/* * generic functions used by VFIO devices * * Copyright Red Hat, Inc. 2012 * * Authors: * Alex Williamson * * This work is licensed under the terms of the GNU GPL, version 2. See * the COPYING file in the top-level directory. * * Based on qemu-kvm device-assignment: * Adapted for KVM by Qumranet. * Copyright (c) 2007, Neocleus, Alex Novik (alex@neocleus.com) * Copyright (c) 2007, Neocleus, Guy Zana (guy@neocleus.com) * Copyright (C) 2008, Qumranet, Amit Shah (amit.shah@qumranet.com) * Copyright (C) 2008, Red Hat, Amit Shah (amit.shah@redhat.com) * Copyright (C) 2008, IBM, Muli Ben-Yehuda (muli@il.ibm.com) */ #include "qemu/osdep.h" #include #ifdef CONFIG_KVM #include #endif #include #include "hw/vfio/vfio-common.h" #include "hw/vfio/pci.h" #include "exec/address-spaces.h" #include "exec/memory.h" #include "exec/ram_addr.h" #include "hw/hw.h" #include "qemu/error-report.h" #include "qemu/main-loop.h" #include "qemu/range.h" #include "sysemu/kvm.h" #include "sysemu/reset.h" #include "sysemu/runstate.h" #include "trace.h" #include "qapi/error.h" #include "migration/migration.h" #include "migration/misc.h" #include "migration/blocker.h" #include "migration/qemu-file.h" #include "sysemu/tpm.h" VFIODeviceList vfio_device_list = QLIST_HEAD_INITIALIZER(vfio_device_list); static QLIST_HEAD(, VFIOAddressSpace) vfio_address_spaces = QLIST_HEAD_INITIALIZER(vfio_address_spaces); #ifdef CONFIG_KVM /* * We have a single VFIO pseudo device per KVM VM. Once created it lives * for the life of the VM. Closing the file descriptor only drops our * reference to it and the device's reference to kvm. Therefore once * initialized, this file descriptor is only released on QEMU exit and * we'll re-use it should another vfio device be attached before then. */ int vfio_kvm_device_fd = -1; #endif /* * Device state interfaces */ bool vfio_mig_active(void) { VFIODevice *vbasedev; if (QLIST_EMPTY(&vfio_device_list)) { return false; } QLIST_FOREACH(vbasedev, &vfio_device_list, global_next) { if (vbasedev->migration_blocker) { return false; } } return true; } static Error *multiple_devices_migration_blocker; /* * Multiple devices migration is allowed only if all devices support P2P * migration. Single device migration is allowed regardless of P2P migration * support. */ static bool vfio_multiple_devices_migration_is_supported(void) { VFIODevice *vbasedev; unsigned int device_num = 0; bool all_support_p2p = true; QLIST_FOREACH(vbasedev, &vfio_device_list, global_next) { if (vbasedev->migration) { device_num++; if (!(vbasedev->migration->mig_flags & VFIO_MIGRATION_P2P)) { all_support_p2p = false; } } } return all_support_p2p || device_num <= 1; } int vfio_block_multiple_devices_migration(VFIODevice *vbasedev, Error **errp) { int ret; if (vfio_multiple_devices_migration_is_supported()) { return 0; } if (vbasedev->enable_migration == ON_OFF_AUTO_ON) { error_setg(errp, "Multiple VFIO devices migration is supported only if " "all of them support P2P migration"); return -EINVAL; } if (multiple_devices_migration_blocker) { return 0; } error_setg(&multiple_devices_migration_blocker, "Multiple VFIO devices migration is supported only if all of " "them support P2P migration"); ret = migrate_add_blocker(&multiple_devices_migration_blocker, errp); return ret; } void vfio_unblock_multiple_devices_migration(void) { if (!multiple_devices_migration_blocker || !vfio_multiple_devices_migration_is_supported()) { return; } migrate_del_blocker(&multiple_devices_migration_blocker); } bool vfio_viommu_preset(VFIODevice *vbasedev) { return vbasedev->container->space->as != &address_space_memory; } static void vfio_set_migration_error(int err) { MigrationState *ms = migrate_get_current(); if (migration_is_setup_or_active(ms->state)) { WITH_QEMU_LOCK_GUARD(&ms->qemu_file_lock) { if (ms->to_dst_file) { qemu_file_set_error(ms->to_dst_file, err); } } } } bool vfio_device_state_is_running(VFIODevice *vbasedev) { VFIOMigration *migration = vbasedev->migration; return migration->device_state == VFIO_DEVICE_STATE_RUNNING || migration->device_state == VFIO_DEVICE_STATE_RUNNING_P2P; } bool vfio_device_state_is_precopy(VFIODevice *vbasedev) { VFIOMigration *migration = vbasedev->migration; return migration->device_state == VFIO_DEVICE_STATE_PRE_COPY || migration->device_state == VFIO_DEVICE_STATE_PRE_COPY_P2P; } static bool vfio_devices_all_dirty_tracking(VFIOContainer *container) { VFIODevice *vbasedev; MigrationState *ms = migrate_get_current(); if (ms->state != MIGRATION_STATUS_ACTIVE && ms->state != MIGRATION_STATUS_DEVICE) { return false; } QLIST_FOREACH(vbasedev, &container->device_list, container_next) { VFIOMigration *migration = vbasedev->migration; if (!migration) { return false; } if (vbasedev->pre_copy_dirty_page_tracking == ON_OFF_AUTO_OFF && (vfio_device_state_is_running(vbasedev) || vfio_device_state_is_precopy(vbasedev))) { return false; } } return true; } bool vfio_devices_all_device_dirty_tracking(VFIOContainer *container) { VFIODevice *vbasedev; QLIST_FOREACH(vbasedev, &container->device_list, container_next) { if (!vbasedev->dirty_pages_supported) { return false; } } return true; } /* * Check if all VFIO devices are running and migration is active, which is * essentially equivalent to the migration being in pre-copy phase. */ bool vfio_devices_all_running_and_mig_active(VFIOContainer *container) { VFIODevice *vbasedev; if (!migration_is_active(migrate_get_current())) { return false; } QLIST_FOREACH(vbasedev, &container->device_list, container_next) { VFIOMigration *migration = vbasedev->migration; if (!migration) { return false; } if (vfio_device_state_is_running(vbasedev) || vfio_device_state_is_precopy(vbasedev)) { continue; } else { return false; } } return true; } static bool vfio_listener_skipped_section(MemoryRegionSection *section) { return (!memory_region_is_ram(section->mr) && !memory_region_is_iommu(section->mr)) || memory_region_is_protected(section->mr) || /* * Sizing an enabled 64-bit BAR can cause spurious mappings to * addresses in the upper part of the 64-bit address space. These * are never accessed by the CPU and beyond the address width of * some IOMMU hardware. TODO: VFIO should tell us the IOMMU width. */ section->offset_within_address_space & (1ULL << 63); } /* Called with rcu_read_lock held. */ static bool vfio_get_xlat_addr(IOMMUTLBEntry *iotlb, void **vaddr, ram_addr_t *ram_addr, bool *read_only) { bool ret, mr_has_discard_manager; ret = memory_get_xlat_addr(iotlb, vaddr, ram_addr, read_only, &mr_has_discard_manager); if (ret && mr_has_discard_manager) { /* * Malicious VMs might trigger discarding of IOMMU-mapped memory. The * pages will remain pinned inside vfio until unmapped, resulting in a * higher memory consumption than expected. If memory would get * populated again later, there would be an inconsistency between pages * pinned by vfio and pages seen by QEMU. This is the case until * unmapped from the IOMMU (e.g., during device reset). * * With malicious guests, we really only care about pinning more memory * than expected. RLIMIT_MEMLOCK set for the user/process can never be * exceeded and can be used to mitigate this problem. */ warn_report_once("Using vfio with vIOMMUs and coordinated discarding of" " RAM (e.g., virtio-mem) works, however, malicious" " guests can trigger pinning of more memory than" " intended via an IOMMU. It's possible to mitigate " " by setting/adjusting RLIMIT_MEMLOCK."); } return ret; } static void vfio_iommu_map_notify(IOMMUNotifier *n, IOMMUTLBEntry *iotlb) { VFIOGuestIOMMU *giommu = container_of(n, VFIOGuestIOMMU, n); VFIOContainer *container = giommu->container; hwaddr iova = iotlb->iova + giommu->iommu_offset; void *vaddr; int ret; trace_vfio_iommu_map_notify(iotlb->perm == IOMMU_NONE ? "UNMAP" : "MAP", iova, iova + iotlb->addr_mask); if (iotlb->target_as != &address_space_memory) { error_report("Wrong target AS \"%s\", only system memory is allowed", iotlb->target_as->name ? iotlb->target_as->name : "none"); vfio_set_migration_error(-EINVAL); return; } rcu_read_lock(); if ((iotlb->perm & IOMMU_RW) != IOMMU_NONE) { bool read_only; if (!vfio_get_xlat_addr(iotlb, &vaddr, NULL, &read_only)) { goto out; } /* * vaddr is only valid until rcu_read_unlock(). But after * vfio_dma_map has set up the mapping the pages will be * pinned by the kernel. This makes sure that the RAM backend * of vaddr will always be there, even if the memory object is * destroyed and its backing memory munmap-ed. */ ret = vfio_dma_map(container, iova, iotlb->addr_mask + 1, vaddr, read_only); if (ret) { error_report("vfio_dma_map(%p, 0x%"HWADDR_PRIx", " "0x%"HWADDR_PRIx", %p) = %d (%s)", container, iova, iotlb->addr_mask + 1, vaddr, ret, strerror(-ret)); } } else { ret = vfio_dma_unmap(container, iova, iotlb->addr_mask + 1, iotlb); if (ret) { error_report("vfio_dma_unmap(%p, 0x%"HWADDR_PRIx", " "0x%"HWADDR_PRIx") = %d (%s)", container, iova, iotlb->addr_mask + 1, ret, strerror(-ret)); vfio_set_migration_error(ret); } } out: rcu_read_unlock(); } static void vfio_ram_discard_notify_discard(RamDiscardListener *rdl, MemoryRegionSection *section) { VFIORamDiscardListener *vrdl = container_of(rdl, VFIORamDiscardListener, listener); const hwaddr size = int128_get64(section->size); const hwaddr iova = section->offset_within_address_space; int ret; /* Unmap with a single call. */ ret = vfio_dma_unmap(vrdl->container, iova, size , NULL); if (ret) { error_report("%s: vfio_dma_unmap() failed: %s", __func__, strerror(-ret)); } } static int vfio_ram_discard_notify_populate(RamDiscardListener *rdl, MemoryRegionSection *section) { VFIORamDiscardListener *vrdl = container_of(rdl, VFIORamDiscardListener, listener); const hwaddr end = section->offset_within_region + int128_get64(section->size); hwaddr start, next, iova; void *vaddr; int ret; /* * Map in (aligned within memory region) minimum granularity, so we can * unmap in minimum granularity later. */ for (start = section->offset_within_region; start < end; start = next) { next = ROUND_UP(start + 1, vrdl->granularity); next = MIN(next, end); iova = start - section->offset_within_region + section->offset_within_address_space; vaddr = memory_region_get_ram_ptr(section->mr) + start; ret = vfio_dma_map(vrdl->container, iova, next - start, vaddr, section->readonly); if (ret) { /* Rollback */ vfio_ram_discard_notify_discard(rdl, section); return ret; } } return 0; } static void vfio_register_ram_discard_listener(VFIOContainer *container, MemoryRegionSection *section) { RamDiscardManager *rdm = memory_region_get_ram_discard_manager(section->mr); VFIORamDiscardListener *vrdl; /* Ignore some corner cases not relevant in practice. */ g_assert(QEMU_IS_ALIGNED(section->offset_within_region, TARGET_PAGE_SIZE)); g_assert(QEMU_IS_ALIGNED(section->offset_within_address_space, TARGET_PAGE_SIZE)); g_assert(QEMU_IS_ALIGNED(int128_get64(section->size), TARGET_PAGE_SIZE)); vrdl = g_new0(VFIORamDiscardListener, 1); vrdl->container = container; vrdl->mr = section->mr; vrdl->offset_within_address_space = section->offset_within_address_space; vrdl->size = int128_get64(section->size); vrdl->granularity = ram_discard_manager_get_min_granularity(rdm, section->mr); g_assert(vrdl->granularity && is_power_of_2(vrdl->granularity)); g_assert(container->pgsizes && vrdl->granularity >= 1ULL << ctz64(container->pgsizes)); ram_discard_listener_init(&vrdl->listener, vfio_ram_discard_notify_populate, vfio_ram_discard_notify_discard, true); ram_discard_manager_register_listener(rdm, &vrdl->listener, section); QLIST_INSERT_HEAD(&container->vrdl_list, vrdl, next); /* * Sanity-check if we have a theoretically problematic setup where we could * exceed the maximum number of possible DMA mappings over time. We assume * that each mapped section in the same address space as a RamDiscardManager * section consumes exactly one DMA mapping, with the exception of * RamDiscardManager sections; i.e., we don't expect to have gIOMMU sections * in the same address space as RamDiscardManager sections. * * We assume that each section in the address space consumes one memslot. * We take the number of KVM memory slots as a best guess for the maximum * number of sections in the address space we could have over time, * also consuming DMA mappings. */ if (container->dma_max_mappings) { unsigned int vrdl_count = 0, vrdl_mappings = 0, max_memslots = 512; #ifdef CONFIG_KVM if (kvm_enabled()) { max_memslots = kvm_get_max_memslots(); } #endif QLIST_FOREACH(vrdl, &container->vrdl_list, next) { hwaddr start, end; start = QEMU_ALIGN_DOWN(vrdl->offset_within_address_space, vrdl->granularity); end = ROUND_UP(vrdl->offset_within_address_space + vrdl->size, vrdl->granularity); vrdl_mappings += (end - start) / vrdl->granularity; vrdl_count++; } if (vrdl_mappings + max_memslots - vrdl_count > container->dma_max_mappings) { warn_report("%s: possibly running out of DMA mappings. E.g., try" " increasing the 'block-size' of virtio-mem devies." " Maximum possible DMA mappings: %d, Maximum possible" " memslots: %d", __func__, container->dma_max_mappings, max_memslots); } } } static void vfio_unregister_ram_discard_listener(VFIOContainer *container, MemoryRegionSection *section) { RamDiscardManager *rdm = memory_region_get_ram_discard_manager(section->mr); VFIORamDiscardListener *vrdl = NULL; QLIST_FOREACH(vrdl, &container->vrdl_list, next) { if (vrdl->mr == section->mr && vrdl->offset_within_address_space == section->offset_within_address_space) { break; } } if (!vrdl) { hw_error("vfio: Trying to unregister missing RAM discard listener"); } ram_discard_manager_unregister_listener(rdm, &vrdl->listener); QLIST_REMOVE(vrdl, next); g_free(vrdl); } static bool vfio_known_safe_misalignment(MemoryRegionSection *section) { MemoryRegion *mr = section->mr; if (!TPM_IS_CRB(mr->owner)) { return false; } /* this is a known safe misaligned region, just trace for debug purpose */ trace_vfio_known_safe_misalignment(memory_region_name(mr), section->offset_within_address_space, section->offset_within_region, qemu_real_host_page_size()); return true; } static bool vfio_listener_valid_section(MemoryRegionSection *section, const char *name) { if (vfio_listener_skipped_section(section)) { trace_vfio_listener_region_skip(name, section->offset_within_address_space, section->offset_within_address_space + int128_get64(int128_sub(section->size, int128_one()))); return false; } if (unlikely((section->offset_within_address_space & ~qemu_real_host_page_mask()) != (section->offset_within_region & ~qemu_real_host_page_mask()))) { if (!vfio_known_safe_misalignment(section)) { error_report("%s received unaligned region %s iova=0x%"PRIx64 " offset_within_region=0x%"PRIx64 " qemu_real_host_page_size=0x%"PRIxPTR, __func__, memory_region_name(section->mr), section->offset_within_address_space, section->offset_within_region, qemu_real_host_page_size()); } return false; } return true; } static bool vfio_get_section_iova_range(VFIOContainer *container, MemoryRegionSection *section, hwaddr *out_iova, hwaddr *out_end, Int128 *out_llend) { Int128 llend; hwaddr iova; iova = REAL_HOST_PAGE_ALIGN(section->offset_within_address_space); llend = int128_make64(section->offset_within_address_space); llend = int128_add(llend, section->size); llend = int128_and(llend, int128_exts64(qemu_real_host_page_mask())); if (int128_ge(int128_make64(iova), llend)) { return false; } *out_iova = iova; *out_end = int128_get64(int128_sub(llend, int128_one())); if (out_llend) { *out_llend = llend; } return true; } static void vfio_listener_region_add(MemoryListener *listener, MemoryRegionSection *section) { VFIOContainer *container = container_of(listener, VFIOContainer, listener); hwaddr iova, end; Int128 llend, llsize; void *vaddr; int ret; Error *err = NULL; if (!vfio_listener_valid_section(section, "region_add")) { return; } if (!vfio_get_section_iova_range(container, section, &iova, &end, &llend)) { if (memory_region_is_ram_device(section->mr)) { trace_vfio_listener_region_add_no_dma_map( memory_region_name(section->mr), section->offset_within_address_space, int128_getlo(section->size), qemu_real_host_page_size()); } return; } if (vfio_container_add_section_window(container, section, &err)) { goto fail; } memory_region_ref(section->mr); if (memory_region_is_iommu(section->mr)) { VFIOGuestIOMMU *giommu; IOMMUMemoryRegion *iommu_mr = IOMMU_MEMORY_REGION(section->mr); int iommu_idx; trace_vfio_listener_region_add_iommu(iova, end); /* * 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). */ giommu = g_malloc0(sizeof(*giommu)); giommu->iommu_mr = iommu_mr; giommu->iommu_offset = section->offset_within_address_space - section->offset_within_region; giommu->container = container; llend = int128_add(int128_make64(section->offset_within_region), section->size); llend = int128_sub(llend, int128_one()); iommu_idx = memory_region_iommu_attrs_to_index(iommu_mr, MEMTXATTRS_UNSPECIFIED); iommu_notifier_init(&giommu->n, vfio_iommu_map_notify, IOMMU_NOTIFIER_IOTLB_EVENTS, section->offset_within_region, int128_get64(llend), iommu_idx); ret = memory_region_iommu_set_page_size_mask(giommu->iommu_mr, container->pgsizes, &err); if (ret) { g_free(giommu); goto fail; } if (container->iova_ranges) { ret = memory_region_iommu_set_iova_ranges(giommu->iommu_mr, container->iova_ranges, &err); if (ret) { g_free(giommu); goto fail; } } ret = memory_region_register_iommu_notifier(section->mr, &giommu->n, &err); if (ret) { g_free(giommu); goto fail; } QLIST_INSERT_HEAD(&container->giommu_list, giommu, giommu_next); memory_region_iommu_replay(giommu->iommu_mr, &giommu->n); return; } /* Here we assume that memory_region_is_ram(section->mr)==true */ /* * For RAM memory regions with a RamDiscardManager, we only want to map the * actually populated parts - and update the mapping whenever we're notified * about changes. */ if (memory_region_has_ram_discard_manager(section->mr)) { vfio_register_ram_discard_listener(container, section); return; } vaddr = memory_region_get_ram_ptr(section->mr) + section->offset_within_region + (iova - section->offset_within_address_space); trace_vfio_listener_region_add_ram(iova, end, vaddr); llsize = int128_sub(llend, int128_make64(iova)); if (memory_region_is_ram_device(section->mr)) { hwaddr pgmask = (1ULL << ctz64(container->pgsizes)) - 1; if ((iova & pgmask) || (int128_get64(llsize) & pgmask)) { trace_vfio_listener_region_add_no_dma_map( memory_region_name(section->mr), section->offset_within_address_space, int128_getlo(section->size), pgmask + 1); return; } } ret = vfio_dma_map(container, iova, int128_get64(llsize), vaddr, section->readonly); if (ret) { error_setg(&err, "vfio_dma_map(%p, 0x%"HWADDR_PRIx", " "0x%"HWADDR_PRIx", %p) = %d (%s)", container, iova, int128_get64(llsize), vaddr, ret, strerror(-ret)); if (memory_region_is_ram_device(section->mr)) { /* Allow unexpected mappings not to be fatal for RAM devices */ error_report_err(err); return; } goto fail; } return; fail: if (memory_region_is_ram_device(section->mr)) { error_reportf_err(err, "PCI p2p may not work: "); return; } /* * 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) { error_propagate_prepend(&container->error, err, "Region %s: ", memory_region_name(section->mr)); } else { error_free(err); } } else { error_report_err(err); hw_error("vfio: DMA mapping failed, unable to continue"); } } static void vfio_listener_region_del(MemoryListener *listener, MemoryRegionSection *section) { VFIOContainer *container = container_of(listener, VFIOContainer, listener); hwaddr iova, end; Int128 llend, llsize; int ret; bool try_unmap = true; if (!vfio_listener_valid_section(section, "region_del")) { return; } if (memory_region_is_iommu(section->mr)) { VFIOGuestIOMMU *giommu; QLIST_FOREACH(giommu, &container->giommu_list, giommu_next) { if (MEMORY_REGION(giommu->iommu_mr) == section->mr && giommu->n.start == section->offset_within_region) { memory_region_unregister_iommu_notifier(section->mr, &giommu->n); QLIST_REMOVE(giommu, giommu_next); g_free(giommu); break; } } /* * FIXME: We assume the one big unmap below is adequate to * remove any individual page mappings in the IOMMU which * might have been copied into VFIO. This works for a page table * based IOMMU where a big unmap flattens a large range of IO-PTEs. * That may not be true for all IOMMU types. */ } if (!vfio_get_section_iova_range(container, section, &iova, &end, &llend)) { return; } llsize = int128_sub(llend, int128_make64(iova)); trace_vfio_listener_region_del(iova, end); if (memory_region_is_ram_device(section->mr)) { hwaddr pgmask; pgmask = (1ULL << ctz64(container->pgsizes)) - 1; try_unmap = !((iova & pgmask) || (int128_get64(llsize) & pgmask)); } else if (memory_region_has_ram_discard_manager(section->mr)) { vfio_unregister_ram_discard_listener(container, section); /* Unregistering will trigger an unmap. */ try_unmap = false; } if (try_unmap) { if (int128_eq(llsize, int128_2_64())) { /* The unmap ioctl doesn't accept a full 64-bit span. */ llsize = int128_rshift(llsize, 1); ret = vfio_dma_unmap(container, iova, int128_get64(llsize), NULL); if (ret) { error_report("vfio_dma_unmap(%p, 0x%"HWADDR_PRIx", " "0x%"HWADDR_PRIx") = %d (%s)", container, iova, int128_get64(llsize), ret, strerror(-ret)); } iova += int128_get64(llsize); } ret = vfio_dma_unmap(container, iova, int128_get64(llsize), NULL); if (ret) { error_report("vfio_dma_unmap(%p, 0x%"HWADDR_PRIx", " "0x%"HWADDR_PRIx") = %d (%s)", container, iova, int128_get64(llsize), ret, strerror(-ret)); } } memory_region_unref(section->mr); vfio_container_del_section_window(container, section); } typedef struct VFIODirtyRanges { hwaddr min32; hwaddr max32; hwaddr min64; hwaddr max64; hwaddr minpci64; hwaddr maxpci64; } VFIODirtyRanges; typedef struct VFIODirtyRangesListener { VFIOContainer *container; VFIODirtyRanges ranges; MemoryListener listener; } VFIODirtyRangesListener; static bool vfio_section_is_vfio_pci(MemoryRegionSection *section, VFIOContainer *container) { VFIOPCIDevice *pcidev; VFIODevice *vbasedev; Object *owner; owner = memory_region_owner(section->mr); QLIST_FOREACH(vbasedev, &container->device_list, container_next) { if (vbasedev->type != VFIO_DEVICE_TYPE_PCI) { continue; } pcidev = container_of(vbasedev, VFIOPCIDevice, vbasedev); if (OBJECT(pcidev) == owner) { return true; } } return false; } static void vfio_dirty_tracking_update(MemoryListener *listener, MemoryRegionSection *section) { VFIODirtyRangesListener *dirty = container_of(listener, VFIODirtyRangesListener, listener); VFIODirtyRanges *range = &dirty->ranges; hwaddr iova, end, *min, *max; if (!vfio_listener_valid_section(section, "tracking_update") || !vfio_get_section_iova_range(dirty->container, section, &iova, &end, NULL)) { return; } /* * The address space passed to the dirty tracker is reduced to three ranges: * one for 32-bit DMA ranges, one for 64-bit DMA ranges and one for the * PCI 64-bit hole. * * The underlying reports of dirty will query a sub-interval of each of * these ranges. * * The purpose of the three range handling is to handle known cases of big * holes in the address space, like the x86 AMD 1T hole, and firmware (like * OVMF) which may relocate the pci-hole64 to the end of the address space. * The latter would otherwise generate large ranges for tracking, stressing * the limits of supported hardware. The pci-hole32 will always be below 4G * (overlapping or not) so it doesn't need special handling and is part of * the 32-bit range. * * The alternative would be an IOVATree but that has a much bigger runtime * overhead and unnecessary complexity. */ if (vfio_section_is_vfio_pci(section, dirty->container) && iova >= UINT32_MAX) { min = &range->minpci64; max = &range->maxpci64; } else { min = (end <= UINT32_MAX) ? &range->min32 : &range->min64; max = (end <= UINT32_MAX) ? &range->max32 : &range->max64; } if (*min > iova) { *min = iova; } if (*max < end) { *max = end; } trace_vfio_device_dirty_tracking_update(iova, end, *min, *max); return; } static const MemoryListener vfio_dirty_tracking_listener = { .name = "vfio-tracking", .region_add = vfio_dirty_tracking_update, }; static void vfio_dirty_tracking_init(VFIOContainer *container, VFIODirtyRanges *ranges) { VFIODirtyRangesListener dirty; memset(&dirty, 0, sizeof(dirty)); dirty.ranges.min32 = UINT32_MAX; dirty.ranges.min64 = UINT64_MAX; dirty.ranges.minpci64 = UINT64_MAX; dirty.listener = vfio_dirty_tracking_listener; dirty.container = container; memory_listener_register(&dirty.listener, container->space->as); *ranges = dirty.ranges; /* * The memory listener is synchronous, and used to calculate the range * to dirty tracking. Unregister it after we are done as we are not * interested in any follow-up updates. */ memory_listener_unregister(&dirty.listener); } static void vfio_devices_dma_logging_stop(VFIOContainer *container) { uint64_t buf[DIV_ROUND_UP(sizeof(struct vfio_device_feature), sizeof(uint64_t))] = {}; struct vfio_device_feature *feature = (struct vfio_device_feature *)buf; VFIODevice *vbasedev; feature->argsz = sizeof(buf); feature->flags = VFIO_DEVICE_FEATURE_SET | VFIO_DEVICE_FEATURE_DMA_LOGGING_STOP; QLIST_FOREACH(vbasedev, &container->device_list, container_next) { if (!vbasedev->dirty_tracking) { continue; } if (ioctl(vbasedev->fd, VFIO_DEVICE_FEATURE, feature)) { warn_report("%s: Failed to stop DMA logging, err %d (%s)", vbasedev->name, -errno, strerror(errno)); } vbasedev->dirty_tracking = false; } } static struct vfio_device_feature * vfio_device_feature_dma_logging_start_create(VFIOContainer *container, VFIODirtyRanges *tracking) { struct vfio_device_feature *feature; size_t feature_size; struct vfio_device_feature_dma_logging_control *control; struct vfio_device_feature_dma_logging_range *ranges; feature_size = sizeof(struct vfio_device_feature) + sizeof(struct vfio_device_feature_dma_logging_control); feature = g_try_malloc0(feature_size); if (!feature) { errno = ENOMEM; return NULL; } feature->argsz = feature_size; feature->flags = VFIO_DEVICE_FEATURE_SET | VFIO_DEVICE_FEATURE_DMA_LOGGING_START; control = (struct vfio_device_feature_dma_logging_control *)feature->data; control->page_size = qemu_real_host_page_size(); /* * DMA logging uAPI guarantees to support at least a number of ranges that * fits into a single host kernel base page. */ control->num_ranges = !!tracking->max32 + !!tracking->max64 + !!tracking->maxpci64; ranges = g_try_new0(struct vfio_device_feature_dma_logging_range, control->num_ranges); if (!ranges) { g_free(feature); errno = ENOMEM; return NULL; } control->ranges = (__u64)(uintptr_t)ranges; if (tracking->max32) { ranges->iova = tracking->min32; ranges->length = (tracking->max32 - tracking->min32) + 1; ranges++; } if (tracking->max64) { ranges->iova = tracking->min64; ranges->length = (tracking->max64 - tracking->min64) + 1; ranges++; } if (tracking->maxpci64) { ranges->iova = tracking->minpci64; ranges->length = (tracking->maxpci64 - tracking->minpci64) + 1; } trace_vfio_device_dirty_tracking_start(control->num_ranges, tracking->min32, tracking->max32, tracking->min64, tracking->max64, tracking->minpci64, tracking->maxpci64); return feature; } static void vfio_device_feature_dma_logging_start_destroy( struct vfio_device_feature *feature) { struct vfio_device_feature_dma_logging_control *control = (struct vfio_device_feature_dma_logging_control *)feature->data; struct vfio_device_feature_dma_logging_range *ranges = (struct vfio_device_feature_dma_logging_range *)(uintptr_t)control->ranges; g_free(ranges); g_free(feature); } static int vfio_devices_dma_logging_start(VFIOContainer *container) { struct vfio_device_feature *feature; VFIODirtyRanges ranges; VFIODevice *vbasedev; int ret = 0; vfio_dirty_tracking_init(container, &ranges); feature = vfio_device_feature_dma_logging_start_create(container, &ranges); if (!feature) { return -errno; } QLIST_FOREACH(vbasedev, &container->device_list, container_next) { if (vbasedev->dirty_tracking) { continue; } ret = ioctl(vbasedev->fd, VFIO_DEVICE_FEATURE, feature); if (ret) { ret = -errno; error_report("%s: Failed to start DMA logging, err %d (%s)", vbasedev->name, ret, strerror(errno)); goto out; } vbasedev->dirty_tracking = true; } out: if (ret) { vfio_devices_dma_logging_stop(container); } vfio_device_feature_dma_logging_start_destroy(feature); return ret; } static void vfio_listener_log_global_start(MemoryListener *listener) { VFIOContainer *container = container_of(listener, VFIOContainer, listener); int ret; if (vfio_devices_all_device_dirty_tracking(container)) { ret = vfio_devices_dma_logging_start(container); } else { ret = vfio_set_dirty_page_tracking(container, true); } if (ret) { error_report("vfio: Could not start dirty page tracking, err: %d (%s)", ret, strerror(-ret)); vfio_set_migration_error(ret); } } static void vfio_listener_log_global_stop(MemoryListener *listener) { VFIOContainer *container = container_of(listener, VFIOContainer, listener); int ret = 0; if (vfio_devices_all_device_dirty_tracking(container)) { vfio_devices_dma_logging_stop(container); } else { ret = vfio_set_dirty_page_tracking(container, false); } if (ret) { error_report("vfio: Could not stop dirty page tracking, err: %d (%s)", ret, strerror(-ret)); vfio_set_migration_error(ret); } } static int vfio_device_dma_logging_report(VFIODevice *vbasedev, hwaddr iova, hwaddr size, void *bitmap) { uint64_t buf[DIV_ROUND_UP(sizeof(struct vfio_device_feature) + sizeof(struct vfio_device_feature_dma_logging_report), sizeof(__u64))] = {}; struct vfio_device_feature *feature = (struct vfio_device_feature *)buf; struct vfio_device_feature_dma_logging_report *report = (struct vfio_device_feature_dma_logging_report *)feature->data; report->iova = iova; report->length = size; report->page_size = qemu_real_host_page_size(); report->bitmap = (__u64)(uintptr_t)bitmap; feature->argsz = sizeof(buf); feature->flags = VFIO_DEVICE_FEATURE_GET | VFIO_DEVICE_FEATURE_DMA_LOGGING_REPORT; if (ioctl(vbasedev->fd, VFIO_DEVICE_FEATURE, feature)) { return -errno; } return 0; } int vfio_devices_query_dirty_bitmap(VFIOContainer *container, VFIOBitmap *vbmap, hwaddr iova, hwaddr size) { VFIODevice *vbasedev; int ret; QLIST_FOREACH(vbasedev, &container->device_list, container_next) { ret = vfio_device_dma_logging_report(vbasedev, iova, size, vbmap->bitmap); if (ret) { error_report("%s: Failed to get DMA logging report, iova: " "0x%" HWADDR_PRIx ", size: 0x%" HWADDR_PRIx ", err: %d (%s)", vbasedev->name, iova, size, ret, strerror(-ret)); return ret; } } return 0; } int vfio_get_dirty_bitmap(VFIOContainer *container, uint64_t iova, uint64_t size, ram_addr_t ram_addr) { bool all_device_dirty_tracking = vfio_devices_all_device_dirty_tracking(container); uint64_t dirty_pages; VFIOBitmap vbmap; int ret; if (!container->dirty_pages_supported && !all_device_dirty_tracking) { cpu_physical_memory_set_dirty_range(ram_addr, size, tcg_enabled() ? DIRTY_CLIENTS_ALL : DIRTY_CLIENTS_NOCODE); return 0; } ret = vfio_bitmap_alloc(&vbmap, size); if (ret) { return ret; } if (all_device_dirty_tracking) { ret = vfio_devices_query_dirty_bitmap(container, &vbmap, iova, size); } else { ret = vfio_query_dirty_bitmap(container, &vbmap, iova, size); } if (ret) { goto out; } dirty_pages = cpu_physical_memory_set_dirty_lebitmap(vbmap.bitmap, ram_addr, vbmap.pages); trace_vfio_get_dirty_bitmap(container->fd, iova, size, vbmap.size, ram_addr, dirty_pages); out: g_free(vbmap.bitmap); return ret; } typedef struct { IOMMUNotifier n; VFIOGuestIOMMU *giommu; } vfio_giommu_dirty_notifier; static void vfio_iommu_map_dirty_notify(IOMMUNotifier *n, IOMMUTLBEntry *iotlb) { vfio_giommu_dirty_notifier *gdn = container_of(n, vfio_giommu_dirty_notifier, n); VFIOGuestIOMMU *giommu = gdn->giommu; VFIOContainer *container = giommu->container; hwaddr iova = iotlb->iova + giommu->iommu_offset; ram_addr_t translated_addr; int ret = -EINVAL; trace_vfio_iommu_map_dirty_notify(iova, iova + iotlb->addr_mask); if (iotlb->target_as != &address_space_memory) { error_report("Wrong target AS \"%s\", only system memory is allowed", iotlb->target_as->name ? iotlb->target_as->name : "none"); goto out; } rcu_read_lock(); if (vfio_get_xlat_addr(iotlb, NULL, &translated_addr, NULL)) { ret = vfio_get_dirty_bitmap(container, iova, iotlb->addr_mask + 1, translated_addr); if (ret) { error_report("vfio_iommu_map_dirty_notify(%p, 0x%"HWADDR_PRIx", " "0x%"HWADDR_PRIx") = %d (%s)", container, iova, iotlb->addr_mask + 1, ret, strerror(-ret)); } } rcu_read_unlock(); out: if (ret) { vfio_set_migration_error(ret); } } static int vfio_ram_discard_get_dirty_bitmap(MemoryRegionSection *section, void *opaque) { const hwaddr size = int128_get64(section->size); const hwaddr iova = section->offset_within_address_space; const ram_addr_t ram_addr = memory_region_get_ram_addr(section->mr) + section->offset_within_region; VFIORamDiscardListener *vrdl = opaque; /* * Sync the whole mapped region (spanning multiple individual mappings) * in one go. */ return vfio_get_dirty_bitmap(vrdl->container, iova, size, ram_addr); } static int vfio_sync_ram_discard_listener_dirty_bitmap(VFIOContainer *container, MemoryRegionSection *section) { RamDiscardManager *rdm = memory_region_get_ram_discard_manager(section->mr); VFIORamDiscardListener *vrdl = NULL; QLIST_FOREACH(vrdl, &container->vrdl_list, next) { if (vrdl->mr == section->mr && vrdl->offset_within_address_space == section->offset_within_address_space) { break; } } if (!vrdl) { hw_error("vfio: Trying to sync missing RAM discard listener"); } /* * We only want/can synchronize the bitmap for actually mapped parts - * which correspond to populated parts. Replay all populated parts. */ return ram_discard_manager_replay_populated(rdm, section, vfio_ram_discard_get_dirty_bitmap, &vrdl); } static int vfio_sync_dirty_bitmap(VFIOContainer *container, MemoryRegionSection *section) { ram_addr_t ram_addr; if (memory_region_is_iommu(section->mr)) { VFIOGuestIOMMU *giommu; QLIST_FOREACH(giommu, &container->giommu_list, giommu_next) { if (MEMORY_REGION(giommu->iommu_mr) == section->mr && giommu->n.start == section->offset_within_region) { Int128 llend; vfio_giommu_dirty_notifier gdn = { .giommu = giommu }; int idx = memory_region_iommu_attrs_to_index(giommu->iommu_mr, MEMTXATTRS_UNSPECIFIED); llend = int128_add(int128_make64(section->offset_within_region), section->size); llend = int128_sub(llend, int128_one()); iommu_notifier_init(&gdn.n, vfio_iommu_map_dirty_notify, IOMMU_NOTIFIER_MAP, section->offset_within_region, int128_get64(llend), idx); memory_region_iommu_replay(giommu->iommu_mr, &gdn.n); break; } } return 0; } else if (memory_region_has_ram_discard_manager(section->mr)) { return vfio_sync_ram_discard_listener_dirty_bitmap(container, section); } ram_addr = memory_region_get_ram_addr(section->mr) + section->offset_within_region; return vfio_get_dirty_bitmap(container, REAL_HOST_PAGE_ALIGN(section->offset_within_address_space), int128_get64(section->size), ram_addr); } static void vfio_listener_log_sync(MemoryListener *listener, MemoryRegionSection *section) { VFIOContainer *container = container_of(listener, VFIOContainer, listener); int ret; if (vfio_listener_skipped_section(section)) { return; } if (vfio_devices_all_dirty_tracking(container)) { ret = vfio_sync_dirty_bitmap(container, section); if (ret) { error_report("vfio: Failed to sync dirty bitmap, err: %d (%s)", ret, strerror(-ret)); vfio_set_migration_error(ret); } } } const MemoryListener vfio_memory_listener = { .name = "vfio", .region_add = vfio_listener_region_add, .region_del = vfio_listener_region_del, .log_global_start = vfio_listener_log_global_start, .log_global_stop = vfio_listener_log_global_stop, .log_sync = vfio_listener_log_sync, }; void vfio_reset_handler(void *opaque) { VFIODevice *vbasedev; QLIST_FOREACH(vbasedev, &vfio_device_list, global_next) { if (vbasedev->dev->realized) { vbasedev->ops->vfio_compute_needs_reset(vbasedev); } } QLIST_FOREACH(vbasedev, &vfio_device_list, global_next) { if (vbasedev->dev->realized && vbasedev->needs_reset) { vbasedev->ops->vfio_hot_reset_multi(vbasedev); } } } int vfio_kvm_device_add_fd(int fd, Error **errp) { #ifdef CONFIG_KVM struct kvm_device_attr attr = { .group = KVM_DEV_VFIO_FILE, .attr = KVM_DEV_VFIO_FILE_ADD, .addr = (uint64_t)(unsigned long)&fd, }; if (!kvm_enabled()) { return 0; } if (vfio_kvm_device_fd < 0) { struct kvm_create_device cd = { .type = KVM_DEV_TYPE_VFIO, }; if (kvm_vm_ioctl(kvm_state, KVM_CREATE_DEVICE, &cd)) { error_setg_errno(errp, errno, "Failed to create KVM VFIO device"); return -errno; } vfio_kvm_device_fd = cd.fd; } if (ioctl(vfio_kvm_device_fd, KVM_SET_DEVICE_ATTR, &attr)) { error_setg_errno(errp, errno, "Failed to add fd %d to KVM VFIO device", fd); return -errno; } #endif return 0; } int vfio_kvm_device_del_fd(int fd, Error **errp) { #ifdef CONFIG_KVM struct kvm_device_attr attr = { .group = KVM_DEV_VFIO_FILE, .attr = KVM_DEV_VFIO_FILE_DEL, .addr = (uint64_t)(unsigned long)&fd, }; if (vfio_kvm_device_fd < 0) { error_setg(errp, "KVM VFIO device isn't created yet"); return -EINVAL; } if (ioctl(vfio_kvm_device_fd, KVM_SET_DEVICE_ATTR, &attr)) { error_setg_errno(errp, errno, "Failed to remove fd %d from KVM VFIO device", fd); return -errno; } #endif return 0; } VFIOAddressSpace *vfio_get_address_space(AddressSpace *as) { VFIOAddressSpace *space; QLIST_FOREACH(space, &vfio_address_spaces, list) { if (space->as == as) { return space; } } /* No suitable VFIOAddressSpace, create a new one */ space = g_malloc0(sizeof(*space)); space->as = as; QLIST_INIT(&space->containers); if (QLIST_EMPTY(&vfio_address_spaces)) { qemu_register_reset(vfio_reset_handler, NULL); } QLIST_INSERT_HEAD(&vfio_address_spaces, space, list); return space; } void vfio_put_address_space(VFIOAddressSpace *space) { if (QLIST_EMPTY(&space->containers)) { QLIST_REMOVE(space, list); g_free(space); } if (QLIST_EMPTY(&vfio_address_spaces)) { qemu_unregister_reset(vfio_reset_handler, NULL); } } struct vfio_device_info *vfio_get_device_info(int fd) { struct vfio_device_info *info; uint32_t argsz = sizeof(*info); info = g_malloc0(argsz); retry: info->argsz = argsz; if (ioctl(fd, VFIO_DEVICE_GET_INFO, info)) { g_free(info); return NULL; } if (info->argsz > argsz) { argsz = info->argsz; info = g_realloc(info, argsz); goto retry; } return info; }