Re: [RFC 1/3] util/vfio-helpers: Collect IOVA reserved regions
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 >>> >> >> >
Re: [RFC 1/3] util/vfio-helpers: Collect IOVA reserved regions
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 > > > >
Re: [RFC 1/3] util/vfio-helpers: Collect IOVA reserved regions
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: >> [0x800, 0x810]. 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_c
Re: [RFC 1/3] util/vfio-helpers: Collect IOVA reserved regions
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: > [0x800, 0x810]. 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. > +} > + > +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