diff options
| -rw-r--r-- | hw/vfio/common.c | 134 | ||||
| -rw-r--r-- | hw/vfio/trace-events | 1 |
2 files changed, 90 insertions, 45 deletions
diff --git a/hw/vfio/common.c b/hw/vfio/common.c index 4262b80c44..df2b4721bf 100644 --- a/hw/vfio/common.c +++ b/hw/vfio/common.c @@ -220,7 +220,25 @@ static int vfio_dma_unmap(VFIOContainer *container, .size = size, }; - if (ioctl(container->fd, VFIO_IOMMU_UNMAP_DMA, &unmap)) { + while (ioctl(container->fd, VFIO_IOMMU_UNMAP_DMA, &unmap)) { + /* + * The type1 backend has an off-by-one bug in the kernel (71a7d3d78e3c + * v4.15) where an overflow in its wrap-around check prevents us from + * unmapping the last page of the address space. Test for the error + * condition and re-try the unmap excluding the last page. The + * expectation is that we've never mapped the last page anyway and this + * unmap request comes via vIOMMU support which also makes it unlikely + * that this page is used. This bug was introduced well after type1 v2 + * support was introduced, so we shouldn't need to test for v1. A fix + * is queued for kernel v5.0 so this workaround can be removed once + * affected kernels are sufficiently deprecated. + */ + if (errno == EINVAL && unmap.size && !(unmap.iova + unmap.size) && + container->iommu_type == VFIO_TYPE1v2_IOMMU) { + trace_vfio_dma_unmap_overflow_workaround(); + unmap.size -= 1ULL << ctz64(container->pgsizes); + continue; + } error_report("VFIO_UNMAP_DMA: %d", -errno); return -errno; } @@ -1036,6 +1054,60 @@ static void vfio_put_address_space(VFIOAddressSpace *space) } } +/* + * vfio_get_iommu_type - selects the richest iommu_type (v2 first) + */ +static int vfio_get_iommu_type(VFIOContainer *container, + Error **errp) +{ + int iommu_types[] = { VFIO_TYPE1v2_IOMMU, VFIO_TYPE1_IOMMU, + VFIO_SPAPR_TCE_v2_IOMMU, VFIO_SPAPR_TCE_IOMMU }; + int i; + + for (i = 0; i < ARRAY_SIZE(iommu_types); i++) { + if (ioctl(container->fd, VFIO_CHECK_EXTENSION, iommu_types[i])) { + return iommu_types[i]; + } + } + error_setg(errp, "No available IOMMU models"); + return -EINVAL; +} + +static int vfio_init_container(VFIOContainer *container, int group_fd, + Error **errp) +{ + int iommu_type, ret; + + iommu_type = vfio_get_iommu_type(container, errp); + if (iommu_type < 0) { + return iommu_type; + } + + ret = ioctl(group_fd, VFIO_GROUP_SET_CONTAINER, &container->fd); + if (ret) { + error_setg_errno(errp, errno, "Failed to set group container"); + return -errno; + } + + while (ioctl(container->fd, VFIO_SET_IOMMU, iommu_type)) { + if (iommu_type == VFIO_SPAPR_TCE_v2_IOMMU) { + /* + * On sPAPR, despite the IOMMU subdriver always advertises v1 and + * v2, the running platform may not support v2 and there is no + * way to guess it until an IOMMU group gets added to the container. + * So in case it fails with v2, try v1 as a fallback. + */ + iommu_type = VFIO_SPAPR_TCE_IOMMU; + continue; + } + error_setg_errno(errp, errno, "Failed to set iommu for container"); + return -errno; + } + + container->iommu_type = iommu_type; + return 0; +} + static int vfio_connect_container(VFIOGroup *group, AddressSpace *as, Error **errp) { @@ -1101,25 +1173,17 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as, container->fd = fd; QLIST_INIT(&container->giommu_list); QLIST_INIT(&container->hostwin_list); - if (ioctl(fd, VFIO_CHECK_EXTENSION, VFIO_TYPE1_IOMMU) || - ioctl(fd, VFIO_CHECK_EXTENSION, VFIO_TYPE1v2_IOMMU)) { - bool v2 = !!ioctl(fd, VFIO_CHECK_EXTENSION, VFIO_TYPE1v2_IOMMU); - struct vfio_iommu_type1_info info; - ret = ioctl(group->fd, VFIO_GROUP_SET_CONTAINER, &fd); - if (ret) { - error_setg_errno(errp, errno, "failed to set group container"); - ret = -errno; - goto free_container_exit; - } + ret = vfio_init_container(container, group->fd, errp); + if (ret) { + goto free_container_exit; + } - container->iommu_type = v2 ? VFIO_TYPE1v2_IOMMU : VFIO_TYPE1_IOMMU; - ret = ioctl(fd, VFIO_SET_IOMMU, container->iommu_type); - if (ret) { - error_setg_errno(errp, errno, "failed to set iommu for container"); - ret = -errno; - goto free_container_exit; - } + switch (container->iommu_type) { + case VFIO_TYPE1v2_IOMMU: + case VFIO_TYPE1_IOMMU: + { + struct vfio_iommu_type1_info info; /* * FIXME: This assumes that a Type1 IOMMU can map any 64-bit @@ -1137,30 +1201,13 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as, } vfio_host_win_add(container, 0, (hwaddr)-1, info.iova_pgsizes); container->pgsizes = info.iova_pgsizes; - } else if (ioctl(fd, VFIO_CHECK_EXTENSION, VFIO_SPAPR_TCE_IOMMU) || - ioctl(fd, VFIO_CHECK_EXTENSION, VFIO_SPAPR_TCE_v2_IOMMU)) { + break; + } + case VFIO_SPAPR_TCE_v2_IOMMU: + case VFIO_SPAPR_TCE_IOMMU: + { struct vfio_iommu_spapr_tce_info info; - bool v2 = !!ioctl(fd, VFIO_CHECK_EXTENSION, VFIO_SPAPR_TCE_v2_IOMMU); - - ret = ioctl(group->fd, VFIO_GROUP_SET_CONTAINER, &fd); - if (ret) { - error_setg_errno(errp, errno, "failed to set group container"); - ret = -errno; - goto free_container_exit; - } - container->iommu_type = - v2 ? VFIO_SPAPR_TCE_v2_IOMMU : VFIO_SPAPR_TCE_IOMMU; - ret = ioctl(fd, VFIO_SET_IOMMU, container->iommu_type); - if (ret) { - container->iommu_type = VFIO_SPAPR_TCE_IOMMU; - v2 = false; - ret = ioctl(fd, VFIO_SET_IOMMU, container->iommu_type); - } - if (ret) { - error_setg_errno(errp, errno, "failed to set iommu for container"); - ret = -errno; - goto free_container_exit; - } + bool v2 = container->iommu_type == VFIO_SPAPR_TCE_v2_IOMMU; /* * The host kernel code implementing VFIO_IOMMU_DISABLE is called @@ -1222,10 +1269,7 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as, info.dma32_window_size - 1, 0x1000); } - } else { - error_setg(errp, "No available IOMMU models"); - ret = -EINVAL; - goto free_container_exit; + } } vfio_kvm_device_add_group(group); diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events index f41ca96160..ed2f333ad7 100644 --- a/hw/vfio/trace-events +++ b/hw/vfio/trace-events @@ -110,6 +110,7 @@ vfio_region_mmaps_set_enabled(const char *name, bool enabled) "Region %s mmaps e vfio_region_sparse_mmap_header(const char *name, int index, int nr_areas) "Device %s region %d: %d sparse mmap entries" vfio_region_sparse_mmap_entry(int i, unsigned long start, unsigned long end) "sparse entry %d [0x%lx - 0x%lx]" vfio_get_dev_region(const char *name, int index, uint32_t type, uint32_t subtype) "%s index %d, %08x/%0x8" +vfio_dma_unmap_overflow_workaround(void) "" # hw/vfio/platform.c vfio_platform_base_device_init(char *name, int groupid) "%s belongs to group #%d" |