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qemu / qemu / 25c4ff29d1688989ca6246e1a34e57505283ea2c / . / hw / vfio / container.c
blob: adc467210ff73422ad2f897abfbcf6eddbb22ad2 [file] [log] [blame]
/*
* generic functions used by VFIO devices
*
* Copyright Red Hat, Inc. 2012
*
* Authors:
* Alex Williamson <alex.williamson@redhat.com>
*
* 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 <sys/ioctl.h>
#ifdef CONFIG_KVM
#include <linux/kvm.h>
#endif
#include <linux/vfio.h>
#include "hw/vfio/vfio-common.h"
#include "hw/vfio/vfio.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/range.h"
#include "sysemu/kvm.h"
#include "sysemu/reset.h"
#include "trace.h"
#include "qapi/error.h"
#include "migration/migration.h"
VFIOGroupList vfio_group_list =
QLIST_HEAD_INITIALIZER(vfio_group_list);
static int vfio_ram_block_discard_disable(VFIOContainer *container, bool state)
{
switch (container->iommu_type) {
case VFIO_TYPE1v2_IOMMU:
case VFIO_TYPE1_IOMMU:
/*
* We support coordinated discarding of RAM via the RamDiscardManager.
*/
return ram_block_uncoordinated_discard_disable(state);
default:
/*
* VFIO_SPAPR_TCE_IOMMU most probably works just fine with
* RamDiscardManager, however, it is completely untested.
*
* VFIO_SPAPR_TCE_v2_IOMMU with "DMA memory preregistering" does
* completely the opposite of managing mapping/pinning dynamically as
* required by RamDiscardManager. We would have to special-case sections
* with a RamDiscardManager.
*/
return ram_block_discard_disable(state);
}
}
static int vfio_dma_unmap_bitmap(VFIOContainer *container,
hwaddr iova, ram_addr_t size,
IOMMUTLBEntry *iotlb)
{
struct vfio_iommu_type1_dma_unmap *unmap;
struct vfio_bitmap *bitmap;
VFIOBitmap vbmap;
int ret;
ret = vfio_bitmap_alloc(&vbmap, size);
if (ret) {
return ret;
}
unmap = g_malloc0(sizeof(*unmap) + sizeof(*bitmap));
unmap->argsz = sizeof(*unmap) + sizeof(*bitmap);
unmap->iova = iova;
unmap->size = size;
unmap->flags |= VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP;
bitmap = (struct vfio_bitmap *)&unmap->data;
/*
* cpu_physical_memory_set_dirty_lebitmap() supports pages in bitmap of
* qemu_real_host_page_size to mark those dirty. Hence set bitmap_pgsize
* to qemu_real_host_page_size.
*/
bitmap->pgsize = qemu_real_host_page_size();
bitmap->size = vbmap.size;
bitmap->data = (__u64 *)vbmap.bitmap;
if (vbmap.size > container->max_dirty_bitmap_size) {
error_report("UNMAP: Size of bitmap too big 0x%"PRIx64, vbmap.size);
ret = -E2BIG;
goto unmap_exit;
}
ret = ioctl(container->fd, VFIO_IOMMU_UNMAP_DMA, unmap);
if (!ret) {
cpu_physical_memory_set_dirty_lebitmap(vbmap.bitmap,
iotlb->translated_addr, vbmap.pages);
} else {
error_report("VFIO_UNMAP_DMA with DIRTY_BITMAP : %m");
}
unmap_exit:
g_free(unmap);
g_free(vbmap.bitmap);
return ret;
}
/*
* DMA - Mapping and unmapping for the "type1" IOMMU interface used on x86
*/
int vfio_dma_unmap(VFIOContainer *container, hwaddr iova,
ram_addr_t size, IOMMUTLBEntry *iotlb)
{
struct vfio_iommu_type1_dma_unmap unmap = {
.argsz = sizeof(unmap),
.flags = 0,
.iova = iova,
.size = size,
};
bool need_dirty_sync = false;
int ret;
if (iotlb && vfio_devices_all_running_and_mig_active(container)) {
if (!vfio_devices_all_device_dirty_tracking(container) &&
container->dirty_pages_supported) {
return vfio_dma_unmap_bitmap(container, iova, size, iotlb);
}
need_dirty_sync = true;
}
while (ioctl(container->fd, VFIO_IOMMU_UNMAP_DMA, &unmap)) {
/*
* The type1 backend has an off-by-one bug in the kernel (71a7d3d78e3c
* v4.15) where an overflow in its wrap-around check prevents us from
* unmapping the last page of the address space. Test for the error
* condition and re-try the unmap excluding the last page. The
* expectation is that we've never mapped the last page anyway and this
* unmap request comes via vIOMMU support which also makes it unlikely
* that this page is used. This bug was introduced well after type1 v2
* support was introduced, so we shouldn't need to test for v1. A fix
* is queued for kernel v5.0 so this workaround can be removed once
* affected kernels are sufficiently deprecated.
*/
if (errno == EINVAL && unmap.size && !(unmap.iova + unmap.size) &&
container->iommu_type == VFIO_TYPE1v2_IOMMU) {
trace_vfio_dma_unmap_overflow_workaround();
unmap.size -= 1ULL << ctz64(container->pgsizes);
continue;
}
error_report("VFIO_UNMAP_DMA failed: %s", strerror(errno));
return -errno;
}
if (need_dirty_sync) {
ret = vfio_get_dirty_bitmap(container, iova, size,
iotlb->translated_addr);
if (ret) {
return ret;
}
}
return 0;
}
int vfio_dma_map(VFIOContainer *container, hwaddr iova,
ram_addr_t size, void *vaddr, bool readonly)
{
struct vfio_iommu_type1_dma_map map = {
.argsz = sizeof(map),
.flags = VFIO_DMA_MAP_FLAG_READ,
.vaddr = (__u64)(uintptr_t)vaddr,
.iova = iova,
.size = size,
};
if (!readonly) {
map.flags |= VFIO_DMA_MAP_FLAG_WRITE;
}
/*
* Try the mapping, if it fails with EBUSY, unmap the region and try
* again. This shouldn't be necessary, but we sometimes see it in
* the VGA ROM space.
*/
if (ioctl(container->fd, VFIO_IOMMU_MAP_DMA, &map) == 0 ||
(errno == EBUSY && vfio_dma_unmap(container, iova, size, NULL) == 0 &&
ioctl(container->fd, VFIO_IOMMU_MAP_DMA, &map) == 0)) {
return 0;
}
error_report("VFIO_MAP_DMA failed: %s", strerror(errno));
return -errno;
}
int vfio_container_add_section_window(VFIOContainer *container,
MemoryRegionSection *section,
Error **errp)
{
VFIOHostDMAWindow *hostwin;
hwaddr pgsize = 0;
int ret;
if (container->iommu_type != VFIO_SPAPR_TCE_v2_IOMMU) {
return 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))) {
error_setg(errp,
"region [0x%"PRIx64",0x%"PRIx64"] overlaps with existing"
"host DMA window [0x%"PRIx64",0x%"PRIx64"]",
section->offset_within_address_space,
section->offset_within_address_space +
int128_get64(section->size) - 1,
hostwin->min_iova, hostwin->max_iova);
return -EINVAL;
}
}
ret = vfio_spapr_create_window(container, section, &pgsize);
if (ret) {
error_setg_errno(errp, -ret, "Failed to create SPAPR window");
return ret;
}
vfio_host_win_add(container, section->offset_within_address_space,
section->offset_within_address_space +
int128_get64(section->size) - 1, pgsize);
#ifdef CONFIG_KVM
if (kvm_enabled()) {
VFIOGroup *group;
IOMMUMemoryRegion *iommu_mr = IOMMU_MEMORY_REGION(section->mr);
struct kvm_vfio_spapr_tce param;
struct kvm_device_attr attr = {
.group = KVM_DEV_VFIO_GROUP,
.attr = KVM_DEV_VFIO_GROUP_SET_SPAPR_TCE,
.addr = (uint64_t)(unsigned long)&param,
};
if (!memory_region_iommu_get_attr(iommu_mr, IOMMU_ATTR_SPAPR_TCE_FD,
&param.tablefd)) {
QLIST_FOREACH(group, &container->group_list, container_next) {
param.groupfd = group->fd;
if (ioctl(vfio_kvm_device_fd, KVM_SET_DEVICE_ATTR, &attr)) {
error_setg_errno(errp, errno,
"vfio: failed GROUP_SET_SPAPR_TCE for "
"KVM VFIO device %d and group fd %d",
param.tablefd, param.groupfd);
return -errno;
}
trace_vfio_spapr_group_attach(param.groupfd, param.tablefd);
}
}
}
#endif
return 0;
}
void vfio_container_del_section_window(VFIOContainer *container,
MemoryRegionSection *section)
{
if (container->iommu_type != VFIO_SPAPR_TCE_v2_IOMMU) {
return;
}
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);
}
}
int vfio_set_dirty_page_tracking(VFIOContainer *container, bool start)
{
int ret;
struct vfio_iommu_type1_dirty_bitmap dirty = {
.argsz = sizeof(dirty),
};
if (!container->dirty_pages_supported) {
return 0;
}
if (start) {
dirty.flags = VFIO_IOMMU_DIRTY_PAGES_FLAG_START;
} else {
dirty.flags = VFIO_IOMMU_DIRTY_PAGES_FLAG_STOP;
}
ret = ioctl(container->fd, VFIO_IOMMU_DIRTY_PAGES, &dirty);
if (ret) {
ret = -errno;
error_report("Failed to set dirty tracking flag 0x%x errno: %d",
dirty.flags, errno);
}
return ret;
}
int vfio_query_dirty_bitmap(VFIOContainer *container, VFIOBitmap *vbmap,
hwaddr iova, hwaddr size)
{
struct vfio_iommu_type1_dirty_bitmap *dbitmap;
struct vfio_iommu_type1_dirty_bitmap_get *range;
int ret;
dbitmap = g_malloc0(sizeof(*dbitmap) + sizeof(*range));
dbitmap->argsz = sizeof(*dbitmap) + sizeof(*range);
dbitmap->flags = VFIO_IOMMU_DIRTY_PAGES_FLAG_GET_BITMAP;
range = (struct vfio_iommu_type1_dirty_bitmap_get *)&dbitmap->data;
range->iova = iova;
range->size = size;
/*
* cpu_physical_memory_set_dirty_lebitmap() supports pages in bitmap of
* qemu_real_host_page_size to mark those dirty. Hence set bitmap's pgsize
* to qemu_real_host_page_size.
*/
range->bitmap.pgsize = qemu_real_host_page_size();
range->bitmap.size = vbmap->size;
range->bitmap.data = (__u64 *)vbmap->bitmap;
ret = ioctl(container->fd, VFIO_IOMMU_DIRTY_PAGES, dbitmap);
if (ret) {
ret = -errno;
error_report("Failed to get dirty bitmap for iova: 0x%"PRIx64
" size: 0x%"PRIx64" err: %d", (uint64_t)range->iova,
(uint64_t)range->size, errno);
}
g_free(dbitmap);
return ret;
}
static void vfio_listener_release(VFIOContainer *container)
{
memory_listener_unregister(&container->listener);
if (container->iommu_type == VFIO_SPAPR_TCE_v2_IOMMU) {
memory_listener_unregister(&container->prereg_listener);
}
}
static struct vfio_info_cap_header *
vfio_get_iommu_type1_info_cap(struct vfio_iommu_type1_info *info, uint16_t id)
{
if (!(info->flags & VFIO_IOMMU_INFO_CAPS)) {
return NULL;
}
return vfio_get_cap((void *)info, info->cap_offset, id);
}
bool vfio_get_info_dma_avail(struct vfio_iommu_type1_info *info,
unsigned int *avail)
{
struct vfio_info_cap_header *hdr;
struct vfio_iommu_type1_info_dma_avail *cap;
/* If the capability cannot be found, assume no DMA limiting */
hdr = vfio_get_iommu_type1_info_cap(info,
VFIO_IOMMU_TYPE1_INFO_DMA_AVAIL);
if (hdr == NULL) {
return false;
}
if (avail != NULL) {
cap = (void *) hdr;
*avail = cap->avail;
}
return true;
}
static void vfio_kvm_device_add_group(VFIOGroup *group)
{
Error *err = NULL;
if (vfio_kvm_device_add_fd(group->fd, &err)) {
error_reportf_err(err, "group ID %d: ", group->groupid);
}
}
static void vfio_kvm_device_del_group(VFIOGroup *group)
{
Error *err = NULL;
if (vfio_kvm_device_del_fd(group->fd, &err)) {
error_reportf_err(err, "group ID %d: ", group->groupid);
}
}
/*
* vfio_get_iommu_type - selects the richest iommu_type (v2 first)
*/
static int vfio_get_iommu_type(VFIOContainer *container,
Error **errp)
{
int iommu_types[] = { VFIO_TYPE1v2_IOMMU, VFIO_TYPE1_IOMMU,
VFIO_SPAPR_TCE_v2_IOMMU, VFIO_SPAPR_TCE_IOMMU };
int i;
for (i = 0; i < ARRAY_SIZE(iommu_types); i++) {
if (ioctl(container->fd, VFIO_CHECK_EXTENSION, iommu_types[i])) {
return iommu_types[i];
}
}
error_setg(errp, "No available IOMMU models");
return -EINVAL;
}
static int vfio_init_container(VFIOContainer *container, int group_fd,
Error **errp)
{
int iommu_type, ret;
iommu_type = vfio_get_iommu_type(container, errp);
if (iommu_type < 0) {
return iommu_type;
}
ret = ioctl(group_fd, VFIO_GROUP_SET_CONTAINER, &container->fd);
if (ret) {
error_setg_errno(errp, errno, "Failed to set group container");
return -errno;
}
while (ioctl(container->fd, VFIO_SET_IOMMU, iommu_type)) {
if (iommu_type == VFIO_SPAPR_TCE_v2_IOMMU) {
/*
* On sPAPR, despite the IOMMU subdriver always advertises v1 and
* v2, the running platform may not support v2 and there is no
* way to guess it until an IOMMU group gets added to the container.
* So in case it fails with v2, try v1 as a fallback.
*/
iommu_type = VFIO_SPAPR_TCE_IOMMU;
continue;
}
error_setg_errno(errp, errno, "Failed to set iommu for container");
return -errno;
}
container->iommu_type = iommu_type;
return 0;
}
static int vfio_get_iommu_info(VFIOContainer *container,
struct vfio_iommu_type1_info **info)
{
size_t argsz = sizeof(struct vfio_iommu_type1_info);
*info = g_new0(struct vfio_iommu_type1_info, 1);
again:
(*info)->argsz = argsz;
if (ioctl(container->fd, VFIO_IOMMU_GET_INFO, *info)) {
g_free(*info);
*info = NULL;
return -errno;
}
if (((*info)->argsz > argsz)) {
argsz = (*info)->argsz;
*info = g_realloc(*info, argsz);
goto again;
}
return 0;
}
static struct vfio_info_cap_header *
vfio_get_iommu_info_cap(struct vfio_iommu_type1_info *info, uint16_t id)
{
struct vfio_info_cap_header *hdr;
void *ptr = info;
if (!(info->flags & VFIO_IOMMU_INFO_CAPS)) {
return NULL;
}
for (hdr = ptr + info->cap_offset; hdr != ptr; hdr = ptr + hdr->next) {
if (hdr->id == id) {
return hdr;
}
}
return NULL;
}
static void vfio_get_iommu_info_migration(VFIOContainer *container,
struct vfio_iommu_type1_info *info)
{
struct vfio_info_cap_header *hdr;
struct vfio_iommu_type1_info_cap_migration *cap_mig;
hdr = vfio_get_iommu_info_cap(info, VFIO_IOMMU_TYPE1_INFO_CAP_MIGRATION);
if (!hdr) {
return;
}
cap_mig = container_of(hdr, struct vfio_iommu_type1_info_cap_migration,
header);
/*
* cpu_physical_memory_set_dirty_lebitmap() supports pages in bitmap of
* qemu_real_host_page_size to mark those dirty.
*/
if (cap_mig->pgsize_bitmap & qemu_real_host_page_size()) {
container->dirty_pages_supported = true;
container->max_dirty_bitmap_size = cap_mig->max_dirty_bitmap_size;
container->dirty_pgsizes = cap_mig->pgsize_bitmap;
}
}
static int vfio_connect_container(VFIOGroup *group, AddressSpace *as,
Error **errp)
{
VFIOContainer *container;
int ret, fd;
VFIOAddressSpace *space;
space = vfio_get_address_space(as);
/*
* VFIO is currently incompatible with discarding of RAM insofar as the
* madvise to purge (zap) the page from QEMU's address space does not
* interact with the memory API and therefore leaves stale virtual to
* physical mappings in the IOMMU if the page was previously pinned. We
* therefore set discarding broken for each group added to a container,
* whether the container is used individually or shared. This provides
* us with options to allow devices within a group to opt-in and allow
* discarding, so long as it is done consistently for a group (for instance
* if the device is an mdev device where it is known that the host vendor
* driver will never pin pages outside of the working set of the guest
* driver, which would thus not be discarding candidates).
*
* The first opportunity to induce pinning occurs here where we attempt to
* attach the group to existing containers within the AddressSpace. If any
* pages are already zapped from the virtual address space, such as from
* previous discards, new pinning will cause valid mappings to be
* re-established. Likewise, when the overall MemoryListener for a new
* container is registered, a replay of mappings within the AddressSpace
* will occur, re-establishing any previously zapped pages as well.
*
* Especially virtio-balloon is currently only prevented from discarding
* new memory, it will not yet set ram_block_discard_set_required() and
* therefore, neither stops us here or deals with the sudden memory
* consumption of inflated memory.
*
* We do support discarding of memory coordinated via the RamDiscardManager
* with some IOMMU types. vfio_ram_block_discard_disable() handles the
* details once we know which type of IOMMU we are using.
*/
QLIST_FOREACH(container, &space->containers, next) {
if (!ioctl(group->fd, VFIO_GROUP_SET_CONTAINER, &container->fd)) {
ret = vfio_ram_block_discard_disable(container, true);
if (ret) {
error_setg_errno(errp, -ret,
"Cannot set discarding of RAM broken");
if (ioctl(group->fd, VFIO_GROUP_UNSET_CONTAINER,
&container->fd)) {
error_report("vfio: error disconnecting group %d from"
" container", group->groupid);
}
return ret;
}
group->container = container;
QLIST_INSERT_HEAD(&container->group_list, group, container_next);
vfio_kvm_device_add_group(group);
return 0;
}
}
fd = qemu_open_old("/dev/vfio/vfio", O_RDWR);
if (fd < 0) {
error_setg_errno(errp, errno, "failed to open /dev/vfio/vfio");
ret = -errno;
goto put_space_exit;
}
ret = ioctl(fd, VFIO_GET_API_VERSION);
if (ret != VFIO_API_VERSION) {
error_setg(errp, "supported vfio version: %d, "
"reported version: %d", VFIO_API_VERSION, ret);
ret = -EINVAL;
goto close_fd_exit;
}
container = g_malloc0(sizeof(*container));
container->space = space;
container->fd = fd;
container->error = NULL;
container->dirty_pages_supported = false;
container->dma_max_mappings = 0;
QLIST_INIT(&container->giommu_list);
QLIST_INIT(&container->hostwin_list);
QLIST_INIT(&container->vrdl_list);
ret = vfio_init_container(container, group->fd, errp);
if (ret) {
goto free_container_exit;
}
ret = vfio_ram_block_discard_disable(container, true);
if (ret) {
error_setg_errno(errp, -ret, "Cannot set discarding of RAM broken");
goto free_container_exit;
}
switch (container->iommu_type) {
case VFIO_TYPE1v2_IOMMU:
case VFIO_TYPE1_IOMMU:
{
struct vfio_iommu_type1_info *info;
ret = vfio_get_iommu_info(container, &info);
if (ret) {
error_setg_errno(errp, -ret, "Failed to get VFIO IOMMU info");
goto enable_discards_exit;
}
if (info->flags & VFIO_IOMMU_INFO_PGSIZES) {
container->pgsizes = info->iova_pgsizes;
} else {
container->pgsizes = qemu_real_host_page_size();
}
if (!vfio_get_info_dma_avail(info, &container->dma_max_mappings)) {
container->dma_max_mappings = 65535;
}
vfio_get_iommu_info_migration(container, info);
g_free(info);
/*
* FIXME: We should parse VFIO_IOMMU_TYPE1_INFO_CAP_IOVA_RANGE
* information to get the actual window extent rather than assume
* a 64-bit IOVA address space.
*/
vfio_host_win_add(container, 0, (hwaddr)-1, container->pgsizes);
break;
}
case VFIO_SPAPR_TCE_v2_IOMMU:
case VFIO_SPAPR_TCE_IOMMU:
{
struct vfio_iommu_spapr_tce_info info;
bool v2 = container->iommu_type == VFIO_SPAPR_TCE_v2_IOMMU;
/*
* The host kernel code implementing VFIO_IOMMU_DISABLE is called
* when container fd is closed so we do not call it explicitly
* in this file.
*/
if (!v2) {
ret = ioctl(fd, VFIO_IOMMU_ENABLE);
if (ret) {
error_setg_errno(errp, errno, "failed to enable container");
ret = -errno;
goto enable_discards_exit;
}
} else {
container->prereg_listener = vfio_prereg_listener;
memory_listener_register(&container->prereg_listener,
&address_space_memory);
if (container->error) {
memory_listener_unregister(&container->prereg_listener);
ret = -1;
error_propagate_prepend(errp, container->error,
"RAM memory listener initialization failed: ");
goto enable_discards_exit;
}
}
info.argsz = sizeof(info);
ret = ioctl(fd, VFIO_IOMMU_SPAPR_TCE_GET_INFO, &info);
if (ret) {
error_setg_errno(errp, errno,
"VFIO_IOMMU_SPAPR_TCE_GET_INFO failed");
ret = -errno;
if (v2) {
memory_listener_unregister(&container->prereg_listener);
}
goto enable_discards_exit;
}
if (v2) {
container->pgsizes = info.ddw.pgsizes;
/*
* 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) {
error_setg_errno(errp, -ret,
"failed to remove existing window");
goto enable_discards_exit;
}
} else {
/* The default table uses 4K pages */
container->pgsizes = 0x1000;
vfio_host_win_add(container, info.dma32_window_start,
info.dma32_window_start +
info.dma32_window_size - 1,
0x1000);
}
}
}
vfio_kvm_device_add_group(group);
QLIST_INIT(&container->group_list);
QLIST_INSERT_HEAD(&space->containers, container, next);
group->container = container;
QLIST_INSERT_HEAD(&container->group_list, group, container_next);
container->listener = vfio_memory_listener;
memory_listener_register(&container->listener, container->space->as);
if (container->error) {
ret = -1;
error_propagate_prepend(errp, container->error,
"memory listener initialization failed: ");
goto listener_release_exit;
}
container->initialized = true;
return 0;
listener_release_exit:
QLIST_REMOVE(group, container_next);
QLIST_REMOVE(container, next);
vfio_kvm_device_del_group(group);
vfio_listener_release(container);
enable_discards_exit:
vfio_ram_block_discard_disable(container, false);
free_container_exit:
g_free(container);
close_fd_exit:
close(fd);
put_space_exit:
vfio_put_address_space(space);
return ret;
}
static void vfio_disconnect_container(VFIOGroup *group)
{
VFIOContainer *container = group->container;
QLIST_REMOVE(group, container_next);
group->container = NULL;
/*
* Explicitly release the listener first before unset container,
* since unset may destroy the backend container if it's the last
* group.
*/
if (QLIST_EMPTY(&container->group_list)) {
vfio_listener_release(container);
}
if (ioctl(group->fd, VFIO_GROUP_UNSET_CONTAINER, &container->fd)) {
error_report("vfio: error disconnecting group %d from container",
group->groupid);
}
if (QLIST_EMPTY(&container->group_list)) {
VFIOAddressSpace *space = container->space;
VFIOGuestIOMMU *giommu, *tmp;
VFIOHostDMAWindow *hostwin, *next;
QLIST_REMOVE(container, next);
QLIST_FOREACH_SAFE(giommu, &container->giommu_list, giommu_next, tmp) {
memory_region_unregister_iommu_notifier(
MEMORY_REGION(giommu->iommu_mr), &giommu->n);
QLIST_REMOVE(giommu, giommu_next);
g_free(giommu);
}
QLIST_FOREACH_SAFE(hostwin, &container->hostwin_list, hostwin_next,
next) {
QLIST_REMOVE(hostwin, hostwin_next);
g_free(hostwin);
}
trace_vfio_disconnect_container(container->fd);
close(container->fd);
g_free(container);
vfio_put_address_space(space);
}
}
static VFIOGroup *vfio_get_group(int groupid, AddressSpace *as, Error **errp)
{
VFIOGroup *group;
char path[32];
struct vfio_group_status status = { .argsz = sizeof(status) };
QLIST_FOREACH(group, &vfio_group_list, next) {
if (group->groupid == groupid) {
/* Found it. Now is it already in the right context? */
if (group->container->space->as == as) {
return group;
} else {
error_setg(errp, "group %d used in multiple address spaces",
group->groupid);
return NULL;
}
}
}
group = g_malloc0(sizeof(*group));
snprintf(path, sizeof(path), "/dev/vfio/%d", groupid);
group->fd = qemu_open_old(path, O_RDWR);
if (group->fd < 0) {
error_setg_errno(errp, errno, "failed to open %s", path);
goto free_group_exit;
}
if (ioctl(group->fd, VFIO_GROUP_GET_STATUS, &status)) {
error_setg_errno(errp, errno, "failed to get group %d status", groupid);
goto close_fd_exit;
}
if (!(status.flags & VFIO_GROUP_FLAGS_VIABLE)) {
error_setg(errp, "group %d is not viable", groupid);
error_append_hint(errp,
"Please ensure all devices within the iommu_group "
"are bound to their vfio bus driver.\n");
goto close_fd_exit;
}
group->groupid = groupid;
QLIST_INIT(&group->device_list);
if (vfio_connect_container(group, as, errp)) {
error_prepend(errp, "failed to setup container for group %d: ",
groupid);
goto close_fd_exit;
}
QLIST_INSERT_HEAD(&vfio_group_list, group, next);
return group;
close_fd_exit:
close(group->fd);
free_group_exit:
g_free(group);
return NULL;
}
static void vfio_put_group(VFIOGroup *group)
{
if (!group || !QLIST_EMPTY(&group->device_list)) {
return;
}
if (!group->ram_block_discard_allowed) {
vfio_ram_block_discard_disable(group->container, false);
}
vfio_kvm_device_del_group(group);
vfio_disconnect_container(group);
QLIST_REMOVE(group, next);
trace_vfio_put_group(group->fd);
close(group->fd);
g_free(group);
}
static int vfio_get_device(VFIOGroup *group, const char *name,
VFIODevice *vbasedev, Error **errp)
{
g_autofree struct vfio_device_info *info = NULL;
int fd;
fd = ioctl(group->fd, VFIO_GROUP_GET_DEVICE_FD, name);
if (fd < 0) {
error_setg_errno(errp, errno, "error getting device from group %d",
group->groupid);
error_append_hint(errp,
"Verify all devices in group %d are bound to vfio-<bus> "
"or pci-stub and not already in use\n", group->groupid);
return fd;
}
info = vfio_get_device_info(fd);
if (!info) {
error_setg_errno(errp, errno, "error getting device info");
close(fd);
return -1;
}
/*
* Set discarding of RAM as not broken for this group if the driver knows
* the device operates compatibly with discarding. Setting must be
* consistent per group, but since compatibility is really only possible
* with mdev currently, we expect singleton groups.
*/
if (vbasedev->ram_block_discard_allowed !=
group->ram_block_discard_allowed) {
if (!QLIST_EMPTY(&group->device_list)) {
error_setg(errp, "Inconsistent setting of support for discarding "
"RAM (e.g., balloon) within group");
close(fd);
return -1;
}
if (!group->ram_block_discard_allowed) {
group->ram_block_discard_allowed = true;
vfio_ram_block_discard_disable(group->container, false);
}
}
vbasedev->fd = fd;
vbasedev->group = group;
QLIST_INSERT_HEAD(&group->device_list, vbasedev, next);
vbasedev->num_irqs = info->num_irqs;
vbasedev->num_regions = info->num_regions;
vbasedev->flags = info->flags;
trace_vfio_get_device(name, info->flags, info->num_regions, info->num_irqs);
vbasedev->reset_works = !!(info->flags & VFIO_DEVICE_FLAGS_RESET);
return 0;
}
static void vfio_put_base_device(VFIODevice *vbasedev)
{
if (!vbasedev->group) {
return;
}
QLIST_REMOVE(vbasedev, next);
vbasedev->group = NULL;
trace_vfio_put_base_device(vbasedev->fd);
close(vbasedev->fd);
}
/*
* Interfaces for IBM EEH (Enhanced Error Handling)
*/
static bool vfio_eeh_container_ok(VFIOContainer *container)
{
/*
* As of 2016-03-04 (linux-4.5) the host kernel EEH/VFIO
* implementation is broken if there are multiple groups in a
* container. The hardware works in units of Partitionable
* Endpoints (== IOMMU groups) and the EEH operations naively
* iterate across all groups in the container, without any logic
* to make sure the groups have their state synchronized. For
* certain operations (ENABLE) that might be ok, until an error
* occurs, but for others (GET_STATE) it's clearly broken.
*/
/*
* XXX Once fixed kernels exist, test for them here
*/
if (QLIST_EMPTY(&container->group_list)) {
return false;
}
if (QLIST_NEXT(QLIST_FIRST(&container->group_list), container_next)) {
return false;
}
return true;
}
static int vfio_eeh_container_op(VFIOContainer *container, uint32_t op)
{
struct vfio_eeh_pe_op pe_op = {
.argsz = sizeof(pe_op),
.op = op,
};
int ret;
if (!vfio_eeh_container_ok(container)) {
error_report("vfio/eeh: EEH_PE_OP 0x%x: "
"kernel requires a container with exactly one group", op);
return -EPERM;
}
ret = ioctl(container->fd, VFIO_EEH_PE_OP, &pe_op);
if (ret < 0) {
error_report("vfio/eeh: EEH_PE_OP 0x%x failed: %m", op);
return -errno;
}
return ret;
}
static VFIOContainer *vfio_eeh_as_container(AddressSpace *as)
{
VFIOAddressSpace *space = vfio_get_address_space(as);
VFIOContainer *container = NULL;
if (QLIST_EMPTY(&space->containers)) {
/* No containers to act on */
goto out;
}
container = QLIST_FIRST(&space->containers);
if (QLIST_NEXT(container, next)) {
/*
* We don't yet have logic to synchronize EEH state across
* multiple containers
*/
container = NULL;
goto out;
}
out:
vfio_put_address_space(space);
return container;
}
bool vfio_eeh_as_ok(AddressSpace *as)
{
VFIOContainer *container = vfio_eeh_as_container(as);
return (container != NULL) && vfio_eeh_container_ok(container);
}
int vfio_eeh_as_op(AddressSpace *as, uint32_t op)
{
VFIOContainer *container = vfio_eeh_as_container(as);
if (!container) {
return -ENODEV;
}
return vfio_eeh_container_op(container, op);
}
static int vfio_device_groupid(VFIODevice *vbasedev, Error **errp)
{
char *tmp, group_path[PATH_MAX], *group_name;
int ret, groupid;
ssize_t len;
tmp = g_strdup_printf("%s/iommu_group", vbasedev->sysfsdev);
len = readlink(tmp, group_path, sizeof(group_path));
g_free(tmp);
if (len <= 0 || len >= sizeof(group_path)) {
ret = len < 0 ? -errno : -ENAMETOOLONG;
error_setg_errno(errp, -ret, "no iommu_group found");
return ret;
}
group_path[len] = 0;
group_name = basename(group_path);
if (sscanf(group_name, "%d", &groupid) != 1) {
error_setg_errno(errp, errno, "failed to read %s", group_path);
return -errno;
}
return groupid;
}
/*
* vfio_attach_device: attach a device to a security context
* @name and @vbasedev->name are likely to be different depending
* on the type of the device, hence the need for passing @name
*/
int vfio_attach_device(char *name, VFIODevice *vbasedev,
AddressSpace *as, Error **errp)
{
int groupid = vfio_device_groupid(vbasedev, errp);
VFIODevice *vbasedev_iter;
VFIOGroup *group;
VFIOContainer *container;
int ret;
if (groupid < 0) {
return groupid;
}
trace_vfio_attach_device(vbasedev->name, groupid);
group = vfio_get_group(groupid, as, errp);
if (!group) {
return -ENOENT;
}
QLIST_FOREACH(vbasedev_iter, &group->device_list, next) {
if (strcmp(vbasedev_iter->name, vbasedev->name) == 0) {
error_setg(errp, "device is already attached");
vfio_put_group(group);
return -EBUSY;
}
}
ret = vfio_get_device(group, name, vbasedev, errp);
if (ret) {
vfio_put_group(group);
return ret;
}
container = group->container;
vbasedev->container = container;
QLIST_INSERT_HEAD(&container->device_list, vbasedev, container_next);
QLIST_INSERT_HEAD(&vfio_device_list, vbasedev, global_next);
return ret;
}
void vfio_detach_device(VFIODevice *vbasedev)
{
VFIOGroup *group = vbasedev->group;
if (!vbasedev->container) {
return;
}
QLIST_REMOVE(vbasedev, global_next);
QLIST_REMOVE(vbasedev, container_next);
vbasedev->container = NULL;
trace_vfio_detach_device(vbasedev->name, group->groupid);
vfio_put_base_device(vbasedev);
vfio_put_group(group);
}