linux-kernel - [PATCH v2 3/3] KVM: x86: dump_vmcs should include the autoload/autostore MSR lists

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Date:   Fri, 19 Feb 2021 14:46:32 +0000
From:   David Edmondson <david.edmondson@...cle.com>
To:     linux-kernel@...r.kernel.org
Cc:     "H. Peter Anvin" <hpa@...or.com>, Joerg Roedel <joro@...tes.org>,
        x86@...nel.org, Thomas Gleixner <tglx@...utronix.de>,
        kvm@...r.kernel.org, Paolo Bonzini <pbonzini@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Ingo Molnar <mingo@...hat.com>,
        Sean Christopherson <seanjc@...gle.com>,
        Jim Mattson <jmattson@...gle.com>,
        Borislav Petkov <bp@...en8.de>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        David Edmondson <david.edmondson@...cle.com>
Subject: [PATCH v2 3/3] KVM: x86: dump_vmcs should include the autoload/autostore MSR lists

When dumping the current VMCS state, include the MSRs that are being
automatically loaded/stored during VM entry/exit.

Signed-off-by: David Edmondson <david.edmondson@...cle.com>
---
 arch/x86/kvm/vmx/vmx.c | 25 +++++++++++++++++++++----
 arch/x86/kvm/vmx/vmx.h |  2 +-
 2 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 25090e3683ca..5dbaab73e576 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -5754,8 +5754,19 @@ static void vmx_dump_dtsel(char *name, uint32_t limit)
 	       vmcs_readl(limit + GUEST_GDTR_BASE - GUEST_GDTR_LIMIT));
 }
 
-void dump_vmcs(void)
+static void vmx_dump_msrs(char *name, struct vmx_msrs *m)
 {
+	unsigned int i;
+	struct vmx_msr_entry *e;
+
+	pr_err("MSR %s:\n", name);
+	for (i = 0, e = m->val; i < m->nr; ++i, ++e)
+		pr_err("  %2d: msr=0x%08x value=0x%016llx\n", i, e->index, e->value);
+}
+
+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;
@@ -5826,6 +5837,10 @@ void dump_vmcs(void)
 	if (secondary_exec_control & SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY)
 		pr_err("InterruptStatus = %04x\n",
 		       vmcs_read16(GUEST_INTR_STATUS));
+	if (vmcs_read32(VM_ENTRY_MSR_LOAD_COUNT) > 0)
+		vmx_dump_msrs("guest autoload", &vmx->msr_autoload.guest);
+	if (vmcs_read32(VM_EXIT_MSR_STORE_COUNT) > 0)
+		vmx_dump_msrs("guest autostore", &vmx->msr_autostore.guest);
 
 	pr_err("*** Host State ***\n");
 	pr_err("RIP = 0x%016lx  RSP = 0x%016lx\n",
@@ -5855,6 +5870,8 @@ void dump_vmcs(void)
 	    vmexit_ctl & VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL)
 		pr_err("PerfGlobCtl = 0x%016llx\n",
 		       vmcs_read64(HOST_IA32_PERF_GLOBAL_CTRL));
+	if (vmcs_read32(VM_EXIT_MSR_LOAD_COUNT) > 0)
+		vmx_dump_msrs("host autoload", &vmx->msr_autoload.host);
 
 	pr_err("*** Control State ***\n");
 	pr_err("PinBased=%08x CPUBased=%08x SecondaryExec=%08x\n",
@@ -5954,7 +5971,7 @@ 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;
@@ -5963,7 +5980,7 @@ 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);
@@ -6048,7 +6065,7 @@ 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 */
-- 
2.30.0