diff mbox series

[v1,05/24] vfio-user: add device IO ops vector

Message ID 1f85784fafd1673277b52b7b7c7e567723c1137f.1667542066.git.john.g.johnson@oracle.com (mailing list archive)
State New, archived
Headers show
Series vfio-user client | expand

Commit Message

John Johnson Nov. 8, 2022, 11:13 p.m. UTC 
Used for communication with VFIO driver
(prep work for vfio-user, which will communicate over a socket)

Signed-off-by: John G Johnson <john.g.johnson@oracle.com>
---
 hw/vfio/ap.c                  |   1 +
 hw/vfio/ccw.c                 |   1 +
 hw/vfio/common.c              | 107 +++++++++++++++++++++++++++-----
 hw/vfio/pci.c                 | 140 ++++++++++++++++++++++++++----------------
 hw/vfio/platform.c            |   1 +
 include/hw/vfio/vfio-common.h |  27 ++++++++
 6 files changed, 209 insertions(+), 68 deletions(-)

Comments

John Levon Dec. 9, 2022, 2:43 p.m. UTC | #1 
On Tue, Nov 08, 2022 at 03:13:27PM -0800, John Johnson wrote:

> Used for communication with VFIO driver
> (prep work for vfio-user, which will communicate over a socket)
> 
> @@ -1166,12 +1178,13 @@ uint32_t vfio_pci_read_config(PCIDevice *pdev, uint32_t addr, int len)
>      if (~emu_bits & (0xffffffffU >> (32 - len * 8))) {
>          ssize_t ret;
>  
> -        ret = pread(vdev->vbasedev.fd, &phys_val, len,
> -                    vdev->config_offset + addr);
> +        ret = VDEV_CONFIG_READ(vbasedev, addr, len, &phys_val);
>          if (ret != len) {
> -            error_report("%s(%s, 0x%x, 0x%x) failed: %m",
> -                         __func__, vdev->vbasedev.name, addr, len);
> -            return -errno;
> +            const char *err = ret < 0 ? strerror(-ret) : "short read";
> +
> +            error_report("%s(%s, 0x%x, 0x%x) failed: %s",
> +                         __func__, vbasedev->name, addr, len, err);
> +            return -1;

Mention this drive-by return value fix in the commit message?

> @@ -1283,10 +1300,13 @@ static int vfio_msi_setup(VFIOPCIDevice *vdev, int pos, Error **errp)
>      int ret, entries;
>      Error *err = NULL;
>  
> -    if (pread(vdev->vbasedev.fd, &ctrl, sizeof(ctrl),
> -              vdev->config_offset + pos + PCI_CAP_FLAGS) != sizeof(ctrl)) {
> -        error_setg_errno(errp, errno, "failed reading MSI PCI_CAP_FLAGS");
> -        return -errno;
> +    ret = VDEV_CONFIG_READ(&vdev->vbasedev, pos + PCI_CAP_FLAGS,
> +                           sizeof(ctrl), &ctrl);
> +    if (ret != sizeof(ctrl)) {
> +        const char *err = ret < 0 ? strerror(-ret) : "short read";
> +
> +        error_setg(errp, "failed reading MSI PCI_CAP_FLAGS %s", err);
> +        return ret;

I suppose this was already broken, but if we get a short read we won't bubble up
an error properly here since ret is not in -errno form. Probably true of some
other short read paths?

regards
john
Cédric Le Goater Dec. 12, 2022, 7:59 a.m. UTC | #2 
On 11/9/22 00:13, John Johnson wrote:
> Used for communication with VFIO driver
> (prep work for vfio-user, which will communicate over a socket)
> 
> Signed-off-by: John G Johnson <john.g.johnson@oracle.com>


I would keep the short rw handling for a subsequent patch to make
sure the changes do not introduce any functional change.

> ---
>   hw/vfio/ap.c                  |   1 +
>   hw/vfio/ccw.c                 |   1 +
>   hw/vfio/common.c              | 107 +++++++++++++++++++++++++++-----
>   hw/vfio/pci.c                 | 140 ++++++++++++++++++++++++++----------------
>   hw/vfio/platform.c            |   1 +
>   include/hw/vfio/vfio-common.h |  27 ++++++++
>   6 files changed, 209 insertions(+), 68 deletions(-)
> 
> diff --git a/hw/vfio/ap.c b/hw/vfio/ap.c
> index e0dd561..7ef42f1 100644
> --- a/hw/vfio/ap.c
> +++ b/hw/vfio/ap.c
> @@ -102,6 +102,7 @@ static void vfio_ap_realize(DeviceState *dev, Error **errp)
>       mdevid = basename(vapdev->vdev.sysfsdev);
>       vapdev->vdev.name = g_strdup_printf("%s", mdevid);
>       vapdev->vdev.dev = dev;
> +    vapdev->vdev.io_ops = &vfio_dev_io_ioctl;
>   
>       /*
>        * vfio-ap devices operate in a way compatible with discarding of
> diff --git a/hw/vfio/ccw.c b/hw/vfio/ccw.c
> index 06b588c..cbd1c25 100644
> --- a/hw/vfio/ccw.c
> +++ b/hw/vfio/ccw.c
> @@ -614,6 +614,7 @@ static void vfio_ccw_get_device(VFIOGroup *group, VFIOCCWDevice *vcdev,
>       vcdev->vdev.type = VFIO_DEVICE_TYPE_CCW;
>       vcdev->vdev.name = name;
>       vcdev->vdev.dev = &vcdev->cdev.parent_obj.parent_obj;
> +    vcdev->vdev.io_ops = &vfio_dev_io_ioctl;
>   
>       return;
>   
> diff --git a/hw/vfio/common.c b/hw/vfio/common.c
> index dd9104f..c7bf0aa 100644
> --- a/hw/vfio/common.c
> +++ b/hw/vfio/common.c
> @@ -71,7 +71,7 @@ void vfio_disable_irqindex(VFIODevice *vbasedev, int index)
>           .count = 0,
>       };
>   
> -    ioctl(vbasedev->fd, VFIO_DEVICE_SET_IRQS, &irq_set);
> +    VDEV_SET_IRQS(vbasedev, &irq_set);
>   }
>   
>   void vfio_unmask_single_irqindex(VFIODevice *vbasedev, int index)
> @@ -84,7 +84,7 @@ void vfio_unmask_single_irqindex(VFIODevice *vbasedev, int index)
>           .count = 1,
>       };
>   
> -    ioctl(vbasedev->fd, VFIO_DEVICE_SET_IRQS, &irq_set);
> +    VDEV_SET_IRQS(vbasedev, &irq_set);
>   }
>   
>   void vfio_mask_single_irqindex(VFIODevice *vbasedev, int index)
> @@ -97,7 +97,7 @@ void vfio_mask_single_irqindex(VFIODevice *vbasedev, int index)
>           .count = 1,
>       };
>   
> -    ioctl(vbasedev->fd, VFIO_DEVICE_SET_IRQS, &irq_set);
> +    VDEV_SET_IRQS(vbasedev, &irq_set);
>   }
>   
>   static inline const char *action_to_str(int action)
> @@ -178,9 +178,7 @@ int vfio_set_irq_signaling(VFIODevice *vbasedev, int index, int subindex,
>       pfd = (int32_t *)&irq_set->data;
>       *pfd = fd;
>   
> -    if (ioctl(vbasedev->fd, VFIO_DEVICE_SET_IRQS, irq_set)) {
> -        ret = -errno;
> -    }
> +    ret = VDEV_SET_IRQS(vbasedev, irq_set);
>       g_free(irq_set);
>   
>       if (!ret) {
> @@ -215,6 +213,7 @@ void vfio_region_write(void *opaque, hwaddr addr,
>           uint32_t dword;
>           uint64_t qword;
>       } buf;
> +    int ret;
>   
>       switch (size) {
>       case 1:
> @@ -234,13 +233,15 @@ void vfio_region_write(void *opaque, hwaddr addr,
>           break;
>       }
>   
> -    if (pwrite(vbasedev->fd, &buf, size, region->fd_offset + addr) != size) {
> +    ret = VDEV_REGION_WRITE(vbasedev, region->nr, addr, size, &buf);
> +    if (ret != size) {
> +        const char *err = ret < 0 ? strerror(-ret) : "short write";
> +
>           error_report("%s(%s:region%d+0x%"HWADDR_PRIx", 0x%"PRIx64
> -                     ",%d) failed: %m",
> +                     ",%d) failed: %s",
>                        __func__, vbasedev->name, region->nr,
> -                     addr, data, size);
> +                     addr, data, size, err);
>       }
> -
>       trace_vfio_region_write(vbasedev->name, region->nr, addr, data, size);
>   
>       /*
> @@ -266,13 +267,18 @@ uint64_t vfio_region_read(void *opaque,
>           uint64_t qword;
>       } buf;
>       uint64_t data = 0;
> +    int ret;
> +
> +    ret = VDEV_REGION_READ(vbasedev, region->nr, addr, size, &buf);
> +    if (ret != size) {
> +        const char *err = ret < 0 ? strerror(-ret) : "short read";
>   
> -    if (pread(vbasedev->fd, &buf, size, region->fd_offset + addr) != size) {
> -        error_report("%s(%s:region%d+0x%"HWADDR_PRIx", %d) failed: %m",
> +        error_report("%s(%s:region%d+0x%"HWADDR_PRIx", %d) failed: %s",
>                        __func__, vbasedev->name, region->nr,
> -                     addr, size);
> +                     addr, size, err);
>           return (uint64_t)-1;
>       }
> +
>       switch (size) {
>       case 1:
>           data = buf.byte;
> @@ -2450,6 +2456,7 @@ int vfio_get_region_info(VFIODevice *vbasedev, int index,
>                            struct vfio_region_info **info)
>   {
>       size_t argsz = sizeof(struct vfio_region_info);
> +    int ret;
>   
>       /* create region cache */
>       if (vbasedev->regions == NULL) {
> @@ -2468,10 +2475,11 @@ int vfio_get_region_info(VFIODevice *vbasedev, int index,
>   retry:
>       (*info)->argsz = argsz;
>   
> -    if (ioctl(vbasedev->fd, VFIO_DEVICE_GET_REGION_INFO, *info)) {
> +    ret = VDEV_GET_REGION_INFO(vbasedev, *info);
> +    if (ret != 0) {
>           g_free(*info);
>           *info = NULL;
> -        return -errno;
> +        return ret;
>       }
>   
>       if ((*info)->argsz > argsz) {
> @@ -2632,6 +2640,75 @@ int vfio_eeh_as_op(AddressSpace *as, uint32_t op)
>    * Traditional ioctl() based io_ops
>    */
>   
> +static int vfio_io_get_info(VFIODevice *vbasedev, struct vfio_device_info *info)
> +{
> +    int ret;
> +
> +    ret = ioctl(vbasedev->fd, VFIO_DEVICE_GET_INFO, info);
> +
> +    return ret < 0 ? -errno : ret;
> +}
> +
> +static int vfio_io_get_region_info(VFIODevice *vbasedev,
> +                                   struct vfio_region_info *info)
> +{
> +    int ret;
> +
> +    ret = ioctl(vbasedev->fd, VFIO_DEVICE_GET_REGION_INFO, info);
> +
> +    return ret < 0 ? -errno : ret;
> +}
> +
> +static int vfio_io_get_irq_info(VFIODevice *vbasedev,
> +                                struct vfio_irq_info *info)
> +{
> +    int ret;
> +
> +    ret = ioctl(vbasedev->fd, VFIO_DEVICE_GET_IRQ_INFO, info);
> +
> +    return ret < 0 ? -errno : ret;
> +}
> +
> +static int vfio_io_set_irqs(VFIODevice *vbasedev, struct vfio_irq_set *irqs)
> +{
> +    int ret;
> +
> +    ret = ioctl(vbasedev->fd, VFIO_DEVICE_SET_IRQS, irqs);
> +
> +    return ret < 0 ? -errno : ret;
> +}
> +
> +static int vfio_io_region_read(VFIODevice *vbasedev, uint8_t index, off_t off,
> +                               uint32_t size, void *data)
> +{
> +    struct vfio_region_info *info = vbasedev->regions[index];
> +    int ret;
> +
> +    ret = pread(vbasedev->fd, data, size, info->offset + off);
> +
> +    return ret < 0 ? -errno : ret;
> +}
> +
> +static int vfio_io_region_write(VFIODevice *vbasedev, uint8_t index, off_t off,
> +                                uint32_t size, void *data)
> +{
> +    struct vfio_region_info *info = vbasedev->regions[index];
> +    int ret;
> +
> +    ret = pwrite(vbasedev->fd, data, size, info->offset + off);
> +
> +    return ret < 0 ? -errno : ret;
> +}
> +
> +VFIODevIO vfio_dev_io_ioctl = {
> +    .get_info = vfio_io_get_info,
> +    .get_region_info = vfio_io_get_region_info,
> +    .get_irq_info = vfio_io_get_irq_info,
> +    .set_irqs = vfio_io_set_irqs,
> +    .region_read = vfio_io_region_read,
> +    .region_write = vfio_io_region_write,
> +};
> +
>   static int vfio_io_dma_map(VFIOContainer *container,
>                              struct vfio_iommu_type1_dma_map *map)
>   {
> diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
> index 1c7618d..80b03a2 100644
> --- a/hw/vfio/pci.c
> +++ b/hw/vfio/pci.c
> @@ -43,6 +43,14 @@
>   #include "migration/blocker.h"
>   #include "migration/qemu-file.h"
>   
> +/* convenience macros for PCI config space */
> +#define VDEV_CONFIG_READ(vbasedev, off, size, data) \
> +    VDEV_REGION_READ((vbasedev), VFIO_PCI_CONFIG_REGION_INDEX, (off), \
> +                     (size), (data))
> +#define VDEV_CONFIG_WRITE(vbasedev, off, size, data) \
> +    VDEV_REGION_WRITE((vbasedev), VFIO_PCI_CONFIG_REGION_INDEX, (off), \
> +                      (size), (data))
> +
>   #define TYPE_VFIO_PCI_NOHOTPLUG "vfio-pci-nohotplug"
>   
>   /* Protected by BQL */
> @@ -406,7 +414,7 @@ static int vfio_enable_vectors(VFIOPCIDevice *vdev, bool msix)
>           fds[i] = fd;
>       }
>   
> -    ret = ioctl(vdev->vbasedev.fd, VFIO_DEVICE_SET_IRQS, irq_set);
> +    ret = VDEV_SET_IRQS(&vdev->vbasedev, irq_set);
>   
>       g_free(irq_set);
>   
> @@ -818,14 +826,16 @@ static void vfio_update_msi(VFIOPCIDevice *vdev)
>   
>   static void vfio_pci_load_rom(VFIOPCIDevice *vdev)
>   {
> +    VFIODevice *vbasedev = &vdev->vbasedev;
>       struct vfio_region_info *reg_info;
>       uint64_t size;
>       off_t off = 0;
>       ssize_t bytes;
> +    int ret;
>   
> -    if (vfio_get_region_info(&vdev->vbasedev,
> -                             VFIO_PCI_ROM_REGION_INDEX, &reg_info)) {
> -        error_report("vfio: Error getting ROM info: %m");
> +    ret = vfio_get_region_info(vbasedev, VFIO_PCI_ROM_REGION_INDEX, &reg_info);
> +    if (ret < 0) {
> +        error_report("vfio: Error getting ROM info: %s", strerror(-ret));
>           return;
>       }
>   
> @@ -850,18 +860,19 @@ static void vfio_pci_load_rom(VFIOPCIDevice *vdev)
>       memset(vdev->rom, 0xff, size);
>   
>       while (size) {
> -        bytes = pread(vdev->vbasedev.fd, vdev->rom + off,
> -                      size, vdev->rom_offset + off);
> +        bytes = VDEV_REGION_READ(vbasedev, VFIO_PCI_ROM_REGION_INDEX, off,
> +                                 size, vdev->rom + off);
>           if (bytes == 0) {
>               break;
>           } else if (bytes > 0) {
>               off += bytes;
>               size -= bytes;
>           } else {
> -            if (errno == EINTR || errno == EAGAIN) {
> +            if (bytes == -EINTR || bytes == -EAGAIN) {
>                   continue;
>               }
> -            error_report("vfio: Error reading device ROM: %m");
> +            error_report("vfio: Error reading device ROM: %s",
> +                         strerror(-bytes));
>               break;
>           }
>       }
> @@ -949,11 +960,10 @@ static const MemoryRegionOps vfio_rom_ops = {
>   
>   static void vfio_pci_size_rom(VFIOPCIDevice *vdev)
>   {
> +    VFIODevice *vbasedev = &vdev->vbasedev;
>       uint32_t orig, size = cpu_to_le32((uint32_t)PCI_ROM_ADDRESS_MASK);
> -    off_t offset = vdev->config_offset + PCI_ROM_ADDRESS;
>       DeviceState *dev = DEVICE(vdev);
>       char *name;
> -    int fd = vdev->vbasedev.fd;
>   
>       if (vdev->pdev.romfile || !vdev->pdev.rom_bar) {
>           /* Since pci handles romfile, just print a message and return */
> @@ -970,11 +980,12 @@ static void vfio_pci_size_rom(VFIOPCIDevice *vdev)
>        * Use the same size ROM BAR as the physical device.  The contents
>        * will get filled in later when the guest tries to read it.
>        */
> -    if (pread(fd, &orig, 4, offset) != 4 ||
> -        pwrite(fd, &size, 4, offset) != 4 ||
> -        pread(fd, &size, 4, offset) != 4 ||
> -        pwrite(fd, &orig, 4, offset) != 4) {
> -        error_report("%s(%s) failed: %m", __func__, vdev->vbasedev.name);
> +    if (VDEV_CONFIG_READ(vbasedev, PCI_ROM_ADDRESS, 4, &orig) != 4 ||
> +        VDEV_CONFIG_WRITE(vbasedev, PCI_ROM_ADDRESS, 4, &size) != 4 ||
> +        VDEV_CONFIG_READ(vbasedev, PCI_ROM_ADDRESS, 4, &size) != 4 ||
> +        VDEV_CONFIG_WRITE(vbasedev, PCI_ROM_ADDRESS, 4, &orig) != 4) {
> +
> +        error_report("%s(%s) ROM access failed", __func__, vbasedev->name);
>           return;
>       }
>   
> @@ -1154,6 +1165,7 @@ static void vfio_sub_page_bar_update_mapping(PCIDevice *pdev, int bar)
>   uint32_t vfio_pci_read_config(PCIDevice *pdev, uint32_t addr, int len)
>   {
>       VFIOPCIDevice *vdev = VFIO_PCI_BASE(pdev);
> +    VFIODevice *vbasedev = &vdev->vbasedev;
>       uint32_t emu_bits = 0, emu_val = 0, phys_val = 0, val;
>   
>       memcpy(&emu_bits, vdev->emulated_config_bits + addr, len);
> @@ -1166,12 +1178,13 @@ uint32_t vfio_pci_read_config(PCIDevice *pdev, uint32_t addr, int len)
>       if (~emu_bits & (0xffffffffU >> (32 - len * 8))) {
>           ssize_t ret;
>   
> -        ret = pread(vdev->vbasedev.fd, &phys_val, len,
> -                    vdev->config_offset + addr);
> +        ret = VDEV_CONFIG_READ(vbasedev, addr, len, &phys_val);
>           if (ret != len) {
> -            error_report("%s(%s, 0x%x, 0x%x) failed: %m",
> -                         __func__, vdev->vbasedev.name, addr, len);
> -            return -errno;
> +            const char *err = ret < 0 ? strerror(-ret) : "short read";
> +
> +            error_report("%s(%s, 0x%x, 0x%x) failed: %s",
> +                         __func__, vbasedev->name, addr, len, err);
> +            return -1;
>           }
>           phys_val = le32_to_cpu(phys_val);
>       }
> @@ -1187,15 +1200,19 @@ void vfio_pci_write_config(PCIDevice *pdev,
>                              uint32_t addr, uint32_t val, int len)
>   {
>       VFIOPCIDevice *vdev = VFIO_PCI_BASE(pdev);
> +    VFIODevice *vbasedev = &vdev->vbasedev;
>       uint32_t val_le = cpu_to_le32(val);
> +    int ret;
>   
>       trace_vfio_pci_write_config(vdev->vbasedev.name, addr, val, len);
>   
>       /* Write everything to VFIO, let it filter out what we can't write */
> -    if (pwrite(vdev->vbasedev.fd, &val_le, len, vdev->config_offset + addr)
> -                != len) {
> -        error_report("%s(%s, 0x%x, 0x%x, 0x%x) failed: %m",
> -                     __func__, vdev->vbasedev.name, addr, val, len);
> +    ret = VDEV_CONFIG_WRITE(vbasedev, addr, len, &val_le);
> +    if (ret != len) {
> +        const char *err = ret < 0 ? strerror(-ret) : "short write";
> +
> +        error_report("%s(%s, 0x%x, 0x%x, 0x%x) failed: %s",
> +                     __func__, vbasedev->name, addr, val, len, err);
>       }
>   
>       /* MSI/MSI-X Enabling/Disabling */
> @@ -1283,10 +1300,13 @@ static int vfio_msi_setup(VFIOPCIDevice *vdev, int pos, Error **errp)
>       int ret, entries;
>       Error *err = NULL;
>   
> -    if (pread(vdev->vbasedev.fd, &ctrl, sizeof(ctrl),
> -              vdev->config_offset + pos + PCI_CAP_FLAGS) != sizeof(ctrl)) {
> -        error_setg_errno(errp, errno, "failed reading MSI PCI_CAP_FLAGS");
> -        return -errno;
> +    ret = VDEV_CONFIG_READ(&vdev->vbasedev, pos + PCI_CAP_FLAGS,
> +                           sizeof(ctrl), &ctrl);
> +    if (ret != sizeof(ctrl)) {
> +        const char *err = ret < 0 ? strerror(-ret) : "short read";
> +
> +        error_setg(errp, "failed reading MSI PCI_CAP_FLAGS %s", err);
> +        return ret;
>       }
>       ctrl = le16_to_cpu(ctrl);
>   
> @@ -1488,33 +1508,39 @@ static void vfio_pci_relocate_msix(VFIOPCIDevice *vdev, Error **errp)
>    */
>   static void vfio_msix_early_setup(VFIOPCIDevice *vdev, Error **errp)
>   {
> +    VFIODevice *vbasedev = &vdev->vbasedev;
>       uint8_t pos;
>       uint16_t ctrl;
>       uint32_t table, pba;
> -    int fd = vdev->vbasedev.fd;
>       VFIOMSIXInfo *msix;
> +    int ret;
>   
>       pos = pci_find_capability(&vdev->pdev, PCI_CAP_ID_MSIX);
>       if (!pos) {
>           return;
>       }
>   
> -    if (pread(fd, &ctrl, sizeof(ctrl),
> -              vdev->config_offset + pos + PCI_MSIX_FLAGS) != sizeof(ctrl)) {
> -        error_setg_errno(errp, errno, "failed to read PCI MSIX FLAGS");
> -        return;
> +    ret = VDEV_CONFIG_READ(vbasedev, pos + PCI_MSIX_FLAGS,
> +                           sizeof(ctrl), &ctrl);
> +    if (ret != sizeof(ctrl)) {
> +        const char *err = ret < 0 ? strerror(-ret) : "short read";
> +
> +        error_setg(errp, "failed to read PCI MSIX FLAGS %s", err);
>       }
>   
> -    if (pread(fd, &table, sizeof(table),
> -              vdev->config_offset + pos + PCI_MSIX_TABLE) != sizeof(table)) {
> -        error_setg_errno(errp, errno, "failed to read PCI MSIX TABLE");
> -        return;
> +    ret = VDEV_CONFIG_READ(vbasedev, pos + PCI_MSIX_TABLE,
> +                           sizeof(table), &table);
> +    if (ret != sizeof(table)) {
> +        const char *err = ret < 0 ? strerror(-ret) : "short read";
> +
> +        error_setg(errp, "failed to read PCI MSIX TABLE %s", err);
>       }
>   
> -    if (pread(fd, &pba, sizeof(pba),
> -              vdev->config_offset + pos + PCI_MSIX_PBA) != sizeof(pba)) {
> -        error_setg_errno(errp, errno, "failed to read PCI MSIX PBA");
> -        return;
> +    ret = VDEV_CONFIG_READ(vbasedev, pos + PCI_MSIX_PBA, sizeof(pba), &pba);
> +    if (ret != sizeof(pba)) {
> +        const char *err = ret < 0 ? strerror(-ret) : "short read";
> +
> +        error_setg(errp, "failed to read PCI MSIX PBA %s", err);
>       }
>   
>       ctrl = le16_to_cpu(ctrl);
> @@ -1652,7 +1678,6 @@ static void vfio_mmap_set_enabled(VFIOPCIDevice *vdev, bool enabled)
>   static void vfio_bar_prepare(VFIOPCIDevice *vdev, int nr)
>   {
>       VFIOBAR *bar = &vdev->bars[nr];
> -
>       uint32_t pci_bar;
>       int ret;
>   
> @@ -1662,10 +1687,12 @@ static void vfio_bar_prepare(VFIOPCIDevice *vdev, int nr)
>       }
>   
>       /* Determine what type of BAR this is for registration */
> -    ret = pread(vdev->vbasedev.fd, &pci_bar, sizeof(pci_bar),
> -                vdev->config_offset + PCI_BASE_ADDRESS_0 + (4 * nr));
> +    ret = VDEV_CONFIG_READ(&vdev->vbasedev, PCI_BASE_ADDRESS_0 + (4 * nr),
> +                           sizeof(pci_bar), &pci_bar);
>       if (ret != sizeof(pci_bar)) {
> -        error_report("vfio: Failed to read BAR %d (%m)", nr);
> +        const char *err =  ret < 0 ? strerror(-ret) : "short read";
> +
> +        error_report("vfio: Failed to read BAR %d (%s)", nr, err);
>           return;
>       }
>   
> @@ -2213,8 +2240,9 @@ static void vfio_pci_pre_reset(VFIOPCIDevice *vdev)
>   
>   static void vfio_pci_post_reset(VFIOPCIDevice *vdev)
>   {
> +    VFIODevice *vbasedev = &vdev->vbasedev;
>       Error *err = NULL;
> -    int nr;
> +    int ret, nr;
>   
>       vfio_intx_enable(vdev, &err);
>       if (err) {
> @@ -2222,13 +2250,16 @@ static void vfio_pci_post_reset(VFIOPCIDevice *vdev)
>       }
>   
>       for (nr = 0; nr < PCI_NUM_REGIONS - 1; ++nr) {
> -        off_t addr = vdev->config_offset + PCI_BASE_ADDRESS_0 + (4 * nr);
> +        off_t addr = PCI_BASE_ADDRESS_0 + (4 * nr);
>           uint32_t val = 0;
>           uint32_t len = sizeof(val);
>   
> -        if (pwrite(vdev->vbasedev.fd, &val, len, addr) != len) {
> -            error_report("%s(%s) reset bar %d failed: %m", __func__,
> -                         vdev->vbasedev.name, nr);
> +        ret = VDEV_CONFIG_WRITE(vbasedev, addr, len, &val);
> +        if (ret != len) {
> +            const char *err = ret < 0 ? strerror(-ret) : "short write";
> +
> +            error_report("%s(%s) reset bar %d failed: %s", __func__,
> +                         vbasedev->name, nr, err);
>           }
>       }
>   
> @@ -2675,7 +2706,7 @@ static void vfio_populate_device(VFIOPCIDevice *vdev, Error **errp)
>   
>       irq_info.index = VFIO_PCI_ERR_IRQ_INDEX;
>   
> -    ret = ioctl(vdev->vbasedev.fd, VFIO_DEVICE_GET_IRQ_INFO, &irq_info);
> +    ret = VDEV_GET_IRQ_INFO(vbasedev, &irq_info);
>       if (ret) {
>           /* This can fail for an old kernel or legacy PCI dev */
>           trace_vfio_populate_device_get_irq_info_failure(strerror(errno));
> @@ -2794,8 +2825,10 @@ static void vfio_register_req_notifier(VFIOPCIDevice *vdev)
>           return;
>       }
>   
> -    if (ioctl(vdev->vbasedev.fd,
> -              VFIO_DEVICE_GET_IRQ_INFO, &irq_info) < 0 || irq_info.count < 1) {
> +    if (VDEV_GET_IRQ_INFO(&vdev->vbasedev, &irq_info) < 0) {
> +        return;
> +    }
> +    if (irq_info.count < 1) {
>           return;
>       }
>   
> @@ -2874,6 +2907,7 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
>       vbasedev->ops = &vfio_pci_ops;
>       vbasedev->type = VFIO_DEVICE_TYPE_PCI;
>       vbasedev->dev = DEVICE(vdev);
> +    vbasedev->io_ops = &vfio_dev_io_ioctl;
>   
>       tmp = g_strdup_printf("%s/iommu_group", vbasedev->sysfsdev);
>       len = readlink(tmp, group_path, sizeof(group_path));
> diff --git a/hw/vfio/platform.c b/hw/vfio/platform.c
> index 5af73f9..c136b09 100644
> --- a/hw/vfio/platform.c
> +++ b/hw/vfio/platform.c
> @@ -621,6 +621,7 @@ static void vfio_platform_realize(DeviceState *dev, Error **errp)
>       vbasedev->type = VFIO_DEVICE_TYPE_PLATFORM;
>       vbasedev->dev = dev;
>       vbasedev->ops = &vfio_platform_ops;
> +    vbasedev->io_ops = &vfio_dev_io_ioctl;
>   
>       qemu_mutex_init(&vdev->intp_mutex);
>   
> diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
> index a1db165..7713d98 100644
> --- a/include/hw/vfio/vfio-common.h
> +++ b/include/hw/vfio/vfio-common.h
> @@ -124,6 +124,7 @@ typedef struct VFIOHostDMAWindow {
>   } VFIOHostDMAWindow;
>   
>   typedef struct VFIODeviceOps VFIODeviceOps;
> +typedef struct VFIODevIO VFIODevIO;
>   
>   typedef struct VFIODevice {
>       QLIST_ENTRY(VFIODevice) next;
> @@ -139,6 +140,7 @@ typedef struct VFIODevice {
>       bool ram_block_discard_allowed;
>       bool enable_migration;
>       VFIODeviceOps *ops;
> +    VFIODevIO *io_ops;

VFIODeviceIoOps ?

>       unsigned int num_irqs;
>       unsigned int num_regions;
>       unsigned int flags;
> @@ -165,6 +167,30 @@ struct VFIODeviceOps {
>    * through ioctl() to the kernel VFIO driver, but vfio-user
>    * can use a socket to a remote process.
>    */
> +struct VFIODevIO {
> +    int (*get_info)(VFIODevice *vdev, struct vfio_device_info *info);
> +    int (*get_region_info)(VFIODevice *vdev,
> +                           struct vfio_region_info *info);
> +    int (*get_irq_info)(VFIODevice *vdev, struct vfio_irq_info *irq);
> +    int (*set_irqs)(VFIODevice *vdev, struct vfio_irq_set *irqs);
> +    int (*region_read)(VFIODevice *vdev, uint8_t nr, off_t off, uint32_t size,
> +                       void *data);
> +    int (*region_write)(VFIODevice *vdev, uint8_t nr, off_t off, uint32_t size,
> +                        void *data);
> +};
> +
> +#define VDEV_GET_INFO(vdev, info) \
> +    ((vdev)->io_ops->get_info((vdev), (info)))
> +#define VDEV_GET_REGION_INFO(vdev, info) \
> +    ((vdev)->io_ops->get_region_info((vdev), (info)))
> +#define VDEV_GET_IRQ_INFO(vdev, irq) \
> +    ((vdev)->io_ops->get_irq_info((vdev), (irq)))
> +#define VDEV_SET_IRQS(vdev, irqs) \
> +    ((vdev)->io_ops->set_irqs((vdev), (irqs)))
> +#define VDEV_REGION_READ(vdev, nr, off, size, data) \
> +    ((vdev)->io_ops->region_read((vdev), (nr), (off), (size), (data)))
> +#define VDEV_REGION_WRITE(vdev, nr, off, size, data) \
> +    ((vdev)->io_ops->region_write((vdev), (nr), (off), (size), (data)))


I don't find these macros very usefull.

Thanks,

C.


>   struct VFIOContIO {
>       int (*dma_map)(VFIOContainer *container,
> @@ -184,6 +210,7 @@ struct VFIOContIO {
>   #define CONT_DIRTY_BITMAP(cont, bitmap, range) \
>       ((cont)->io_ops->dirty_bitmap((cont), (bitmap), (range)))
>   
> +extern VFIODevIO vfio_dev_io_ioctl;
>   extern VFIOContIO vfio_cont_io_ioctl;
>   
>   #endif /* CONFIG_LINUX */
diff mbox series

Patch

diff --git a/hw/vfio/ap.c b/hw/vfio/ap.c
index e0dd561..7ef42f1 100644
--- a/hw/vfio/ap.c
+++ b/hw/vfio/ap.c
@@ -102,6 +102,7 @@  static void vfio_ap_realize(DeviceState *dev, Error **errp)
     mdevid = basename(vapdev->vdev.sysfsdev);
     vapdev->vdev.name = g_strdup_printf("%s", mdevid);
     vapdev->vdev.dev = dev;
+    vapdev->vdev.io_ops = &vfio_dev_io_ioctl;
 
     /*
      * vfio-ap devices operate in a way compatible with discarding of
diff --git a/hw/vfio/ccw.c b/hw/vfio/ccw.c
index 06b588c..cbd1c25 100644
--- a/hw/vfio/ccw.c
+++ b/hw/vfio/ccw.c
@@ -614,6 +614,7 @@  static void vfio_ccw_get_device(VFIOGroup *group, VFIOCCWDevice *vcdev,
     vcdev->vdev.type = VFIO_DEVICE_TYPE_CCW;
     vcdev->vdev.name = name;
     vcdev->vdev.dev = &vcdev->cdev.parent_obj.parent_obj;
+    vcdev->vdev.io_ops = &vfio_dev_io_ioctl;
 
     return;
 
diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index dd9104f..c7bf0aa 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -71,7 +71,7 @@  void vfio_disable_irqindex(VFIODevice *vbasedev, int index)
         .count = 0,
     };
 
-    ioctl(vbasedev->fd, VFIO_DEVICE_SET_IRQS, &irq_set);
+    VDEV_SET_IRQS(vbasedev, &irq_set);
 }
 
 void vfio_unmask_single_irqindex(VFIODevice *vbasedev, int index)
@@ -84,7 +84,7 @@  void vfio_unmask_single_irqindex(VFIODevice *vbasedev, int index)
         .count = 1,
     };
 
-    ioctl(vbasedev->fd, VFIO_DEVICE_SET_IRQS, &irq_set);
+    VDEV_SET_IRQS(vbasedev, &irq_set);
 }
 
 void vfio_mask_single_irqindex(VFIODevice *vbasedev, int index)
@@ -97,7 +97,7 @@  void vfio_mask_single_irqindex(VFIODevice *vbasedev, int index)
         .count = 1,
     };
 
-    ioctl(vbasedev->fd, VFIO_DEVICE_SET_IRQS, &irq_set);
+    VDEV_SET_IRQS(vbasedev, &irq_set);
 }
 
 static inline const char *action_to_str(int action)
@@ -178,9 +178,7 @@  int vfio_set_irq_signaling(VFIODevice *vbasedev, int index, int subindex,
     pfd = (int32_t *)&irq_set->data;
     *pfd = fd;
 
-    if (ioctl(vbasedev->fd, VFIO_DEVICE_SET_IRQS, irq_set)) {
-        ret = -errno;
-    }
+    ret = VDEV_SET_IRQS(vbasedev, irq_set);
     g_free(irq_set);
 
     if (!ret) {
@@ -215,6 +213,7 @@  void vfio_region_write(void *opaque, hwaddr addr,
         uint32_t dword;
         uint64_t qword;
     } buf;
+    int ret;
 
     switch (size) {
     case 1:
@@ -234,13 +233,15 @@  void vfio_region_write(void *opaque, hwaddr addr,
         break;
     }
 
-    if (pwrite(vbasedev->fd, &buf, size, region->fd_offset + addr) != size) {
+    ret = VDEV_REGION_WRITE(vbasedev, region->nr, addr, size, &buf);
+    if (ret != size) {
+        const char *err = ret < 0 ? strerror(-ret) : "short write";
+
         error_report("%s(%s:region%d+0x%"HWADDR_PRIx", 0x%"PRIx64
-                     ",%d) failed: %m",
+                     ",%d) failed: %s",
                      __func__, vbasedev->name, region->nr,
-                     addr, data, size);
+                     addr, data, size, err);
     }
-
     trace_vfio_region_write(vbasedev->name, region->nr, addr, data, size);
 
     /*
@@ -266,13 +267,18 @@  uint64_t vfio_region_read(void *opaque,
         uint64_t qword;
     } buf;
     uint64_t data = 0;
+    int ret;
+
+    ret = VDEV_REGION_READ(vbasedev, region->nr, addr, size, &buf);
+    if (ret != size) {
+        const char *err = ret < 0 ? strerror(-ret) : "short read";
 
-    if (pread(vbasedev->fd, &buf, size, region->fd_offset + addr) != size) {
-        error_report("%s(%s:region%d+0x%"HWADDR_PRIx", %d) failed: %m",
+        error_report("%s(%s:region%d+0x%"HWADDR_PRIx", %d) failed: %s",
                      __func__, vbasedev->name, region->nr,
-                     addr, size);
+                     addr, size, err);
         return (uint64_t)-1;
     }
+
     switch (size) {
     case 1:
         data = buf.byte;
@@ -2450,6 +2456,7 @@  int vfio_get_region_info(VFIODevice *vbasedev, int index,
                          struct vfio_region_info **info)
 {
     size_t argsz = sizeof(struct vfio_region_info);
+    int ret;
 
     /* create region cache */
     if (vbasedev->regions == NULL) {
@@ -2468,10 +2475,11 @@  int vfio_get_region_info(VFIODevice *vbasedev, int index,
 retry:
     (*info)->argsz = argsz;
 
-    if (ioctl(vbasedev->fd, VFIO_DEVICE_GET_REGION_INFO, *info)) {
+    ret = VDEV_GET_REGION_INFO(vbasedev, *info);
+    if (ret != 0) {
         g_free(*info);
         *info = NULL;
-        return -errno;
+        return ret;
     }
 
     if ((*info)->argsz > argsz) {
@@ -2632,6 +2640,75 @@  int vfio_eeh_as_op(AddressSpace *as, uint32_t op)
  * Traditional ioctl() based io_ops
  */
 
+static int vfio_io_get_info(VFIODevice *vbasedev, struct vfio_device_info *info)
+{
+    int ret;
+
+    ret = ioctl(vbasedev->fd, VFIO_DEVICE_GET_INFO, info);
+
+    return ret < 0 ? -errno : ret;
+}
+
+static int vfio_io_get_region_info(VFIODevice *vbasedev,
+                                   struct vfio_region_info *info)
+{
+    int ret;
+
+    ret = ioctl(vbasedev->fd, VFIO_DEVICE_GET_REGION_INFO, info);
+
+    return ret < 0 ? -errno : ret;
+}
+
+static int vfio_io_get_irq_info(VFIODevice *vbasedev,
+                                struct vfio_irq_info *info)
+{
+    int ret;
+
+    ret = ioctl(vbasedev->fd, VFIO_DEVICE_GET_IRQ_INFO, info);
+
+    return ret < 0 ? -errno : ret;
+}
+
+static int vfio_io_set_irqs(VFIODevice *vbasedev, struct vfio_irq_set *irqs)
+{
+    int ret;
+
+    ret = ioctl(vbasedev->fd, VFIO_DEVICE_SET_IRQS, irqs);
+
+    return ret < 0 ? -errno : ret;
+}
+
+static int vfio_io_region_read(VFIODevice *vbasedev, uint8_t index, off_t off,
+                               uint32_t size, void *data)
+{
+    struct vfio_region_info *info = vbasedev->regions[index];
+    int ret;
+
+    ret = pread(vbasedev->fd, data, size, info->offset + off);
+
+    return ret < 0 ? -errno : ret;
+}
+
+static int vfio_io_region_write(VFIODevice *vbasedev, uint8_t index, off_t off,
+                                uint32_t size, void *data)
+{
+    struct vfio_region_info *info = vbasedev->regions[index];
+    int ret;
+
+    ret = pwrite(vbasedev->fd, data, size, info->offset + off);
+
+    return ret < 0 ? -errno : ret;
+}
+
+VFIODevIO vfio_dev_io_ioctl = {
+    .get_info = vfio_io_get_info,
+    .get_region_info = vfio_io_get_region_info,
+    .get_irq_info = vfio_io_get_irq_info,
+    .set_irqs = vfio_io_set_irqs,
+    .region_read = vfio_io_region_read,
+    .region_write = vfio_io_region_write,
+};
+
 static int vfio_io_dma_map(VFIOContainer *container,
                            struct vfio_iommu_type1_dma_map *map)
 {
diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index 1c7618d..80b03a2 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -43,6 +43,14 @@ 
 #include "migration/blocker.h"
 #include "migration/qemu-file.h"
 
+/* convenience macros for PCI config space */
+#define VDEV_CONFIG_READ(vbasedev, off, size, data) \
+    VDEV_REGION_READ((vbasedev), VFIO_PCI_CONFIG_REGION_INDEX, (off), \
+                     (size), (data))
+#define VDEV_CONFIG_WRITE(vbasedev, off, size, data) \
+    VDEV_REGION_WRITE((vbasedev), VFIO_PCI_CONFIG_REGION_INDEX, (off), \
+                      (size), (data))
+
 #define TYPE_VFIO_PCI_NOHOTPLUG "vfio-pci-nohotplug"
 
 /* Protected by BQL */
@@ -406,7 +414,7 @@  static int vfio_enable_vectors(VFIOPCIDevice *vdev, bool msix)
         fds[i] = fd;
     }
 
-    ret = ioctl(vdev->vbasedev.fd, VFIO_DEVICE_SET_IRQS, irq_set);
+    ret = VDEV_SET_IRQS(&vdev->vbasedev, irq_set);
 
     g_free(irq_set);
 
@@ -818,14 +826,16 @@  static void vfio_update_msi(VFIOPCIDevice *vdev)
 
 static void vfio_pci_load_rom(VFIOPCIDevice *vdev)
 {
+    VFIODevice *vbasedev = &vdev->vbasedev;
     struct vfio_region_info *reg_info;
     uint64_t size;
     off_t off = 0;
     ssize_t bytes;
+    int ret;
 
-    if (vfio_get_region_info(&vdev->vbasedev,
-                             VFIO_PCI_ROM_REGION_INDEX, &reg_info)) {
-        error_report("vfio: Error getting ROM info: %m");
+    ret = vfio_get_region_info(vbasedev, VFIO_PCI_ROM_REGION_INDEX, &reg_info);
+    if (ret < 0) {
+        error_report("vfio: Error getting ROM info: %s", strerror(-ret));
         return;
     }
 
@@ -850,18 +860,19 @@  static void vfio_pci_load_rom(VFIOPCIDevice *vdev)
     memset(vdev->rom, 0xff, size);
 
     while (size) {
-        bytes = pread(vdev->vbasedev.fd, vdev->rom + off,
-                      size, vdev->rom_offset + off);
+        bytes = VDEV_REGION_READ(vbasedev, VFIO_PCI_ROM_REGION_INDEX, off,
+                                 size, vdev->rom + off);
         if (bytes == 0) {
             break;
         } else if (bytes > 0) {
             off += bytes;
             size -= bytes;
         } else {
-            if (errno == EINTR || errno == EAGAIN) {
+            if (bytes == -EINTR || bytes == -EAGAIN) {
                 continue;
             }
-            error_report("vfio: Error reading device ROM: %m");
+            error_report("vfio: Error reading device ROM: %s",
+                         strerror(-bytes));
             break;
         }
     }
@@ -949,11 +960,10 @@  static const MemoryRegionOps vfio_rom_ops = {
 
 static void vfio_pci_size_rom(VFIOPCIDevice *vdev)
 {
+    VFIODevice *vbasedev = &vdev->vbasedev;
     uint32_t orig, size = cpu_to_le32((uint32_t)PCI_ROM_ADDRESS_MASK);
-    off_t offset = vdev->config_offset + PCI_ROM_ADDRESS;
     DeviceState *dev = DEVICE(vdev);
     char *name;
-    int fd = vdev->vbasedev.fd;
 
     if (vdev->pdev.romfile || !vdev->pdev.rom_bar) {
         /* Since pci handles romfile, just print a message and return */
@@ -970,11 +980,12 @@  static void vfio_pci_size_rom(VFIOPCIDevice *vdev)
      * Use the same size ROM BAR as the physical device.  The contents
      * will get filled in later when the guest tries to read it.
      */
-    if (pread(fd, &orig, 4, offset) != 4 ||
-        pwrite(fd, &size, 4, offset) != 4 ||
-        pread(fd, &size, 4, offset) != 4 ||
-        pwrite(fd, &orig, 4, offset) != 4) {
-        error_report("%s(%s) failed: %m", __func__, vdev->vbasedev.name);
+    if (VDEV_CONFIG_READ(vbasedev, PCI_ROM_ADDRESS, 4, &orig) != 4 ||
+        VDEV_CONFIG_WRITE(vbasedev, PCI_ROM_ADDRESS, 4, &size) != 4 ||
+        VDEV_CONFIG_READ(vbasedev, PCI_ROM_ADDRESS, 4, &size) != 4 ||
+        VDEV_CONFIG_WRITE(vbasedev, PCI_ROM_ADDRESS, 4, &orig) != 4) {
+
+        error_report("%s(%s) ROM access failed", __func__, vbasedev->name);
         return;
     }
 
@@ -1154,6 +1165,7 @@  static void vfio_sub_page_bar_update_mapping(PCIDevice *pdev, int bar)
 uint32_t vfio_pci_read_config(PCIDevice *pdev, uint32_t addr, int len)
 {
     VFIOPCIDevice *vdev = VFIO_PCI_BASE(pdev);
+    VFIODevice *vbasedev = &vdev->vbasedev;
     uint32_t emu_bits = 0, emu_val = 0, phys_val = 0, val;
 
     memcpy(&emu_bits, vdev->emulated_config_bits + addr, len);
@@ -1166,12 +1178,13 @@  uint32_t vfio_pci_read_config(PCIDevice *pdev, uint32_t addr, int len)
     if (~emu_bits & (0xffffffffU >> (32 - len * 8))) {
         ssize_t ret;
 
-        ret = pread(vdev->vbasedev.fd, &phys_val, len,
-                    vdev->config_offset + addr);
+        ret = VDEV_CONFIG_READ(vbasedev, addr, len, &phys_val);
         if (ret != len) {
-            error_report("%s(%s, 0x%x, 0x%x) failed: %m",
-                         __func__, vdev->vbasedev.name, addr, len);
-            return -errno;
+            const char *err = ret < 0 ? strerror(-ret) : "short read";
+
+            error_report("%s(%s, 0x%x, 0x%x) failed: %s",
+                         __func__, vbasedev->name, addr, len, err);
+            return -1;
         }
         phys_val = le32_to_cpu(phys_val);
     }
@@ -1187,15 +1200,19 @@  void vfio_pci_write_config(PCIDevice *pdev,
                            uint32_t addr, uint32_t val, int len)
 {
     VFIOPCIDevice *vdev = VFIO_PCI_BASE(pdev);
+    VFIODevice *vbasedev = &vdev->vbasedev;
     uint32_t val_le = cpu_to_le32(val);
+    int ret;
 
     trace_vfio_pci_write_config(vdev->vbasedev.name, addr, val, len);
 
     /* Write everything to VFIO, let it filter out what we can't write */
-    if (pwrite(vdev->vbasedev.fd, &val_le, len, vdev->config_offset + addr)
-                != len) {
-        error_report("%s(%s, 0x%x, 0x%x, 0x%x) failed: %m",
-                     __func__, vdev->vbasedev.name, addr, val, len);
+    ret = VDEV_CONFIG_WRITE(vbasedev, addr, len, &val_le);
+    if (ret != len) {
+        const char *err = ret < 0 ? strerror(-ret) : "short write";
+
+        error_report("%s(%s, 0x%x, 0x%x, 0x%x) failed: %s",
+                     __func__, vbasedev->name, addr, val, len, err);
     }
 
     /* MSI/MSI-X Enabling/Disabling */
@@ -1283,10 +1300,13 @@  static int vfio_msi_setup(VFIOPCIDevice *vdev, int pos, Error **errp)
     int ret, entries;
     Error *err = NULL;
 
-    if (pread(vdev->vbasedev.fd, &ctrl, sizeof(ctrl),
-              vdev->config_offset + pos + PCI_CAP_FLAGS) != sizeof(ctrl)) {
-        error_setg_errno(errp, errno, "failed reading MSI PCI_CAP_FLAGS");
-        return -errno;
+    ret = VDEV_CONFIG_READ(&vdev->vbasedev, pos + PCI_CAP_FLAGS,
+                           sizeof(ctrl), &ctrl);
+    if (ret != sizeof(ctrl)) {
+        const char *err = ret < 0 ? strerror(-ret) : "short read";
+
+        error_setg(errp, "failed reading MSI PCI_CAP_FLAGS %s", err);
+        return ret;
     }
     ctrl = le16_to_cpu(ctrl);
 
@@ -1488,33 +1508,39 @@  static void vfio_pci_relocate_msix(VFIOPCIDevice *vdev, Error **errp)
  */
 static void vfio_msix_early_setup(VFIOPCIDevice *vdev, Error **errp)
 {
+    VFIODevice *vbasedev = &vdev->vbasedev;
     uint8_t pos;
     uint16_t ctrl;
     uint32_t table, pba;
-    int fd = vdev->vbasedev.fd;
     VFIOMSIXInfo *msix;
+    int ret;
 
     pos = pci_find_capability(&vdev->pdev, PCI_CAP_ID_MSIX);
     if (!pos) {
         return;
     }
 
-    if (pread(fd, &ctrl, sizeof(ctrl),
-              vdev->config_offset + pos + PCI_MSIX_FLAGS) != sizeof(ctrl)) {
-        error_setg_errno(errp, errno, "failed to read PCI MSIX FLAGS");
-        return;
+    ret = VDEV_CONFIG_READ(vbasedev, pos + PCI_MSIX_FLAGS,
+                           sizeof(ctrl), &ctrl);
+    if (ret != sizeof(ctrl)) {
+        const char *err = ret < 0 ? strerror(-ret) : "short read";
+
+        error_setg(errp, "failed to read PCI MSIX FLAGS %s", err);
     }
 
-    if (pread(fd, &table, sizeof(table),
-              vdev->config_offset + pos + PCI_MSIX_TABLE) != sizeof(table)) {
-        error_setg_errno(errp, errno, "failed to read PCI MSIX TABLE");
-        return;
+    ret = VDEV_CONFIG_READ(vbasedev, pos + PCI_MSIX_TABLE,
+                           sizeof(table), &table);
+    if (ret != sizeof(table)) {
+        const char *err = ret < 0 ? strerror(-ret) : "short read";
+
+        error_setg(errp, "failed to read PCI MSIX TABLE %s", err);
     }
 
-    if (pread(fd, &pba, sizeof(pba),
-              vdev->config_offset + pos + PCI_MSIX_PBA) != sizeof(pba)) {
-        error_setg_errno(errp, errno, "failed to read PCI MSIX PBA");
-        return;
+    ret = VDEV_CONFIG_READ(vbasedev, pos + PCI_MSIX_PBA, sizeof(pba), &pba);
+    if (ret != sizeof(pba)) {
+        const char *err = ret < 0 ? strerror(-ret) : "short read";
+
+        error_setg(errp, "failed to read PCI MSIX PBA %s", err);
     }
 
     ctrl = le16_to_cpu(ctrl);
@@ -1652,7 +1678,6 @@  static void vfio_mmap_set_enabled(VFIOPCIDevice *vdev, bool enabled)
 static void vfio_bar_prepare(VFIOPCIDevice *vdev, int nr)
 {
     VFIOBAR *bar = &vdev->bars[nr];
-
     uint32_t pci_bar;
     int ret;
 
@@ -1662,10 +1687,12 @@  static void vfio_bar_prepare(VFIOPCIDevice *vdev, int nr)
     }
 
     /* Determine what type of BAR this is for registration */
-    ret = pread(vdev->vbasedev.fd, &pci_bar, sizeof(pci_bar),
-                vdev->config_offset + PCI_BASE_ADDRESS_0 + (4 * nr));
+    ret = VDEV_CONFIG_READ(&vdev->vbasedev, PCI_BASE_ADDRESS_0 + (4 * nr),
+                           sizeof(pci_bar), &pci_bar);
     if (ret != sizeof(pci_bar)) {
-        error_report("vfio: Failed to read BAR %d (%m)", nr);
+        const char *err =  ret < 0 ? strerror(-ret) : "short read";
+
+        error_report("vfio: Failed to read BAR %d (%s)", nr, err);
         return;
     }
 
@@ -2213,8 +2240,9 @@  static void vfio_pci_pre_reset(VFIOPCIDevice *vdev)
 
 static void vfio_pci_post_reset(VFIOPCIDevice *vdev)
 {
+    VFIODevice *vbasedev = &vdev->vbasedev;
     Error *err = NULL;
-    int nr;
+    int ret, nr;
 
     vfio_intx_enable(vdev, &err);
     if (err) {
@@ -2222,13 +2250,16 @@  static void vfio_pci_post_reset(VFIOPCIDevice *vdev)
     }
 
     for (nr = 0; nr < PCI_NUM_REGIONS - 1; ++nr) {
-        off_t addr = vdev->config_offset + PCI_BASE_ADDRESS_0 + (4 * nr);
+        off_t addr = PCI_BASE_ADDRESS_0 + (4 * nr);
         uint32_t val = 0;
         uint32_t len = sizeof(val);
 
-        if (pwrite(vdev->vbasedev.fd, &val, len, addr) != len) {
-            error_report("%s(%s) reset bar %d failed: %m", __func__,
-                         vdev->vbasedev.name, nr);
+        ret = VDEV_CONFIG_WRITE(vbasedev, addr, len, &val);
+        if (ret != len) {
+            const char *err = ret < 0 ? strerror(-ret) : "short write";
+
+            error_report("%s(%s) reset bar %d failed: %s", __func__,
+                         vbasedev->name, nr, err);
         }
     }
 
@@ -2675,7 +2706,7 @@  static void vfio_populate_device(VFIOPCIDevice *vdev, Error **errp)
 
     irq_info.index = VFIO_PCI_ERR_IRQ_INDEX;
 
-    ret = ioctl(vdev->vbasedev.fd, VFIO_DEVICE_GET_IRQ_INFO, &irq_info);
+    ret = VDEV_GET_IRQ_INFO(vbasedev, &irq_info);
     if (ret) {
         /* This can fail for an old kernel or legacy PCI dev */
         trace_vfio_populate_device_get_irq_info_failure(strerror(errno));
@@ -2794,8 +2825,10 @@  static void vfio_register_req_notifier(VFIOPCIDevice *vdev)
         return;
     }
 
-    if (ioctl(vdev->vbasedev.fd,
-              VFIO_DEVICE_GET_IRQ_INFO, &irq_info) < 0 || irq_info.count < 1) {
+    if (VDEV_GET_IRQ_INFO(&vdev->vbasedev, &irq_info) < 0) {
+        return;
+    }
+    if (irq_info.count < 1) {
         return;
     }
 
@@ -2874,6 +2907,7 @@  static void vfio_realize(PCIDevice *pdev, Error **errp)
     vbasedev->ops = &vfio_pci_ops;
     vbasedev->type = VFIO_DEVICE_TYPE_PCI;
     vbasedev->dev = DEVICE(vdev);
+    vbasedev->io_ops = &vfio_dev_io_ioctl;
 
     tmp = g_strdup_printf("%s/iommu_group", vbasedev->sysfsdev);
     len = readlink(tmp, group_path, sizeof(group_path));
diff --git a/hw/vfio/platform.c b/hw/vfio/platform.c
index 5af73f9..c136b09 100644
--- a/hw/vfio/platform.c
+++ b/hw/vfio/platform.c
@@ -621,6 +621,7 @@  static void vfio_platform_realize(DeviceState *dev, Error **errp)
     vbasedev->type = VFIO_DEVICE_TYPE_PLATFORM;
     vbasedev->dev = dev;
     vbasedev->ops = &vfio_platform_ops;
+    vbasedev->io_ops = &vfio_dev_io_ioctl;
 
     qemu_mutex_init(&vdev->intp_mutex);
 
diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
index a1db165..7713d98 100644
--- a/include/hw/vfio/vfio-common.h
+++ b/include/hw/vfio/vfio-common.h
@@ -124,6 +124,7 @@  typedef struct VFIOHostDMAWindow {
 } VFIOHostDMAWindow;
 
 typedef struct VFIODeviceOps VFIODeviceOps;
+typedef struct VFIODevIO VFIODevIO;
 
 typedef struct VFIODevice {
     QLIST_ENTRY(VFIODevice) next;
@@ -139,6 +140,7 @@  typedef struct VFIODevice {
     bool ram_block_discard_allowed;
     bool enable_migration;
     VFIODeviceOps *ops;
+    VFIODevIO *io_ops;
     unsigned int num_irqs;
     unsigned int num_regions;
     unsigned int flags;
@@ -165,6 +167,30 @@  struct VFIODeviceOps {
  * through ioctl() to the kernel VFIO driver, but vfio-user
  * can use a socket to a remote process.
  */
+struct VFIODevIO {
+    int (*get_info)(VFIODevice *vdev, struct vfio_device_info *info);
+    int (*get_region_info)(VFIODevice *vdev,
+                           struct vfio_region_info *info);
+    int (*get_irq_info)(VFIODevice *vdev, struct vfio_irq_info *irq);
+    int (*set_irqs)(VFIODevice *vdev, struct vfio_irq_set *irqs);
+    int (*region_read)(VFIODevice *vdev, uint8_t nr, off_t off, uint32_t size,
+                       void *data);
+    int (*region_write)(VFIODevice *vdev, uint8_t nr, off_t off, uint32_t size,
+                        void *data);
+};
+
+#define VDEV_GET_INFO(vdev, info) \
+    ((vdev)->io_ops->get_info((vdev), (info)))
+#define VDEV_GET_REGION_INFO(vdev, info) \
+    ((vdev)->io_ops->get_region_info((vdev), (info)))
+#define VDEV_GET_IRQ_INFO(vdev, irq) \
+    ((vdev)->io_ops->get_irq_info((vdev), (irq)))
+#define VDEV_SET_IRQS(vdev, irqs) \
+    ((vdev)->io_ops->set_irqs((vdev), (irqs)))
+#define VDEV_REGION_READ(vdev, nr, off, size, data) \
+    ((vdev)->io_ops->region_read((vdev), (nr), (off), (size), (data)))
+#define VDEV_REGION_WRITE(vdev, nr, off, size, data) \
+    ((vdev)->io_ops->region_write((vdev), (nr), (off), (size), (data)))
 
 struct VFIOContIO {
     int (*dma_map)(VFIOContainer *container,
@@ -184,6 +210,7 @@  struct VFIOContIO {
 #define CONT_DIRTY_BITMAP(cont, bitmap, range) \
     ((cont)->io_ops->dirty_bitmap((cont), (bitmap), (range)))
 
+extern VFIODevIO vfio_dev_io_ioctl;
 extern VFIOContIO vfio_cont_io_ioctl;
 
 #endif /* CONFIG_LINUX */