[PATCH] KVM: x86: move LAPIC initialization after VMCS creation

From: Paolo Bonzini
Date: Fri Feb 23 2018 - 17:43:17 EST


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: 851c1a18c5412fd321e387cfe60739387cdbf37d
Cc: Liran Alon <liran.alon@xxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
arch/x86/kvm/lapic.c | 1 -
arch/x86/kvm/x86.c | 1 +
2 files changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 924ac8ce9d50..cc5fe7a50dde 100644
--- 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 c8a0b545ac20..ca90d9515137 100644
--- 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;
--
1.8.3.1