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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 28A6EC4332F for ; Thu, 28 Oct 2021 09:59:00 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id A4FE861039 for ; Thu, 28 Oct 2021 09:58:59 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org A4FE861039 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=lists.cs.columbia.edu Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 47E684B12E; Thu, 28 Oct 2021 05:58:59 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Authentication-Results: mm01.cs.columbia.edu (amavisd-new); dkim=softfail (fail, message has been altered) header.i=@redhat.com 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 Mq4ezWUPFsPU; 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bh=QW1VwJpwnVmxxU7z0qT05ZJcs1uisimu/KzjDIJrxzY=; b=YeUC4xU3uGU0Gli7HlwrbCjdXO3seIOYnYGWK6TKjnHilLx8jkKDozXwc1KRO8hFI8/axX kpAHztnPk0FrFvQZtQuj4NW+MGul4Yd9GOVLxXc7rRU6TDYSpAeFqxzO19RaRYk429arEu hnpzlE2SFWCnp10Zcyns6XJYMlJQig8= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-575-FpD08W43OridSh2IluPe8g-1; Thu, 28 Oct 2021 02:06:25 -0400 X-MC-Unique: FpD08W43OridSh2IluPe8g-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 2367679EEF; Thu, 28 Oct 2021 06:06:17 +0000 (UTC) Received: from starship (unknown [10.40.194.243]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9A8DC70953; Thu, 28 Oct 2021 06:05:36 +0000 (UTC) Message-ID: <49c6c208841a85dbcb397acdc7f20b81402e71fb.camel@redhat.com> Subject: Re: [PATCH v2 23/43] KVM: VMX: Use boolean returns for Posted Interrupt "test" helpers From: Maxim Levitsky To: Sean Christopherson , Marc Zyngier , Huacai Chen , Aleksandar Markovic , Paul Mackerras , Anup Patel , Paul Walmsley , Palmer Dabbelt , Albert Ou , Christian Borntraeger , Janosch Frank , Paolo Bonzini Date: Thu, 28 Oct 2021 09:05:35 +0300 In-Reply-To: <20211009021236.4122790-24-seanjc@google.com> References: <20211009021236.4122790-1-seanjc@google.com> <20211009021236.4122790-24-seanjc@google.com> User-Agent: Evolution 3.36.5 (3.36.5-2.fc32) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Mailman-Approved-At: Thu, 28 Oct 2021 05:58:55 -0400 Cc: Wanpeng Li , kvm@vger.kernel.org, David Hildenbrand , linux-kernel@vger.kernel.org, Atish Patra , linux-riscv@lists.infradead.org, Claudio Imbrenda , kvmarm@lists.cs.columbia.edu, Joerg Roedel , kvm-ppc@vger.kernel.org, David Matlack , linux-arm-kernel@lists.infradead.org, Jim Mattson , Cornelia Huck , linux-mips@vger.kernel.org, kvm-riscv@lists.infradead.org, Vitaly Kuznetsov 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 On Fri, 2021-10-08 at 19:12 -0700, Sean Christopherson wrote: > Return bools instead of ints for the posted interrupt "test" helpers. > The bit position of the flag being test does not matter to the callers, > and is in fact lost by virtue of test_bit() itself returning a bool. > > Returning ints is potentially dangerous, e.g. "pi_test_on(pi_desc) == 1" > is safe-ish because ON is bit 0 and thus any sane implementation of > pi_test_on() will work, but for SN (bit 1), checking "== 1" would rely on > pi_test_on() to return 0 or 1, a.k.a. bools, as opposed to 0 or 2 (the > positive bit position). > > Signed-off-by: Sean Christopherson > --- > arch/x86/kvm/vmx/posted_intr.c | 4 ++-- > arch/x86/kvm/vmx/posted_intr.h | 6 +++--- > 2 files changed, 5 insertions(+), 5 deletions(-) > > diff --git a/arch/x86/kvm/vmx/posted_intr.c b/arch/x86/kvm/vmx/posted_intr.c > index 6c2110d91b06..1688f8dc535a 100644 > --- a/arch/x86/kvm/vmx/posted_intr.c > +++ b/arch/x86/kvm/vmx/posted_intr.c > @@ -185,7 +185,7 @@ int pi_pre_block(struct kvm_vcpu *vcpu) > new.control) != old.control); > > /* We should not block the vCPU if an interrupt is posted for it. */ > - if (pi_test_on(pi_desc) == 1) > + if (pi_test_on(pi_desc)) > __pi_post_block(vcpu); > > local_irq_enable(); > @@ -216,7 +216,7 @@ void pi_wakeup_handler(void) > blocked_vcpu_list) { > struct pi_desc *pi_desc = vcpu_to_pi_desc(vcpu); > > - if (pi_test_on(pi_desc) == 1) > + if (pi_test_on(pi_desc)) > kvm_vcpu_kick(vcpu); > } > spin_unlock(&per_cpu(blocked_vcpu_on_cpu_lock, cpu)); > diff --git a/arch/x86/kvm/vmx/posted_intr.h b/arch/x86/kvm/vmx/posted_intr.h > index 7f7b2326caf5..36ae035f14aa 100644 > --- a/arch/x86/kvm/vmx/posted_intr.h > +++ b/arch/x86/kvm/vmx/posted_intr.h > @@ -40,7 +40,7 @@ static inline bool pi_test_and_clear_on(struct pi_desc *pi_desc) > (unsigned long *)&pi_desc->control); > } > > -static inline int pi_test_and_set_pir(int vector, struct pi_desc *pi_desc) > +static inline bool pi_test_and_set_pir(int vector, struct pi_desc *pi_desc) > { > return test_and_set_bit(vector, (unsigned long *)pi_desc->pir); > } > @@ -74,13 +74,13 @@ static inline void pi_clear_sn(struct pi_desc *pi_desc) > (unsigned long *)&pi_desc->control); > } > > -static inline int pi_test_on(struct pi_desc *pi_desc) > +static inline bool pi_test_on(struct pi_desc *pi_desc) > { > return test_bit(POSTED_INTR_ON, > (unsigned long *)&pi_desc->control); > } > > -static inline int pi_test_sn(struct pi_desc *pi_desc) > +static inline bool pi_test_sn(struct pi_desc *pi_desc) > { > return test_bit(POSTED_INTR_SN, > (unsigned long *)&pi_desc->control); Reviewed-by: Maxim Levitsky Best regards, Maxim Levitsky _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm