 >> --- a/arch/x86/kvm/trace.h >> +++ b/arch/x86/kvm/trace.h >> @@ -273,11 +273,11 @@ TRACE_EVENT(kvm_apic, >> >> #define TRACE_EVENT_KVM_EXIT(name) \ >> TRACE_EVENT(name, \ >> - TP_PROTO(unsigned int exit_reason, struct kvm_vcpu *vcpu, u32 isa), \ >> - TP_ARGS(exit_reason, vcpu, isa), \ >> + TP_PROTO(struct kvm_vcpu *vcpu, u32 isa), \ >> + TP_ARGS(vcpu, isa), \ >> \ >> TP_STRUCT__entry( \ >> - __field( unsigned int, exit_reason ) \ >> + __field( u64, exit_reason ) \ > > Converting to a u64 is unnecessary and misleading. vmcs.EXIT_REASON and > vmcb.EXIT_CODE are both u32s, a.k.a. unsigned ints. There is vmcb.EXIT_CODE_HI, > but that's not being included, and AFAICT isn't even sanity checked by KVM. Thanks for pointing this out, I can only blame brain fade. >> __field( unsigned long, guest_rip ) \ >> __field( u32, isa ) \ >> __field( u64, info1 ) \
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 974cbfb1eefe..dfb902930cdc 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1377,10 +1377,11 @@ struct kvm_x86_ops { void (*write_tsc_multiplier)(struct kvm_vcpu *vcpu, u64 multiplier); /* - * Retrieve somewhat arbitrary exit information. Intended to be used - * only from within tracepoints to avoid VMREADs when tracing is off. + * Retrieve somewhat arbitrary exit information. Intended to + * be used only from within tracepoints or error paths. */ - void (*get_exit_info)(struct kvm_vcpu *vcpu, u64 *info1, u64 *info2, + void (*get_exit_info)(struct kvm_vcpu *vcpu, u64 *reason, + u64 *info1, u64 *info2, u32 *exit_int_info, u32 *exit_int_info_err_code); int (*check_intercept)(struct kvm_vcpu *vcpu, diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 664d20f0689c..e5c4354dcc6f 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -3301,11 +3301,13 @@ int svm_invoke_exit_handler(struct kvm_vcpu *vcpu, u64 exit_code) return svm_exit_handlers[exit_code](vcpu); } -static void svm_get_exit_info(struct kvm_vcpu *vcpu, u64 *info1, u64 *info2, +static void svm_get_exit_info(struct kvm_vcpu *vcpu, u64 *reason, + u64 *info1, u64 *info2, u32 *intr_info, u32 *error_code) { struct vmcb_control_area *control = &to_svm(vcpu)->vmcb->control; + *reason = control->exit_code; *info1 = control->exit_info_1; *info2 = control->exit_info_2; *intr_info = control->exit_int_info; @@ -3322,7 +3324,7 @@ static int handle_exit(struct kvm_vcpu *vcpu, fastpath_t exit_fastpath) struct kvm_run *kvm_run = vcpu->run; u32 exit_code = svm->vmcb->control.exit_code; - trace_kvm_exit(exit_code, vcpu, KVM_ISA_SVM); + trace_kvm_exit(vcpu, KVM_ISA_SVM); /* SEV-ES guests must use the CR write traps to track CR registers. */ if (!sev_es_guest(vcpu->kvm)) { @@ -3335,7 +3337,7 @@ static int handle_exit(struct kvm_vcpu *vcpu, fastpath_t exit_fastpath) if (is_guest_mode(vcpu)) { int vmexit; - trace_kvm_nested_vmexit(exit_code, vcpu, KVM_ISA_SVM); + trace_kvm_nested_vmexit(vcpu, KVM_ISA_SVM); vmexit = nested_svm_exit_special(svm); diff --git a/arch/x86/kvm/trace.h b/arch/x86/kvm/trace.h index b484141ea15b..2228565beda2 100644 --- a/arch/x86/kvm/trace.h +++ b/arch/x86/kvm/trace.h @@ -273,11 +273,11 @@ TRACE_EVENT(kvm_apic, #define TRACE_EVENT_KVM_EXIT(name) \ TRACE_EVENT(name, \ - TP_PROTO(unsigned int exit_reason, struct kvm_vcpu *vcpu, u32 isa), \ - TP_ARGS(exit_reason, vcpu, isa), \ + TP_PROTO(struct kvm_vcpu *vcpu, u32 isa), \ + TP_ARGS(vcpu, isa), \ \ TP_STRUCT__entry( \ - __field( unsigned int, exit_reason ) \ + __field( u64, exit_reason ) \ __field( unsigned long, guest_rip ) \ __field( u32, isa ) \ __field( u64, info1 ) \ @@ -288,11 +288,12 @@ TRACE_EVENT(name, \ ), \ \ TP_fast_assign( \ - __entry->exit_reason = exit_reason; \ __entry->guest_rip = kvm_rip_read(vcpu); \ __entry->isa = isa; \ __entry->vcpu_id = vcpu->vcpu_id; \ - static_call(kvm_x86_get_exit_info)(vcpu, &__entry->info1, \ + static_call(kvm_x86_get_exit_info)(vcpu, \ + &__entry->exit_reason, \ + &__entry->info1, \ &__entry->info2, \ &__entry->intr_info, \ &__entry->error_code); \ diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 1a52134b0c42..fbbc01e9570b 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -6025,7 +6025,7 @@ bool nested_vmx_reflect_vmexit(struct kvm_vcpu *vcpu) goto reflect_vmexit; } - trace_kvm_nested_vmexit(exit_reason.full, vcpu, KVM_ISA_VMX); + trace_kvm_nested_vmexit(vcpu, KVM_ISA_VMX); /* If L0 (KVM) wants the exit, it trumps L1's desires. */ if (nested_vmx_l0_wants_exit(vcpu, exit_reason)) diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 927a552393b9..fefdecb0ff3d 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -5617,11 +5617,13 @@ static int (*kvm_vmx_exit_handlers[])(struct kvm_vcpu *vcpu) = { static const int kvm_vmx_max_exit_handlers = ARRAY_SIZE(kvm_vmx_exit_handlers); -static void vmx_get_exit_info(struct kvm_vcpu *vcpu, u64 *info1, u64 *info2, +static void vmx_get_exit_info(struct kvm_vcpu *vcpu, u64 *reason, + u64 *info1, u64 *info2, u32 *intr_info, u32 *error_code) { struct vcpu_vmx *vmx = to_vmx(vcpu); + *reason = vmx->exit_reason.full; *info1 = vmx_get_exit_qual(vcpu); if (!(vmx->exit_reason.failed_vmentry)) { *info2 = vmx->idt_vectoring_info; @@ -6748,7 +6750,7 @@ static fastpath_t vmx_vcpu_run(struct kvm_vcpu *vcpu) if (likely(!vmx->exit_reason.failed_vmentry)) vmx->idt_vectoring_info = vmcs_read32(IDT_VECTORING_INFO_FIELD); - trace_kvm_exit(vmx->exit_reason.full, vcpu, KVM_ISA_VMX); + trace_kvm_exit(vcpu, KVM_ISA_VMX); if (unlikely(vmx->exit_reason.failed_vmentry)) return EXIT_FASTPATH_NONE;
Extend the get_exit_info static call to provide the reason for the VM exit. Modify relevant trace points to use this rather than extracting the reason in the caller. Signed-off-by: David Edmondson <david.edmondson@oracle.com> --- arch/x86/include/asm/kvm_host.h | 7 ++++--- arch/x86/kvm/svm/svm.c | 8 +++++--- arch/x86/kvm/trace.h | 11 ++++++----- arch/x86/kvm/vmx/nested.c | 2 +- arch/x86/kvm/vmx/vmx.c | 6 ++++-- 5 files changed, 20 insertions(+), 14 deletions(-)