Commit c4118026 authored by Marc Zyngier's avatar Marc Zyngier Committed by Luis Henriques

arm64: KVM: Disable virtual timer even if the guest is not using it

commit c4cbba9f 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.
Reviewed-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
parent 9ecac394
...@@ -485,8 +485,6 @@ CPU_BE( rev w5, w5 ) ...@@ -485,8 +485,6 @@ CPU_BE( rev w5, w5 )
mrs x3, cntv_ctl_el0 mrs x3, cntv_ctl_el0
and x3, x3, #3 and x3, x3, #3
str w3, [x0, #VCPU_TIMER_CNTV_CTL] str w3, [x0, #VCPU_TIMER_CNTV_CTL]
bic x3, x3, #1 // Clear Enable
msr cntv_ctl_el0, x3
isb isb
...@@ -494,6 +492,9 @@ CPU_BE( rev w5, w5 ) ...@@ -494,6 +492,9 @@ CPU_BE( rev w5, w5 )
str x3, [x0, #VCPU_TIMER_CNTV_CVAL] str x3, [x0, #VCPU_TIMER_CNTV_CVAL]
1: 1:
// Disable the virtual timer
msr cntv_ctl_el0, xzr
// Allow physical timer/counter access for the host // Allow physical timer/counter access for the host
mrs x2, cnthctl_el2 mrs x2, cnthctl_el2
orr x2, x2, #3 orr x2, x2, #3
......
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