From patchwork Thu Apr 28 16:45:28 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andre Przywara X-Patchwork-Id: 66907 Delivered-To: patch@linaro.org Received: by 10.140.93.198 with SMTP id d64csp322011qge; Thu, 28 Apr 2016 09:48:27 -0700 (PDT) X-Received: by 10.98.16.198 with SMTP id 67mr22060920pfq.21.1461862107565; Thu, 28 Apr 2016 09:48:27 -0700 (PDT) Return-Path: Received: from bombadil.infradead.org (bombadil.infradead.org. [2001:1868:205::9]) by mx.google.com with ESMTPS id y10si12542690pas.77.2016.04.28.09.48.27 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 28 Apr 2016 09:48:27 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-arm-kernel-bounces+patch=linaro.org@lists.infradead.org designates 2001:1868:205::9 as permitted sender) client-ip=2001:1868:205::9; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-arm-kernel-bounces+patch=linaro.org@lists.infradead.org designates 2001:1868:205::9 as permitted sender) smtp.mailfrom=linux-arm-kernel-bounces+patch=linaro.org@lists.infradead.org Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1avp6G-0002jJ-Ty; Thu, 28 Apr 2016 16:47:36 +0000 Received: from foss.arm.com ([217.140.101.70]) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1avp5L-0001Qm-SI for linux-arm-kernel@lists.infradead.org; Thu, 28 Apr 2016 16:46:43 +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 0A92F548; Thu, 28 Apr 2016 09:46:14 -0700 (PDT) Received: from e104803-lin.lan (unknown [10.1.203.153]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 4CA6A3F218; Thu, 28 Apr 2016 09:46:11 -0700 (PDT) From: Andre Przywara To: Marc Zyngier , Christoffer Dall Subject: [PATCH v2 09/54] KVM: arm/arm64: Fix MMIO emulation data handling Date: Thu, 28 Apr 2016 17:45:28 +0100 Message-Id: <1461861973-26464-10-git-send-email-andre.przywara@arm.com> X-Mailer: git-send-email 2.7.3 In-Reply-To: <1461861973-26464-1-git-send-email-andre.przywara@arm.com> References: <1461861973-26464-1-git-send-email-andre.przywara@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160428_094640_129624_1B6CB0C2 X-CRM114-Status: GOOD ( 13.52 ) X-Spam-Score: -7.9 (-------) X-Spam-Report: SpamAssassin version 3.4.0 on bombadil.infradead.org summary: Content analysis details: (-7.9 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] -1.0 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -0.0 SPF_PASS SPF: sender matches SPF record -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: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, Eric Auger MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patch=linaro.org@lists.infradead.org From: Christoffer Dall When the kernel was handling a guest MMIO read access internally, we need to copy the emulation result into the run->mmio structure in order for the kvm_handle_mmio_return() function to pick it up and inject the result back into the guest. Currently the only user of kvm_io_bus for ARM is the VGIC, which did this copying itself, so this was not causing issues so far. But with the upcoming new vgic implementation we need this done properly. Update the kvm_handle_mmio_return description and cleanup the code to only perform a single copying when needed. Code and commit message inspired by Andre Przywara. Reported-by: Andre Przywara Signed-off-by: Christoffer Dall Signed-off-by: Andre Przywara --- arch/arm/kvm/mmio.c | 14 +++++++------- virt/kvm/arm/vgic.c | 7 ------- 2 files changed, 7 insertions(+), 14 deletions(-) -- 2.7.3 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel diff --git a/arch/arm/kvm/mmio.c b/arch/arm/kvm/mmio.c index 0f6600f..0158e9e 100644 --- a/arch/arm/kvm/mmio.c +++ b/arch/arm/kvm/mmio.c @@ -87,11 +87,10 @@ static unsigned long mmio_read_buf(char *buf, unsigned int len) /** * kvm_handle_mmio_return -- Handle MMIO loads after user space emulation + * or in-kernel IO emulation + * * @vcpu: The VCPU pointer * @run: The VCPU run struct containing the mmio data - * - * This should only be called after returning from userspace for MMIO load - * emulation. */ int kvm_handle_mmio_return(struct kvm_vcpu *vcpu, struct kvm_run *run) { @@ -206,18 +205,19 @@ int io_mem_abort(struct kvm_vcpu *vcpu, struct kvm_run *run, run->mmio.is_write = is_write; run->mmio.phys_addr = fault_ipa; run->mmio.len = len; - if (is_write) - memcpy(run->mmio.data, data_buf, len); if (!ret) { /* We handled the access successfully in the kernel. */ + if (!is_write) + memcpy(run->mmio.data, data_buf, len); vcpu->stat.mmio_exit_kernel++; kvm_handle_mmio_return(vcpu, run); return 1; - } else { - vcpu->stat.mmio_exit_user++; } + if (is_write) + memcpy(run->mmio.data, data_buf, len); + vcpu->stat.mmio_exit_user++; run->exit_reason = KVM_EXIT_MMIO; return 0; } diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c index 5efc298..e70cee4 100644 --- a/virt/kvm/arm/vgic.c +++ b/virt/kvm/arm/vgic.c @@ -820,7 +820,6 @@ static int vgic_handle_mmio_access(struct kvm_vcpu *vcpu, struct vgic_dist *dist = &vcpu->kvm->arch.vgic; struct vgic_io_device *iodev = container_of(this, struct vgic_io_device, dev); - struct kvm_run *run = vcpu->run; const struct vgic_io_range *range; struct kvm_exit_mmio mmio; bool updated_state; @@ -849,12 +848,6 @@ static int vgic_handle_mmio_access(struct kvm_vcpu *vcpu, updated_state = false; } spin_unlock(&dist->lock); - run->mmio.is_write = is_write; - run->mmio.len = len; - run->mmio.phys_addr = addr; - memcpy(run->mmio.data, val, len); - - kvm_handle_mmio_return(vcpu, run); if (updated_state) vgic_kick_vcpus(vcpu->kvm);