RE: [PATCH v4 28/41] vfio/iommufd: Implement the iommufd backend

[Duan, Zhenzhong]

>-----Original Message-----
>From: Cédric Le Goater <clg@redhat.com>
>Sent: Tuesday, November 7, 2023 9:41 PM
>Subject: Re: [PATCH v4 28/41] vfio/iommufd: Implement the iommufd backend
>
>On 11/2/23 08:12, Zhenzhong Duan wrote:
>> From: Yi Liu <yi.l.liu@intel.com>
>>
>> Add the iommufd backend. The IOMMUFD container class is implemented
>> based on the new /dev/iommu user API. This backend obviously depends
>> on CONFIG_IOMMUFD.
>>
>> So far, the iommufd backend doesn't support dirty page sync yet due
>> to missing support in the host kernel.
>>
>> Co-authored-by: Eric Auger <eric.auger@redhat.com>
>> Signed-off-by: Eric Auger <eric.auger@redhat.com>
>
>I think one tag for Eric is enough.
>
>> Signed-off-by: Yi Liu <yi.l.liu@intel.com>
>> Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
>> ---
>> v4: use SPDX identifier, use iommufd_cdev_* prefix, merge with manual alloc
>patch
>>
>>   include/hw/vfio/vfio-common.h |  23 ++
>>   hw/vfio/common.c              |  19 +-
>>   hw/vfio/iommufd.c             | 504 ++++++++++++++++++++++++++++++++++
>>   hw/vfio/meson.build           |   3 +
>>   hw/vfio/trace-events          |  13 +
>>   5 files changed, 558 insertions(+), 4 deletions(-)
>>   create mode 100644 hw/vfio/iommufd.c
>>
>> diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
>> index 24ecc0e7ee..3f1a39a991 100644
>> --- a/include/hw/vfio/vfio-common.h
>> +++ b/include/hw/vfio/vfio-common.h
>> @@ -89,6 +89,23 @@ typedef struct VFIOHostDMAWindow {
>>       QLIST_ENTRY(VFIOHostDMAWindow) hostwin_next;
>>   } VFIOHostDMAWindow;
>>
>> +#ifdef CONFIG_IOMMUFD
>
>Please remove the #ifdef.

Will do.

>
>> +typedef struct VFIOIOASHwpt {
>> +    uint32_t hwpt_id;
>> +    QLIST_HEAD(, VFIODevice) device_list;
>> +    QLIST_ENTRY(VFIOIOASHwpt) next;
>> +} VFIOIOASHwpt;
>> +
>> +typedef struct IOMMUFDBackend IOMMUFDBackend;
>> +
>> +typedef struct VFIOIOMMUFDContainer {
>> +    VFIOContainerBase bcontainer;
>> +    IOMMUFDBackend *be;
>> +    uint32_t ioas_id;
>> +    QLIST_HEAD(, VFIOIOASHwpt) hwpt_list;
>> +} VFIOIOMMUFDContainer;
>> +#endif
>> +
>>   typedef struct VFIODeviceOps VFIODeviceOps;
>>
>>   typedef struct VFIODevice {
>> @@ -116,6 +133,11 @@ typedef struct VFIODevice {
>>       OnOffAuto pre_copy_dirty_page_tracking;
>>       bool dirty_pages_supported;
>>       bool dirty_tracking;
>> +#ifdef CONFIG_IOMMUFD
>> +    int devid;
>> +    VFIOIOASHwpt *hwpt;
>> +    IOMMUFDBackend *iommufd;
>> +#endif
>>   } VFIODevice;
>>
>>   struct VFIODeviceOps {
>> @@ -201,6 +223,7 @@ typedef QLIST_HEAD(VFIODeviceList, VFIODevice)
>VFIODeviceList;
>>   extern VFIOGroupList vfio_group_list;
>>   extern VFIODeviceList vfio_device_list;
>>   extern const VFIOIOMMUOps vfio_legacy_ops;
>> +extern const VFIOIOMMUOps vfio_iommufd_ops;
>>   extern const MemoryListener vfio_memory_listener;
>>   extern int vfio_kvm_device_fd;
>>
>> diff --git a/hw/vfio/common.c b/hw/vfio/common.c
>> index 572ae7c934..a61dce2845 100644
>> --- a/hw/vfio/common.c
>> +++ b/hw/vfio/common.c
>> @@ -1462,10 +1462,13 @@ VFIOAddressSpace
>*vfio_get_address_space(AddressSpace *as)
>>
>>   void vfio_put_address_space(VFIOAddressSpace *space)
>>   {
>> -    if (QLIST_EMPTY(&space->containers)) {
>> -        QLIST_REMOVE(space, list);
>> -        g_free(space);
>> +    if (!QLIST_EMPTY(&space->containers)) {
>> +        return;
>>       }
>> +
>> +    QLIST_REMOVE(space, list);
>> +    g_free(space);
>> +
>>       if (QLIST_EMPTY(&vfio_address_spaces)) {
>>           qemu_unregister_reset(vfio_reset_handler, NULL);
>>       }
>> @@ -1498,8 +1501,16 @@ retry:
>>   int vfio_attach_device(char *name, VFIODevice *vbasedev,
>>                          AddressSpace *as, Error **errp)
>>   {
>> -    const VFIOIOMMUOps *ops = &vfio_legacy_ops;
>> +    const VFIOIOMMUOps *ops;
>>
>> +#ifdef CONFIG_IOMMUFD
>
>You can keep this one though.

Will do.

>
>> +    if (vbasedev->iommufd) {
>> +        ops = &vfio_iommufd_ops;
>> +    } else
>> +#endif
>> +    {
>> +        ops = &vfio_legacy_ops;
>> +    }
>>       return ops->attach_device(name, vbasedev, as, errp);
>>   }
>>
>> diff --git a/hw/vfio/iommufd.c b/hw/vfio/iommufd.c
>> new file mode 100644
>> index 0000000000..1bb55ca2c4
>> --- /dev/null
>> +++ b/hw/vfio/iommufd.c
>> @@ -0,0 +1,504 @@
>> +/*
>> + * iommufd container backend
>> + *
>> + * Copyright (C) 2023 Intel Corporation.
>> + * Copyright Red Hat, Inc. 2023
>> + *
>> + * Authors: Yi Liu <yi.l.liu@intel.com>
>> + *          Eric Auger <eric.auger@redhat.com>
>> + *
>> + * SPDX-License-Identifier: GPL-2.0-or-later
>> + */
>> +
>> +#include "qemu/osdep.h"
>> +#include <sys/ioctl.h>
>> +#include <linux/vfio.h>
>> +#include <linux/iommufd.h>
>> +
>> +#include "hw/vfio/vfio-common.h"
>> +#include "qemu/error-report.h"
>> +#include "trace.h"
>> +#include "qapi/error.h"
>> +#include "sysemu/iommufd.h"
>> +#include "hw/qdev-core.h"
>> +#include "sysemu/reset.h"
>> +#include "qemu/cutils.h"
>> +#include "qemu/chardev_open.h"
>> +
>> +static int iommufd_map(VFIOContainerBase *bcontainer, hwaddr iova,
>> +                       ram_addr_t size, void *vaddr, bool readonly)
>> +{
>> +    VFIOIOMMUFDContainer *container =
>> +        container_of(bcontainer, VFIOIOMMUFDContainer, bcontainer);
>> +
>> +    return iommufd_backend_map_dma(container->be,
>> +                                   container->ioas_id,
>> +                                   iova, size, vaddr, readonly);
>> +}
>> +
>> +static int iommufd_unmap(VFIOContainerBase *bcontainer,
>> +                         hwaddr iova, ram_addr_t size,
>> +                         IOMMUTLBEntry *iotlb)
>> +{
>> +    VFIOIOMMUFDContainer *container =
>> +        container_of(bcontainer, VFIOIOMMUFDContainer, bcontainer);
>> +
>> +    /* TODO: Handle dma_unmap_bitmap with iotlb args (migration) */
>> +    return iommufd_backend_unmap_dma(container->be,
>> +                                     container->ioas_id, iova, size);
>> +}
>> +
>> +static void iommufd_cdev_kvm_device_add(VFIODevice *vbasedev)
>> +{
>> +    Error *err = NULL;
>> +
>> +    if (vfio_kvm_device_add_fd(vbasedev->fd, &err)) {
>> +        error_report_err(err);
>> +    }
>> +}
>> +
>> +static void iommufd_cdev_kvm_device_del(VFIODevice *vbasedev)
>> +{
>> +    Error *err = NULL;
>> +
>> +    if (vfio_kvm_device_del_fd(vbasedev->fd, &err)) {
>> +        error_report_err(err);
>> +    }
>> +}
>> +
>> +static int iommufd_connect_and_bind(VFIODevice *vbasedev, Error **errp)
>> +{
>> +    IOMMUFDBackend *iommufd = vbasedev->iommufd;
>> +    struct vfio_device_bind_iommufd bind = {
>> +        .argsz = sizeof(bind),
>> +        .flags = 0,
>> +    };
>> +    int ret;
>> +
>> +    ret = iommufd_backend_connect(iommufd, errp);
>> +    if (ret) {
>> +        return ret;
>> +    }
>> +
>> +    /*
>> +     * Add device to kvm-vfio to be prepared for the tracking
>> +     * in KVM. Especially for some emulated devices, it requires
>> +     * to have kvm information in the device open.
>> +     */
>> +    iommufd_cdev_kvm_device_add(vbasedev);
>> +
>> +    /* Bind device to iommufd */
>> +    bind.iommufd = iommufd->fd;
>> +    ret = ioctl(vbasedev->fd, VFIO_DEVICE_BIND_IOMMUFD, &bind);
>> +    if (ret) {
>> +        error_setg_errno(errp, errno, "error bind device fd=%d to 
>> iommufd=%d",
>> +                         vbasedev->fd, bind.iommufd);
>> +        goto err_bind;
>> +    }
>> +
>> +    vbasedev->devid = bind.out_devid;
>> +    trace_iommufd_connect_and_bind(bind.iommufd, vbasedev->name,
>vbasedev->fd,
>> +                                   vbasedev->devid);
>> +    return ret;
>> +err_bind:
>> +    iommufd_cdev_kvm_device_del(vbasedev);
>> +    iommufd_backend_disconnect(iommufd);
>> +    return ret;
>> +}
>> +
>> +static void iommufd_unbind_and_disconnect(VFIODevice *vbasedev)
>> +{
>> +    /* Unbind is automatically conducted when device fd is closed */
>> +    iommufd_cdev_kvm_device_del(vbasedev);
>> +    iommufd_backend_disconnect(vbasedev->iommufd);
>> +}
>> +
>> +static int iommufd_cdev_getfd(const char *sysfs_path, Error **errp)
>> +{
>> +    long int ret = -ENOTTY;
>> +    char *path, *vfio_dev_path = NULL, *vfio_path = NULL;
>> +    DIR *dir = NULL;
>> +    struct dirent *dent;
>> +    gchar *contents;
>> +    struct stat st;
>> +    gsize length;
>> +    int major, minor;
>> +    dev_t vfio_devt;
>> +
>> +    path = g_strdup_printf("%s/vfio-dev", sysfs_path);
>> +    if (stat(path, &st) < 0) {
>> +        error_setg_errno(errp, errno, "no such host device");
>> +        goto out_free_path;
>> +    }
>> +
>> +    dir = opendir(path);
>> +    if (!dir) {
>> +        error_setg_errno(errp, errno, "couldn't open dirrectory %s", path);
>> +        goto out_free_path;
>> +    }
>> +
>> +    while ((dent = readdir(dir))) {
>> +        if (!strncmp(dent->d_name, "vfio", 4)) {
>> +            vfio_dev_path = g_strdup_printf("%s/%s/dev", path, 
>> dent->d_name);
>> +            break;
>> +        }
>> +    }
>> +
>> +    if (!vfio_dev_path) {
>> +        error_setg(errp, "failed to find vfio-dev/vfioX/dev");
>> +        goto out_close_dir;
>> +    }
>> +
>> +    if (!g_file_get_contents(vfio_dev_path, &contents, &length, NULL)) {
>> +        error_setg(errp, "failed to load \"%s\"", vfio_dev_path);
>> +        goto out_free_dev_path;
>> +    }
>> +
>> +    if (sscanf(contents, "%d:%d", &major, &minor) != 2) {
>> +        error_setg(errp, "failed to get major:minor for \"%s\"", 
>> vfio_dev_path);
>> +        goto out_free_dev_path;
>> +    }
>> +    g_free(contents);
>> +    vfio_devt = makedev(major, minor);
>> +
>> +    vfio_path = g_strdup_printf("/dev/vfio/devices/%s", dent->d_name);
>> +    ret = open_cdev(vfio_path, vfio_devt);
>> +    if (ret < 0) {
>> +        error_setg(errp, "Failed to open %s", vfio_path);
>> +    }
>> +
>> +    trace_iommufd_cdev_getfd(vfio_path, ret);
>> +    g_free(vfio_path);
>> +
>> +out_free_dev_path:
>> +    g_free(vfio_dev_path);
>> +out_close_dir:
>> +    closedir(dir);
>> +out_free_path:
>> +    if (*errp) {
>> +        error_prepend(errp, VFIO_MSG_PREFIX, path);
>> +    }
>> +    g_free(path);
>> +
>> +    return ret;
>> +}
>> +
>> +static VFIOIOASHwpt
>*iommufd_container_get_hwpt(VFIOIOMMUFDContainer *container,
>> +                                                uint32_t hwpt_id)
>> +{
>> +    VFIOIOASHwpt *hwpt;
>> +
>> +    QLIST_FOREACH(hwpt, &container->hwpt_list, next) {
>> +        if (hwpt->hwpt_id == hwpt_id) {
>> +            return hwpt;
>> +        }
>> +    }
>> +
>> +    hwpt = g_malloc0(sizeof(*hwpt));
>> +
>> +    hwpt->hwpt_id = hwpt_id;
>> +    QLIST_INIT(&hwpt->device_list);
>> +    QLIST_INSERT_HEAD(&container->hwpt_list, hwpt, next);
>> +
>> +    return hwpt;
>> +}
>> +
>> +static void iommufd_container_put_hwpt(IOMMUFDBackend *be,
>VFIOIOASHwpt *hwpt)
>> +{
>> +    QLIST_REMOVE(hwpt, next);
>> +    iommufd_backend_free_id(be->fd, hwpt->hwpt_id);
>> +    g_free(hwpt);
>> +}
>> +
>> +static int iommufd_cdev_attach_hwpt(VFIODevice *vbasedev, uint32_t
>hwpt_id,
>> +                                    Error **errp)
>> +{
>> +    int ret, iommufd = vbasedev->iommufd->fd;
>> +    struct vfio_device_attach_iommufd_pt attach_data = {
>> +        .argsz = sizeof(attach_data),
>> +        .flags = 0,
>> +        .pt_id = hwpt_id,
>> +    };
>> +
>> +    /* Attach device to an hwpt within iommufd */
>> +    ret = ioctl(vbasedev->fd, VFIO_DEVICE_ATTACH_IOMMUFD_PT,
>&attach_data);
>> +    if (ret) {
>> +        error_setg_errno(errp, errno,
>> +                         "[iommufd=%d] error attach %s (%d) to hwpt_id=%d",
>> +                         iommufd, vbasedev->name, vbasedev->fd, hwpt_id);
>> +    }
>> +    trace_iommufd_cdev_attach_hwpt(iommufd, vbasedev->name, vbasedev-
>>fd,
>> +                                   hwpt_id);
>> +    return ret;
>> +}
>> +
>> +static int iommufd_cdev_detach_hwpt(VFIODevice *vbasedev, Error **errp)
>> +{
>> +    int ret, iommufd = vbasedev->iommufd->fd;
>> +    struct vfio_device_detach_iommufd_pt detach_data = {
>> +        .argsz = sizeof(detach_data),
>> +        .flags = 0,
>> +    };
>> +
>> +    ret = ioctl(vbasedev->fd, VFIO_DEVICE_DETACH_IOMMUFD_PT,
>&detach_data);
>> +    if (ret) {
>> +        error_setg_errno(errp, errno, "detach %s from ioas failed",
>> +                         vbasedev->name);
>> +    }
>> +    trace_iommufd_cdev_detach_hwpt(iommufd, vbasedev->name,
>> +                                   vbasedev->hwpt->hwpt_id);
>> +    return ret;
>> +}
>> +
>> +static int iommufd_cdev_attach_container(VFIODevice *vbasedev,
>> +                                         VFIOIOMMUFDContainer *container,
>> +                                         Error **errp)
>> +{
>> +    int ret, iommufd = vbasedev->iommufd->fd;
>> +    VFIOIOASHwpt *hwpt;
>> +    uint32_t hwpt_id;
>> +    Error *err = NULL;
>> +
>> +    /* try to attach to an existing hwpt in this container */
>> +    QLIST_FOREACH(hwpt, &container->hwpt_list, next) {
>> +        ret = iommufd_cdev_attach_hwpt(vbasedev, hwpt->hwpt_id, &err);
>> +        if (ret) {
>> +            const char *msg = error_get_pretty(err);
>> +
>> +            trace_iommufd_cdev_fail_attach_existing_hwpt(msg);
>> +            error_free(err);
>> +            err = NULL;
>> +        } else {
>> +            goto found_hwpt;
>> +        }
>> +    }
>> +
>> +    ret = iommufd_backend_alloc_hwpt(iommufd, vbasedev->devid,
>> +                                     container->ioas_id, &hwpt_id);
>> +
>> +    if (ret) {
>> +        error_setg_errno(errp, errno, "error alloc shadow hwpt");
>> +        return ret;
>> +    }
>> +
>> +    /* Attach cdev to a new allocated hwpt within iommufd */
>> +    ret = iommufd_cdev_attach_hwpt(vbasedev, hwpt_id, errp);
>> +    if (ret) {
>> +        iommufd_backend_free_id(iommufd, hwpt_id);
>> +        return ret;
>> +    }
>> +
>> +    hwpt = iommufd_container_get_hwpt(container, hwpt_id);
>> +found_hwpt:
>> +    QLIST_INSERT_HEAD(&hwpt->device_list, vbasedev, next);
>> +    vbasedev->hwpt = hwpt;
>> +
>> +    trace_iommufd_cdev_attach_container(iommufd, vbasedev->name,
>vbasedev->fd,
>> +                                        container->ioas_id, hwpt->hwpt_id);
>> +    return ret;
>> +}
>> +
>> +static void iommufd_cdev_detach_container(VFIODevice *vbasedev,
>> +                                          VFIOIOMMUFDContainer *container)
>> +{
>> +    VFIOIOASHwpt *hwpt = vbasedev->hwpt;
>> +    Error *err = NULL;
>> +    int ret;
>> +
>> +    ret = iommufd_cdev_detach_hwpt(vbasedev, &err);
>> +    if (ret) {
>> +        error_report_err(err);
>> +    }
>> +
>> +    QLIST_REMOVE(vbasedev, next);
>> +    vbasedev->hwpt = NULL;
>> +    if (QLIST_EMPTY(&hwpt->device_list)) {
>> +        iommufd_container_put_hwpt(vbasedev->iommufd, hwpt);
>> +    }
>> +
>> +    trace_iommufd_cdev_detach_container(container->be->fd, vbasedev-
>>name,
>> +                                        container->ioas_id);
>> +}
>> +
>> +static void iommufd_container_destroy(VFIOIOMMUFDContainer *container)
>> +{
>> +    VFIOContainerBase *bcontainer = &container->bcontainer;
>> +
>> +    if (!QLIST_EMPTY(&container->hwpt_list)) {
>> +        return;
>> +    }
>> +    memory_listener_unregister(&bcontainer->listener);
>> +    vfio_container_destroy(bcontainer);
>> +    iommufd_backend_put_ioas(container->be, container->ioas_id);
>> +    g_free(container);
>> +}
>> +
>> +static int iommufd_ram_block_discard_disable(bool state)
>> +{
>> +    /*
>> +     * We support coordinated discarding of RAM via the RamDiscardManager.
>> +     */
>> +    return ram_block_uncoordinated_discard_disable(state);
>> +}
>> +
>> +static int iommufd_attach_device(const char *name, VFIODevice *vbasedev,
>> +                                 AddressSpace *as, Error **errp)
>> +{
>> +    VFIOContainerBase *bcontainer;
>> +    VFIOIOMMUFDContainer *container;
>> +    VFIOAddressSpace *space;
>> +    struct vfio_device_info dev_info = { .argsz = sizeof(dev_info) };
>> +    int ret, devfd;
>> +    uint32_t ioas_id;
>> +    Error *err = NULL;
>> +
>> +    devfd = iommufd_cdev_getfd(vbasedev->sysfsdev, errp);
>> +    if (devfd < 0) {
>> +        return devfd;
>> +    }
>> +    vbasedev->fd = devfd;
>> +
>> +    ret = iommufd_connect_and_bind(vbasedev, errp);
>> +    if (ret) {
>> +        goto err_connect_bind;
>> +    }
>> +
>> +    space = vfio_get_address_space(as);
>> +
>> +    /* try to attach to an existing container in this space */
>> +    QLIST_FOREACH(bcontainer, &space->containers, next) {
>> +        container = container_of(bcontainer, VFIOIOMMUFDContainer,
>bcontainer);
>> +        if (bcontainer->ops != &vfio_iommufd_ops ||
>> +            vbasedev->iommufd != container->be) {
>> +            continue;
>> +        }
>> +        if (iommufd_cdev_attach_container(vbasedev, container, &err)) {
>> +            const char *msg = error_get_pretty(err);
>> +
>> +            trace_iommufd_cdev_fail_attach_existing_container(msg);
>> +            error_free(err);
>> +            err = NULL;
>> +        } else {
>> +            ret = iommufd_ram_block_discard_disable(true);
>> +            if (ret) {
>> +                error_setg(errp,
>> +                              "Cannot set discarding of RAM broken (%d)", 
>> ret);
>> +                goto err_discard_disable;
>> +            }
>> +            goto found_container;
>> +        }
>> +    }
>> +
>> +    /* Need to allocate a new dedicated container */
>> +    ret = iommufd_backend_get_ioas(vbasedev->iommufd, &ioas_id);
>> +    if (ret < 0) {
>> +        error_setg_errno(errp, errno, "Failed to alloc ioas");
>> +        goto err_get_ioas;
>> +    }
>> +
>> +    trace_iommufd_cdev_alloc_ioas(vbasedev->iommufd->fd, ioas_id);
>> +
>> +    container = g_malloc0(sizeof(*container));
>> +    container->be = vbasedev->iommufd;
>> +    container->ioas_id = ioas_id;
>> +    QLIST_INIT(&container->hwpt_list);
>> +
>> +    bcontainer = &container->bcontainer;
>> +    vfio_container_init(bcontainer, space, &vfio_iommufd_ops);
>> +    QLIST_INSERT_HEAD(&space->containers, bcontainer, next);
>> +
>> +    ret = iommufd_cdev_attach_container(vbasedev, container, errp);
>> +    if (ret) {
>> +        goto err_attach_container;
>> +    }
>> +
>> +    ret = iommufd_ram_block_discard_disable(true);
>> +    if (ret) {
>> +        goto err_discard_disable;
>> +    }
>> +
>> +    bcontainer->pgsizes = qemu_real_host_page_size();
>> +
>> +    bcontainer->listener = vfio_memory_listener;
>> +    memory_listener_register(&bcontainer->listener, bcontainer->space->as);
>> +
>> +    if (bcontainer->error) {
>> +        ret = -1;
>> +        error_propagate_prepend(errp, bcontainer->error,
>> +                                "memory listener initialization failed: ");
>> +        goto err_listener_register;
>> +    }
>> +
>> +    bcontainer->initialized = true;
>> +
>> +found_container:
>> +    ret = ioctl(devfd, VFIO_DEVICE_GET_INFO, &dev_info);
>> +    if (ret) {
>> +        error_setg_errno(errp, errno, "error getting device info");
>> +        goto err_listener_register;
>> +    }
>> +
>> +    /*
>> +     * TODO: examine RAM_BLOCK_DISCARD stuff, should we do group level
>> +     * for discarding incompatibility check as well?
>> +     */
>> +    if (vbasedev->ram_block_discard_allowed) {
>> +        iommufd_ram_block_discard_disable(false);
>> +    }
>> +
>> +    vbasedev->group = 0;
>> +    vbasedev->num_irqs = dev_info.num_irqs;
>> +    vbasedev->num_regions = dev_info.num_regions;
>> +    vbasedev->flags = dev_info.flags;
>> +    vbasedev->reset_works = !!(dev_info.flags & VFIO_DEVICE_FLAGS_RESET);
>> +    vbasedev->bcontainer = bcontainer;
>> +    QLIST_INSERT_HEAD(&bcontainer->device_list, vbasedev, container_next);
>> +    QLIST_INSERT_HEAD(&vfio_device_list, vbasedev, global_next);
>> +
>> +    trace_iommufd_cdev_device_info(vbasedev->name, devfd, vbasedev-
>>num_irqs,
>> +                                   vbasedev->num_regions, vbasedev->flags);
>> +    return 0;
>> +
>> +err_listener_register:
>> +    iommufd_ram_block_discard_disable(false);
>> +err_discard_disable:
>> +    iommufd_cdev_detach_container(vbasedev, container);
>> +err_attach_container:
>> +    iommufd_container_destroy(container);
>> +err_get_ioas:
>> +    vfio_put_address_space(space);
>> +    iommufd_unbind_and_disconnect(vbasedev);
>> +err_connect_bind:
>> +    close(vbasedev->fd);
>> +    return ret;
>> +}
>> +
>> +static void iommufd_detach_device(VFIODevice *vbasedev)
>> +{
>> +    VFIOContainerBase *bcontainer = vbasedev->bcontainer;
>> +    VFIOIOMMUFDContainer *container;
>> +    VFIOAddressSpace *space = bcontainer->space;
>> +
>> +    QLIST_REMOVE(vbasedev, global_next);
>> +    QLIST_REMOVE(vbasedev, container_next);
>> +    vbasedev->bcontainer = NULL;
>> +
>> +    if (!vbasedev->ram_block_discard_allowed) {
>> +        iommufd_ram_block_discard_disable(false);
>> +    }
>> +
>> +    container = container_of(bcontainer, VFIOIOMMUFDContainer, bcontainer);
>> +    iommufd_cdev_detach_container(vbasedev, container);
>> +    iommufd_container_destroy(container);
>> +    vfio_put_address_space(space);
>> +
>> +    iommufd_unbind_and_disconnect(vbasedev);
>> +    close(vbasedev->fd);
>> +}
>> +
>> +const VFIOIOMMUOps vfio_iommufd_ops = {
>> +    .dma_map = iommufd_map,
>> +    .dma_unmap = iommufd_unmap,
>> +    .attach_device = iommufd_attach_device,
>> +    .detach_device = iommufd_detach_device,
>> +};
>> diff --git a/hw/vfio/meson.build b/hw/vfio/meson.build
>> index eb6ce6229d..9cae2c9e21 100644
>> --- a/hw/vfio/meson.build
>> +++ b/hw/vfio/meson.build
>> @@ -7,6 +7,9 @@ vfio_ss.add(files(
>>     'spapr.c',
>>     'migration.c',
>>   ))
>> +if have_iommufd
>> +  vfio_ss.add(files('iommufd.c'))
>> +endif
>
>Instead,
>
>vfio_ss.add(when: 'CONFIG_IOMMUFD', if_true: files(
>   'iommufd.c',
>))

Will do.

Thanks
Zhenzhong