KVM: x86: move LAPIC initialization after VMCS creation

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: 4191db26b714 ("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>

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 924ac8c..cc5fe7a 100644 (file)
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -2165,7 +2165,6 @@ 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;

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index c8a0b54..ca90d95 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -7975,6 +7975,7 @@ int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
        kvm_vcpu_mtrr_init(vcpu);
        vcpu_load(vcpu);
        kvm_vcpu_reset(vcpu, false);
+       kvm_lapic_reset(vcpu, false);
        kvm_mmu_setup(vcpu);
        vcpu_put(vcpu);
        return 0;