From 2e4109de8e589beecd69996ee14f24021b991c0d Mon Sep 17 00:00:00 2001 From: Alexey Kardashevskiy Date: Mon, 4 Jul 2016 13:33:06 +1000 Subject: vfio/spapr: Create DMA window dynamically (SPAPR IOMMU v2) 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 a helper to vfio_listener_region_add which makes VFIO_IOMMU_SPAPR_TCE_CREATE ioctl 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 Reviewed-by: David Gibson [dwg: Added some casts to prevent printf() warnings on certain targets where the kernel headers' __u64 doesn't match uint64_t or PRIx64] Signed-off-by: David Gibson --- hw/vfio/common.c | 80 +++++++++++++++++++++++++++++++++++++++++++++------- hw/vfio/spapr.c | 71 ++++++++++++++++++++++++++++++++++++++++++++++ hw/vfio/trace-events | 2 ++ 3 files changed, 143 insertions(+), 10 deletions(-) (limited to 'hw') diff --git a/hw/vfio/common.c b/hw/vfio/common.c index 7c8a5310ae..f3c0522e7e 100644 --- a/hw/vfio/common.c +++ b/hw/vfio/common.c @@ -265,6 +265,21 @@ 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, + hwaddr max_iova) +{ + VFIOHostDMAWindow *hostwin; + + QLIST_FOREACH(hostwin, &container->hostwin_list, hostwin_next) { + if (hostwin->min_iova == min_iova && hostwin->max_iova == max_iova) { + QLIST_REMOVE(hostwin, hostwin_next); + return 0; + } + } + + return -1; +} + static bool vfio_listener_skipped_section(MemoryRegionSection *section) { return (!memory_region_is_ram(section->mr) && @@ -380,6 +395,31 @@ 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))) { + ret = -1; + 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); + } + hostwin_found = false; QLIST_FOREACH(hostwin, &container->hostwin_list, hostwin_next) { if (hostwin->min_iova <= iova && end <= hostwin->max_iova) { @@ -523,6 +563,18 @@ 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); + if (vfio_host_win_del(container, + section->offset_within_address_space, + section->offset_within_address_space + + int128_get64(section->size) - 1) < 0) { + hw_error("%s: Cannot delete missing window at %"HWADDR_PRIx, + __func__, section->offset_within_address_space); + } + } } static const MemoryListener vfio_memory_listener = { @@ -961,11 +1013,6 @@ 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) { @@ -977,11 +1024,24 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as) goto free_container_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 7d64443b7f..0af342332c 100644 --- a/hw/vfio/spapr.c +++ b/hw/vfio/spapr.c @@ -137,3 +137,74 @@ 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 pagesize = memory_region_iommu_get_min_page_size(section->mr); + 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); + /* + * 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, + (uint64_t)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, + (uint64_t)remove.start_addr); + return -errno; + } + + trace_vfio_spapr_remove_window(offset_within_address_space); + + return 0; +} diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events index 0b02a3bd54..4bb7690c46 100644 --- a/hw/vfio/trace-events +++ b/hw/vfio/trace-events @@ -121,3 +121,5 @@ vfio_prereg_listener_region_add_skip(uint64_t start, uint64_t end) "%"PRIx64" - vfio_prereg_listener_region_del_skip(uint64_t start, uint64_t end) "%"PRIx64" - %"PRIx64 vfio_prereg_register(uint64_t va, uint64_t size, int ret) "va=%"PRIx64" size=%"PRIx64" ret=%d" vfio_prereg_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 -- cgit v1.2.3