| Message ID | 20250219082228.3303163-4-zhenzhong.duan@intel.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | intel_iommu: Enable stage-1 translation for passthrough device | expand |
On 2/19/25 9:22 AM, Zhenzhong Duan wrote: > Currently we have realize() callback which is called before attachment. > But there are still some elements e.g., hwpt_id is not ready before > attachment. So we need a realize_late() callback to further initialize > them. from the description it is not obvious why the realize() could not have been called after the attach. Could you remind the reader what is the reason? Thanks Eric > > Currently, this callback is only useful for iommufd backend. For legacy > backend nothing needs to be initialized after attachment. > > Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com> > --- > include/system/host_iommu_device.h | 17 +++++++++++++++++ > hw/vfio/common.c | 17 ++++++++++++++--- > 2 files changed, 31 insertions(+), 3 deletions(-) > > diff --git a/include/system/host_iommu_device.h b/include/system/host_iommu_device.h > index 809cced4ba..df782598f2 100644 > --- a/include/system/host_iommu_device.h > +++ b/include/system/host_iommu_device.h > @@ -66,6 +66,23 @@ struct HostIOMMUDeviceClass { > * Returns: true on success, false on failure. > */ > bool (*realize)(HostIOMMUDevice *hiod, void *opaque, Error **errp); > + /** > + * @realize_late: initialize host IOMMU device instance after attachment, > + * some elements e.g., ioas are ready only after attachment. > + * This callback initialize them. > + * > + * Optional callback. > + * > + * @hiod: pointer to a host IOMMU device instance. > + * > + * @opaque: pointer to agent device of this host IOMMU device, > + * e.g., VFIO base device or VDPA device. > + * > + * @errp: pass an Error out when realize fails. > + * > + * Returns: true on success, false on failure. > + */ > + bool (*realize_late)(HostIOMMUDevice *hiod, void *opaque, Error **errp); > /** > * @get_cap: check if a host IOMMU device capability is supported. > * > diff --git a/hw/vfio/common.c b/hw/vfio/common.c > index abbdc56b6d..e198b1e5a2 100644 > --- a/hw/vfio/common.c > +++ b/hw/vfio/common.c > @@ -1550,6 +1550,7 @@ bool vfio_attach_device(char *name, VFIODevice *vbasedev, > const VFIOIOMMUClass *ops = > VFIO_IOMMU_CLASS(object_class_by_name(TYPE_VFIO_IOMMU_LEGACY)); > HostIOMMUDevice *hiod = NULL; > + HostIOMMUDeviceClass *hiod_ops = NULL; > > if (vbasedev->iommufd) { > ops = VFIO_IOMMU_CLASS(object_class_by_name(TYPE_VFIO_IOMMU_IOMMUFD)); > @@ -1560,16 +1561,26 @@ bool vfio_attach_device(char *name, VFIODevice *vbasedev, > > if (!vbasedev->mdev) { > hiod = HOST_IOMMU_DEVICE(object_new(ops->hiod_typename)); > + hiod_ops = HOST_IOMMU_DEVICE_GET_CLASS(hiod); > vbasedev->hiod = hiod; > } > > if (!ops->attach_device(name, vbasedev, as, errp)) { > - object_unref(hiod); > - vbasedev->hiod = NULL; > - return false; > + goto err_attach; > + } > + > + if (hiod_ops && hiod_ops->realize_late && > + !hiod_ops->realize_late(hiod, vbasedev, errp)) { > + ops->detach_device(vbasedev); > + goto err_attach; > } > > return true; > + > +err_attach: > + object_unref(hiod); > + vbasedev->hiod = NULL; > + return false; > } > > void vfio_detach_device(VFIODevice *vbasedev)
>-----Original Message----- >From: Eric Auger <eric.auger@redhat.com> >Subject: Re: [PATCH rfcv2 03/20] HostIOMMUDevice: Introduce realize_late >callback > > > > >On 2/19/25 9:22 AM, Zhenzhong Duan wrote: >> Currently we have realize() callback which is called before attachment. >> But there are still some elements e.g., hwpt_id is not ready before >> attachment. So we need a realize_late() callback to further initialize >> them. >from the description it is not obvious why the realize() could not have >been called after the attach. Could you remind the reader what is the >reason? Sure, will rephrase as below: " HostIOMMUDevice provides some elements to vIOMMU, but there are some which are ready after attachment, e.g., hwpt_id. Before create and attach to a new hwpt with IOMMU dirty tracking capability, we have to call realize() to get if hardware IOMMU supports dirty tracking capability. So moving realize() after attach() will not work here, we need a new callback realize_late() to further initialize those elements. Currently, this callback is only useful for iommufd backend. For legacy backend nothing needs to be initialized after attachment. " Thanks Zhenzhong
Hi Zhenzhong, On 2/28/25 9:16 AM, Duan, Zhenzhong wrote: > >> -----Original Message----- >> From: Eric Auger <eric.auger@redhat.com> >> Subject: Re: [PATCH rfcv2 03/20] HostIOMMUDevice: Introduce realize_late >> callback >> >> >> >> >> On 2/19/25 9:22 AM, Zhenzhong Duan wrote: >>> Currently we have realize() callback which is called before attachment. >>> But there are still some elements e.g., hwpt_id is not ready before >>> attachment. So we need a realize_late() callback to further initialize >>> them. > >from the description it is not obvious why the realize() could not have >> been called after the attach. Could you remind the reader what is the >> reason? > Sure, will rephrase as below: > > " HostIOMMUDevice provides some elements to vIOMMU, but there are some which > are ready after attachment, e.g., hwpt_id. > > Before create and attach to a new hwpt with IOMMU dirty tracking capability, > we have to call realize() to get if hardware IOMMU supports dirty tracking > capability. > > So moving realize() after attach() will not work here, we need a new callback > realize_late() to further initialize those elements. > > Currently, this callback is only useful for iommufd backend. For legacy > backend nothing needs to be initialized after attachment. " OK this helps me Thanks Eric > > Thanks > Zhenzhong >
diff --git a/include/system/host_iommu_device.h b/include/system/host_iommu_device.h index 809cced4ba..df782598f2 100644 --- a/include/system/host_iommu_device.h +++ b/include/system/host_iommu_device.h @@ -66,6 +66,23 @@ struct HostIOMMUDeviceClass { * Returns: true on success, false on failure. */ bool (*realize)(HostIOMMUDevice *hiod, void *opaque, Error **errp); + /** + * @realize_late: initialize host IOMMU device instance after attachment, + * some elements e.g., ioas are ready only after attachment. + * This callback initialize them. + * + * Optional callback. + * + * @hiod: pointer to a host IOMMU device instance. + * + * @opaque: pointer to agent device of this host IOMMU device, + * e.g., VFIO base device or VDPA device. + * + * @errp: pass an Error out when realize fails. + * + * Returns: true on success, false on failure. + */ + bool (*realize_late)(HostIOMMUDevice *hiod, void *opaque, Error **errp); /** * @get_cap: check if a host IOMMU device capability is supported. * diff --git a/hw/vfio/common.c b/hw/vfio/common.c index abbdc56b6d..e198b1e5a2 100644 --- a/hw/vfio/common.c +++ b/hw/vfio/common.c @@ -1550,6 +1550,7 @@ bool vfio_attach_device(char *name, VFIODevice *vbasedev, const VFIOIOMMUClass *ops = VFIO_IOMMU_CLASS(object_class_by_name(TYPE_VFIO_IOMMU_LEGACY)); HostIOMMUDevice *hiod = NULL; + HostIOMMUDeviceClass *hiod_ops = NULL; if (vbasedev->iommufd) { ops = VFIO_IOMMU_CLASS(object_class_by_name(TYPE_VFIO_IOMMU_IOMMUFD)); @@ -1560,16 +1561,26 @@ bool vfio_attach_device(char *name, VFIODevice *vbasedev, if (!vbasedev->mdev) { hiod = HOST_IOMMU_DEVICE(object_new(ops->hiod_typename)); + hiod_ops = HOST_IOMMU_DEVICE_GET_CLASS(hiod); vbasedev->hiod = hiod; } if (!ops->attach_device(name, vbasedev, as, errp)) { - object_unref(hiod); - vbasedev->hiod = NULL; - return false; + goto err_attach; + } + + if (hiod_ops && hiod_ops->realize_late && + !hiod_ops->realize_late(hiod, vbasedev, errp)) { + ops->detach_device(vbasedev); + goto err_attach; } return true; + +err_attach: + object_unref(hiod); + vbasedev->hiod = NULL; + return false; } void vfio_detach_device(VFIODevice *vbasedev)
Currently we have realize() callback which is called before attachment. But there are still some elements e.g., hwpt_id is not ready before attachment. So we need a realize_late() callback to further initialize them. Currently, this callback is only useful for iommufd backend. For legacy backend nothing needs to be initialized after attachment. Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com> --- include/system/host_iommu_device.h | 17 +++++++++++++++++ hw/vfio/common.c | 17 ++++++++++++++--- 2 files changed, 31 insertions(+), 3 deletions(-)