From patchwork Fri Jun 30 08:44:24 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 782711 Return-Path: X-Original-To: incoming-imx@patchwork.ozlabs.org Delivered-To: patchwork-incoming-imx@bilbo.ozlabs.org Received: from bombadil.infradead.org (bombadil.infradead.org [65.50.211.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3wzVXm1S89z9sNd for ; Fri, 30 Jun 2017 18:47:52 +1000 (AEST) Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="NGpbsoOB"; dkim-atps=neutral DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=XJcvfYSeq6CGHBA44Z6iyRfpIaaveagog8aB2tksj+4=; b=NGpbsoOBv8YhUs rhGV3KkmVHjnrxS4uOsqkCHQlR2LDO2OFlWY1g847F9LLyPq9j1+vzjmqaOrr4l11M32vynWtHSn6 sGYOE+ApoaPgfIHOZAhyzh7u8HaNPIu3q3pAtYMp3nftcx8xRRrDPGfLzWW1hc508vm5bM0nfkyUq mIjkPK3LMTmMV7ZCIXc18E5LckyfRWh6/s7j+xGWH98Z1gkEoe9/xUd4ga/INuLLfl35vxXAC9W56 a2rO6bCenMtxH69ktQ6DXBK9Zpygw3+hJ7TpgyIZqBv+b9F1iTiK29HzG/XiYPNWH0U7nPGm95A6Y 3LqmPf3Hajz0gUKXOGew==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.87 #1 (Red Hat Linux)) id 1dQrae-0005aq-0M; Fri, 30 Jun 2017 08:47:48 +0000 Received: from foss.arm.com ([217.140.101.70]) by bombadil.infradead.org with esmtp (Exim 4.87 #1 (Red Hat Linux)) id 1dQrZL-0003fZ-OA for linux-arm-kernel@lists.infradead.org; Fri, 30 Jun 2017 08:46:37 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 4E6461684; Fri, 30 Jun 2017 01:46:07 -0700 (PDT) Received: from approximate.cambridge.arm.com (approximate.cambridge.arm.com [10.1.207.16]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0D73F3F581; Fri, 30 Jun 2017 01:46:04 -0700 (PDT) From: Marc Zyngier To: =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= , Paolo Bonzini Subject: [PATCH 08/58] KVM: add kvm_request_pending Date: Fri, 30 Jun 2017 09:44:24 +0100 Message-Id: <20170630084514.6779-9-marc.zyngier@arm.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20170630084514.6779-1-marc.zyngier@arm.com> References: <20170630084514.6779-1-marc.zyngier@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20170630_014628_193746_EC5F0FCF X-CRM114-Status: GOOD ( 13.42 ) X-Spam-Score: -6.4 (------) X-Spam-Report: SpamAssassin version 3.4.1 on bombadil.infradead.org summary: Content analysis details: (-6.4 points) pts rule name description ---- ---------------------- -------------------------------------------------- -5.0 RCVD_IN_DNSWL_HI RBL: Sender listed at http://www.dnswl.org/, high trust [217.140.101.70 listed in list.dnswl.org] 0.5 RCVD_IN_SORBS_SPAM RBL: SORBS: sender is a spam source [217.140.101.70 listed in dnsbl.sorbs.net] -0.0 SPF_PASS SPF: sender matches SPF record -0.0 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Christoffer Dall , Andrew Jones , Stefan Traby , kvm@vger.kernel.org, David Daney , Catalin Marinas , Alexander Graf , Eric Auger , James Morse , Hu Huajun , kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+incoming-imx=patchwork.ozlabs.org@lists.infradead.org List-Id: linux-imx-kernel.lists.patchwork.ozlabs.org From: Radim Krčmář A first step in vcpu->requests encapsulation. Additionally, we now use READ_ONCE() when accessing vcpu->requests, which ensures we always load vcpu->requests when it's accessed. This is important as other threads can change it any time. Also, READ_ONCE() documents that vcpu->requests is used with other threads, likely requiring memory barriers, which it does. Signed-off-by: Radim Krčmář [ Documented the new use of READ_ONCE() and converted another check in arch/mips/kvm/vz.c ] Signed-off-by: Andrew Jones Acked-by: Christoffer Dall Signed-off-by: Christoffer Dall --- arch/mips/kvm/trap_emul.c | 2 +- arch/mips/kvm/vz.c | 2 +- arch/powerpc/kvm/booke.c | 2 +- arch/powerpc/kvm/powerpc.c | 5 ++--- arch/s390/kvm/kvm-s390.c | 2 +- arch/x86/kvm/x86.c | 4 ++-- include/linux/kvm_host.h | 5 +++++ 7 files changed, 13 insertions(+), 9 deletions(-) diff --git a/arch/mips/kvm/trap_emul.c b/arch/mips/kvm/trap_emul.c index a563759fd142..6a0d7040d882 100644 --- a/arch/mips/kvm/trap_emul.c +++ b/arch/mips/kvm/trap_emul.c @@ -1094,7 +1094,7 @@ static void kvm_trap_emul_check_requests(struct kvm_vcpu *vcpu, int cpu, struct mm_struct *mm; int i; - if (likely(!vcpu->requests)) + if (likely(!kvm_request_pending(vcpu))) return; if (kvm_check_request(KVM_REQ_TLB_FLUSH, vcpu)) { diff --git a/arch/mips/kvm/vz.c b/arch/mips/kvm/vz.c index 71d8856ade64..74805035edc8 100644 --- a/arch/mips/kvm/vz.c +++ b/arch/mips/kvm/vz.c @@ -2337,7 +2337,7 @@ static int kvm_vz_check_requests(struct kvm_vcpu *vcpu, int cpu) int ret = 0; int i; - if (!vcpu->requests) + if (!kvm_request_pending(vcpu)) return 0; if (kvm_check_request(KVM_REQ_TLB_FLUSH, vcpu)) { diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c index 3eaac3809977..071b87ee682f 100644 --- a/arch/powerpc/kvm/booke.c +++ b/arch/powerpc/kvm/booke.c @@ -687,7 +687,7 @@ int kvmppc_core_prepare_to_enter(struct kvm_vcpu *vcpu) kvmppc_core_check_exceptions(vcpu); - if (vcpu->requests) { + if (kvm_request_pending(vcpu)) { /* Exception delivery raised request; start over */ return 1; } diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c index f7cf2cd564ef..fd64f087737c 100644 --- a/arch/powerpc/kvm/powerpc.c +++ b/arch/powerpc/kvm/powerpc.c @@ -55,8 +55,7 @@ EXPORT_SYMBOL_GPL(kvmppc_pr_ops); int kvm_arch_vcpu_runnable(struct kvm_vcpu *v) { - return !!(v->arch.pending_exceptions) || - v->requests; + return !!(v->arch.pending_exceptions) || kvm_request_pending(v); } int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu) @@ -108,7 +107,7 @@ int kvmppc_prepare_to_enter(struct kvm_vcpu *vcpu) */ smp_mb(); - if (vcpu->requests) { + if (kvm_request_pending(vcpu)) { /* Make sure we process requests preemptable */ local_irq_enable(); trace_kvm_check_requests(vcpu); diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 689ac48361c6..ad41e0fa3a21 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -2440,7 +2440,7 @@ static int kvm_s390_handle_requests(struct kvm_vcpu *vcpu) { retry: kvm_s390_vcpu_request_handled(vcpu); - if (!vcpu->requests) + if (!kvm_request_pending(vcpu)) return 0; /* * We use MMU_RELOAD just to re-arm the ipte notifier for the diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 464da936c53d..f81060518635 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -6710,7 +6710,7 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) bool req_immediate_exit = false; - if (vcpu->requests) { + if (kvm_request_pending(vcpu)) { if (kvm_check_request(KVM_REQ_MMU_RELOAD, vcpu)) kvm_mmu_unload(vcpu); if (kvm_check_request(KVM_REQ_MIGRATE_TIMER, vcpu)) @@ -6874,7 +6874,7 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) kvm_x86_ops->sync_pir_to_irr(vcpu); } - if (vcpu->mode == EXITING_GUEST_MODE || vcpu->requests + if (vcpu->mode == EXITING_GUEST_MODE || kvm_request_pending(vcpu) || need_resched() || signal_pending(current)) { vcpu->mode = OUTSIDE_GUEST_MODE; smp_wmb(); diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 3724b51aab64..0b50e7b35ed4 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -1105,6 +1105,11 @@ static inline void kvm_make_request(int req, struct kvm_vcpu *vcpu) set_bit(req & KVM_REQUEST_MASK, &vcpu->requests); } +static inline bool kvm_request_pending(struct kvm_vcpu *vcpu) +{ + return READ_ONCE(vcpu->requests); +} + static inline bool kvm_test_request(int req, struct kvm_vcpu *vcpu) { return test_bit(req & KVM_REQUEST_MASK, &vcpu->requests);