On Thursday, 2021-02-18 at 14:01:40 +01, Paolo Bonzini wrote: > On 18/02/21 13:56, David Edmondson wrote: >> On Thursday, 2021-02-18 at 12:54:52 +01, Paolo Bonzini wrote: >> >>> On 18/02/21 11:04, David Edmondson wrote: >>>> When dumping the VMCS, retrieve the current guest value of EFER from >>>> the kvm_vcpu structure if neither VM_EXIT_SAVE_IA32_EFER or >>>> VM_ENTRY_LOAD_IA32_EFER is set, which can occur if the processor does >>>> not support the relevant VM-exit/entry controls. >>> >>> Printing vcpu->arch.efer is not the best choice however. Could we dump >>> the whole MSR load/store area instead? >> >> I'm happy to do that, and think that it would be useful, but it won't >> help with the original problem (which I should have explained more). >> >> If the guest has EFER_LMA set but we aren't using the entry/exit >> controls, vm_read64(GUEST_IA32_EFER) returns 0, causing dump_vmcs() to >> erroneously dump the PDPTRs. > > Got it now. It would sort of help, because while dumping the MSR > load/store area you could get hold of the real EFER, and use it to > decide whether to dump the PDPTRs. Okay, I'll do that and come back. Thanks! > Thanks, > > Paolo > > >>> Paolo >>> >>>> Fixes: 4eb64dce8d0a ("KVM: x86: dump VMCS on invalid entry") >>>> Signed-off-by: David Edmondson <david.edmondson@xxxxxxxxxx> >>>> --- >>>> arch/x86/kvm/vmx/vmx.c | 14 +++++++++----- >>>> arch/x86/kvm/vmx/vmx.h | 2 +- >>>> 2 files changed, 10 insertions(+), 6 deletions(-) >>>> >>>> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c >>>> index eb69fef57485..74ea4fe6f35e 100644 >>>> --- a/arch/x86/kvm/vmx/vmx.c >>>> +++ b/arch/x86/kvm/vmx/vmx.c >>>> @@ -5754,7 +5754,7 @@ static void vmx_dump_dtsel(char *name, uint32_t limit) >>>> vmcs_readl(limit + GUEST_GDTR_BASE - GUEST_GDTR_LIMIT)); >>>> } >>>> >>>> -void dump_vmcs(void) >>>> +void dump_vmcs(struct kvm_vcpu *vcpu) >>>> { >>>> u32 vmentry_ctl, vmexit_ctl; >>>> u32 cpu_based_exec_ctrl, pin_based_exec_ctrl, secondary_exec_control; >>>> @@ -5771,7 +5771,11 @@ void dump_vmcs(void) >>>> cpu_based_exec_ctrl = vmcs_read32(CPU_BASED_VM_EXEC_CONTROL); >>>> pin_based_exec_ctrl = vmcs_read32(PIN_BASED_VM_EXEC_CONTROL); >>>> cr4 = vmcs_readl(GUEST_CR4); >>>> - efer = vmcs_read64(GUEST_IA32_EFER); >>>> + if ((vmexit_ctl & VM_EXIT_SAVE_IA32_EFER) || >>>> + (vmentry_ctl & VM_ENTRY_LOAD_IA32_EFER)) >>>> + efer = vmcs_read64(GUEST_IA32_EFER); >>>> + else >>>> + efer = vcpu->arch.efer; >>>> secondary_exec_control = 0; >>>> if (cpu_has_secondary_exec_ctrls()) >>>> secondary_exec_control = vmcs_read32(SECONDARY_VM_EXEC_CONTROL); >>>> @@ -5955,7 +5959,7 @@ static int vmx_handle_exit(struct kvm_vcpu *vcpu, fastpath_t exit_fastpath) >>>> } >>>> >>>> if (exit_reason & VMX_EXIT_REASONS_FAILED_VMENTRY) { >>>> - dump_vmcs(); >>>> + dump_vmcs(vcpu); >>>> vcpu->run->exit_reason = KVM_EXIT_FAIL_ENTRY; >>>> vcpu->run->fail_entry.hardware_entry_failure_reason >>>> = exit_reason; >>>> @@ -5964,7 +5968,7 @@ static int vmx_handle_exit(struct kvm_vcpu *vcpu, fastpath_t exit_fastpath) >>>> } >>>> >>>> if (unlikely(vmx->fail)) { >>>> - dump_vmcs(); >>>> + dump_vmcs(vcpu); >>>> vcpu->run->exit_reason = KVM_EXIT_FAIL_ENTRY; >>>> vcpu->run->fail_entry.hardware_entry_failure_reason >>>> = vmcs_read32(VM_INSTRUCTION_ERROR); >>>> @@ -6049,7 +6053,7 @@ static int vmx_handle_exit(struct kvm_vcpu *vcpu, fastpath_t exit_fastpath) >>>> >>>> unexpected_vmexit: >>>> vcpu_unimpl(vcpu, "vmx: unexpected exit reason 0x%x\n", exit_reason); >>>> - dump_vmcs(); >>>> + dump_vmcs(vcpu); >>>> vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR; >>>> vcpu->run->internal.suberror = >>>> KVM_INTERNAL_ERROR_UNEXPECTED_EXIT_REASON; >>>> diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h >>>> index 9d3a557949ac..f8a0ce74798e 100644 >>>> --- a/arch/x86/kvm/vmx/vmx.h >>>> +++ b/arch/x86/kvm/vmx/vmx.h >>>> @@ -489,6 +489,6 @@ static inline bool vmx_guest_state_valid(struct kvm_vcpu *vcpu) >>>> return is_unrestricted_guest(vcpu) || __vmx_guest_state_valid(vcpu); >>>> } >>>> >>>> -void dump_vmcs(void); >>>> +void dump_vmcs(struct kvm_vcpu *vcpu); >>>> >>>> #endif /* __KVM_X86_VMX_H */ >>>> >> >> dme. >> dme. -- But he said, leave me alone, I'm a family man.