diff options
Diffstat (limited to 'hw/vfio/spapr.c')
| -rw-r--r-- | hw/vfio/spapr.c | 210 |
1 files changed, 210 insertions, 0 deletions
diff --git a/hw/vfio/spapr.c b/hw/vfio/spapr.c new file mode 100644 index 0000000000..0af342332c --- /dev/null +++ b/hw/vfio/spapr.c @@ -0,0 +1,210 @@ +/* + * DMA memory preregistration + * + * Authors: + * Alexey Kardashevskiy <aik@ozlabs.ru> + * + * This work is licensed under the terms of the GNU GPL, version 2. See + * the COPYING file in the top-level directory. + */ + +#include "qemu/osdep.h" +#include "cpu.h" +#include <sys/ioctl.h> +#include <linux/vfio.h> + +#include "hw/vfio/vfio-common.h" +#include "hw/hw.h" +#include "qemu/error-report.h" +#include "trace.h" + +static bool vfio_prereg_listener_skipped_section(MemoryRegionSection *section) +{ + if (memory_region_is_iommu(section->mr)) { + hw_error("Cannot possibly preregister IOMMU memory"); + } + + return !memory_region_is_ram(section->mr) || + memory_region_is_skip_dump(section->mr); +} + +static void *vfio_prereg_gpa_to_vaddr(MemoryRegionSection *section, hwaddr gpa) +{ + return memory_region_get_ram_ptr(section->mr) + + section->offset_within_region + + (gpa - section->offset_within_address_space); +} + +static void vfio_prereg_listener_region_add(MemoryListener *listener, + MemoryRegionSection *section) +{ + VFIOContainer *container = container_of(listener, VFIOContainer, + prereg_listener); + const hwaddr gpa = section->offset_within_address_space; + hwaddr end; + int ret; + hwaddr page_mask = qemu_real_host_page_mask; + struct vfio_iommu_spapr_register_memory reg = { + .argsz = sizeof(reg), + .flags = 0, + }; + + if (vfio_prereg_listener_skipped_section(section)) { + trace_vfio_prereg_listener_region_add_skip( + section->offset_within_address_space, + section->offset_within_address_space + + int128_get64(int128_sub(section->size, int128_one()))); + return; + } + + if (unlikely((section->offset_within_address_space & ~page_mask) || + (section->offset_within_region & ~page_mask) || + (int128_get64(section->size) & ~page_mask))) { + error_report("%s received unaligned region", __func__); + return; + } + + end = section->offset_within_address_space + int128_get64(section->size); + if (gpa >= end) { + return; + } + + memory_region_ref(section->mr); + + reg.vaddr = (uintptr_t) vfio_prereg_gpa_to_vaddr(section, gpa); + reg.size = end - gpa; + + ret = ioctl(container->fd, VFIO_IOMMU_SPAPR_REGISTER_MEMORY, ®); + trace_vfio_prereg_register(reg.vaddr, reg.size, ret ? -errno : 0); + if (ret) { + /* + * On the initfn path, store the first error in the container so we + * can gracefully fail. Runtime, there's not much we can do other + * than throw a hardware error. + */ + if (!container->initialized) { + if (!container->error) { + container->error = ret; + } + } else { + hw_error("vfio: Memory registering failed, unable to continue"); + } + } +} + +static void vfio_prereg_listener_region_del(MemoryListener *listener, + MemoryRegionSection *section) +{ + VFIOContainer *container = container_of(listener, VFIOContainer, + prereg_listener); + const hwaddr gpa = section->offset_within_address_space; + hwaddr end; + int ret; + hwaddr page_mask = qemu_real_host_page_mask; + struct vfio_iommu_spapr_register_memory reg = { + .argsz = sizeof(reg), + .flags = 0, + }; + + if (vfio_prereg_listener_skipped_section(section)) { + trace_vfio_prereg_listener_region_del_skip( + section->offset_within_address_space, + section->offset_within_address_space + + int128_get64(int128_sub(section->size, int128_one()))); + return; + } + + if (unlikely((section->offset_within_address_space & ~page_mask) || + (section->offset_within_region & ~page_mask) || + (int128_get64(section->size) & ~page_mask))) { + error_report("%s received unaligned region", __func__); + return; + } + + end = section->offset_within_address_space + int128_get64(section->size); + if (gpa >= end) { + return; + } + + reg.vaddr = (uintptr_t) vfio_prereg_gpa_to_vaddr(section, gpa); + reg.size = end - gpa; + + ret = ioctl(container->fd, VFIO_IOMMU_SPAPR_UNREGISTER_MEMORY, ®); + trace_vfio_prereg_unregister(reg.vaddr, reg.size, ret ? -errno : 0); +} + +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; +} |