From mboxrd@z Thu Jan 1 00:00:00 1970 From: christoffer.dall@linaro.org (Christoffer Dall) Date: Fri, 4 Sep 2015 16:24:39 +0200 Subject: [PATCH 2/2] arm/arm64: KVM: arch timer: Reset CNTV_CTL to 0 In-Reply-To: <1441376679-8341-1-git-send-email-christoffer.dall@linaro.org> References: <1441376679-8341-1-git-send-email-christoffer.dall@linaro.org> Message-ID: <1441376679-8341-3-git-send-email-christoffer.dall@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Provide a better quality of implementation and be architecture compliant on ARMv7 for the architected timer by resetting the CNTV_CTL to 0 on reset of the timer, and call kvm_timer_update_state(vcpu) at the same time, ensuring the timer output is not asserted after, for example, a PSCI system reset. This change alone fixes the UEFI reset issue reported by Laszlo back in February. Cc: Laszlo Ersek Cc: Ard Biesheuvel Cc: Drew Jones Cc: Wei Huang Cc: Peter Maydell Reviewed-by: Marc Zyngier Signed-off-by: Christoffer Dall --- virt/kvm/arm/arch_timer.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c index 76e38d2..48c6e1a 100644 --- a/virt/kvm/arm/arch_timer.c +++ b/virt/kvm/arm/arch_timer.c @@ -200,6 +200,14 @@ int kvm_timer_vcpu_reset(struct kvm_vcpu *vcpu, timer->irq = irq; /* + * The bits in CNTV_CTL are architecturally reset to UNKNOWN for ARMv8 + * and to 0 for ARMv7. We provide an implementation that always + * resets the timer to be disabled and unmasked and is compliant with + * the ARMv7 architecture. + */ + timer->cntv_ctl = 0; + + /* * Tell the VGIC that the virtual interrupt is tied to a * physical interrupt. We do that once per VCPU. */ -- 2.1.2.330.g565301e.dirty