Re: [RFC PATCH 02/33] vfio: selftests: Add a helper library for VFIO selftests

On 2025/5/24 7:29, David Matlack wrote:

Add a basic helper library to be used by VFIO selftests.

The basic unit of the library is struct vfio_pci_device, which represents a single PCI device that is bound to the vfio-pci driver. The library currently only supports a single device per group and container, and VFIO IOMMU types.

The code in this library was heavily based on prior work done by Raghavendra Rao Ananta rananta@google.com, and the VFIO_ASSERT*() macros were written by Vipin Sharma vipinsh@google.com.

Separate that Makefile rules for building the library into a separate script so that the library can be built by and linked into KVM selftests in a subsequent commit.

Signed-off-by: David Matlack dmatlack@google.com

tools/testing/selftests/vfio/Makefile | 13 + .../selftests/vfio/lib/include/vfio_util.h | 126 +++++++ tools/testing/selftests/vfio/lib/libvfio.mk | 17 + .../selftests/vfio/lib/vfio_pci_device.c | 330 ++++++++++++++++++ 4 files changed, 486 insertions(+) create mode 100644 tools/testing/selftests/vfio/lib/include/vfio_util.h create mode 100644 tools/testing/selftests/vfio/lib/libvfio.mk create mode 100644 tools/testing/selftests/vfio/lib/vfio_pci_device.c

diff --git a/tools/testing/selftests/vfio/Makefile b/tools/testing/selftests/vfio/Makefile index 2bba39aff5d9..f8933dcdc8e1 100644 --- a/tools/testing/selftests/vfio/Makefile +++ b/tools/testing/selftests/vfio/Makefile

You should provide a configuration file that allows users to select which features require the self-testing function to be enabled.

Thanks.

@@ -1,2 +1,15 @@ CFLAGS = $(KHDR_INCLUDES) include ../lib.mk +include lib/libvfio.mk

+CFLAGS += -I$(top_srcdir)/tools/include +CFLAGS += -MD

+$(TEST_GEN_PROGS_EXTENDED): %: %.o $(LIBVFIO_O)

• $(CC) $(CFLAGS) $(CPPFLAGS) $(LDFLAGS) $< $(LIBVFIO_O) $(LDLIBS) -o $@

+TEST_GEN_PROGS_EXTENDED_O = $(patsubst %, %.o, $(TEST_GEN_PROGS_EXTENDED)) +TEST_DEP_FILES = $(patsubst %.o, %.d, $(TEST_GEN_PROGS_EXTENDED_O) $(LIBVFIO_O)) +-include $(TEST_DEP_FILES)

+EXTRA_CLEAN += $(TEST_GEN_PROGS_EXTENDED_O) $(TEST_DEP_FILES) diff --git a/tools/testing/selftests/vfio/lib/include/vfio_util.h b/tools/testing/selftests/vfio/lib/include/vfio_util.h new file mode 100644 index 000000000000..ea54754a8b16 --- /dev/null +++ b/tools/testing/selftests/vfio/lib/include/vfio_util.h @@ -0,0 +1,126 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef SELFTESTS_VFIO_LIB_INCLUDE_VFIO_UTIL_H +#define SELFTESTS_VFIO_LIB_INCLUDE_VFIO_UTIL_H

+#include <string.h> +#include <linux/vfio.h> +#include <linux/list.h> +#include <linux/pci_regs.h>

+#include "../../../kselftest.h"

+#define VFIO_LOG_AND_EXIT(...) do { \

• fprintf(stderr, " " __VA_ARGS__); \
• fprintf(stderr, "\n"); \
• exit(KSFT_FAIL); \

+} while (0)

+#define VFIO_ASSERT_OP(_lhs, _rhs, _op, ...) do { \

• typeof(_lhs) __lhs = (_lhs); \
• typeof(_rhs) __rhs = (_rhs); \

• 								\
  

• if (__lhs _op __rhs) \

• break;								\
  

• 								\
  

• fprintf(stderr, "%s:%u: Assertion Failure\n\n", __FILE__, __LINE__); \
• fprintf(stderr, " Expression: " #_lhs " " #_op " " #_rhs "\n"); \
• fprintf(stderr, " Observed: %#lx %s %#lx\n", \

• 	(u64)__lhs, #_op, (u64)__rhs);				\
  

• fprintf(stderr, " [errno: %d - %s\n]", errno, strerror(errno)); \
• VFIO_LOG_AND_EXIT(__VA_ARGS__); \

+} while (0)

+#define VFIO_ASSERT_EQ(_a, _b, ...) VFIO_ASSERT_OP(_a, _b, ==, ##__VA_ARGS__) +#define VFIO_ASSERT_NE(_a, _b, ...) VFIO_ASSERT_OP(_a, _b, !=, ##__VA_ARGS__) +#define VFIO_ASSERT_LT(_a, _b, ...) VFIO_ASSERT_OP(_a, _b, <, ##__VA_ARGS__) +#define VFIO_ASSERT_LE(_a, _b, ...) VFIO_ASSERT_OP(_a, _b, <=, ##__VA_ARGS__) +#define VFIO_ASSERT_GT(_a, _b, ...) VFIO_ASSERT_OP(_a, _b, >, ##__VA_ARGS__) +#define VFIO_ASSERT_GE(_a, _b, ...) VFIO_ASSERT_OP(_a, _b, >=, ##__VA_ARGS__) +#define VFIO_ASSERT_TRUE(_a, ...) VFIO_ASSERT_NE(false, (_a), ##__VA_ARGS__) +#define VFIO_ASSERT_FALSE(_a, ...) VFIO_ASSERT_EQ(false, (_a), ##__VA_ARGS__) +#define VFIO_ASSERT_NULL(_a, ...) VFIO_ASSERT_EQ(NULL, _a, ##__VA_ARGS__) +#define VFIO_ASSERT_NOT_NULL(_a, ...) VFIO_ASSERT_NE(NULL, _a, ##__VA_ARGS__)

+#define VFIO_FAIL(_fmt, ...) do { \

• fprintf(stderr, "%s:%u: FAIL\n\n", __FILE__, __LINE__); \
• VFIO_LOG_AND_EXIT(_fmt, ##__VA_ARGS__); \

+} while (0)

+struct vfio_pci_bar {

• struct vfio_region_info info;
• void *vaddr;

+};

+struct vfio_pci_device {

• int fd;
• int group_fd;
• int container_fd;
• struct vfio_device_info info;
• struct vfio_region_info config_space;
• struct vfio_pci_bar bars[PCI_STD_NUM_BARS];
• struct vfio_irq_info msi_info;
• struct vfio_irq_info msix_info;
• /* eventfds for MSI and MSI-x interrupts */
• int msi_eventfds[PCI_MSIX_FLAGS_QSIZE + 1];

+};

+struct vfio_pci_device *vfio_pci_device_init(const char *bdf, int iommu_type); +void vfio_pci_device_cleanup(struct vfio_pci_device *device);

+void vfio_pci_dma_map(struct vfio_pci_device *device, u64 iova, u64 size,

•       void *vaddr);
  

+void vfio_pci_dma_unmap(struct vfio_pci_device *device, u64 iova, u64 size);

+void vfio_pci_config_access(struct vfio_pci_device *device, bool write,

• 	    size_t config, size_t size, void *data);
  

+#define vfio_pci_config_read(_device, _offset, _type) ({ \

• _type __data; \
• vfio_pci_config_access((_device), false, _offset, sizeof(__data), &__data); \
• __data; \

+})

+#define vfio_pci_config_readb(_d, _o) vfio_pci_config_read(_d, _o, u8) +#define vfio_pci_config_readw(_d, _o) vfio_pci_config_read(_d, _o, u16) +#define vfio_pci_config_readl(_d, _o) vfio_pci_config_read(_d, _o, u32)

+#define vfio_pci_config_write(_device, _offset, _value, _type) do { \

• _type __data = (_value); \
• vfio_pci_config_access((_device), true, _offset, sizeof(_type), &__data); \

+} while (0)

+#define vfio_pci_config_writeb(_d, _o, _v) vfio_pci_config_write(_d, _o, _v, u8) +#define vfio_pci_config_writew(_d, _o, _v) vfio_pci_config_write(_d, _o, _v, u16) +#define vfio_pci_config_writel(_d, _o, _v) vfio_pci_config_write(_d, _o, _v, u32)

+void vfio_pci_irq_enable(struct vfio_pci_device *device, u32 index,

• 	 u32 vector, int count);
  

+void vfio_pci_irq_disable(struct vfio_pci_device *device, u32 index); +void vfio_pci_irq_trigger(struct vfio_pci_device *device, u32 index, u32 vector);

+static inline void vfio_pci_msi_enable(struct vfio_pci_device *device,

• 		       u32 vector, int count)
  

+{

• vfio_pci_irq_enable(device, VFIO_PCI_MSI_IRQ_INDEX, vector, count);

+}

+static inline void vfio_pci_msi_disable(struct vfio_pci_device *device) +{

• vfio_pci_irq_disable(device, VFIO_PCI_MSI_IRQ_INDEX);

+}

+static inline void vfio_pci_msix_enable(struct vfio_pci_device *device,

• 			u32 vector, int count)
  

+{

• vfio_pci_irq_enable(device, VFIO_PCI_MSIX_IRQ_INDEX, vector, count);

+}

+static inline void vfio_pci_msix_disable(struct vfio_pci_device *device) +{

• vfio_pci_irq_disable(device, VFIO_PCI_MSIX_IRQ_INDEX);

+}

+#endif /* SELFTESTS_VFIO_LIB_INCLUDE_VFIO_UTIL_H */ diff --git a/tools/testing/selftests/vfio/lib/libvfio.mk b/tools/testing/selftests/vfio/lib/libvfio.mk new file mode 100644 index 000000000000..388533f8d407 --- /dev/null +++ b/tools/testing/selftests/vfio/lib/libvfio.mk @@ -0,0 +1,17 @@ +VFIO_DIR := $(selfdir)/vfio

+LIBVFIO_C := lib/vfio_pci_device.c

+LIBVFIO_O := $(patsubst %.c, $(OUTPUT)/%.o, $(LIBVFIO_C))

+LIBVFIO_O_DIRS := $(shell dirname $(LIBVFIO_O) | uniq)

+CFLAGS += -I$(VFIO_DIR)/lib/include

+$(LIBVFIO_O): $(OUTPUT)/%.o : $(VFIO_DIR)/%.c $(LIBVFIO_O_DIRS)

• $(CC) $(CFLAGS) $(CPPFLAGS) $(TARGET_ARCH) -c $< -o $@

+$(LIBVFIO_O_DIRS):

• mkdir -p $@

+EXTRA_CLEAN += $(LIBVFIO_O) diff --git a/tools/testing/selftests/vfio/lib/vfio_pci_device.c b/tools/testing/selftests/vfio/lib/vfio_pci_device.c new file mode 100644 index 000000000000..922f21138532 --- /dev/null +++ b/tools/testing/selftests/vfio/lib/vfio_pci_device.c @@ -0,0 +1,330 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include <fcntl.h> +#include <libgen.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h>

+#include <sys/eventfd.h> +#include <sys/ioctl.h> +#include <sys/mman.h>

+#include <linux/limits.h> +#include <linux/mman.h> +#include <linux/types.h> +#include <linux/vfio.h>

+#include "../../../kselftest.h" +#include <vfio_util.h>

+#define VFIO_DEV_PATH "/dev/vfio/vfio" +#define PCI_SYSFS_PATH "/sys/bus/pci/devices"

+#define ioctl_assert(_fd, _op, _arg) do { \

• void *__arg = (_arg); \
• int __ret = ioctl((_fd), (_op), (__arg)); \
• VFIO_ASSERT_EQ(__ret, 0, \

•     "ioctl(%s, %s, %s) returned %d\n", #_fd, #_op, #_arg, __ret); \
  

+} while (0)

+static void vfio_pci_irq_set(struct vfio_pci_device *device,

• 	     u32 index, u32 vector, u32 count, int *fds)
  

+{

• u8 buf[sizeof(struct vfio_irq_set) + sizeof(int) * count] = {};
• struct vfio_irq_set *irq = (void *)&buf;
• int *irq_fds = (void *)&irq->data;
• irq->argsz = sizeof(buf);
• irq->flags = VFIO_IRQ_SET_ACTION_TRIGGER;
• irq->index = index;
• irq->start = vector;
• irq->count = count;
• if (count) {

• irq->flags |= VFIO_IRQ_SET_DATA_EVENTFD;
  

• memcpy(irq_fds, fds, sizeof(int) * count);
  

• } else {

• irq->flags |= VFIO_IRQ_SET_DATA_NONE;
  

• }
• ioctl_assert(device->fd, VFIO_DEVICE_SET_IRQS, irq);

+}

+void vfio_pci_irq_trigger(struct vfio_pci_device *device, u32 index, u32 vector) +{

• struct vfio_irq_set irq = {

• .argsz = sizeof(irq),
  

• .flags = VFIO_IRQ_SET_ACTION_TRIGGER | VFIO_IRQ_SET_DATA_NONE,
  

• .index = index,
  

• .start = vector,
  

• .count = 1,
  

• };
• ioctl_assert(device->fd, VFIO_DEVICE_SET_IRQS, &irq);

+}

+static void check_supported_irq_index(u32 index) +{

• /* VFIO selftests only supports MSI and MSI-x for now. */
• VFIO_ASSERT_TRUE(index == VFIO_PCI_MSI_IRQ_INDEX ||

• 	 index == VFIO_PCI_MSIX_IRQ_INDEX,
  

• 	 "Unsupported IRQ index: %u\n", index);
  

+}

+void vfio_pci_irq_enable(struct vfio_pci_device *device, u32 index, u32 vector,

• 	 int count)
  

+{

• int i;
• check_supported_irq_index(index);
• for (i = vector; i < vector + count; i++) {

• VFIO_ASSERT_LT(device->msi_eventfds[i], 0);
  

• device->msi_eventfds[i] = eventfd(0, 0);
  

• VFIO_ASSERT_GE(device->msi_eventfds[i], 0);
  

• }
• vfio_pci_irq_set(device, index, vector, count, device->msi_eventfds + vector);

+}

+void vfio_pci_irq_disable(struct vfio_pci_device *device, u32 index) +{

• int i;
• check_supported_irq_index(index);
• for (i = 0; i < ARRAY_SIZE(device->msi_eventfds); i++) {

• if (device->msi_eventfds[i] < 0)
  

• 	continue;
  

• VFIO_ASSERT_EQ(close(device->msi_eventfds[i]), 0);
  

• device->msi_eventfds[i] = -1;
  

• }
• vfio_pci_irq_set(device, index, 0, 0, NULL);

+}

+static void vfio_pci_irq_get(struct vfio_pci_device *device, u32 index,

• 	     struct vfio_irq_info *irq_info)
  

+{

• irq_info->argsz = sizeof(*irq_info);
• irq_info->index = index;
• ioctl_assert(device->fd, VFIO_DEVICE_GET_IRQ_INFO, irq_info);

+}

+void vfio_pci_dma_map(struct vfio_pci_device *device, u64 iova, u64 size, void *vaddr) +{

• struct vfio_iommu_type1_dma_map map = {

• .argsz = sizeof(map),
  

• .flags = VFIO_DMA_MAP_FLAG_READ | VFIO_DMA_MAP_FLAG_WRITE,
  

• .vaddr = (u64)vaddr,
  

• .iova = iova,
  

• .size = size,
  

• };
• ioctl_assert(device->container_fd, VFIO_IOMMU_MAP_DMA, &map);

+}

+void vfio_pci_dma_unmap(struct vfio_pci_device *device, u64 iova, u64 size) +{

• struct vfio_iommu_type1_dma_unmap unmap = {

• .argsz = sizeof(unmap),
  

• .iova = iova,
  

• .size = size,
  

• };
• ioctl_assert(device->container_fd, VFIO_IOMMU_UNMAP_DMA, &unmap);

+}

+static void vfio_pci_region_get(struct vfio_pci_device *device, int index,

• 		struct vfio_region_info *info)
  

+{

• memset(info, 0, sizeof(*info));
• info->argsz = sizeof(*info);
• info->index = index;
• ioctl_assert(device->fd, VFIO_DEVICE_GET_REGION_INFO, info);

+}

+static void vfio_pci_bar_map(struct vfio_pci_device *device, int index) +{

• struct vfio_pci_bar *bar = &device->bars[index];
• int prot = 0;
• VFIO_ASSERT_LT(index, PCI_STD_NUM_BARS);
• VFIO_ASSERT_NULL(bar->vaddr);
• VFIO_ASSERT_TRUE(bar->info.flags & VFIO_REGION_INFO_FLAG_MMAP);
• if (bar->info.flags & VFIO_REGION_INFO_FLAG_READ)

• prot |= PROT_READ;
  

• if (bar->info.flags & VFIO_REGION_INFO_FLAG_WRITE)

• prot |= PROT_WRITE;
  

• bar->vaddr = mmap(NULL, bar->info.size, prot, MAP_FILE | MAP_SHARED,

• 	  device->fd, bar->info.offset);
  

• VFIO_ASSERT_NE(bar->vaddr, MAP_FAILED);

+}

+static void vfio_pci_bar_unmap(struct vfio_pci_device *device, int index) +{

• struct vfio_pci_bar *bar = &device->bars[index];
• VFIO_ASSERT_LT(index, PCI_STD_NUM_BARS);
• VFIO_ASSERT_NOT_NULL(bar->vaddr);
• VFIO_ASSERT_EQ(munmap(bar->vaddr, bar->info.size), 0);
• bar->vaddr = NULL;

+}

+static void vfio_pci_bar_unmap_all(struct vfio_pci_device *device) +{

• int i;
• for (i = 0; i < PCI_STD_NUM_BARS; i++) {

• if (device->bars[i].vaddr)
  

• 	vfio_pci_bar_unmap(device, i);
  

• }

+}

+void vfio_pci_config_access(struct vfio_pci_device *device, bool write,

• 	    size_t config, size_t size, void *data)
  

+{

• struct vfio_region_info *config_space = &device->config_space;
• int ret;
• if (write)

• ret = pwrite(device->fd, data, size, config_space->offset + config);
  

• else

• ret = pread(device->fd, data, size, config_space->offset + config);
  

• VFIO_ASSERT_EQ(ret, size, "Failed to %s PCI config space: 0x%lx\n",

•        write ? "write to" : "read from", config);
  

+}

+static unsigned int vfio_pci_get_group_from_dev(const char *bdf) +{

• char dev_iommu_group_path[PATH_MAX] = {0};
• char sysfs_path[PATH_MAX] = {0};
• unsigned int group;
• int ret;
• snprintf(sysfs_path, PATH_MAX, "%s/%s/iommu_group", PCI_SYSFS_PATH, bdf);
• ret = readlink(sysfs_path, dev_iommu_group_path, sizeof(dev_iommu_group_path));
• VFIO_ASSERT_NE(ret, -1, "Failed to get the IOMMU group for device: %s\n", bdf);
• ret = sscanf(basename(dev_iommu_group_path), "%u", &group);
• VFIO_ASSERT_EQ(ret, 1, "Failed to get the IOMMU group for device: %s\n", bdf);
• return group;

+}

+static void vfio_pci_container_setup(struct vfio_pci_device *device) +{

• int version;
• device->container_fd = open(VFIO_DEV_PATH, O_RDWR);
• VFIO_ASSERT_GE(device->container_fd, 0, "open(%s) failed\n", VFIO_DEV_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 = {

• .argsz = sizeof(group_status),
  

• };
• char group_path[32];
• int group;
• group = vfio_pci_get_group_from_dev(bdf);
• snprintf(group_path, sizeof(group_path), "/dev/vfio/%d", group);
• device->group_fd = open(group_path, O_RDWR);
• VFIO_ASSERT_GE(device->group_fd, 0, "open(%s) failed\n", group_path);
• ioctl_assert(device->group_fd, VFIO_GROUP_GET_STATUS, &group_status);
• VFIO_ASSERT_TRUE(group_status.flags & VFIO_GROUP_FLAGS_VIABLE);
• ioctl_assert(device->group_fd, VFIO_GROUP_SET_CONTAINER, &device->container_fd);

+}

+static void vfio_pci_iommu_setup(struct vfio_pci_device *device, unsigned long iommu_type) +{

• int ret;
• 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);
• device->info.argsz = sizeof(device->info);
• ioctl_assert(device->fd, VFIO_DEVICE_GET_INFO, &device->info);
• vfio_pci_region_get(device, VFIO_PCI_CONFIG_REGION_INDEX, &device->config_space);
• /* Sanity check VFIO does not advertise mmap for config space */
• VFIO_ASSERT_TRUE(!(device->config_space.flags & VFIO_REGION_INFO_FLAG_MMAP),

• 	 "PCI config space should not support mmap()\n");
  

• for (i = 0; i < PCI_STD_NUM_BARS; i++) {

• struct vfio_pci_bar *bar = device->bars + i;
  

• vfio_pci_region_get(device, i, &bar->info);
  

• if (bar->info.flags & VFIO_REGION_INFO_FLAG_MMAP)
  

• 	vfio_pci_bar_map(device, i);
  

• }
• vfio_pci_irq_get(device, VFIO_PCI_MSI_IRQ_INDEX, &device->msi_info);
• vfio_pci_irq_get(device, VFIO_PCI_MSIX_IRQ_INDEX, &device->msix_info);
• for (i = 0; i < ARRAY_SIZE(device->msi_eventfds); i++)

• device->msi_eventfds[i] = -1;
  

+}

+struct vfio_pci_device *vfio_pci_device_init(const char *bdf, int iommu_type) +{

• struct vfio_pci_device *device;
• device = calloc(1, sizeof(*device));
• VFIO_ASSERT_NOT_NULL(device);
• vfio_pci_container_setup(device);
• vfio_pci_group_setup(device, bdf);
• vfio_pci_iommu_setup(device, iommu_type);
• vfio_pci_device_setup(device, bdf);
• return device;

+}

+void vfio_pci_device_cleanup(struct vfio_pci_device *device) +{

• int i;
• vfio_pci_bar_unmap_all(device);
• VFIO_ASSERT_EQ(close(device->fd), 0);
• for (i = 0; i < ARRAY_SIZE(device->msi_eventfds); i++) {

• if (device->msi_eventfds[i] < 0)
  

• 	continue;
  

• 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);
• free(device);

+}