KVM: nVMX: sync vmcs02 segment regs prior to vmx_set_cr0 (9d1887ef) · Commits · 戴 / test

Segment registers must be synchronized prior to any code that may trigger a call to emulation_required()/guest_state_valid(), e.g. vmx_set_cr0(). Because preparing vmcs02 writes segmentation fields directly, i.e. doesn't use vmx_set_segment(), emulation_required will not be re-evaluated when synchronizing the segment registers, which can result in L0 incorrectly starting emulation of L2. Fixes: ("KVM: nVMX: initialize descriptor cache fields in prepare_vmcs02_full") Signed-off-by:

Sean Christopherson <sean.j.christopherson@intel.com> [Move all of prepare_vmcs02_full earlier, not just segment registers. - Paolo] Signed-off-by:

Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/vmx.c

+5 −5

Original line number	Diff line number	Diff line
		@@ -10704,6 +10704,11 @@ static int prepare_vmcs02(struct kvm_vcpu vcpu, struct vmcs12 vmcs12,
		struct vcpu_vmx *vmx = to_vmx(vcpu);
		u32 exec_control, vmcs12_exec_ctrl;

		if (vmx->nested.dirty_vmcs12) {
		prepare_vmcs02_full(vcpu, vmcs12, from_vmentry);
		vmx->nested.dirty_vmcs12 = false;
		}

		/*
		* First, the fields that are shadowed. This must be kept in sync
		* with vmx_shadow_fields.h.
		@@ -10941,11 +10946,6 @@ static int prepare_vmcs02(struct kvm_vcpu vcpu, struct vmcs12 vmcs12,
		/* Note: modifies VM_ENTRY/EXIT_CONTROLS and GUEST/HOST_IA32_EFER */
		vmx_set_efer(vcpu, vcpu->arch.efer);

		if (vmx->nested.dirty_vmcs12) {
		prepare_vmcs02_full(vcpu, vmcs12, from_vmentry);
		vmx->nested.dirty_vmcs12 = false;
		}

		/* Shadow page tables on either EPT or shadow page tables. */
		if (nested_vmx_load_cr3(vcpu, vmcs12->guest_cr3, nested_cpu_has_ept(vmcs12),
		entry_failure_code))

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