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Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.5.0 MIME-Version: 1.0 In-Reply-To: <20200925144307.GA3809989@dev> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=eric.auger@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=63.128.21.124; envelope-from=eric.auger@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/09/25 01:07:33 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -34 X-Spam_score: -3.5 X-Spam_bar: --- X-Spam_report: (-3.5 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1.199, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, NICE_REPLY_A=-0.238, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no 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: lvivier@redhat.com, kwolf@redhat.com, cohuck@redhat.com, qemu-devel@nongnu.org, mreitz@redhat.com, alex.williamson@redhat.com, qemu-arm@nongnu.org, stefanha@redhat.com, philmd@redhat.com, eric.auger.pro@gmail.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Hi Fam, On 9/25/20 4:43 PM, Fam Zheng wrote: > On 2020-09-25 15:48, Eric Auger wrote: >> The IOVA allocator currently ignores host reserved regions. >> As a result some chosen IOVAs may collide with some of them, >> resulting in VFIO MAP_DMA errors later on. This happens on ARM >> where the MSI reserved window quickly is encountered: >> [0x8000000, 0x8100000]. since 5.4 kernel, VFIO returns the usable >> IOVA regions. So let's enumerate them in the prospect to avoid >> them, later on. >> >> Signed-off-by: Eric Auger >> --- >> util/vfio-helpers.c | 75 +++++++++++++++++++++++++++++++++++++++++++-- >> 1 file changed, 73 insertions(+), 2 deletions(-) >> >> diff --git a/util/vfio-helpers.c b/util/vfio-helpers.c >> index 583bdfb36f..8e91beba95 100644 >> --- a/util/vfio-helpers.c >> +++ b/util/vfio-helpers.c >> @@ -40,6 +40,11 @@ typedef struct { >> uint64_t iova; >> } IOVAMapping; >> >> +struct IOVARange { >> + uint64_t start; >> + uint64_t end; >> +}; >> + >> struct QEMUVFIOState { >> QemuMutex lock; >> >> @@ -49,6 +54,8 @@ struct QEMUVFIOState { >> int device; >> RAMBlockNotifier ram_notifier; >> struct vfio_region_info config_region_info, bar_region_info[6]; >> + struct IOVARange *usable_iova_ranges; >> + uint8_t nb_iova_ranges; >> >> /* These fields are protected by @lock */ >> /* VFIO's IO virtual address space is managed by splitting into a few >> @@ -236,6 +243,36 @@ static int qemu_vfio_pci_write_config(QEMUVFIOState *s, void *buf, int size, int >> return ret == size ? 0 : -errno; >> } >> >> +static void collect_usable_iova_ranges(QEMUVFIOState *s, void *first_cap) >> +{ >> + struct vfio_iommu_type1_info_cap_iova_range *cap_iova_range; >> + struct vfio_info_cap_header *cap = first_cap; >> + void *offset = first_cap; >> + int i; >> + >> + while (cap->id != VFIO_IOMMU_TYPE1_INFO_CAP_IOVA_RANGE) { >> + if (cap->next) { > > This check looks reversed. > >> + return; >> + } >> + offset += cap->next; > > @offset is unused. > >> + cap = (struct vfio_info_cap_header *)cap; > > This assignment is nop. ugh indeed, that loop implementation is totally crap. I will test the rewriting by adding an extra cap on kernel side. > >> + } >> + >> + cap_iova_range = (struct vfio_iommu_type1_info_cap_iova_range *)cap; >> + >> + s->nb_iova_ranges = cap_iova_range->nr_iovas; >> + if (s->nb_iova_ranges > 1) { >> + s->usable_iova_ranges = >> + g_realloc(s->usable_iova_ranges, >> + s->nb_iova_ranges * sizeof(struct IOVARange)); >> + } >> + >> + for (i = 0; i < s->nb_iova_ranges; i++) { > > s/ / / ok > >> + s->usable_iova_ranges[i].start = cap_iova_range->iova_ranges[i].start; >> + s->usable_iova_ranges[i].end = cap_iova_range->iova_ranges[i].end; >> + } >> +} >> + >> static int qemu_vfio_init_pci(QEMUVFIOState *s, const char *device, >> Error **errp) >> { >> @@ -243,10 +280,13 @@ static int qemu_vfio_init_pci(QEMUVFIOState *s, const char *device, >> int i; >> uint16_t pci_cmd; >> struct vfio_group_status group_status = { .argsz = sizeof(group_status) }; >> - struct vfio_iommu_type1_info iommu_info = { .argsz = sizeof(iommu_info) }; >> + struct vfio_iommu_type1_info *iommu_info = NULL; >> + size_t iommu_info_size = sizeof(*iommu_info); >> struct vfio_device_info device_info = { .argsz = sizeof(device_info) }; >> char *group_file = NULL; >> >> + s->usable_iova_ranges = NULL; >> + >> /* Create a new container */ >> s->container = open("/dev/vfio/vfio", O_RDWR); >> >> @@ -310,13 +350,38 @@ static int qemu_vfio_init_pci(QEMUVFIOState *s, const char *device, >> goto fail; >> } >> >> + iommu_info = g_malloc0(iommu_info_size); >> + iommu_info->argsz = iommu_info_size; >> + >> /* Get additional IOMMU info */ >> - if (ioctl(s->container, VFIO_IOMMU_GET_INFO, &iommu_info)) { >> + if (ioctl(s->container, VFIO_IOMMU_GET_INFO, iommu_info)) { >> error_setg_errno(errp, errno, "Failed to get IOMMU info"); >> ret = -errno; >> goto fail; >> } >> >> + /* >> + * if the kernel does not report usable IOVA regions, choose >> + * the legacy [QEMU_VFIO_IOVA_MIN, QEMU_VFIO_IOVA_MAX -1] region >> + */ >> + s->nb_iova_ranges = 1; >> + s->usable_iova_ranges = g_new0(struct IOVARange, 1); >> + s->usable_iova_ranges[0].start = QEMU_VFIO_IOVA_MIN; >> + s->usable_iova_ranges[0].end = QEMU_VFIO_IOVA_MAX - 1; >> + >> + if (iommu_info->argsz > iommu_info_size) { >> + void *first_cap; >> + >> + iommu_info_size = iommu_info->argsz; >> + iommu_info = g_realloc(iommu_info, iommu_info_size); >> + if (ioctl(s->container, VFIO_IOMMU_GET_INFO, iommu_info)) { >> + ret = -errno; >> + goto fail; >> + } >> + first_cap = (void *)iommu_info + iommu_info->cap_offset; >> + collect_usable_iova_ranges(s, first_cap); >> + } >> + >> s->device = ioctl(s->group, VFIO_GROUP_GET_DEVICE_FD, device); >> >> if (s->device < 0) { >> @@ -365,8 +430,12 @@ static int qemu_vfio_init_pci(QEMUVFIOState *s, const char *device, >> if (ret) { >> goto fail; >> } >> + g_free(iommu_info); >> return 0; >> fail: >> + g_free(s->usable_iova_ranges); > > Set s->usable_iova_ranges to NULL to avoid double free? I think I did at the beginning of qemu_vfio_init_pci() Thanks Eric > >> + s->nb_iova_ranges = 0; >> + g_free(iommu_info); >> close(s->group); >> fail_container: >> close(s->container); >> @@ -716,6 +785,8 @@ void qemu_vfio_close(QEMUVFIOState *s) >> qemu_vfio_undo_mapping(s, &s->mappings[i], NULL); >> } >> ram_block_notifier_remove(&s->ram_notifier); >> + g_free(s->usable_iova_ranges); >> + s->nb_iova_ranges = 0; >> qemu_vfio_reset(s); >> close(s->device); >> close(s->group); >> -- >> 2.21.3 >> >> > > Fam >