kvm: x86: Read PDPTEs on CR0.CD and CR0.NW changes (d42e3fae) · Commits · 戴 / test

According to the SDM, when PAE paging would be in use following a MOV-to-CR0 that modifies any of CR0.CD, CR0.NW, or CR0.PG, then the PDPTEs are loaded from the address in CR3. Previously, kvm only loaded the PDPTEs when PAE paging would be in use following a MOV-to-CR0 that modified CR0.PG. Signed-off-by:

Jim Mattson <jmattson@google.com> Reviewed-by:

Oliver Upton <oupton@google.com> Reviewed-by:

Peter Shier <pshier@google.com> Message-Id: <20200707223630.336700-1-jmattson@google.com> Signed-off-by:

Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/x86.c

+5 −4

Original line number	Diff line number	Diff line
		@@ -798,6 +798,7 @@ EXPORT_SYMBOL_GPL(pdptrs_changed);
		int kvm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
		{
		unsigned long old_cr0 = kvm_read_cr0(vcpu);
		unsigned long pdptr_bits = X86_CR0_CD \| X86_CR0_NW \| X86_CR0_PG;
		unsigned long update_bits = X86_CR0_PG \| X86_CR0_WP;

		cr0 \|= X86_CR0_ET;
		@@ -815,9 +816,9 @@ int kvm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
		if ((cr0 & X86_CR0_PG) && !(cr0 & X86_CR0_PE))
		return 1;

		if (!is_paging(vcpu) && (cr0 & X86_CR0_PG)) {
		if (cr0 & X86_CR0_PG) {
		#ifdef CONFIG_X86_64
		if ((vcpu->arch.efer & EFER_LME)) {
		if (!is_paging(vcpu) && (vcpu->arch.efer & EFER_LME)) {
		int cs_db, cs_l;

		if (!is_pae(vcpu))
		@@ -827,8 +828,8 @@ int kvm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
		return 1;
		} else
		#endif
		if (is_pae(vcpu) && !load_pdptrs(vcpu, vcpu->arch.walk_mmu,
		kvm_read_cr3(vcpu)))
		if (is_pae(vcpu) && ((cr0 ^ old_cr0) & pdptr_bits) &&
		!load_pdptrs(vcpu, vcpu->arch.walk_mmu, kvm_read_cr3(vcpu)))
		return 1;
		}

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