On Mon, Jun 06, 2016 at 04:45:50PM +1000, Alexey Kardashevskiy wrote: > 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 <a...@ozlabs.ru> > >> --- > >> 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.
Hmm.. yes, I guess so. Probably best to have a comment here saying why it's safe to ignore an error you should usually test for. > > > >> + 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; Yes, I think that's better. > 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" > > > > -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson
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