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vfio: selftests: Add iommufd mode

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Add a new IOMMU mode for using iommufd directly. In this mode userspace
opens /dev/iommu and binds it to a device FD acquired through
/dev/vfio/devices/vfioX.

Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20250822212518.4156428-29-dmatlack@google.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
This commit is contained in:
David Matlack
2025-08-22 21:25:15 +00:00
committed by Alex Williamson
parent d1a17495bb
commit 61cbfe5014
2 changed files with 149 additions and 38 deletions
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181
tools/testing/selftests/vfio/lib/vfio_pci_device.c
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@@ -10,10 +10,12 @@
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <uapi/linux/types.h>
#include <linux/limits.h>
#include <linux/mman.h>
#include <linux/types.h>
#include <linux/vfio.h>
#include <linux/iommufd.h>
#include "../../../kselftest.h"
#include <vfio_util.h>
@@ -139,32 +141,80 @@ static void vfio_pci_irq_get(struct vfio_pci_device *device, u32 index,
ioctl_assert(device->fd, VFIO_DEVICE_GET_IRQ_INFO, irq_info);
}
void vfio_pci_dma_map(struct vfio_pci_device *device,
struct vfio_dma_region *region)
static void vfio_iommu_dma_map(struct vfio_pci_device *device,
struct vfio_dma_region *region)
{
struct vfio_iommu_type1_dma_map map = {
.argsz = sizeof(map),
struct vfio_iommu_type1_dma_map args = {
.argsz = sizeof(args),
.flags = VFIO_DMA_MAP_FLAG_READ | VFIO_DMA_MAP_FLAG_WRITE,
.vaddr = (u64)region->vaddr,
.iova = region->iova,
.size = region->size,
};
ioctl_assert(device->container_fd, VFIO_IOMMU_MAP_DMA, &map);
ioctl_assert(device->container_fd, VFIO_IOMMU_MAP_DMA, &args);
}
static void iommufd_dma_map(struct vfio_pci_device *device,
struct vfio_dma_region *region)
{
struct iommu_ioas_map args = {
.size = sizeof(args),
.flags = IOMMU_IOAS_MAP_READABLE |
IOMMU_IOAS_MAP_WRITEABLE |
IOMMU_IOAS_MAP_FIXED_IOVA,
.user_va = (u64)region->vaddr,
.iova = region->iova,
.length = region->size,
.ioas_id = device->ioas_id,
};
ioctl_assert(device->iommufd, IOMMU_IOAS_MAP, &args);
}
void vfio_pci_dma_map(struct vfio_pci_device *device,
struct vfio_dma_region *region)
{
if (device->iommufd)
iommufd_dma_map(device, region);
else
vfio_iommu_dma_map(device, region);
list_add(&region->link, &device->dma_regions);
}
static void vfio_iommu_dma_unmap(struct vfio_pci_device *device,
struct vfio_dma_region *region)
{
struct vfio_iommu_type1_dma_unmap args = {
.argsz = sizeof(args),
.iova = region->iova,
.size = region->size,
};
ioctl_assert(device->container_fd, VFIO_IOMMU_UNMAP_DMA, &args);
}
static void iommufd_dma_unmap(struct vfio_pci_device *device,
struct vfio_dma_region *region)
{
struct iommu_ioas_unmap args = {
.size = sizeof(args),
.iova = region->iova,
.length = region->size,
.ioas_id = device->ioas_id,
};
ioctl_assert(device->iommufd, IOMMU_IOAS_UNMAP, &args);
}
void vfio_pci_dma_unmap(struct vfio_pci_device *device,
struct vfio_dma_region *region)
{
struct vfio_iommu_type1_dma_unmap unmap = {
.argsz = sizeof(unmap),
.iova = region->iova,
.size = region->size,
};
ioctl_assert(device->container_fd, VFIO_IOMMU_UNMAP_DMA, &unmap);
if (device->iommufd)
iommufd_dma_unmap(device, region);
else
vfio_iommu_dma_unmap(device, region);
list_del(&region->link);
}
@@ -258,18 +308,6 @@ static unsigned int vfio_pci_get_group_from_dev(const char *bdf)
return group;
}
static void vfio_pci_container_setup(struct vfio_pci_device *device)
{
const char *path = device->iommu_mode->container_path;
int version;
device->container_fd = open(path, O_RDWR);
VFIO_ASSERT_GE(device->container_fd, 0, "open(%s) failed\n", path);
version = ioctl(device->container_fd, VFIO_GET_API_VERSION);
VFIO_ASSERT_EQ(version, VFIO_API_VERSION);
}
static void vfio_pci_group_setup(struct vfio_pci_device *device, const char *bdf)
{
struct vfio_group_status group_status = {
@@ -290,25 +328,33 @@ static void vfio_pci_group_setup(struct vfio_pci_device *device, const char *bdf
ioctl_assert(device->group_fd, VFIO_GROUP_SET_CONTAINER, &device->container_fd);
}
static void vfio_pci_iommu_setup(struct vfio_pci_device *device)
static void vfio_pci_container_setup(struct vfio_pci_device *device, const char *bdf)
{
unsigned long iommu_type = device->iommu_mode->iommu_type;
const char *path = device->iommu_mode->container_path;
int version;
int ret;
INIT_LIST_HEAD(&device->dma_regions);
device->container_fd = open(path, O_RDWR);
VFIO_ASSERT_GE(device->container_fd, 0, "open(%s) failed\n", path);
version = ioctl(device->container_fd, VFIO_GET_API_VERSION);
VFIO_ASSERT_EQ(version, VFIO_API_VERSION, "Unsupported version: %d\n", version);
vfio_pci_group_setup(device, bdf);
ret = ioctl(device->container_fd, VFIO_CHECK_EXTENSION, iommu_type);
VFIO_ASSERT_GT(ret, 0, "VFIO IOMMU type %lu not supported\n", iommu_type);
ioctl_assert(device->container_fd, VFIO_SET_IOMMU, (void *)iommu_type);
}
static void vfio_pci_device_setup(struct vfio_pci_device *device, const char *bdf)
{
int i;
device->fd = ioctl(device->group_fd, VFIO_GROUP_GET_DEVICE_FD, bdf);
VFIO_ASSERT_GE(device->fd, 0);
}
static void vfio_pci_device_setup(struct vfio_pci_device *device)
{
int i;
device->info.argsz = sizeof(device->info);
ioctl_assert(device->fd, VFIO_DEVICE_GET_INFO, &device->info);
@@ -386,6 +432,9 @@ static const struct vfio_iommu_mode iommu_modes[] = {
.container_path = "/dev/iommu",
.iommu_type = VFIO_TYPE1v2_IOMMU,
},
{
.name = "iommufd",
},
};
const char *default_iommu_mode = "vfio_type1_iommu";
@@ -407,6 +456,57 @@ static const struct vfio_iommu_mode *lookup_iommu_mode(const char *iommu_mode)
VFIO_FAIL("Unrecognized IOMMU mode: %s\n", iommu_mode);
}
static void vfio_device_bind_iommufd(int device_fd, int iommufd)
{
struct vfio_device_bind_iommufd args = {
.argsz = sizeof(args),
.iommufd = iommufd,
};
ioctl_assert(device_fd, VFIO_DEVICE_BIND_IOMMUFD, &args);
}
static u32 iommufd_ioas_alloc(int iommufd)
{
struct iommu_ioas_alloc args = {
.size = sizeof(args),
};
ioctl_assert(iommufd, IOMMU_IOAS_ALLOC, &args);
return args.out_ioas_id;
}
static void vfio_device_attach_iommufd_pt(int device_fd, u32 pt_id)
{
struct vfio_device_attach_iommufd_pt args = {
.argsz = sizeof(args),
.pt_id = pt_id,
};
ioctl_assert(device_fd, VFIO_DEVICE_ATTACH_IOMMUFD_PT, &args);
}
static void vfio_pci_iommufd_setup(struct vfio_pci_device *device, const char *bdf)
{
const char *cdev_path = vfio_pci_get_cdev_path(bdf);
device->fd = open(cdev_path, O_RDWR);
VFIO_ASSERT_GE(device->fd, 0);
free((void *)cdev_path);
/*
* Require device->iommufd to be >0 so that a simple non-0 check can be
* used to check if iommufd is enabled. In practice open() will never
* return 0 unless stdin is closed.
*/
device->iommufd = open("/dev/iommu", O_RDWR);
VFIO_ASSERT_GT(device->iommufd, 0);
vfio_device_bind_iommufd(device->fd, device->iommufd);
device->ioas_id = iommufd_ioas_alloc(device->iommufd);
vfio_device_attach_iommufd_pt(device->fd, device->ioas_id);
}
struct vfio_pci_device *vfio_pci_device_init(const char *bdf, const char *iommu_mode)
{
struct vfio_pci_device *device;
@@ -414,13 +514,16 @@ struct vfio_pci_device *vfio_pci_device_init(const char *bdf, const char *iommu_
device = calloc(1, sizeof(*device));
VFIO_ASSERT_NOT_NULL(device);
INIT_LIST_HEAD(&device->dma_regions);
device->iommu_mode = lookup_iommu_mode(iommu_mode);
vfio_pci_container_setup(device);
vfio_pci_group_setup(device, bdf);
vfio_pci_iommu_setup(device);
vfio_pci_device_setup(device, bdf);
if (device->iommu_mode->container_path)
vfio_pci_container_setup(device, bdf);
else
vfio_pci_iommufd_setup(device, bdf);
vfio_pci_device_setup(device);
vfio_pci_driver_probe(device);
return device;
@@ -444,8 +547,12 @@ void vfio_pci_device_cleanup(struct vfio_pci_device *device)
VFIO_ASSERT_EQ(close(device->msi_eventfds[i]), 0);
}
VFIO_ASSERT_EQ(close(device->group_fd), 0);
VFIO_ASSERT_EQ(close(device->container_fd), 0);
if (device->iommufd) {
VFIO_ASSERT_EQ(close(device->iommufd), 0);
} else {
VFIO_ASSERT_EQ(close(device->group_fd), 0);
VFIO_ASSERT_EQ(close(device->container_fd), 0);
}
free(device);
}