Patch "KVM: x86: move LAPIC initialization after VMCS creation" has been added to the 4.14-stable tree

Patch "KVM: x86: move LAPIC initialization after VMCS creation" has been added to the 4.14-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    KVM: x86: move LAPIC initialization after VMCS creation

to the 4.14-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     kvm-x86-move-lapic-initialization-after-vmcs-creation.patch
and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 0b2e9904c15963e715d33e5f3f1387f17d19333a Mon Sep 17 00:00:00 2001
From: Paolo Bonzini <pbonzini@redhat.com>
Date: Fri, 23 Feb 2018 23:29:32 +0100
Subject: KVM: x86: move LAPIC initialization after VMCS creation

From: Paolo Bonzini <pbonzini@redhat.com>

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: 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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/x86/kvm/lapic.c |    1 -
 arch/x86/kvm/x86.c   |    1 +
 2 files changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -2107,7 +2107,6 @@ int kvm_create_lapic(struct kvm_vcpu *vc
 	 */
 	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;
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -7779,6 +7779,7 @@ int kvm_arch_vcpu_setup(struct kvm_vcpu
 	if (r)
 		return r;
 	kvm_vcpu_reset(vcpu, false);
+	kvm_lapic_reset(vcpu, false);
 	kvm_mmu_setup(vcpu);
 	vcpu_put(vcpu);
 	return r;


Patches currently in stable-queue which might be from pbonzini@redhat.com are

queue-4.14/kvm-x86-fix-smram-accessing-even-if-vm-is-shutdown.patch
queue-4.14/kvm-x86-remove-indirect-msr-op-calls-from-spec_ctrl.patch
queue-4.14/kvm-x86-move-lapic-initialization-after-vmcs-creation.patch
queue-4.14/kvm-mmu-fix-overlap-between-public-and-private-memslots.patch
queue-4.14/kvm-vmx-optimize-vmx_vcpu_run-and-svm_vcpu_run-by-marking-the-rdmsr-path-as-unlikely.patch

Re: Patch "KVM: x86: move LAPIC initialization after VMCS creation" has been added to the 4.14-stable tree

[Liran Alon]

----- gregkh@linuxfoundation.org wrote:

> This is a note to let you know that I've just added the patch titled
> 
>     KVM: x86: move LAPIC initialization after VMCS creation
> 
> to the 4.14-stable tree which can be found at:
>    
> https://urldefense.proofpoint.com/v2/url?u=http-3A__www.kernel.org_git_-3Fp-3Dlinux_kernel_git_stable_stable-2Dqueue.git-3Ba-3Dsummary&d=DwIDAg&c=RoP1YumCXCgaWHvlZYR8PZh8Bv7qIrMUB65eapI_JnE&r=Jk6Q8nNzkQ6LJ6g42qARkg6ryIDGQr-yKXPNGZbpTx0&m=Maz6LWKMTB3dNz16rCuylqFxbAmuN_jMYMfsJWQAFFg&s=xUqY2YU9eAMKcYfwjC-gwZHcI3260P5mO4BpR_YGViM&e=
> 
> The filename of the patch is:
>      kvm-x86-move-lapic-initialization-after-vmcs-creation.patch
> and it can be found in the queue-4.14 subdirectory.
> 
> If you, or anyone else, feels it should not be added to the stable
> tree,
> please let <stable@vger.kernel.org> know about it.
> 
> 
> From 0b2e9904c15963e715d33e5f3f1387f17d19333a Mon Sep 17 00:00:00
> 2001
> From: Paolo Bonzini <pbonzini@redhat.com>
> Date: Fri, 23 Feb 2018 23:29:32 +0100
> Subject: KVM: x86: move LAPIC initialization after VMCS creation
> 
> From: Paolo Bonzini <pbonzini@redhat.com>
> 
> 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: 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>
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This commit broke a rare configuration.
Don't we want to apply this to stable-tree together with the fix for that?
The fix is at upstream commit b7e31be38558 ("KVM: x86: fix vcpu initialization with userspace lapic")

-Liran

Re: Patch "KVM: x86: move LAPIC initialization after VMCS creation" has been added to the 4.14-stable tree

[Paolo Bonzini]

On 07/03/2018 09:32, Liran Alon wrote:
>> 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>
>> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> This commit broke a rare configuration.
> Don't we want to apply this to stable-tree together with the fix for that?
> The fix is at upstream commit b7e31be38558 ("KVM: x86: fix vcpu initialization with userspace lapic")

Yes, definitely.

Paolo

Re: Patch "KVM: x86: move LAPIC initialization after VMCS creation" has been added to the 4.14-stable tree

[Greg KH]

On Wed, Mar 07, 2018 at 01:12:52PM +0100, Paolo Bonzini wrote:
> On 07/03/2018 09:32, Liran Alon wrote:
> >> 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>
> >> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > This commit broke a rare configuration.
> > Don't we want to apply this to stable-tree together with the fix for that?
> > The fix is at upstream commit b7e31be38558 ("KVM: x86: fix vcpu initialization with userspace lapic")
> 
> Yes, definitely.

Ok, now queued up.  How did I miss that one before?  odd...