Commit f3380ca5 authored Aug 05, 2014 by Wanpeng Li Committed by Paolo Bonzini Aug 05, 2014

KVM: nVMX: Fix nested vmexit ack intr before load vmcs01



An external interrupt will cause a vmexit with reason "external interrupt"
when L2 is running.  L1 will pick up the interrupt through vmcs12 if
L1 set the ack interrupt bit.  Commit 77b0f5d6 (KVM: nVMX: Ack and write
vector info to intr_info if L1 asks us to) retrieves the interrupt that
belongs to L1 before vmcs01 is loaded.

This will lead to problems in the next patch, which would write to SVI
of vmcs02 instead of vmcs01 (SVI of vmcs02 doesn't make sense because
L2 runs without APICv).

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Tested-by: Liu, RongrongX <rongrongx.liu@intel.com>
Tested-by: Felipe Reyes <freyes@suse.com>
Fixes: 77b0f5d6
Cc: stable@vger.kernel.org
Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com>
[Move tracepoint as well. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

parent 25a2150b

arch/x86/kvm/vmx.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -8754,6 +8754,8 @@ static void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 exit_reason,
		prepare_vmcs12(vcpu, vmcs12, exit_reason, exit_intr_info,
		exit_qualification);

		vmx_load_vmcs01(vcpu);

		if ((exit_reason == EXIT_REASON_EXTERNAL_INTERRUPT)
		&& nested_exit_intr_ack_set(vcpu)) {
		int irq = kvm_cpu_get_interrupt(vcpu);
		@@ -8769,8 +8771,6 @@ static void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 exit_reason,
		vmcs12->vm_exit_intr_error_code,
		KVM_ISA_VMX);

		vmx_load_vmcs01(vcpu);

		vm_entry_controls_init(vmx, vmcs_read32(VM_ENTRY_CONTROLS));
		vm_exit_controls_init(vmx, vmcs_read32(VM_EXIT_CONTROLS));
		vmx_segment_cache_clear(vmx);

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