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authorMarc Zyngier <marc.zyngier@arm.com>2015-09-16 16:18:59 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-10-22 14:43:11 -0700
commita5b48a8ed5004bc857cd15b4a5e4f93773251874 (patch)
treec56cb5e61816f515945e6fabde9236b454bcc141 /arch/arm/kvm
parentc286128ffc7ffaeaf5cf8d7b0b64c9883160a636 (diff)
arm: KVM: Disable virtual timer even if the guest is not using it
commit 688bc577ac42ae3d07c889a1f0a72f0b23763d58 upstream. When running a guest with the architected timer disabled (with QEMU and the kernel_irqchip=off option, for example), it is important to make sure the timer gets turned off. Otherwise, the guest may try to enable it anyway, leading to a screaming HW interrupt. The fix is to unconditionally turn off the virtual timer on guest exit. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/arm/kvm')
-rw-r--r--arch/arm/kvm/interrupts_head.S6
1 files changed, 4 insertions, 2 deletions
diff --git a/arch/arm/kvm/interrupts_head.S b/arch/arm/kvm/interrupts_head.S
index 48efe2ee452c..58048b333d31 100644
--- a/arch/arm/kvm/interrupts_head.S
+++ b/arch/arm/kvm/interrupts_head.S
@@ -518,8 +518,7 @@ ARM_BE8(rev r6, r6 )
mrc p15, 0, r2, c14, c3, 1 @ CNTV_CTL
str r2, [vcpu, #VCPU_TIMER_CNTV_CTL]
- bic r2, #1 @ Clear ENABLE
- mcr p15, 0, r2, c14, c3, 1 @ CNTV_CTL
+
isb
mrrc p15, 3, rr_lo_hi(r2, r3), c14 @ CNTV_CVAL
@@ -532,6 +531,9 @@ ARM_BE8(rev r6, r6 )
mcrr p15, 4, r2, r2, c14 @ CNTVOFF
1:
+ mov r2, #0 @ Clear ENABLE
+ mcr p15, 0, r2, c14, c3, 1 @ CNTV_CTL
+
@ Allow physical timer/counter access for the host
mrc p15, 4, r2, c14, c1, 0 @ CNTHCTL
orr r2, r2, #(CNTHCTL_PL1PCEN | CNTHCTL_PL1PCTEN)