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Groups > linux.kernel > #1238212
| From | Jiri Slaby <jslaby@suse.cz> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH 3.12 42/84] arm64: KVM: Disable virtual timer even if the guest is not using it |
| Date | 2015-10-02 15:30 +0200 |
| Message-ID | <qf8zq-4Bq-57@gated-at.bofh.it> (permalink) |
| References | <qf8zn-4Bq-3@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
From: Marc Zyngier <marc.zyngier@arm.com> 3.12-stable review patch. If anyone has any objections, please let me know. =============== 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: Jiri Slaby <jslaby@suse.cz> --- arch/arm64/kvm/hyp.S | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kvm/hyp.S b/arch/arm64/kvm/hyp.S index a255167baf6a..44b00eb7b340 100644 --- a/arch/arm64/kvm/hyp.S +++ b/arch/arm64/kvm/hyp.S @@ -472,8 +472,6 @@ __kvm_hyp_code_start: 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 @@ -481,6 +479,9 @@ __kvm_hyp_code_start: 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 -- 2.6.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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[PATCH 3.12 42/84] arm64: KVM: Disable virtual timer even if the guest is not using it Jiri Slaby <jslaby@suse.cz> - 2015-10-02 15:30 +0200
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