[3.11.y.z extended stable] Patch "KVM: x86: Fix APIC map calculation after re-enabling" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    KVM: x86: Fix APIC map calculation after re-enabling

to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 404bcf42b1272c2e86176a90b0f8617c7c27365d Mon Sep 17 00:00:00 2001
From: Jan Kiszka <jan.kiszka at siemens.com>
Date: Sun, 29 Dec 2013 02:29:30 +0100
Subject: KVM: x86: Fix APIC map calculation after re-enabling

commit e66d2ae7c67bd9ac982a3d1890564de7f7eabf4b upstream.

Update arch.apic_base before triggering recalculate_apic_map. Otherwise
the recalculation will work against the previous state of the APIC and
will fail to build the correct map when an APIC is hardware-enabled
again.

This fixes a regression of 1e08ec4a13.

Signed-off-by: Jan Kiszka <jan.kiszka at siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti at redhat.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 arch/x86/kvm/lapic.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 81d7b23..dedd7c2 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1364,6 +1364,10 @@ void kvm_lapic_set_base(struct kvm_vcpu *vcpu, u64 value)
 		return;
 	}

+	if (!kvm_vcpu_is_bsp(apic->vcpu))
+		value &= ~MSR_IA32_APICBASE_BSP;
+	vcpu->arch.apic_base = value;
+
 	/* update jump label if enable bit changes */
 	if ((vcpu->arch.apic_base ^ value) & MSR_IA32_APICBASE_ENABLE) {
 		if (value & MSR_IA32_APICBASE_ENABLE)
@@ -1373,10 +1377,6 @@ void kvm_lapic_set_base(struct kvm_vcpu *vcpu, u64 value)
 		recalculate_apic_map(vcpu->kvm);
 	}

-	if (!kvm_vcpu_is_bsp(apic->vcpu))
-		value &= ~MSR_IA32_APICBASE_BSP;
-
-	vcpu->arch.apic_base = value;
 	if ((old_value ^ value) & X2APIC_ENABLE) {
 		if (value & X2APIC_ENABLE) {
 			u32 id = kvm_apic_id(apic);
--
1.8.3.2