| Message ID | 20200925134845.21053-2-eric.auger@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | NVMe passthrough: Take into account host IOVA reserved regions | expand |
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 <eric.auger@redhat.com> > --- > 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. > + } > + > + 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/ / / > + 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? > + 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
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 <eric.auger@redhat.com> >> --- >> 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 >
On Fri, 2020-09-25 at 17:23 +0200, Auger Eric wrote: > > > @@ -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() Yes, but I mean clearing the pointer will make calling qemu_vfio_close() safe, there is also a g_free() on this one. Fam > > 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 > > > >
Hi Fam, On 9/25/20 5:44 PM, Fam Zheng wrote: > On Fri, 2020-09-25 at 17:23 +0200, Auger Eric wrote: >>>> @@ -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() > > Yes, but I mean clearing the pointer will make calling > qemu_vfio_close() safe, there is also a g_free() on this one. Oh yes, got it. Thank you for the review. Best Regards Eric > > Fam > >> >> 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 >>> >> >> >
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) { + return; + } + offset += cap->next; + cap = (struct vfio_info_cap_header *)cap; + } + + 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->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); + 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);
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 <eric.auger@redhat.com> --- util/vfio-helpers.c | 75 +++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 73 insertions(+), 2 deletions(-)