linux-kernel - [PATCH v5 4/5] KVM: x86: dump_vmcs should show the effective EFER

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Date:   Thu, 18 Mar 2021 12:08:40 +0000
From:   David Edmondson <david.edmondson@...cle.com>
To:     linux-kernel@...r.kernel.org
Cc:     Ingo Molnar <mingo@...hat.com>, Joerg Roedel <joro@...tes.org>,
        "H. Peter Anvin" <hpa@...or.com>,
        Paolo Bonzini <pbonzini@...hat.com>, kvm@...r.kernel.org,
        Wanpeng Li <wanpengli@...cent.com>, x86@...nel.org,
        Borislav Petkov <bp@...en8.de>,
        Thomas Gleixner <tglx@...utronix.de>,
        Sean Christopherson <seanjc@...gle.com>,
        Jim Mattson <jmattson@...gle.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        David Edmondson <david.edmondson@...cle.com>
Subject: [PATCH v5 4/5] KVM: x86: dump_vmcs should show the effective EFER

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

Suggested-by: Sean Christopherson <seanjc@...gle.com>
Signed-off-by: David Edmondson <david.edmondson@...cle.com>
---
 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 67e574deced1..0a41a8ec2bd9 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -5787,11 +5787,13 @@ 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");
@@ -5837,8 +5839,18 @@ 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",
@@ -5993,7 +6005,7 @@ 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;
@@ -6002,7 +6014,7 @@ 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);
@@ -6088,7 +6100,7 @@ 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 89da5e1251f1..c35af2daa0bd 100644
--- a/arch/x86/kvm/vmx/vmx.h
+++ b/arch/x86/kvm/vmx/vmx.h
@@ -543,6 +543,6 @@ 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 */
-- 
2.30.2