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FRET-qemu/hw/vfio/common.c
Cédric Le Goater 3688fec892 memory: Add Error** argument to .log_global_start() handler 
Modify all .log_global_start() handlers to take an Error** parameter
and return a bool. Adapt memory_global_dirty_log_start() to interrupt
on the first error the loop on handlers. In such case, a rollback is
performed to stop dirty logging on all listeners where it was
previously enabled.

Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Anthony Perard <anthony.perard@citrix.com>
Cc: Paul Durrant <paul@xen.org>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Link: https://lore.kernel.org/r/20240320064911.545001-10-clg@redhat.com
[peterx: modify & enrich the comment for listener_add_address_space() ]
Signed-off-by: Peter Xu <peterx@redhat.com>
2024-04-23 18:36:01 -04:00

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/*
* 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/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/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_normal(&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->bcontainer->space->as != &address_space_memory;
}
static void vfio_set_migration_error(int err)
{
if (migration_is_setup_or_active()) {
migration_file_set_error(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(VFIOContainerBase *bcontainer)
{
VFIODevice *vbasedev;
if (!migration_is_active() && !migration_is_device()) {
return false;
}
QLIST_FOREACH(vbasedev, &bcontainer->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(const VFIOContainerBase *bcontainer)
{
VFIODevice *vbasedev;
QLIST_FOREACH(vbasedev, &bcontainer->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(const VFIOContainerBase *bcontainer)
{
VFIODevice *vbasedev;
if (!migration_is_active()) {
return false;
}
QLIST_FOREACH(vbasedev, &bcontainer->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);
VFIOContainerBase *bcontainer = giommu->bcontainer;
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_container_dma_map(bcontainer, iova,
iotlb->addr_mask + 1, vaddr,
read_only);
if (ret) {
error_report("vfio_container_dma_map(%p, 0x%"HWADDR_PRIx", "
"0x%"HWADDR_PRIx", %p) = %d (%s)",
bcontainer, iova,
iotlb->addr_mask + 1, vaddr, ret, strerror(-ret));
}
} else {
ret = vfio_container_dma_unmap(bcontainer, iova,
iotlb->addr_mask + 1, iotlb);
if (ret) {
error_report("vfio_container_dma_unmap(%p, 0x%"HWADDR_PRIx", "
"0x%"HWADDR_PRIx") = %d (%s)",
bcontainer, 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);
VFIOContainerBase *bcontainer = vrdl->bcontainer;
const hwaddr size = int128_get64(section->size);
const hwaddr iova = section->offset_within_address_space;
int ret;
/* Unmap with a single call. */
ret = vfio_container_dma_unmap(bcontainer, iova, size , NULL);
if (ret) {
error_report("%s: vfio_container_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);
VFIOContainerBase *bcontainer = vrdl->bcontainer;
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_container_dma_map(bcontainer, 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(VFIOContainerBase *bcontainer,
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->bcontainer = bcontainer;
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(bcontainer->pgsizes &&
vrdl->granularity >= 1ULL << ctz64(bcontainer->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(&bcontainer->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 (bcontainer->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, &bcontainer->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 >
bcontainer->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__, bcontainer->dma_max_mappings,
max_memslots);
}
}
}
static void vfio_unregister_ram_discard_listener(VFIOContainerBase *bcontainer,
MemoryRegionSection *section)
{
RamDiscardManager *rdm = memory_region_get_ram_discard_manager(section->mr);
VFIORamDiscardListener *vrdl = NULL;
QLIST_FOREACH(vrdl, &bcontainer->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(VFIOContainerBase *bcontainer,
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)
{
VFIOContainerBase *bcontainer = container_of(listener, VFIOContainerBase,
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(bcontainer, 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(bcontainer, 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->bcontainer = bcontainer;
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,
bcontainer->pgsizes,
&err);
if (ret) {
g_free(giommu);
goto fail;
}
if (bcontainer->iova_ranges) {
ret = memory_region_iommu_set_iova_ranges(giommu->iommu_mr,
bcontainer->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(&bcontainer->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(bcontainer, 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(bcontainer->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_container_dma_map(bcontainer, iova, int128_get64(llsize),
vaddr, section->readonly);
if (ret) {
error_setg(&err, "vfio_container_dma_map(%p, 0x%"HWADDR_PRIx", "
"0x%"HWADDR_PRIx", %p) = %d (%s)",
bcontainer, 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 (!bcontainer->initialized) {
if (!bcontainer->error) {
error_propagate_prepend(&bcontainer->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)
{
VFIOContainerBase *bcontainer = container_of(listener, VFIOContainerBase,
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, &bcontainer->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(bcontainer, 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(bcontainer->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(bcontainer, 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_container_dma_unmap(bcontainer, iova,
int128_get64(llsize), NULL);
if (ret) {
error_report("vfio_container_dma_unmap(%p, 0x%"HWADDR_PRIx", "
"0x%"HWADDR_PRIx") = %d (%s)",
bcontainer, iova, int128_get64(llsize), ret,
strerror(-ret));
}
iova += int128_get64(llsize);
}
ret = vfio_container_dma_unmap(bcontainer, iova,
int128_get64(llsize), NULL);
if (ret) {
error_report("vfio_container_dma_unmap(%p, 0x%"HWADDR_PRIx", "
"0x%"HWADDR_PRIx") = %d (%s)",
bcontainer, iova, int128_get64(llsize), ret,
strerror(-ret));
}
}
memory_region_unref(section->mr);
vfio_container_del_section_window(bcontainer, section);
}
typedef struct VFIODirtyRanges {
hwaddr min32;
hwaddr max32;
hwaddr min64;
hwaddr max64;
hwaddr minpci64;
hwaddr maxpci64;
} VFIODirtyRanges;
typedef struct VFIODirtyRangesListener {
VFIOContainerBase *bcontainer;
VFIODirtyRanges ranges;
MemoryListener listener;
} VFIODirtyRangesListener;
static bool vfio_section_is_vfio_pci(MemoryRegionSection *section,
VFIOContainerBase *bcontainer)
{
VFIOPCIDevice *pcidev;
VFIODevice *vbasedev;
Object *owner;
owner = memory_region_owner(section->mr);
QLIST_FOREACH(vbasedev, &bcontainer->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->bcontainer, 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->bcontainer) &&
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(VFIOContainerBase *bcontainer,
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.bcontainer = bcontainer;
memory_listener_register(&dirty.listener,
bcontainer->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(VFIOContainerBase *bcontainer)
{
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, &bcontainer->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(VFIOContainerBase *bcontainer,
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 = (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(VFIOContainerBase *bcontainer)
{
struct vfio_device_feature *feature;
VFIODirtyRanges ranges;
VFIODevice *vbasedev;
int ret = 0;
vfio_dirty_tracking_init(bcontainer, &ranges);
feature = vfio_device_feature_dma_logging_start_create(bcontainer,
&ranges);
if (!feature) {
return -errno;
}
QLIST_FOREACH(vbasedev, &bcontainer->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(bcontainer);
}
vfio_device_feature_dma_logging_start_destroy(feature);
return ret;
}
static bool vfio_listener_log_global_start(MemoryListener *listener,
Error **errp)
{
VFIOContainerBase *bcontainer = container_of(listener, VFIOContainerBase,
listener);
int ret;
if (vfio_devices_all_device_dirty_tracking(bcontainer)) {
ret = vfio_devices_dma_logging_start(bcontainer);
} else {
ret = vfio_container_set_dirty_page_tracking(bcontainer, true);
}
if (ret) {
error_report("vfio: Could not start dirty page tracking, err: %d (%s)",
ret, strerror(-ret));
vfio_set_migration_error(ret);
}
return !ret;
}
static void vfio_listener_log_global_stop(MemoryListener *listener)
{
VFIOContainerBase *bcontainer = container_of(listener, VFIOContainerBase,
listener);
int ret = 0;
if (vfio_devices_all_device_dirty_tracking(bcontainer)) {
vfio_devices_dma_logging_stop(bcontainer);
} else {
ret = vfio_container_set_dirty_page_tracking(bcontainer, 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(uint64_t))] = {};
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 = (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(const VFIOContainerBase *bcontainer,
VFIOBitmap *vbmap, hwaddr iova,
hwaddr size)
{
VFIODevice *vbasedev;
int ret;
QLIST_FOREACH(vbasedev, &bcontainer->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(const VFIOContainerBase *bcontainer, uint64_t iova,
uint64_t size, ram_addr_t ram_addr)
{
bool all_device_dirty_tracking =
vfio_devices_all_device_dirty_tracking(bcontainer);
uint64_t dirty_pages;
VFIOBitmap vbmap;
int ret;
if (!bcontainer->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(bcontainer, &vbmap, iova, size);
} else {
ret = vfio_container_query_dirty_bitmap(bcontainer, &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(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;
VFIOContainerBase *bcontainer = giommu->bcontainer;
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(bcontainer, 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)",
bcontainer, 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->bcontainer, iova, size, ram_addr);
}
static int
vfio_sync_ram_discard_listener_dirty_bitmap(VFIOContainerBase *bcontainer,
MemoryRegionSection *section)
{
RamDiscardManager *rdm = memory_region_get_ram_discard_manager(section->mr);
VFIORamDiscardListener *vrdl = NULL;
QLIST_FOREACH(vrdl, &bcontainer->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(VFIOContainerBase *bcontainer,
MemoryRegionSection *section)
{
ram_addr_t ram_addr;
if (memory_region_is_iommu(section->mr)) {
VFIOGuestIOMMU *giommu;
QLIST_FOREACH(giommu, &bcontainer->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(bcontainer, section);
}
ram_addr = memory_region_get_ram_addr(section->mr) +
section->offset_within_region;
return vfio_get_dirty_bitmap(bcontainer,
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)
{
VFIOContainerBase *bcontainer = container_of(listener, VFIOContainerBase,
listener);
int ret;
if (vfio_listener_skipped_section(section)) {
return;
}
if (vfio_devices_all_dirty_tracking(bcontainer)) {
ret = vfio_sync_dirty_bitmap(bcontainer, 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)) {
return;
}
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;
}
int vfio_attach_device(char *name, VFIODevice *vbasedev,
AddressSpace *as, Error **errp)
{
const VFIOIOMMUClass *ops =
VFIO_IOMMU_CLASS(object_class_by_name(TYPE_VFIO_IOMMU_LEGACY));
if (vbasedev->iommufd) {
ops = VFIO_IOMMU_CLASS(object_class_by_name(TYPE_VFIO_IOMMU_IOMMUFD));
}
assert(ops);
return ops->attach_device(name, vbasedev, as, errp);
}
void vfio_detach_device(VFIODevice *vbasedev)
{
if (!vbasedev->bcontainer) {
return;
}
vbasedev->bcontainer->ops->detach_device(vbasedev);
}
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