From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 83E62C07E9A for ; Wed, 14 Jul 2021 16:11:06 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id F3053613C0 for ; Wed, 14 Jul 2021 16:11:05 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F3053613C0 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvmarm-bounces@lists.cs.columbia.edu Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 5CA924B08C; Wed, 14 Jul 2021 12:11:05 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu 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 Y1EoAw8f5WpT; Wed, 14 Jul 2021 12:11:04 -0400 (EDT) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 09C754A4FC; Wed, 14 Jul 2021 12:11:04 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 6C8484A4FC for ; Wed, 14 Jul 2021 12:11:02 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu 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 UeK0NcDqmxS2 for ; Wed, 14 Jul 2021 12:11:01 -0400 (EDT) Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 334144A19F for ; Wed, 14 Jul 2021 12:11:01 -0400 (EDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 9B666D6E; Wed, 14 Jul 2021 09:11:00 -0700 (PDT) Received: from [192.168.0.110] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 206BC3F7D8; Wed, 14 Jul 2021 09:10:57 -0700 (PDT) Subject: Re: [PATCH 2/3] KVM: arm64: Drop unnecessary masking of PMU registers To: Marc Zyngier , linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu References: <20210713135900.1473057-1-maz@kernel.org> <20210713135900.1473057-3-maz@kernel.org> From: Alexandru Elisei Message-ID: Date: Wed, 14 Jul 2021 17:12:03 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <20210713135900.1473057-3-maz@kernel.org> Content-Language: en-US Cc: kernel-team@android.com, Robin Murphy X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu Hi Marc, On 7/13/21 2:58 PM, Marc Zyngier wrote: > We always sanitise our PMU sysreg on the write side, so there > is no need to do it on the read side as well. > > Drop the unnecessary masking. Checked for all the remaining uses of kvm_pmu_valid_counter_mask in sys_regs.c and in pmu-emul.c, and nothing stands out: Reviewed-by: Alexandru Elisei Thanks, Alex > > Signed-off-by: Marc Zyngier > --- > arch/arm64/kvm/pmu-emul.c | 3 +-- > arch/arm64/kvm/sys_regs.c | 6 +++--- > 2 files changed, 4 insertions(+), 5 deletions(-) > > diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c > index f33825c995cb..fae4e95b586c 100644 > --- a/arch/arm64/kvm/pmu-emul.c > +++ b/arch/arm64/kvm/pmu-emul.c > @@ -373,7 +373,6 @@ static u64 kvm_pmu_overflow_status(struct kvm_vcpu *vcpu) > reg = __vcpu_sys_reg(vcpu, PMOVSSET_EL0); > reg &= __vcpu_sys_reg(vcpu, PMCNTENSET_EL0); > reg &= __vcpu_sys_reg(vcpu, PMINTENSET_EL1); > - reg &= kvm_pmu_valid_counter_mask(vcpu); > } > > return reg; > @@ -569,7 +568,7 @@ void kvm_pmu_handle_pmcr(struct kvm_vcpu *vcpu, u64 val) > > if (val & ARMV8_PMU_PMCR_E) { > kvm_pmu_enable_counter_mask(vcpu, > - __vcpu_sys_reg(vcpu, PMCNTENSET_EL0) & mask); > + __vcpu_sys_reg(vcpu, PMCNTENSET_EL0)); > } else { > kvm_pmu_disable_counter_mask(vcpu, mask); > } > diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c > index 95ccb8f45409..7ead93a8d67f 100644 > --- a/arch/arm64/kvm/sys_regs.c > +++ b/arch/arm64/kvm/sys_regs.c > @@ -883,7 +883,7 @@ static bool access_pmcnten(struct kvm_vcpu *vcpu, struct sys_reg_params *p, > kvm_pmu_disable_counter_mask(vcpu, val); > } > } else { > - p->regval = __vcpu_sys_reg(vcpu, PMCNTENSET_EL0) & mask; > + p->regval = __vcpu_sys_reg(vcpu, PMCNTENSET_EL0); > } > > return true; > @@ -907,7 +907,7 @@ static bool access_pminten(struct kvm_vcpu *vcpu, struct sys_reg_params *p, > /* accessing PMINTENCLR_EL1 */ > __vcpu_sys_reg(vcpu, PMINTENSET_EL1) &= ~val; > } else { > - p->regval = __vcpu_sys_reg(vcpu, PMINTENSET_EL1) & mask; > + p->regval = __vcpu_sys_reg(vcpu, PMINTENSET_EL1); > } > > return true; > @@ -929,7 +929,7 @@ static bool access_pmovs(struct kvm_vcpu *vcpu, struct sys_reg_params *p, > /* accessing PMOVSCLR_EL0 */ > __vcpu_sys_reg(vcpu, PMOVSSET_EL0) &= ~(p->regval & mask); > } else { > - p->regval = __vcpu_sys_reg(vcpu, PMOVSSET_EL0) & mask; > + p->regval = __vcpu_sys_reg(vcpu, PMOVSSET_EL0); > } > > return true; _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm