Commit 03d62460 authored Feb 23, 2018 by Paolo Bonzini Committed by Greg Kroah-Hartman Mar 08, 2018

KVM: x86: move LAPIC initialization after VMCS creation



commit 0b2e9904c15963e715d33e5f3f1387f17d19333a upstream.

The initial reset of the local APIC is performed before the VMCS has been
created, but it tries to do a vmwrite:

 vmwrite error: reg 810 value 4a00 (err 18944)
 CPU: 54 PID: 38652 Comm: qemu-kvm Tainted: G        W I      4.16.0-0.rc2.git0.1.fc28.x86_64 #1
 Hardware name: Intel Corporation S2600CW/S2600CW, BIOS SE5C610.86B.01.01.0003.090520141303 09/05/2014
 Call Trace:
  vmx_set_rvi [kvm_intel]
  vmx_hwapic_irr_update [kvm_intel]
  kvm_lapic_reset [kvm]
  kvm_create_lapic [kvm]
  kvm_arch_vcpu_init [kvm]
  kvm_vcpu_init [kvm]
  vmx_create_vcpu [kvm_intel]
  kvm_vm_ioctl [kvm]

Move it later, after the VMCS has been created.

Fixes: 4191db26 ("KVM: x86: Update APICv on APIC reset")
Cc: stable@vger.kernel.org
Cc: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 0d62a56d

arch/x86/kvm/lapic.c

+0 −1

Original line number	Diff line number	Diff line
		@@ -2107,7 +2107,6 @@ int kvm_create_lapic(struct kvm_vcpu *vcpu)
		*/
		vcpu->arch.apic_base = MSR_IA32_APICBASE_ENABLE;
		static_key_slow_inc(&apic_sw_disabled.key); /* sw disabled at reset */
		kvm_lapic_reset(vcpu, false);
		kvm_iodevice_init(&apic->dev, &apic_mmio_ops);

		return 0;

arch/x86/kvm/x86.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -7779,6 +7779,7 @@ int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
		if (r)
		return r;
		kvm_vcpu_reset(vcpu, false);
		kvm_lapic_reset(vcpu, false);
		kvm_mmu_setup(vcpu);
		vcpu_put(vcpu);
		return r;