>-----Original Message----- >From: Eric Auger <eric.au...@redhat.com> >Sent: Wednesday, September 27, 2023 3:36 PM >Subject: Re: [PATCH v2 06/12] vfio/pci: Introduce vfio_[attach/detach]_device > >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. > >you may add: no functional change intended
Will do. >> >> 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); >hum looking at that again, I was confused by the fact we passed the name >arg in > >vfio_attach_device() whereas vbasedev->name was already filled. Looking at pci >vfio_realize() >both are sometimes different > > if (!qemu_uuid_is_null(&vdev->vf_token)) { > qemu_uuid_unparse(&vdev->vf_token, uuid); > name = g_strdup_printf("%s vf_token=%s", vbasedev->name, uuid); > } else { > name = g_strdup(vbasedev->name); > } >This may be worth a doc comment. Yes, agree this is confusing. Just want to ask about the doc comment? Should I create a vfio doc or just a small comment on call site of vfio_attach_device()? Thanks Zhenzhong