[PATCH v4 4/5] KVM: x86: dump_vmcs should show the effective EFER

From: David Edmondson
Date: Wed Feb 24 2021 - 10:06:34 EST


If EFER is not being loaded from the VMCS, show the effective value by
reference to the MSR autoload list or calculation.

Signed-off-by: David Edmondson <david.edmondson@xxxxxxxxxx>
---
arch/x86/kvm/vmx/vmx.c | 20 ++++++++++++++++----
arch/x86/kvm/vmx/vmx.h | 2 +-
2 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index faeb3d3bd1b8..b9bb66ad2ac4 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -5810,11 +5810,13 @@ 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)
{
+ struct vcpu_vmx *vmx = to_vmx(vcpu);
u32 vmentry_ctl, vmexit_ctl;
u32 cpu_based_exec_ctrl, pin_based_exec_ctrl, secondary_exec_control;
unsigned long cr4;
+ int efer_slot;

if (!dump_invalid_vmcs) {
pr_warn_ratelimited("set kvm_intel.dump_invalid_vmcs=1 to dump internal KVM state.\n");
@@ -5860,8 +5862,18 @@ void dump_vmcs(void)
vmx_dump_sel("LDTR:", GUEST_LDTR_SELECTOR);
vmx_dump_dtsel("IDTR:", GUEST_IDTR_LIMIT);
vmx_dump_sel("TR: ", GUEST_TR_SELECTOR);
+ efer_slot = vmx_find_loadstore_msr_slot(&vmx->msr_autoload.guest, MSR_EFER);
if (vmentry_ctl & VM_ENTRY_LOAD_IA32_EFER)
pr_err("EFER= 0x%016llx\n", vmcs_read64(GUEST_IA32_EFER));
+ else if (efer_slot >= 0)
+ pr_err("EFER= 0x%016llx (autoload)\n",
+ vmx->msr_autoload.guest.val[efer_slot].value);
+ else if (vmentry_ctl & VM_ENTRY_IA32E_MODE)
+ pr_err("EFER= 0x%016llx (effective)\n",
+ vcpu->arch.efer | (EFER_LMA | EFER_LME));
+ else
+ pr_err("EFER= 0x%016llx (effective)\n",
+ vcpu->arch.efer & ~(EFER_LMA | EFER_LME));
if (vmentry_ctl & VM_ENTRY_LOAD_IA32_PAT)
pr_err("PAT = 0x%016llx\n", vmcs_read64(GUEST_IA32_PAT));
pr_err("DebugCtl = 0x%016llx DebugExceptions = 0x%016lx\n",
@@ -6008,7 +6020,7 @@ static int __vmx_handle_exit(struct kvm_vcpu *vcpu, fastpath_t exit_fastpath)
}

if (exit_reason.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.full;
@@ -6017,7 +6029,7 @@ 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);
@@ -6103,7 +6115,7 @@ 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.full);
- 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 12c53d05a902..4d4a24e00012 100644
--- a/arch/x86/kvm/vmx/vmx.h
+++ b/arch/x86/kvm/vmx/vmx.h
@@ -541,6 +541,6 @@ 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 */
--
2.30.0