]> git.ipfire.org Git - thirdparty/kernel/stable.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)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Tue, 29 Sep 2015 17:33:21 +0000 (19:33 +0200)
commit c4cbba9fa078f55d9f6d081dbb4aec7cf969e7c7 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: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arch/arm64/kvm/hyp.S

index 7bd37d05b4e8d0a58ef57bf1a02270368e9d2571..3c6051cbf4427005910b7d5256f963d26e2ccfd4 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