Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.32 as permitted sender) client-ip=23.128.96.32;
MIME-Version: 1.0
References: <20231103171641.1703146-1-lulu@redhat.com> <20231103171641.1703146-4-lulu@redhat.com>
 <CACGkMEtVfHL2WPwxkYEfTKBE10uWfB2a75QQOO8rzn3=Y9FiBg@mail.gmail.com>
In-Reply-To: <CACGkMEtVfHL2WPwxkYEfTKBE10uWfB2a75QQOO8rzn3=Y9FiBg@mail.gmail.com>
From:   Cindy Lu <lulu@redhat.com>
Date:   Tue, 7 Nov 2023 14:57:04 +0800
Message-ID: <CACLfguX9-wEQPUyZkJZoRMmgPDRFNyZCmt0nvHROhyP1yooiYA@mail.gmail.com>
Subject: Re: [RFC v1 3/8] vhost: Add 3 new uapi to support iommufd
To:     Jason Wang <jasowang@redhat.com>
Cc:     mst@redhat.com, yi.l.liu@intel.com, jgg@nvidia.com,
        linux-kernel@vger.kernel.org,
        virtualization@lists.linux-foundation.org, netdev@vger.kernel.org
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

On Mon, Nov 6, 2023 at 3:30=E2=80=AFPM Jason Wang <jasowang@redhat.com> wro=
te:
>
> On Sat, Nov 4, 2023 at 1:17=E2=80=AFAM Cindy Lu <lulu@redhat.com> wrote:
> >
> > VHOST_VDPA_SET_IOMMU_FD: bind the device to iommufd device
> >
> > VDPA_DEVICE_ATTACH_IOMMUFD_AS: Attach a vdpa device to an iommufd
> > address space specified by IOAS id.
> >
> > VDPA_DEVICE_DETACH_IOMMUFD_AS: Detach a vdpa device
> > from the iommufd address space
> >
> > Signed-off-by: Cindy Lu <lulu@redhat.com>
> > ---
>
> [...]
>
> > diff --git a/include/uapi/linux/vhost.h b/include/uapi/linux/vhost.h
> > index f5c48b61ab62..07e1b2c443ca 100644
> > --- a/include/uapi/linux/vhost.h
> > +++ b/include/uapi/linux/vhost.h
> > @@ -219,4 +219,70 @@
> >   */
> >  #define VHOST_VDPA_RESUME              _IO(VHOST_VIRTIO, 0x7E)
> >
> > +/* vhost_vdpa_set_iommufd
> > + * Input parameters:
> > + * @iommufd: file descriptor from /dev/iommu; pass -1 to unset
> > + * @iommufd_ioasid: IOAS identifier returned from ioctl(IOMMU_IOAS_ALL=
OC)
> > + * Output parameters:
> > + * @out_dev_id: device identifier
> > + */
> > +struct vhost_vdpa_set_iommufd {
> > +       __s32 iommufd;
> > +       __u32 iommufd_ioasid;
> > +       __u32 out_dev_id;
> > +};
> > +
> > +#define VHOST_VDPA_SET_IOMMU_FD \
> > +       _IOW(VHOST_VIRTIO, 0x7F, struct vhost_vdpa_set_iommufd)
> > +
> > +/*
> > + * VDPA_DEVICE_ATTACH_IOMMUFD_AS -
> > + * _IOW(VHOST_VIRTIO, 0x7f, struct vdpa_device_attach_iommufd_as)
> > + *
> > + * Attach a vdpa device to an iommufd address space specified by IOAS
> > + * id.
> > + *
> > + * Available only after a device has been bound to iommufd via
> > + * VHOST_VDPA_SET_IOMMU_FD
> > + *
> > + * Undo by VDPA_DEVICE_DETACH_IOMMUFD_AS or device fd close.
> > + *
> > + * @argsz:     user filled size of this data.
> > + * @flags:     must be 0.
> > + * @ioas_id:   Input the target id which can represent an ioas
> > + *             allocated via iommufd subsystem.
> > + *
> > + * Return: 0 on success, -errno on failure.
> > + */
> > +struct vdpa_device_attach_iommufd_as {
> > +       __u32 argsz;
> > +       __u32 flags;
> > +       __u32 ioas_id;
> > +};
>
> I think we need to map ioas to vDPA AS, so there should be an ASID
> from the view of vDPA?
>
> Thanks
>
The qemu will have a structure save and  maintain this information,So
I didn't add this
 in kernel=EF=BC=8Cwe can add this but maybe only for check?
this in
Thanks
Cindy
> > +
> > +#define VDPA_DEVICE_ATTACH_IOMMUFD_AS \
> > +       _IOW(VHOST_VIRTIO, 0x82, struct vdpa_device_attach_iommufd_as)
> > +
> > +/*
> > + * VDPA_DEVICE_DETACH_IOMMUFD_AS
> > + *
> > + * Detach a vdpa device from the iommufd address space it has been
> > + * attached to. After it, device should be in a blocking DMA state.
> > + *
> > + * Available only after a device has been bound to iommufd via
> > + * VHOST_VDPA_SET_IOMMU_FD
> > + *
> > + * @argsz:     user filled size of this data.
> > + * @flags:     must be 0.
> > + *
> > + * Return: 0 on success, -errno on failure.
> > + */
> > +struct vdpa_device_detach_iommufd_as {
> > +       __u32 argsz;
> > +       __u32 flags;
> > +};
> > +
> > +#define VDPA_DEVICE_DETACH_IOMMUFD_AS \
> > +       _IOW(VHOST_VIRTIO, 0x83, struct vdpa_device_detach_iommufd_as)
> > +
> >  #endif
> > --
> > 2.34.3
> >
>