>-----Original Message-----
>From: Joao Martins <joao.m.mart...@oracle.com>
>Subject: [PATCH v4 07/12] vfio/{iommufd,container}: Initialize
>HostIOMMUDeviceCaps during attach_device()
>
>Fetch IOMMU hw raw caps behind the device and thus move the
>HostIOMMUDevice::realize() to be done during the attach of the device. It
>allows it to cache the information obtained from IOMMU_GET_HW_INFO
>from
>iommufd early on. However, while legacy HostIOMMUDevice caps
>always return true and doesn't have dependency on other things, the
>IOMMUFD
>backend requires the iommufd FD to be connected and having a devid to be
>able to query capabilities. Hence when exactly is HostIOMMUDevice
>initialized inside backend ::attach_device() implementation is backend
>specific.
>
>This is in preparation to fetch parse hw capabilities and understand if
>dirty tracking is supported by device backing IOMMU without necessarily
>duplicating the amount of calls we do to IOMMU_GET_HW_INFO.
>
>Suggested-by: Cédric Le Goater <c...@redhat.com>
>Signed-off-by: Joao Martins <joao.m.mart...@oracle.com>
>---
> include/sysemu/host_iommu_device.h | 1 +
> hw/vfio/common.c | 16 ++++++----------
> hw/vfio/container.c | 6 ++++++
> hw/vfio/iommufd.c | 7 +++++++
> 4 files changed, 20 insertions(+), 10 deletions(-)
>
>diff --git a/include/sysemu/host_iommu_device.h
>b/include/sysemu/host_iommu_device.h
>index 20e77cf54568..b1e5f4b8ac3e 100644
>--- a/include/sysemu/host_iommu_device.h
>+++ b/include/sysemu/host_iommu_device.h
>@@ -24,6 +24,7 @@
> */
> typedef struct HostIOMMUDeviceCaps {
> uint32_t type;
>+ uint64_t hw_caps;
> } HostIOMMUDeviceCaps;
>
> #define TYPE_HOST_IOMMU_DEVICE "host-iommu-device"
>diff --git a/hw/vfio/common.c b/hw/vfio/common.c
>index b0beed44116e..cc14f0e3fe24 100644
>--- a/hw/vfio/common.c
>+++ b/hw/vfio/common.c
>@@ -1544,7 +1544,7 @@ bool vfio_attach_device(char *name, VFIODevice
>*vbasedev,
> {
> const VFIOIOMMUClass *ops =
>
>VFIO_IOMMU_CLASS(object_class_by_name(TYPE_VFIO_IOMMU_LEGACY));
>- HostIOMMUDevice *hiod;
>+ HostIOMMUDevice *hiod = NULL;
No need to NULL it?
>
> if (vbasedev->iommufd) {
> ops =
>VFIO_IOMMU_CLASS(object_class_by_name(TYPE_VFIO_IOMMU_IOMMUF
>D));
>@@ -1552,21 +1552,17 @@ bool vfio_attach_device(char *name,
>VFIODevice *vbasedev,
>
> assert(ops);
>
>- if (!ops->attach_device(name, vbasedev, as, errp)) {
>- return false;
>- }
>
>- if (vbasedev->mdev) {
>- return true;
>+ if (!vbasedev->mdev) {
>+ hiod = HOST_IOMMU_DEVICE(object_new(ops->hiod_typename));
>+ vbasedev->hiod = hiod;
> }
>
>- hiod = HOST_IOMMU_DEVICE(object_new(ops->hiod_typename));
>- if (!HOST_IOMMU_DEVICE_GET_CLASS(hiod)->realize(hiod, vbasedev,
>errp)) {
>+ if (!ops->attach_device(name, vbasedev, as, errp)) {
> object_unref(hiod);
>- ops->detach_device(vbasedev);
>+ vbasedev->hiod = NULL;
> return false;
> }
>- vbasedev->hiod = hiod;
>
> return true;
> }
>diff --git a/hw/vfio/container.c b/hw/vfio/container.c
>index c27f448ba26e..29da261bbf3e 100644
>--- a/hw/vfio/container.c
>+++ b/hw/vfio/container.c
>@@ -907,6 +907,7 @@ static bool vfio_legacy_attach_device(const char
>*name, VFIODevice *vbasedev,
> AddressSpace *as, Error **errp)
> {
> int groupid = vfio_device_groupid(vbasedev, errp);
>+ HostIOMMUDevice *hiod = vbasedev->hiod;
Hiod is used only once in this func, may be use vbasedev->hiod directly?
> VFIODevice *vbasedev_iter;
> VFIOGroup *group;
> VFIOContainerBase *bcontainer;
>@@ -917,6 +918,11 @@ static bool vfio_legacy_attach_device(const char
>*name, VFIODevice *vbasedev,
>
> trace_vfio_attach_device(vbasedev->name, groupid);
>
>+ if (hiod &&
>+ !HOST_IOMMU_DEVICE_GET_CLASS(hiod)->realize(hiod, vbasedev,
>errp)) {
>+ return false;
>+ }
>+
> group = vfio_get_group(groupid, as, errp);
> if (!group) {
> return false;
>diff --git a/hw/vfio/iommufd.c b/hw/vfio/iommufd.c
>index 873c919e319c..d34dc88231ec 100644
>--- a/hw/vfio/iommufd.c
>+++ b/hw/vfio/iommufd.c
>@@ -384,6 +384,7 @@ static bool iommufd_cdev_attach(const char *name,
>VFIODevice *vbasedev,
> Error *err = NULL;
> const VFIOIOMMUClass *iommufd_vioc =
>
>VFIO_IOMMU_CLASS(object_class_by_name(TYPE_VFIO_IOMMU_IOMMUF
>D));
>+ HostIOMMUDevice *hiod = vbasedev->hiod;
Same here.
>
> if (vbasedev->fd < 0) {
> devfd = iommufd_cdev_getfd(vbasedev->sysfsdev, errp);
>@@ -401,6 +402,11 @@ static bool iommufd_cdev_attach(const char
>*name, VFIODevice *vbasedev,
>
> space = vfio_get_address_space(as);
>
>+ if (hiod &&
>+ !HOST_IOMMU_DEVICE_GET_CLASS(hiod)->realize(hiod, vbasedev,
>errp)) {
>+ return false;
>+ }
>+
> /* try to attach to an existing container in this space */
> QLIST_FOREACH(bcontainer, &space->containers, next) {
> container = container_of(bcontainer, VFIOIOMMUFDContainer,
>bcontainer);
>@@ -722,6 +728,7 @@ static bool
>hiod_iommufd_vfio_realize(HostIOMMUDevice *hiod, void *opaque,
>
> hiod->name = g_strdup(vdev->name);
> caps->type = type;
>+ caps->hw_caps = hw_caps;
>
> return true;
> }
>--
>2.17.2
