]> git.proxmox.com Git - mirror_ubuntu-kernels.git/commitdiff
arm64: KVM: Disable virtual timer even if the guest is not using it
authorMarc Zyngier <marc.zyngier@arm.com>
Wed, 16 Sep 2015 15:18:59 +0000 (16:18 +0100)
committerMarc Zyngier <marc.zyngier@arm.com>
Thu, 17 Sep 2015 12:11:18 +0000 (13:11 +0100)
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.

Cc: stable@vger.kernel.org
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
arch/arm64/kvm/hyp.S

index 39aa322765f9fd8db6ab411131f2fce51d7e9429..60a83e2900a7bbe54d9266d2e85d832bc5300608 100644 (file)
        mrs     x3, cntv_ctl_el0
        and     x3, x3, #3
        str     w3, [x0, #VCPU_TIMER_CNTV_CTL]
-       bic     x3, x3, #1              // Clear Enable
-       msr     cntv_ctl_el0, x3
 
        isb
 
        str     x3, [x0, #VCPU_TIMER_CNTV_CVAL]
 
 1:
+       // Disable the virtual timer
+       msr     cntv_ctl_el0, xzr
+
        // Allow physical timer/counter access for the host
        mrs     x2, cnthctl_el2
        orr     x2, x2, #3