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bus/pci: add VFIO sparse mmap support
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This patch adds sparse mmap support in PCI bus. Sparse mmap is a
capability defined in VFIO which allows multiple mmap areas in one
VFIO region.

In this patch, the sparse mmap regions are mapped to one continuous
virtual address region that follows device-specific BAR layout. So,
driver can still access all mapped sparse mmap regions by using
'bar_base_address + bar_offset'.

Signed-off-by: Miao Li <miao.li@intel.com>
Signed-off-by: Chenbo Xia <chenbo.xia@intel.com>
Acked-by: Sunil Kumar Kori <skori@marvell.com>
Acked-by: Yahui Cao <yahui.cao@intel.com>
Signed-off-by: 0-day Robot <robot@bytheb.org>
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@limiao-intel @ovsrobot
limiao-intel authored and ovsrobot committed May 31, 2023
1 parent 8ecbb47 commit 49cc543
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Showing 2 changed files with 122 additions and 18 deletions.
138 changes: 120 additions & 18 deletions drivers/bus/pci/linux/pci_vfio.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -674,6 +674,54 @@ pci_vfio_mmap_bar(int vfio_dev_fd, struct mapped_pci_resource *vfio_res,
return 0;
}

static int
pci_vfio_sparse_mmap_bar(int vfio_dev_fd, struct mapped_pci_resource *vfio_res,
int bar_index, int additional_flags)
{
struct pci_map *bar = &vfio_res->maps[bar_index];
struct vfio_region_sparse_mmap_area *sparse;
void *bar_addr;
uint32_t i;

if (bar->size == 0) {
RTE_LOG(DEBUG, EAL, "Bar size is 0, skip BAR%d\n", bar_index);
return 0;
}

/* reserve the address using an inaccessible mapping */
bar_addr = mmap(bar->addr, bar->size, 0, MAP_PRIVATE |
MAP_ANONYMOUS | additional_flags, -1, 0);
if (bar_addr != MAP_FAILED) {
void *map_addr = NULL;
for (i = 0; i < bar->nr_areas; i++) {
sparse = &bar->areas[i];
if (sparse->size) {
void *addr = RTE_PTR_ADD(bar_addr, (uintptr_t)sparse->offset);
map_addr = pci_map_resource(addr, vfio_dev_fd,
bar->offset + sparse->offset, sparse->size,
RTE_MAP_FORCE_ADDRESS);
if (map_addr == NULL) {
munmap(bar_addr, bar->size);
RTE_LOG(ERR, EAL, "Failed to map pci BAR%d\n",
bar_index);
goto err_map;
}
}
}
} else {
RTE_LOG(ERR, EAL, "Failed to create inaccessible mapping for BAR%d\n",
bar_index);
goto err_map;
}

bar->addr = bar_addr;
return 0;

err_map:
bar->nr_areas = 0;
return -1;
}

/*
* region info may contain capability headers, so we need to keep reallocating
* the memory until we match allocated memory size with argsz.
Expand Down Expand Up @@ -799,7 +847,7 @@ pci_vfio_map_resource_primary(struct rte_pci_device *dev)
char pci_addr[PATH_MAX] = {0};
int vfio_dev_fd;
struct rte_pci_addr *loc = &dev->addr;
int i, ret;
int i, j, ret;
struct mapped_pci_resource *vfio_res = NULL;
struct mapped_pci_res_list *vfio_res_list =
RTE_TAILQ_CAST(rte_vfio_tailq.head, mapped_pci_res_list);
Expand Down Expand Up @@ -876,13 +924,15 @@ pci_vfio_map_resource_primary(struct rte_pci_device *dev)

for (i = 0; i < vfio_res->nb_maps; i++) {
void *bar_addr;
struct vfio_info_cap_header *hdr;
struct vfio_region_info_cap_sparse_mmap *sparse;

ret = pci_vfio_get_region_info(vfio_dev_fd, &reg, i);
if (ret < 0) {
RTE_LOG(ERR, EAL,
"%s cannot get device region info error "
"%i (%s)\n", pci_addr, errno, strerror(errno));
goto err_vfio_res;
goto err_map;
}

pdev->region[i].size = reg->size;
Expand All @@ -892,7 +942,7 @@ pci_vfio_map_resource_primary(struct rte_pci_device *dev)
ret = pci_vfio_is_ioport_bar(dev, vfio_dev_fd, i);
if (ret < 0) {
free(reg);
goto err_vfio_res;
goto err_map;
} else if (ret) {
RTE_LOG(INFO, EAL, "Ignore mapping IO port bar(%d)\n",
i);
Expand Down Expand Up @@ -921,12 +971,41 @@ pci_vfio_map_resource_primary(struct rte_pci_device *dev)
maps[i].size = reg->size;
maps[i].path = NULL; /* vfio doesn't have per-resource paths */

ret = pci_vfio_mmap_bar(vfio_dev_fd, vfio_res, i, 0);
if (ret < 0) {
RTE_LOG(ERR, EAL, "%s mapping BAR%i failed: %s\n",
pci_addr, i, strerror(errno));
free(reg);
goto err_vfio_res;
hdr = pci_vfio_info_cap(reg, VFIO_REGION_INFO_CAP_SPARSE_MMAP);

if (hdr != NULL) {
sparse = container_of(hdr,
struct vfio_region_info_cap_sparse_mmap, header);
if (sparse->nr_areas > 0) {
maps[i].nr_areas = sparse->nr_areas;
maps[i].areas = rte_zmalloc(NULL,
sizeof(*maps[i].areas) * maps[i].nr_areas, 0);
if (maps[i].areas == NULL) {
RTE_LOG(ERR, EAL,
"Cannot alloc memory for sparse map areas\n");
goto err_map;
}
memcpy(maps[i].areas, sparse->areas,
sizeof(*maps[i].areas) * maps[i].nr_areas);
}
}

if (maps[i].nr_areas > 0) {
ret = pci_vfio_sparse_mmap_bar(vfio_dev_fd, vfio_res, i, 0);
if (ret < 0) {
RTE_LOG(ERR, EAL, "%s sparse mapping BAR%i failed: %s\n",
pci_addr, i, strerror(errno));
free(reg);
goto err_map;
}
} else {
ret = pci_vfio_mmap_bar(vfio_dev_fd, vfio_res, i, 0);
if (ret < 0) {
RTE_LOG(ERR, EAL, "%s mapping BAR%i failed: %s\n",
pci_addr, i, strerror(errno));
free(reg);
goto err_map;
}
}

dev->mem_resource[i].addr = maps[i].addr;
Expand All @@ -936,19 +1015,26 @@ pci_vfio_map_resource_primary(struct rte_pci_device *dev)

if (pci_rte_vfio_setup_device(dev, vfio_dev_fd) < 0) {
RTE_LOG(ERR, EAL, "%s setup device failed\n", pci_addr);
goto err_vfio_res;
goto err_map;
}

#ifdef HAVE_VFIO_DEV_REQ_INTERFACE
if (pci_vfio_enable_notifier(dev, vfio_dev_fd) != 0) {
RTE_LOG(ERR, EAL, "Error setting up notifier!\n");
goto err_vfio_res;
goto err_map;
}

#endif
TAILQ_INSERT_TAIL(vfio_res_list, vfio_res, next);

return 0;
err_map:
for (j = 0; j < i; j++) {
if (maps[j].addr)
pci_unmap_resource(maps[j].addr, maps[j].size);
if (maps[j].nr_areas > 0)
rte_free(maps[j].areas);
}
err_vfio_res:
rte_free(vfio_res);
err_vfio_dev_fd:
Expand All @@ -964,7 +1050,7 @@ pci_vfio_map_resource_secondary(struct rte_pci_device *dev)
char pci_addr[PATH_MAX] = {0};
int vfio_dev_fd;
struct rte_pci_addr *loc = &dev->addr;
int i, ret;
int i, j, ret;
struct mapped_pci_resource *vfio_res = NULL;
struct mapped_pci_res_list *vfio_res_list =
RTE_TAILQ_CAST(rte_vfio_tailq.head, mapped_pci_res_list);
Expand Down Expand Up @@ -1009,11 +1095,20 @@ pci_vfio_map_resource_secondary(struct rte_pci_device *dev)
maps = vfio_res->maps;

for (i = 0; i < vfio_res->nb_maps; i++) {
ret = pci_vfio_mmap_bar(vfio_dev_fd, vfio_res, i, MAP_FIXED);
if (ret < 0) {
RTE_LOG(ERR, EAL, "%s mapping BAR%i failed: %s\n",
pci_addr, i, strerror(errno));
goto err_vfio_dev_fd;
if (maps[i].nr_areas > 0) {
ret = pci_vfio_sparse_mmap_bar(vfio_dev_fd, vfio_res, i, MAP_FIXED);
if (ret < 0) {
RTE_LOG(ERR, EAL, "%s sparse mapping BAR%i failed: %s\n",
pci_addr, i, strerror(errno));
goto err_vfio_dev_fd;
}
} else {
ret = pci_vfio_mmap_bar(vfio_dev_fd, vfio_res, i, MAP_FIXED);
if (ret < 0) {
RTE_LOG(ERR, EAL, "%s mapping BAR%i failed: %s\n",
pci_addr, i, strerror(errno));
goto err_vfio_dev_fd;
}
}

dev->mem_resource[i].addr = maps[i].addr;
Expand All @@ -1029,6 +1124,10 @@ pci_vfio_map_resource_secondary(struct rte_pci_device *dev)

return 0;
err_vfio_dev_fd:
for (j = 0; j < i; j++) {
if (maps[j].addr)
pci_unmap_resource(maps[j].addr, maps[j].size);
}
rte_vfio_release_device(rte_pci_get_sysfs_path(),
pci_addr, vfio_dev_fd);
return -1;
Expand Down Expand Up @@ -1063,7 +1162,7 @@ find_and_unmap_vfio_resource(struct mapped_pci_res_list *vfio_res_list,
break;
}

if (vfio_res == NULL)
if (vfio_res == NULL)
return vfio_res;

RTE_LOG(INFO, EAL, "Releasing PCI mapped resource for %s\n",
Expand All @@ -1081,6 +1180,9 @@ find_and_unmap_vfio_resource(struct mapped_pci_res_list *vfio_res_list,
pci_addr, maps[i].addr);
pci_unmap_resource(maps[i].addr, maps[i].size);
}

if (maps[i].nr_areas > 0)
rte_free(maps[i].areas);
}

return vfio_res;
Expand Down
2 changes: 2 additions & 0 deletions drivers/bus/pci/private.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -121,6 +121,8 @@ struct pci_map {
uint64_t offset;
uint64_t size;
uint64_t phaddr;
uint32_t nr_areas;
struct vfio_region_sparse_mmap_area *areas;
};

struct pci_msix_table {
Expand Down

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