From mboxrd@z Thu Jan 1 00:00:00 1970 From: Shannon Zhao Subject: Re: [PATCH v6 14/21] KVM: ARM64: Add reset and access handlers for PMOVSSET and PMOVSCLR register Date: Wed, 9 Dec 2015 16:47:52 +0800 Message-ID: <5667EAB8.9030502@huawei.com> References: <1449578860-15808-1-git-send-email-zhaoshenglong@huawei.com> <1449578860-15808-15-git-send-email-zhaoshenglong@huawei.com> <56670C5D.3020407@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 41444412C2 for ; Wed, 9 Dec 2015 03:46:46 -0500 (EST) Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id qpP5EiATickv for ; Wed, 9 Dec 2015 03:46:42 -0500 (EST) Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [119.145.14.66]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id 7224940C9D for ; Wed, 9 Dec 2015 03:46:41 -0500 (EST) In-Reply-To: <56670C5D.3020407@arm.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu To: Marc Zyngier , kvmarm@lists.cs.columbia.edu, christoffer.dall@linaro.org Cc: kvm@vger.kernel.org, will.deacon@arm.com, linux-arm-kernel@lists.infradead.org, shannon.zhao@linaro.org List-Id: kvmarm@lists.cs.columbia.edu On 2015/12/9 0:59, Marc Zyngier wrote: >> > + } >> > + >> > + /* If all overflow bits are cleared, kick the vcpu to clear interrupt >> > + * pending status. >> > + */ >> > + if (val == 0) >> > + kvm_vcpu_kick(vcpu); > Do we really need to do so? This will be dropped on the next entry > anyway, so i don't see the need to kick the vcpu again. Or am I missing > something? > I thought maybe it could not set the interrupt low immediately when all the overflow bits are cleared for some reason, so add a kick to force it to sync the interrupt. But as you said, I'll remove this. Thanks, -- Shannon From mboxrd@z Thu Jan 1 00:00:00 1970 From: zhaoshenglong@huawei.com (Shannon Zhao) Date: Wed, 9 Dec 2015 16:47:52 +0800 Subject: [PATCH v6 14/21] KVM: ARM64: Add reset and access handlers for PMOVSSET and PMOVSCLR register In-Reply-To: <56670C5D.3020407@arm.com> References: <1449578860-15808-1-git-send-email-zhaoshenglong@huawei.com> <1449578860-15808-15-git-send-email-zhaoshenglong@huawei.com> <56670C5D.3020407@arm.com> Message-ID: <5667EAB8.9030502@huawei.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 2015/12/9 0:59, Marc Zyngier wrote: >> > + } >> > + >> > + /* If all overflow bits are cleared, kick the vcpu to clear interrupt >> > + * pending status. >> > + */ >> > + if (val == 0) >> > + kvm_vcpu_kick(vcpu); > Do we really need to do so? This will be dropped on the next entry > anyway, so i don't see the need to kick the vcpu again. Or am I missing > something? > I thought maybe it could not set the interrupt low immediately when all the overflow bits are cleared for some reason, so add a kick to force it to sync the interrupt. But as you said, I'll remove this. Thanks, -- Shannon From mboxrd@z Thu Jan 1 00:00:00 1970 From: Shannon Zhao Subject: Re: [PATCH v6 14/21] KVM: ARM64: Add reset and access handlers for PMOVSSET and PMOVSCLR register Date: Wed, 9 Dec 2015 16:47:52 +0800 Message-ID: <5667EAB8.9030502@huawei.com> References: <1449578860-15808-1-git-send-email-zhaoshenglong@huawei.com> <1449578860-15808-15-git-send-email-zhaoshenglong@huawei.com> <56670C5D.3020407@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org, will.deacon@arm.com, linux-arm-kernel@lists.infradead.org, shannon.zhao@linaro.org To: Marc Zyngier , , Return-path: In-Reply-To: <56670C5D.3020407@arm.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu List-Id: kvm.vger.kernel.org On 2015/12/9 0:59, Marc Zyngier wrote: >> > + } >> > + >> > + /* If all overflow bits are cleared, kick the vcpu to clear interrupt >> > + * pending status. >> > + */ >> > + if (val == 0) >> > + kvm_vcpu_kick(vcpu); > Do we really need to do so? This will be dropped on the next entry > anyway, so i don't see the need to kick the vcpu again. Or am I missing > something? > I thought maybe it could not set the interrupt low immediately when all the overflow bits are cleared for some reason, so add a kick to force it to sync the interrupt. But as you said, I'll remove this. Thanks, -- Shannon