Commit 11f0cbf0 authored by Sean Christopherson's avatar Sean Christopherson Committed by Paolo Bonzini
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KVM: nSVM: Trace VM-Enter consistency check failures 



Use trace_kvm_nested_vmenter_failed() and its macro magic to trace
consistency check failures on nested VMRUN.  Tracing such failures by
running the buggy VMM as a KVM guest is often the only way to get a
precise explanation of why VMRUN failed.

Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
Message-Id: <20210204000117.3303214-13-seanjc@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 648fc8ae

arch/x86/kvm/svm/nested.c

+19 −14
Original line number Diff line number Diff line
@@ -29,6 +29,8 @@ 
#include "lapic.h"

#include "svm.h"



#define CC KVM_NESTED_VMENTER_CONSISTENCY_CHECK



static void nested_svm_inject_npf_exit(struct kvm_vcpu *vcpu,

				       struct x86_exception *fault)

{
@@ -233,14 +235,13 @@ static bool svm_get_nested_state_pages(struct kvm_vcpu *vcpu) 


static bool nested_vmcb_check_controls(struct vmcb_control_area *control)

{

	if ((vmcb_is_intercept(control, INTERCEPT_VMRUN)) == 0)

	if (CC(!vmcb_is_intercept(control, INTERCEPT_VMRUN)))

		return false;



	if (control->asid == 0)

	if (CC(control->asid == 0))

		return false;



	if ((control->nested_ctl & SVM_NESTED_CTL_NP_ENABLE) &&

	    !npt_enabled)

	if (CC((control->nested_ctl & SVM_NESTED_CTL_NP_ENABLE) && !npt_enabled))

		return false;



	return true;
@@ -257,32 +258,36 @@ static bool nested_vmcb_check_cr3_cr4(struct vcpu_svm *svm, 
	 * CR0.PG && EFER.LME.

	 */

	if ((save->efer & EFER_LME) && (save->cr0 & X86_CR0_PG)) {

		if (!(save->cr4 & X86_CR4_PAE) || !(save->cr0 & X86_CR0_PE) ||

		    kvm_vcpu_is_illegal_gpa(vcpu, save->cr3))

		if (CC(!(save->cr4 & X86_CR4_PAE)) ||

		    CC(!(save->cr0 & X86_CR0_PE)) ||

		    CC(kvm_vcpu_is_illegal_gpa(vcpu, save->cr3)))

			return false;

	}



	return kvm_is_valid_cr4(&svm->vcpu, save->cr4);

	if (CC(!kvm_is_valid_cr4(vcpu, save->cr4)))

		return false;



	return true;

}



/* Common checks that apply to both L1 and L2 state.  */

static bool nested_vmcb_valid_sregs(struct vcpu_svm *svm,

				    struct vmcb_save_area *save)

{

	if (!(save->efer & EFER_SVME))

	if (CC(!(save->efer & EFER_SVME)))

		return false;



	if (((save->cr0 & X86_CR0_CD) == 0 && (save->cr0 & X86_CR0_NW)) ||

	    (save->cr0 & ~0xffffffffULL))

	if (CC((save->cr0 & X86_CR0_CD) == 0 && (save->cr0 & X86_CR0_NW)) ||

	    CC(save->cr0 & ~0xffffffffULL))

		return false;



	if (!kvm_dr6_valid(save->dr6) || !kvm_dr7_valid(save->dr7))

	if (CC(!kvm_dr6_valid(save->dr6)) || CC(!kvm_dr7_valid(save->dr7)))

		return false;



	if (!nested_vmcb_check_cr3_cr4(svm, save))

		return false;



	if (!kvm_valid_efer(&svm->vcpu, save->efer))

	if (CC(!kvm_valid_efer(&svm->vcpu, save->efer)))

		return false;



	return true;
@@ -384,12 +389,12 @@ static inline bool nested_npt_enabled(struct vcpu_svm *svm) 
static int nested_svm_load_cr3(struct kvm_vcpu *vcpu, unsigned long cr3,

			       bool nested_npt)

{

	if (kvm_vcpu_is_illegal_gpa(vcpu, cr3))

	if (CC(kvm_vcpu_is_illegal_gpa(vcpu, cr3)))

		return -EINVAL;



	if (!nested_npt && is_pae_paging(vcpu) &&

	    (cr3 != kvm_read_cr3(vcpu) || pdptrs_changed(vcpu))) {

		if (!load_pdptrs(vcpu, vcpu->arch.walk_mmu, cr3))

		if (CC(!load_pdptrs(vcpu, vcpu->arch.walk_mmu, cr3)))

			return -EINVAL;

	}