On 03/06/16 17:37, David Gibson wrote: > On Wed, Jun 01, 2016 at 06:57:41PM +1000, Alexey Kardashevskiy wrote: >> New VFIO_SPAPR_TCE_v2_IOMMU type supports dynamic DMA window management. >> This adds ability to VFIO common code to dynamically allocate/remove >> DMA windows in the host kernel when new VFIO container is added/removed. >> >> This adds VFIO_IOMMU_SPAPR_TCE_CREATE ioctl to vfio_listener_region_add >> and adds just created IOMMU into the host IOMMU list; the opposite >> action is taken in vfio_listener_region_del. >> >> When creating a new window, this uses heuristic to decide on the TCE table >> levels number. >> >> This should cause no guest visible change in behavior. >> >> Signed-off-by: Alexey Kardashevskiy >> --- >> Changes: >> v17: >> * moved spapr window create/remove helpers to separate file >> * added hw_error() if vfio_host_win_del() failed >> >> v16: >> * used memory_region_iommu_get_page_sizes() in vfio_listener_region_add() >> * enforced no intersections between windows >> >> v14: >> * new to the series >> --- >> hw/vfio/common.c | 76 +++++++++++++++++++++++++++++++++++++------ >> hw/vfio/spapr.c | 70 +++++++++++++++++++++++++++++++++++++++ >> include/hw/vfio/vfio-common.h | 6 ++++ >> trace-events | 2 ++ >> 4 files changed, 144 insertions(+), 10 deletions(-) >> >> diff --git a/hw/vfio/common.c b/hw/vfio/common.c >> index 52b08fd..7f55c26 100644 >> --- a/hw/vfio/common.c >> +++ b/hw/vfio/common.c >> @@ -275,6 +275,18 @@ static void vfio_host_win_add(VFIOContainer *container, >> QLIST_INSERT_HEAD(&container->hostwin_list, hostwin, hostwin_next); >> } >> >> +static int vfio_host_win_del(VFIOContainer *container, hwaddr min_iova) >> +{ >> + VFIOHostDMAWindow *hostwin = vfio_host_win_lookup(container, min_iova, 1); > > Hrm.. and for this case I think you want exact match, rather than > looking for range inclusion. I suppose so, I'll change this. >> + >> + if (!hostwin) { >> + return -1; >> + } >> + QLIST_REMOVE(hostwin, hostwin_next); >> + >> + return 0; >> +} >> + >> static bool vfio_listener_skipped_section(MemoryRegionSection *section) >> { >> return (!memory_region_is_ram(section->mr) && >> @@ -388,6 +400,30 @@ static void vfio_listener_region_add(MemoryListener *listener, >> } >> end = int128_get64(int128_sub(llend, int128_one())); >> >> + if (container->iommu_type == VFIO_SPAPR_TCE_v2_IOMMU) { >> + VFIOHostDMAWindow *hostwin; >> + hwaddr pgsize = 0; >> + >> + /* For now intersections are not allowed, we may relax this later */ >> + QLIST_FOREACH(hostwin, &container->hostwin_list, hostwin_next) { >> + if (ranges_overlap(hostwin->min_iova, >> + hostwin->max_iova - hostwin->min_iova + 1, >> + section->offset_within_address_space, >> + int128_get64(section->size))) { >> + goto fail; >> + } >> + } >> + >> + ret = vfio_spapr_create_window(container, section, &pgsize); >> + if (ret) { >> + goto fail; >> + } >> + >> + vfio_host_win_add(container, section->offset_within_address_space, >> + section->offset_within_address_space + >> + int128_get64(section->size) - 1, pgsize); >> + } >> + >> if (!vfio_host_win_lookup(container, iova, end)) { >> error_report("vfio: IOMMU container %p can't map guest IOVA region" >> " 0x%"HWADDR_PRIx"..0x%"HWADDR_PRIx, >> @@ -523,6 +559,18 @@ static void vfio_listener_region_del(MemoryListener *listener, >> "0x%"HWADDR_PRIx") = %d (%m)", >> container, iova, int128_get64(llsize), ret); >> } >> + >> + if (container->iommu_type == VFIO_SPAPR_TCE_v2_IOMMU) { >> + vfio_spapr_remove_window(container, >> + section->offset_within_address_space); > > Should check for error here. And do what here? vfio_spapr_remove_window() calls error_report() already and I still want to remove the host window here. > >> + if (vfio_host_win_del(container, >> + section->offset_within_address_space) < 0) { >> + hw_error("%s: Cannot delete missing window at %"HWADDR_PRIx, >> + __func__, section->offset_within_address_space); > > Personally I think assert() would be better here, but Alex doesn't > like them so I'm ok with this. > >> + } >> + >> + trace_vfio_spapr_remove_window(section->offset_within_address_space); >> + } >> } >> >> static const MemoryListener vfio_memory_listener = { >> @@ -960,11 +1008,6 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as) >> } >> } >> >> - /* >> - * This only considers the host IOMMU's 32-bit window. At >> - * some point we need to add support for the optional 64-bit >> - * window and dynamic windows >> - */ >> info.argsz = sizeof(info); >> ret = ioctl(fd, VFIO_IOMMU_SPAPR_TCE_GET_INFO, &info); >> if (ret) { >> @@ -973,11 +1016,24 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as) >> goto listener_release_exit; >> } >> >> - /* The default table uses 4K pages */ >> - vfio_host_win_add(container, info.dma32_window_start, >> - info.dma32_window_start + >> - info.dma32_window_size - 1, >> - 0x1000); >> + if (v2) { >> + /* >> + * There is a default window in just created container. >> + * To make region_add/del simpler, we better remove this >> + * window now and let those iommu_listener callbacks >> + * create/remove them when needed. >> + */ >> + ret = vfio_spapr_remove_window(container, info.dma32_window_start); >> + if (ret) { >> + goto free_container_exit; >> + } >> + } else { >> + /* The default table uses 4K pages */ >> + vfio_host_win_add(container, info.dma32_window_start, >> + info.dma32_window_start + >> + info.dma32_window_size - 1, >> + 0x1000); >> + } >> } else { >> error_report("vfio: No available IOMMU models"); >> ret = -EINVAL; >> diff --git a/hw/vfio/spapr.c b/hw/vfio/spapr.c >> index f339472..0c784c4 100644 >> --- a/hw/vfio/spapr.c >> +++ b/hw/vfio/spapr.c >> @@ -135,3 +135,73 @@ const MemoryListener vfio_prereg_listener = { >> .region_add = vfio_prereg_listener_region_add, >> .region_del = vfio_prereg_listener_region_del, >> }; >> + >> +int vfio_spapr_create_window(VFIOContainer *container, >> + MemoryRegionSection *section, >> + hwaddr *pgsize) >> +{ >> + int ret; >> + unsigned pagesizes = memory_region_iommu_get_page_sizes(section->mr); >> + unsigned pagesize = (hwaddr)1 << ctz64(pagesizes); >> + unsigned entries, pages; >> + struct vfio_iommu_spapr_tce_create create = { .argsz = sizeof(create) }; >> + >> + /* >> + * FIXME: For VFIO iommu types which have KVM acceleration to >> + * avoid bouncing all map/unmaps through qemu this way, this >> + * would be the right place to wire that up (tell the KVM >> + * device emulation the VFIO iommu handles to use). >> + */ >> + create.window_size = int128_get64(section->size); >> + create.page_shift = ctz64(pagesize); > > Doing a ctz on a value which is defined as 1 << n seems a bit > perverse. Well, this way it felt more obvious that pagesize is a single page size, not a mask. Not sure if memory_region_iommu_get_page_sizes() returning a mask (rather than a page size) is a good idea after all... I'll make it: create.page_shift = ctz64(pagesizes); and (below): *pgsize = 1ULL << create.page_shift; and remove pagesize. >> + /* >> + * SPAPR host supports multilevel TCE tables, there is some >> + * heuristic to decide how many levels we want for our table: >> + * 0..64 = 1; 65..4096 = 2; 4097..262144 = 3; 262145.. = 4 >> + */ >> + entries = create.window_size >> create.page_shift; >> + pages = MAX((entries * sizeof(uint64_t)) / getpagesize(), 1); >> + pages = MAX(pow2ceil(pages) - 1, 1); /* Round up */ >> + create.levels = ctz64(pages) / 6 + 1; >> + >> + ret = ioctl(container->fd, VFIO_IOMMU_SPAPR_TCE_CREATE, &create); >> + if (ret) { >> + error_report("Failed to create a window, ret = %d (%m)", ret); >> + return -errno; >> + } >> + >> + if (create.start_addr != section->offset_within_address_space) { >> + vfio_spapr_remove_window(container, create.start_addr); >> + >> + error_report("Host doesn't support DMA window at %"HWADDR_PRIx", must be %"PRIx64, >> + section->offset_within_address_space, >> + create.start_addr); >> + ioctl(container->fd, VFIO_IOMMU_SPAPR_TCE_REMOVE, &remove); >> + return -EINVAL; >> + } >> + trace_vfio_spapr_create_window(create.page_shift, >> + create.window_size, >> + create.start_addr); >> + *pgsize = pagesize; >> + >> + return 0; >> +} >> + >> +int vfio_spapr_remove_window(VFIOContainer *container, >> + hwaddr offset_within_address_space) >> +{ >> + struct vfio_iommu_spapr_tce_remove remove = { >> + .argsz = sizeof(remove), >> + .start_addr = offset_within_address_space, >> + }; >> + int ret; >> + >> + ret = ioctl(container->fd, VFIO_IOMMU_SPAPR_TCE_REMOVE, &remove); >> + if (ret) { >> + error_report("Failed to remove window at %"PRIx64, >> + remove.start_addr); >> + return -errno; >> + } >> + >> + return 0; >> +} >> diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h >> index c76ddc4..7e80382 100644 >> --- a/include/hw/vfio/vfio-common.h >> +++ b/include/hw/vfio/vfio-common.h >> @@ -167,4 +167,10 @@ int vfio_get_dev_region_info(VFIODevice *vbasedev, uint32_t type, >> #endif >> extern const MemoryListener vfio_prereg_listener; >> >> +int vfio_spapr_create_window(VFIOContainer *container, >> + MemoryRegionSection *section, >> + hwaddr *pgsize); >> +int vfio_spapr_remove_window(VFIOContainer *container, >> + hwaddr offset_within_address_space); >> + >> #endif /* !HW_VFIO_VFIO_COMMON_H */ >> diff --git a/trace-events b/trace-events >> index ddb8676..ec32c20 100644 >> --- a/trace-events >> +++ b/trace-events >> @@ -1768,6 +1768,8 @@ vfio_region_sparse_mmap_entry(int i, unsigned long start, unsigned long end) "sp >> vfio_get_dev_region(const char *name, int index, uint32_t type, uint32_t subtype) "%s index %d, %08x/%0x8" >> vfio_ram_register(uint64_t va, uint64_t size, int ret) "va=%"PRIx64" size=%"PRIx64" ret=%d" >> vfio_ram_unregister(uint64_t va, uint64_t size, int ret) "va=%"PRIx64" size=%"PRIx64" ret=%d" >> +vfio_spapr_create_window(int ps, uint64_t ws, uint64_t off) "pageshift=0x%x winsize=0x%"PRIx64" offset=0x%"PRIx64 >> +vfio_spapr_remove_window(uint64_t off) "offset=%"PRIx64 >> >> # hw/vfio/platform.c >> vfio_platform_base_device_init(char *name, int groupid) "%s belongs to group #%d" > -- Alexey