Hi Zhenzhong,
On 9/26/23 13:32, Zhenzhong Duan wrote:
> From: Eric Auger <eric.au...@redhat.com>
>
> We want the VFIO devices to be able to use two different
> IOMMU backends, the legacy VFIO one and the new iommufd one.
>
> Introduce vfio_[attach/detach]_device which aim at hiding the
> underlying IOMMU backend (IOCTLs, datatypes, ...).
>
> Once vfio_attach_device completes, the device is attached
> to a security context and its fd can be used. Conversely
> When vfio_detach_device completes, the device has been
> detached from the security context.
>
> At the moment only the implementation based on the legacy
> container/group exists. Let's use it from the vfio-pci device.
> Subsequent patches will handle other devices.
>
> Signed-off-by: Eric Auger <eric.au...@redhat.com>
> Signed-off-by: Yi Liu <yi.l....@intel.com>
> Signed-off-by: Zhenzhong Duan <zhenzhong.d...@intel.com>
> ---
> include/hw/vfio/vfio-common.h | 3 ++
> hw/vfio/common.c | 68 +++++++++++++++++++++++++++++++++++
> hw/vfio/pci.c | 50 +++-----------------------
> hw/vfio/trace-events | 2 +-
> 4 files changed, 77 insertions(+), 46 deletions(-)
>
> diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
> index c4e7c3b4a7..12fbfbc37d 100644
> --- a/include/hw/vfio/vfio-common.h
> +++ b/include/hw/vfio/vfio-common.h
> @@ -225,6 +225,9 @@ void vfio_put_group(VFIOGroup *group);
> struct vfio_device_info *vfio_get_device_info(int fd);
> int vfio_get_device(VFIOGroup *group, const char *name,
> VFIODevice *vbasedev, Error **errp);
> +int vfio_attach_device(char *name, VFIODevice *vbasedev,
> + AddressSpace *as, Error **errp);
> +void vfio_detach_device(VFIODevice *vbasedev);
>
> int vfio_kvm_device_add_fd(int fd, Error **errp);
> int vfio_kvm_device_del_fd(int fd, Error **errp);
> diff --git a/hw/vfio/common.c b/hw/vfio/common.c
> index 959b1362bb..7f3798b152 100644
> --- a/hw/vfio/common.c
> +++ b/hw/vfio/common.c
> @@ -2611,3 +2611,71 @@ int vfio_eeh_as_op(AddressSpace *as, uint32_t op)
> }
> return vfio_eeh_container_op(container, op);
> }
> +
> +static int vfio_device_groupid(VFIODevice *vbasedev, Error **errp)
> +{
> + char *tmp, group_path[PATH_MAX], *group_name;
> + int ret, groupid;
> + ssize_t len;
> +
> + tmp = g_strdup_printf("%s/iommu_group", vbasedev->sysfsdev);
> + len = readlink(tmp, group_path, sizeof(group_path));
> + g_free(tmp);
> +
> + if (len <= 0 || len >= sizeof(group_path)) {
> + ret = len < 0 ? -errno : -ENAMETOOLONG;
> + error_setg_errno(errp, -ret, "no iommu_group found");
> + return ret;
> + }
> +
> + group_path[len] = 0;
> +
> + group_name = basename(group_path);
> + if (sscanf(group_name, "%d", &groupid) != 1) {
> + error_setg_errno(errp, errno, "failed to read %s", group_path);
> + return -errno;
> + }
> + return groupid;
> +}
> +
> +int vfio_attach_device(char *name, VFIODevice *vbasedev,
> + AddressSpace *as, Error **errp)
> +{
> + int groupid = vfio_device_groupid(vbasedev, errp);
> + VFIODevice *vbasedev_iter;
> + VFIOGroup *group;
> + int ret;
> +
> + if (groupid < 0) {
> + return groupid;
> + }
> +
> + trace_vfio_attach_device(vbasedev->name, groupid);
> +
> + group = vfio_get_group(groupid, as, errp);
> + if (!group) {
> + return -ENOENT;
> + }
> +
> + QLIST_FOREACH(vbasedev_iter, &group->device_list, next) {
> + if (strcmp(vbasedev_iter->name, vbasedev->name) == 0) {
> + error_setg(errp, "device is already attached");
> + vfio_put_group(group);
> + return -EBUSY;
> + }
> + }
> + ret = vfio_get_device(group, name, vbasedev, errp);
> + if (ret) {
> + vfio_put_group(group);
> + }
> +
> + return ret;
> +}
> +
> +void vfio_detach_device(VFIODevice *vbasedev)
> +{
> + VFIOGroup *group = vbasedev->group;
> +
> + vfio_put_base_device(vbasedev);
> + vfio_put_group(group);
> +}
> diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
> index 3b2ca3c24c..fe56789893 100644
> --- a/hw/vfio/pci.c
> +++ b/hw/vfio/pci.c
> @@ -2828,10 +2828,10 @@ static void vfio_populate_device(VFIOPCIDevice *vdev,
> Error **errp)
>
> static void vfio_put_device(VFIOPCIDevice *vdev)
> {
> + vfio_detach_device(&vdev->vbasedev);
> +
> g_free(vdev->vbasedev.name);
> g_free(vdev->msix);
> -
> - vfio_put_base_device(&vdev->vbasedev);
> }
>
> static void vfio_err_notifier_handler(void *opaque)
> @@ -2978,13 +2978,9 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
> {
> VFIOPCIDevice *vdev = VFIO_PCI(pdev);
> VFIODevice *vbasedev = &vdev->vbasedev;
> - VFIODevice *vbasedev_iter;
> - VFIOGroup *group;
> - char *tmp, *subsys, group_path[PATH_MAX], *group_name;
> + char *tmp, *subsys;
> Error *err = NULL;
> - ssize_t len;
> struct stat st;
> - int groupid;
> int i, ret;
> bool is_mdev;
> char uuid[UUID_FMT_LEN];
> @@ -3015,39 +3011,6 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
> vbasedev->type = VFIO_DEVICE_TYPE_PCI;
> vbasedev->dev = DEVICE(vdev);
>
> - tmp = g_strdup_printf("%s/iommu_group", vbasedev->sysfsdev);
> - len = readlink(tmp, group_path, sizeof(group_path));
> - g_free(tmp);
> -
> - if (len <= 0 || len >= sizeof(group_path)) {
> - error_setg_errno(errp, len < 0 ? errno : ENAMETOOLONG,
> - "no iommu_group found");
> - goto error;
> - }
> -
> - group_path[len] = 0;
> -
> - group_name = basename(group_path);
> - if (sscanf(group_name, "%d", &groupid) != 1) {
> - error_setg_errno(errp, errno, "failed to read %s", group_path);
> - goto error;
> - }
> -
> - trace_vfio_realize(vbasedev->name, groupid);
> -
> - group = vfio_get_group(groupid, pci_device_iommu_address_space(pdev),
> errp);
> - if (!group) {
> - goto error;
> - }
> -
> - QLIST_FOREACH(vbasedev_iter, &group->device_list, next) {
> - if (strcmp(vbasedev_iter->name, vbasedev->name) == 0) {
> - error_setg(errp, "device is already attached");
> - vfio_put_group(group);
> - goto error;
> - }
> - }
> -
> /*
> * Mediated devices *might* operate compatibly with discarding of RAM,
> but
> * we cannot know for certain, it depends on whether the mdev vendor
> driver
> @@ -3065,7 +3028,6 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
> if (vbasedev->ram_block_discard_allowed && !is_mdev) {
> error_setg(errp, "x-balloon-allowed only potentially compatible "
> "with mdev devices");
> - vfio_put_group(group);
> goto error;
> }
>
> @@ -3076,10 +3038,10 @@ static void vfio_realize(PCIDevice *pdev, Error
> **errp)
> name = g_strdup(vbasedev->name);
> }
>
> - ret = vfio_get_device(group, name, vbasedev, errp);
> + ret = vfio_attach_device(name, vbasedev,
> + pci_device_iommu_address_space(pdev), errp);
> g_free(name);
> if (ret) {
> - vfio_put_group(group);
independently on this patch, I think in case of error we leak
vbasedev->name. Please have a look and if confirmed you can send a
separate patch.
Also I think if any subsequent action fail we shoudl properly detach the
detach the device so introduce an extra error goto label, my bad sorry.
Thanks
Eric
> goto error;
> }
>
> @@ -3304,7 +3266,6 @@ error:
> static void vfio_instance_finalize(Object *obj)
> {
> VFIOPCIDevice *vdev = VFIO_PCI(obj);
> - VFIOGroup *group = vdev->vbasedev.group;
>
> vfio_display_finalize(vdev);
> vfio_bars_finalize(vdev);
> @@ -3318,7 +3279,6 @@ static void vfio_instance_finalize(Object *obj)
> * g_free(vdev->igd_opregion);
> */
> vfio_put_device(vdev);
> - vfio_put_group(group);
> }
>
> static void vfio_exitfn(PCIDevice *pdev)
> diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events
> index e64ca4a019..e710026a73 100644
> --- a/hw/vfio/trace-events
> +++ b/hw/vfio/trace-events
> @@ -37,7 +37,7 @@ vfio_pci_hot_reset_dep_devices(int domain, int bus, int
> slot, int function, int
> vfio_pci_hot_reset_result(const char *name, const char *result) "%s hot
> reset: %s"
> vfio_populate_device_config(const char *name, unsigned long size, unsigned
> long offset, unsigned long flags) "Device %s config:\n size: 0x%lx, offset:
> 0x%lx, flags: 0x%lx"
> vfio_populate_device_get_irq_info_failure(const char *errstr)
> "VFIO_DEVICE_GET_IRQ_INFO failure: %s"
> -vfio_realize(const char *name, int group_id) " (%s) group %d"
> +vfio_attach_device(const char *name, int group_id) " (%s) group %d"
> vfio_mdev(const char *name, bool is_mdev) " (%s) is_mdev %d"
> vfio_add_ext_cap_dropped(const char *name, uint16_t cap, uint16_t offset)
> "%s 0x%x@0x%x"
> vfio_pci_reset(const char *name) " (%s)"
