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Fri, 8 May 2020 06:23:19 +0000 (UTC) Subject: Re: [PATCH 2/5] virtio-iommu: Implement RESV_MEM probe request To: Peter Xu References: <20200507143201.31080-1-eric.auger@redhat.com> <20200507143201.31080-3-eric.auger@redhat.com> <20200507194032.GL228260@xz-x1> From: Auger Eric Message-ID: <4d9c0131-7a88-3c6d-5c0c-9f19662fec2d@redhat.com> Date: Fri, 8 May 2020 08:23:18 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.4.0 MIME-Version: 1.0 In-Reply-To: <20200507194032.GL228260@xz-x1> Content-Language: en-US X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=207.211.31.120; envelope-from=eric.auger@redhat.com; helo=us-smtp-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/05/08 02:23:32 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_PASS=-0.001 autolearn=_AUTOLEARN X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: peter.maydell@linaro.org, jean-philippe@linaro.org, mst@redhat.com, qemu-devel@nongnu.org, armbru@redhat.com, qemu-arm@nongnu.org, bbhushan2@marvell.com, eric.auger.pro@gmail.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Hi Peter, On 5/7/20 9:40 PM, Peter Xu wrote: > Hi, Eric, > > On Thu, May 07, 2020 at 04:31:58PM +0200, Eric Auger wrote: > > [...] > >> @@ -452,17 +520,33 @@ static void virtio_iommu_handle_command(VirtIODevice *vdev, VirtQueue *vq) >> case VIRTIO_IOMMU_T_UNMAP: >> tail.status = virtio_iommu_handle_unmap(s, iov, iov_cnt); >> break; >> + case VIRTIO_IOMMU_T_PROBE: >> + { >> + struct virtio_iommu_req_tail *ptail; >> + uint8_t *buf = g_malloc0(s->config.probe_size + sizeof(tail)); >> + >> + ptail = (struct virtio_iommu_req_tail *) >> + (buf + s->config.probe_size); >> + ptail->status = virtio_iommu_handle_probe(s, iov, iov_cnt, buf); >> + >> + sz = iov_from_buf(elem->in_sg, elem->in_num, 0, >> + buf, s->config.probe_size + sizeof(tail)); >> + g_free(buf); >> + assert(sz == s->config.probe_size + sizeof(tail)); >> + goto push; >> + } >> default: >> tail.status = VIRTIO_IOMMU_S_UNSUPP; >> } >> - qemu_mutex_unlock(&s->mutex); >> >> out: >> sz = iov_from_buf(elem->in_sg, elem->in_num, 0, >> &tail, sizeof(tail)); >> assert(sz == sizeof(tail)); >> >> - virtqueue_push(vq, elem, sizeof(tail)); >> +push: >> + qemu_mutex_unlock(&s->mutex); > > I think we can't move this unlock to here because otherwise "goto out" could > potentially try to unlock it without locked first. Thanks, You're right. I will revisit that. Thanks! Eric > >> + virtqueue_push(vq, elem, sz); >> virtio_notify(vdev, vq); >> g_free(elem); >> } >