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qemu/util/vfio-helpers.c
Stefan Hajnoczi 1f0fea38f4 numa: call ->ram_block_removed() in ram_block_notifer_remove() 
When a RAMBlockNotifier is added, ->ram_block_added() is called with all
existing RAMBlocks. There is no equivalent ->ram_block_removed() call
when a RAMBlockNotifier is removed.

The util/vfio-helpers.c code (the sole user of RAMBlockNotifier) is fine
with this asymmetry because it does not rely on RAMBlockNotifier for
cleanup. It walks its internal list of DMA mappings and unmaps them by
itself.

Future users of RAMBlockNotifier may not have an internal data structure
that records added RAMBlocks so they will need ->ram_block_removed()
callbacks.

This patch makes ram_block_notifier_remove() symmetric with respect to
callbacks. Now util/vfio-helpers.c needs to unmap remaining DMA mappings
after ram_block_notifier_remove() has been called. This is necessary
since users like block/nvme.c may create additional DMA mappings that do
not originate from the RAMBlockNotifier.

Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20221013185908.1297568-4-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2022-10-26 14:56:42 -04:00

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/*
* VFIO utility
*
* Copyright 2016 - 2018 Red Hat, Inc.
*
* Authors:
* Fam Zheng <famz@redhat.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*/
#include "qemu/osdep.h"
#include <sys/ioctl.h>
#include <linux/vfio.h>
#include "qapi/error.h"
#include "exec/ramlist.h"
#include "exec/cpu-common.h"
#include "exec/memory.h"
#include "trace.h"
#include "qemu/error-report.h"
#include "standard-headers/linux/pci_regs.h"
#include "qemu/event_notifier.h"
#include "qemu/vfio-helpers.h"
#include "qemu/lockable.h"
#include "trace.h"
#define QEMU_VFIO_DEBUG 0
#define QEMU_VFIO_IOVA_MIN 0x10000ULL
/* XXX: Once VFIO exposes the iova bit width in the IOMMU capability interface,
* we can use a runtime limit; alternatively it's also possible to do platform
* specific detection by reading sysfs entries. Until then, 39 is a safe bet.
**/
#define QEMU_VFIO_IOVA_MAX (1ULL << 39)
typedef struct {
/* Page aligned addr. */
void *host;
size_t size;
uint64_t iova;
} IOVAMapping;
struct IOVARange {
uint64_t start;
uint64_t end;
};
struct QEMUVFIOState {
QemuMutex lock;
/* These fields are protected by BQL */
int container;
int group;
int device;
RAMBlockNotifier ram_notifier;
struct vfio_region_info config_region_info, bar_region_info[6];
struct IOVARange *usable_iova_ranges;
uint8_t nb_iova_ranges;
/* These fields are protected by @lock */
/* VFIO's IO virtual address space is managed by splitting into a few
* sections:
*
* --------------- <= 0
* |xxxxxxxxxxxxx|
* |-------------| <= QEMU_VFIO_IOVA_MIN
* | |
* | Fixed |
* | |
* |-------------| <= low_water_mark
* | |
* | Free |
* | |
* |-------------| <= high_water_mark
* | |
* | Temp |
* | |
* |-------------| <= QEMU_VFIO_IOVA_MAX
* |xxxxxxxxxxxxx|
* |xxxxxxxxxxxxx|
* ---------------
*
* - Addresses lower than QEMU_VFIO_IOVA_MIN are reserved as invalid;
*
* - Fixed mappings of HVAs are assigned "low" IOVAs in the range of
* [QEMU_VFIO_IOVA_MIN, low_water_mark). Once allocated they will not be
* reclaimed - low_water_mark never shrinks;
*
* - IOVAs in range [low_water_mark, high_water_mark) are free;
*
* - IOVAs in range [high_water_mark, QEMU_VFIO_IOVA_MAX) are volatile
* mappings. At each qemu_vfio_dma_reset_temporary() call, the whole area
* is recycled. The caller should make sure I/O's depending on these
* mappings are completed before calling.
**/
uint64_t low_water_mark;
uint64_t high_water_mark;
IOVAMapping *mappings;
int nr_mappings;
};
/**
* Find group file by PCI device address as specified @device, and return the
* path. The returned string is owned by caller and should be g_free'ed later.
*/
static char *sysfs_find_group_file(const char *device, Error **errp)
{
char *sysfs_link;
char *sysfs_group;
char *p;
char *path = NULL;
sysfs_link = g_strdup_printf("/sys/bus/pci/devices/%s/iommu_group", device);
sysfs_group = g_malloc0(PATH_MAX);
if (readlink(sysfs_link, sysfs_group, PATH_MAX - 1) == -1) {
error_setg_errno(errp, errno, "Failed to find iommu group sysfs path");
goto out;
}
p = strrchr(sysfs_group, '/');
if (!p) {
error_setg(errp, "Failed to find iommu group number");
goto out;
}
path = g_strdup_printf("/dev/vfio/%s", p + 1);
out:
g_free(sysfs_link);
g_free(sysfs_group);
return path;
}
static inline void assert_bar_index_valid(QEMUVFIOState *s, int index)
{
assert(index >= 0 && index < ARRAY_SIZE(s->bar_region_info));
}
static int qemu_vfio_pci_init_bar(QEMUVFIOState *s, int index, Error **errp)
{
g_autofree char *barname = NULL;
assert_bar_index_valid(s, index);
s->bar_region_info[index] = (struct vfio_region_info) {
.index = VFIO_PCI_BAR0_REGION_INDEX + index,
.argsz = sizeof(struct vfio_region_info),
};
if (ioctl(s->device, VFIO_DEVICE_GET_REGION_INFO, &s->bar_region_info[index])) {
error_setg_errno(errp, errno, "Failed to get BAR region info");
return -errno;
}
barname = g_strdup_printf("bar[%d]", index);
trace_qemu_vfio_region_info(barname, s->bar_region_info[index].offset,
s->bar_region_info[index].size,
s->bar_region_info[index].cap_offset);
return 0;
}
/**
* Map a PCI bar area.
*/
void *qemu_vfio_pci_map_bar(QEMUVFIOState *s, int index,
uint64_t offset, uint64_t size, int prot,
Error **errp)
{
void *p;
assert(QEMU_IS_ALIGNED(offset, qemu_real_host_page_size()));
assert_bar_index_valid(s, index);
p = mmap(NULL, MIN(size, s->bar_region_info[index].size - offset),
prot, MAP_SHARED,
s->device, s->bar_region_info[index].offset + offset);
trace_qemu_vfio_pci_map_bar(index, s->bar_region_info[index].offset ,
size, offset, p);
if (p == MAP_FAILED) {
error_setg_errno(errp, errno, "Failed to map BAR region");
p = NULL;
}
return p;
}
/**
* Unmap a PCI bar area.
*/
void qemu_vfio_pci_unmap_bar(QEMUVFIOState *s, int index, void *bar,
uint64_t offset, uint64_t size)
{
if (bar) {
munmap(bar, MIN(size, s->bar_region_info[index].size - offset));
}
}
/**
* Initialize device IRQ with @irq_type and register an event notifier.
*/
int qemu_vfio_pci_init_irq(QEMUVFIOState *s, EventNotifier *e,
int irq_type, Error **errp)
{
int r;
struct vfio_irq_set *irq_set;
size_t irq_set_size;
struct vfio_irq_info irq_info = { .argsz = sizeof(irq_info) };
irq_info.index = irq_type;
if (ioctl(s->device, VFIO_DEVICE_GET_IRQ_INFO, &irq_info)) {
error_setg_errno(errp, errno, "Failed to get device interrupt info");
return -errno;
}
if (!(irq_info.flags & VFIO_IRQ_INFO_EVENTFD)) {
error_setg(errp, "Device interrupt doesn't support eventfd");
return -EINVAL;
}
irq_set_size = sizeof(*irq_set) + sizeof(int);
irq_set = g_malloc0(irq_set_size);
/* Get to a known IRQ state */
*irq_set = (struct vfio_irq_set) {
.argsz = irq_set_size,
.flags = VFIO_IRQ_SET_DATA_EVENTFD | VFIO_IRQ_SET_ACTION_TRIGGER,
.index = irq_info.index,
.start = 0,
.count = 1,
};
*(int *)&irq_set->data = event_notifier_get_fd(e);
r = ioctl(s->device, VFIO_DEVICE_SET_IRQS, irq_set);
g_free(irq_set);
if (r) {
error_setg_errno(errp, errno, "Failed to setup device interrupt");
return -errno;
}
return 0;
}
static int qemu_vfio_pci_read_config(QEMUVFIOState *s, void *buf,
int size, int ofs)
{
int ret;
trace_qemu_vfio_pci_read_config(buf, ofs, size,
s->config_region_info.offset,
s->config_region_info.size);
assert(QEMU_IS_ALIGNED(s->config_region_info.offset + ofs, size));
do {
ret = pread(s->device, buf, size, s->config_region_info.offset + ofs);
} while (ret == -1 && errno == EINTR);
return ret == size ? 0 : -errno;
}
static int qemu_vfio_pci_write_config(QEMUVFIOState *s, void *buf, int size, int ofs)
{
int ret;
trace_qemu_vfio_pci_write_config(buf, ofs, size,
s->config_region_info.offset,
s->config_region_info.size);
assert(QEMU_IS_ALIGNED(s->config_region_info.offset + ofs, size));
do {
ret = pwrite(s->device, buf, size, s->config_region_info.offset + ofs);
} while (ret == -1 && errno == EINTR);
return ret == size ? 0 : -errno;
}
static void collect_usable_iova_ranges(QEMUVFIOState *s, void *buf)
{
struct vfio_iommu_type1_info *info = (struct vfio_iommu_type1_info *)buf;
struct vfio_info_cap_header *cap = (void *)buf + info->cap_offset;
struct vfio_iommu_type1_info_cap_iova_range *cap_iova_range;
int i;
while (cap->id != VFIO_IOMMU_TYPE1_INFO_CAP_IOVA_RANGE) {
if (!cap->next) {
return;
}
cap = (struct vfio_info_cap_header *)(buf + cap->next);
}
cap_iova_range = (struct vfio_iommu_type1_info_cap_iova_range *)cap;
s->nb_iova_ranges = cap_iova_range->nr_iovas;
if (s->nb_iova_ranges > 1) {
s->usable_iova_ranges =
g_renew(struct IOVARange, s->usable_iova_ranges,
s->nb_iova_ranges);
}
for (i = 0; i < s->nb_iova_ranges; i++) {
s->usable_iova_ranges[i].start = cap_iova_range->iova_ranges[i].start;
s->usable_iova_ranges[i].end = cap_iova_range->iova_ranges[i].end;
}
}
static int qemu_vfio_init_pci(QEMUVFIOState *s, const char *device,
Error **errp)
{
int ret;
int i;
uint16_t pci_cmd;
struct vfio_group_status group_status = { .argsz = sizeof(group_status) };
struct vfio_iommu_type1_info *iommu_info = NULL;
size_t iommu_info_size = sizeof(*iommu_info);
struct vfio_device_info device_info = { .argsz = sizeof(device_info) };
char *group_file = NULL;
s->usable_iova_ranges = NULL;
/* Create a new container */
s->container = open("/dev/vfio/vfio", O_RDWR);
if (s->container == -1) {
error_setg_errno(errp, errno, "Failed to open /dev/vfio/vfio");
return -errno;
}
if (ioctl(s->container, VFIO_GET_API_VERSION) != VFIO_API_VERSION) {
error_setg(errp, "Invalid VFIO version");
ret = -EINVAL;
goto fail_container;
}
if (!ioctl(s->container, VFIO_CHECK_EXTENSION, VFIO_TYPE1_IOMMU)) {
error_setg_errno(errp, errno, "VFIO IOMMU Type1 is not supported");
ret = -EINVAL;
goto fail_container;
}
/* Open the group */
group_file = sysfs_find_group_file(device, errp);
if (!group_file) {
ret = -EINVAL;
goto fail_container;
}
s->group = open(group_file, O_RDWR);
if (s->group == -1) {
error_setg_errno(errp, errno, "Failed to open VFIO group file: %s",
group_file);
g_free(group_file);
ret = -errno;
goto fail_container;
}
g_free(group_file);
/* Test the group is viable and available */
if (ioctl(s->group, VFIO_GROUP_GET_STATUS, &group_status)) {
error_setg_errno(errp, errno, "Failed to get VFIO group status");
ret = -errno;
goto fail;
}
if (!(group_status.flags & VFIO_GROUP_FLAGS_VIABLE)) {
error_setg(errp, "VFIO group is not viable");
ret = -EINVAL;
goto fail;
}
/* Add the group to the container */
if (ioctl(s->group, VFIO_GROUP_SET_CONTAINER, &s->container)) {
error_setg_errno(errp, errno, "Failed to add group to VFIO container");
ret = -errno;
goto fail;
}
/* Enable the IOMMU model we want */
if (ioctl(s->container, VFIO_SET_IOMMU, VFIO_TYPE1_IOMMU)) {
error_setg_errno(errp, errno, "Failed to set VFIO IOMMU type");
ret = -errno;
goto fail;
}
iommu_info = g_malloc0(iommu_info_size);
iommu_info->argsz = iommu_info_size;
/* Get additional IOMMU info */
if (ioctl(s->container, VFIO_IOMMU_GET_INFO, iommu_info)) {
error_setg_errno(errp, errno, "Failed to get IOMMU info");
ret = -errno;
goto fail;
}
/*
* if the kernel does not report usable IOVA regions, choose
* the legacy [QEMU_VFIO_IOVA_MIN, QEMU_VFIO_IOVA_MAX -1] region
*/
s->nb_iova_ranges = 1;
s->usable_iova_ranges = g_new0(struct IOVARange, 1);
s->usable_iova_ranges[0].start = QEMU_VFIO_IOVA_MIN;
s->usable_iova_ranges[0].end = QEMU_VFIO_IOVA_MAX - 1;
if (iommu_info->argsz > iommu_info_size) {
iommu_info_size = iommu_info->argsz;
iommu_info = g_realloc(iommu_info, iommu_info_size);
if (ioctl(s->container, VFIO_IOMMU_GET_INFO, iommu_info)) {
ret = -errno;
goto fail;
}
collect_usable_iova_ranges(s, iommu_info);
}
s->device = ioctl(s->group, VFIO_GROUP_GET_DEVICE_FD, device);
if (s->device < 0) {
error_setg_errno(errp, errno, "Failed to get device fd");
ret = -errno;
goto fail;
}
/* Test and setup the device */
if (ioctl(s->device, VFIO_DEVICE_GET_INFO, &device_info)) {
error_setg_errno(errp, errno, "Failed to get device info");
ret = -errno;
goto fail;
}
if (device_info.num_regions < VFIO_PCI_CONFIG_REGION_INDEX) {
error_setg(errp, "Invalid device regions");
ret = -EINVAL;
goto fail;
}
s->config_region_info = (struct vfio_region_info) {
.index = VFIO_PCI_CONFIG_REGION_INDEX,
.argsz = sizeof(struct vfio_region_info),
};
if (ioctl(s->device, VFIO_DEVICE_GET_REGION_INFO, &s->config_region_info)) {
error_setg_errno(errp, errno, "Failed to get config region info");
ret = -errno;
goto fail;
}
trace_qemu_vfio_region_info("config", s->config_region_info.offset,
s->config_region_info.size,
s->config_region_info.cap_offset);
for (i = 0; i < ARRAY_SIZE(s->bar_region_info); i++) {
ret = qemu_vfio_pci_init_bar(s, i, errp);
if (ret) {
goto fail;
}
}
/* Enable bus master */
ret = qemu_vfio_pci_read_config(s, &pci_cmd, sizeof(pci_cmd), PCI_COMMAND);
if (ret) {
goto fail;
}
pci_cmd |= PCI_COMMAND_MASTER;
ret = qemu_vfio_pci_write_config(s, &pci_cmd, sizeof(pci_cmd), PCI_COMMAND);
if (ret) {
goto fail;
}
g_free(iommu_info);
return 0;
fail:
g_free(s->usable_iova_ranges);
s->usable_iova_ranges = NULL;
s->nb_iova_ranges = 0;
g_free(iommu_info);
close(s->group);
fail_container:
close(s->container);
return ret;
}
static void qemu_vfio_ram_block_added(RAMBlockNotifier *n, void *host,
size_t size, size_t max_size)
{
QEMUVFIOState *s = container_of(n, QEMUVFIOState, ram_notifier);
Error *local_err = NULL;
int ret;
trace_qemu_vfio_ram_block_added(s, host, max_size);
ret = qemu_vfio_dma_map(s, host, max_size, false, NULL, &local_err);
if (ret) {
error_reportf_err(local_err,
"qemu_vfio_dma_map(%p, %zu) failed: ",
host, max_size);
}
}
static void qemu_vfio_ram_block_removed(RAMBlockNotifier *n, void *host,
size_t size, size_t max_size)
{
QEMUVFIOState *s = container_of(n, QEMUVFIOState, ram_notifier);
if (host) {
trace_qemu_vfio_ram_block_removed(s, host, max_size);
qemu_vfio_dma_unmap(s, host);
}
}
static void qemu_vfio_open_common(QEMUVFIOState *s)
{
qemu_mutex_init(&s->lock);
s->ram_notifier.ram_block_added = qemu_vfio_ram_block_added;
s->ram_notifier.ram_block_removed = qemu_vfio_ram_block_removed;
s->low_water_mark = QEMU_VFIO_IOVA_MIN;
s->high_water_mark = QEMU_VFIO_IOVA_MAX;
ram_block_notifier_add(&s->ram_notifier);
}
/**
* Open a PCI device, e.g. "0000:00:01.0".
*/
QEMUVFIOState *qemu_vfio_open_pci(const char *device, Error **errp)
{
int r;
QEMUVFIOState *s = g_new0(QEMUVFIOState, 1);
/*
* VFIO may pin all memory inside mappings, resulting it in pinning
* all memory inside RAM blocks unconditionally.
*/
r = ram_block_discard_disable(true);
if (r) {
error_setg_errno(errp, -r, "Cannot set discarding of RAM broken");
g_free(s);
return NULL;
}
r = qemu_vfio_init_pci(s, device, errp);
if (r) {
ram_block_discard_disable(false);
g_free(s);
return NULL;
}
qemu_vfio_open_common(s);
return s;
}
static void qemu_vfio_dump_mappings(QEMUVFIOState *s)
{
for (int i = 0; i < s->nr_mappings; ++i) {
trace_qemu_vfio_dump_mapping(s->mappings[i].host,
s->mappings[i].iova,
s->mappings[i].size);
}
}
/**
* Find the mapping entry that contains [host, host + size) and set @index to
* the position. If no entry contains it, @index is the position _after_ which
* to insert the new mapping. IOW, it is the index of the largest element that
* is smaller than @host, or -1 if no entry is.
*/
static IOVAMapping *qemu_vfio_find_mapping(QEMUVFIOState *s, void *host,
int *index)
{
IOVAMapping *p = s->mappings;
IOVAMapping *q = p ? p + s->nr_mappings - 1 : NULL;
IOVAMapping *mid;
trace_qemu_vfio_find_mapping(s, host);
if (!p) {
*index = -1;
return NULL;
}
while (true) {
mid = p + (q - p) / 2;
if (mid == p) {
break;
}
if (mid->host > host) {
q = mid;
} else if (mid->host < host) {
p = mid;
} else {
break;
}
}
if (mid->host > host) {
mid--;
} else if (mid < &s->mappings[s->nr_mappings - 1]
&& (mid + 1)->host <= host) {
mid++;
}
*index = mid - &s->mappings[0];
if (mid >= &s->mappings[0] &&
mid->host <= host && mid->host + mid->size > host) {
assert(mid < &s->mappings[s->nr_mappings]);
return mid;
}
/* At this point *index + 1 is the right position to insert the new
* mapping.*/
return NULL;
}
/**
* Allocate IOVA and create a new mapping record and insert it in @s.
*/
static IOVAMapping *qemu_vfio_add_mapping(QEMUVFIOState *s,
void *host, size_t size,
int index, uint64_t iova)
{
int shift;
IOVAMapping m = {.host = host, .size = size, .iova = iova};
IOVAMapping *insert;
assert(QEMU_IS_ALIGNED(size, qemu_real_host_page_size()));
assert(QEMU_IS_ALIGNED(s->low_water_mark, qemu_real_host_page_size()));
assert(QEMU_IS_ALIGNED(s->high_water_mark, qemu_real_host_page_size()));
trace_qemu_vfio_new_mapping(s, host, size, index, iova);
assert(index >= 0);
s->nr_mappings++;
s->mappings = g_renew(IOVAMapping, s->mappings, s->nr_mappings);
insert = &s->mappings[index];
shift = s->nr_mappings - index - 1;
if (shift) {
memmove(insert + 1, insert, shift * sizeof(s->mappings[0]));
}
*insert = m;
return insert;
}
/* Do the DMA mapping with VFIO. */
static int qemu_vfio_do_mapping(QEMUVFIOState *s, void *host, size_t size,
uint64_t iova, Error **errp)
{
struct vfio_iommu_type1_dma_map dma_map = {
.argsz = sizeof(dma_map),
.flags = VFIO_DMA_MAP_FLAG_READ | VFIO_DMA_MAP_FLAG_WRITE,
.iova = iova,
.vaddr = (uintptr_t)host,
.size = size,
};
trace_qemu_vfio_do_mapping(s, host, iova, size);
if (ioctl(s->container, VFIO_IOMMU_MAP_DMA, &dma_map)) {
error_setg_errno(errp, errno, "VFIO_MAP_DMA failed");
return -errno;
}
return 0;
}
/**
* Undo the DMA mapping from @s with VFIO, and remove from mapping list.
*/
static void qemu_vfio_undo_mapping(QEMUVFIOState *s, IOVAMapping *mapping,
Error **errp)
{
int index;
struct vfio_iommu_type1_dma_unmap unmap = {
.argsz = sizeof(unmap),
.flags = 0,
.iova = mapping->iova,
.size = mapping->size,
};
index = mapping - s->mappings;
assert(mapping->size > 0);
assert(QEMU_IS_ALIGNED(mapping->size, qemu_real_host_page_size()));
assert(index >= 0 && index < s->nr_mappings);
if (ioctl(s->container, VFIO_IOMMU_UNMAP_DMA, &unmap)) {
error_setg_errno(errp, errno, "VFIO_UNMAP_DMA failed");
}
memmove(mapping, &s->mappings[index + 1],
sizeof(s->mappings[0]) * (s->nr_mappings - index - 1));
s->nr_mappings--;
s->mappings = g_renew(IOVAMapping, s->mappings, s->nr_mappings);
}
/* Check if the mapping list is (ascending) ordered. */
static bool qemu_vfio_verify_mappings(QEMUVFIOState *s)
{
int i;
if (QEMU_VFIO_DEBUG) {
for (i = 0; i < s->nr_mappings - 1; ++i) {
if (!(s->mappings[i].host < s->mappings[i + 1].host)) {
error_report("item %d not sorted!", i);
qemu_vfio_dump_mappings(s);
return false;
}
if (!(s->mappings[i].host + s->mappings[i].size <=
s->mappings[i + 1].host)) {
error_report("item %d overlap with next!", i);
qemu_vfio_dump_mappings(s);
return false;
}
}
}
return true;
}
static bool qemu_vfio_find_fixed_iova(QEMUVFIOState *s, size_t size,
uint64_t *iova, Error **errp)
{
int i;
for (i = 0; i < s->nb_iova_ranges; i++) {
if (s->usable_iova_ranges[i].end < s->low_water_mark) {
continue;
}
s->low_water_mark =
MAX(s->low_water_mark, s->usable_iova_ranges[i].start);
if (s->usable_iova_ranges[i].end - s->low_water_mark + 1 >= size ||
s->usable_iova_ranges[i].end - s->low_water_mark + 1 == 0) {
*iova = s->low_water_mark;
s->low_water_mark += size;
return true;
}
}
error_setg(errp, "fixed iova range not found");
return false;
}
static bool qemu_vfio_find_temp_iova(QEMUVFIOState *s, size_t size,
uint64_t *iova, Error **errp)
{
int i;
for (i = s->nb_iova_ranges - 1; i >= 0; i--) {
if (s->usable_iova_ranges[i].start > s->high_water_mark) {
continue;
}
s->high_water_mark =
MIN(s->high_water_mark, s->usable_iova_ranges[i].end + 1);
if (s->high_water_mark - s->usable_iova_ranges[i].start + 1 >= size ||
s->high_water_mark - s->usable_iova_ranges[i].start + 1 == 0) {
*iova = s->high_water_mark - size;
s->high_water_mark = *iova;
return true;
}
}
error_setg(errp, "temporary iova range not found");
return false;
}
/**
* qemu_vfio_water_mark_reached:
*
* Returns %true if high watermark has been reached, %false otherwise.
*/
static bool qemu_vfio_water_mark_reached(QEMUVFIOState *s, size_t size,
Error **errp)
{
if (s->high_water_mark - s->low_water_mark + 1 < size) {
error_setg(errp, "iova exhausted (water mark reached)");
return true;
}
return false;
}
/* Map [host, host + size) area into a contiguous IOVA address space, and store
* the result in @iova if not NULL. The caller need to make sure the area is
* aligned to page size, and mustn't overlap with existing mapping areas (split
* mapping status within this area is not allowed).
*/
int qemu_vfio_dma_map(QEMUVFIOState *s, void *host, size_t size,
bool temporary, uint64_t *iova, Error **errp)
{
int index;
IOVAMapping *mapping;
uint64_t iova0;
assert(QEMU_PTR_IS_ALIGNED(host, qemu_real_host_page_size()));
assert(QEMU_IS_ALIGNED(size, qemu_real_host_page_size()));
trace_qemu_vfio_dma_map(s, host, size, temporary, iova);
QEMU_LOCK_GUARD(&s->lock);
mapping = qemu_vfio_find_mapping(s, host, &index);
if (mapping) {
iova0 = mapping->iova + ((uint8_t *)host - (uint8_t *)mapping->host);
} else {
int ret;
if (qemu_vfio_water_mark_reached(s, size, errp)) {
return -ENOMEM;
}
if (!temporary) {
if (!qemu_vfio_find_fixed_iova(s, size, &iova0, errp)) {
return -ENOMEM;
}
mapping = qemu_vfio_add_mapping(s, host, size, index + 1, iova0);
assert(qemu_vfio_verify_mappings(s));
ret = qemu_vfio_do_mapping(s, host, size, iova0, errp);
if (ret < 0) {
qemu_vfio_undo_mapping(s, mapping, NULL);
return ret;
}
qemu_vfio_dump_mappings(s);
} else {
if (!qemu_vfio_find_temp_iova(s, size, &iova0, errp)) {
return -ENOMEM;
}
ret = qemu_vfio_do_mapping(s, host, size, iova0, errp);
if (ret < 0) {
return ret;
}
}
}
trace_qemu_vfio_dma_mapped(s, host, iova0, size);
if (iova) {
*iova = iova0;
}
return 0;
}
/* Reset the high watermark and free all "temporary" mappings. */
int qemu_vfio_dma_reset_temporary(QEMUVFIOState *s)
{
struct vfio_iommu_type1_dma_unmap unmap = {
.argsz = sizeof(unmap),
.flags = 0,
.iova = s->high_water_mark,
.size = QEMU_VFIO_IOVA_MAX - s->high_water_mark,
};
trace_qemu_vfio_dma_reset_temporary(s);
QEMU_LOCK_GUARD(&s->lock);
if (ioctl(s->container, VFIO_IOMMU_UNMAP_DMA, &unmap)) {
error_report("VFIO_UNMAP_DMA failed: %s", strerror(errno));
return -errno;
}
s->high_water_mark = QEMU_VFIO_IOVA_MAX;
return 0;
}
/* Unmapping the whole area that was previously mapped with
* qemu_vfio_dma_map(). */
void qemu_vfio_dma_unmap(QEMUVFIOState *s, void *host)
{
int index = 0;
IOVAMapping *m;
if (!host) {
return;
}
trace_qemu_vfio_dma_unmap(s, host);
QEMU_LOCK_GUARD(&s->lock);
m = qemu_vfio_find_mapping(s, host, &index);
if (!m) {
return;
}
qemu_vfio_undo_mapping(s, m, NULL);
}
static void qemu_vfio_reset(QEMUVFIOState *s)
{
ioctl(s->device, VFIO_DEVICE_RESET);
}
/* Close and free the VFIO resources. */
void qemu_vfio_close(QEMUVFIOState *s)
{
int i;
if (!s) {
return;
}
ram_block_notifier_remove(&s->ram_notifier);
for (i = 0; i < s->nr_mappings; ++i) {
qemu_vfio_undo_mapping(s, &s->mappings[i], NULL);
}
g_free(s->usable_iova_ranges);
s->nb_iova_ranges = 0;
qemu_vfio_reset(s);
close(s->device);
close(s->group);
close(s->container);
ram_block_discard_disable(false);
}
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