> -----Original Message-----
> From: Alex Williamson [mailto:[email protected]]
> Sent: Saturday, October 03, 2015 4:16 AM
> To: Bhushan Bharat-R65777 <[email protected]>
> Cc: [email protected]; [email protected];
> [email protected]; [email protected]; [email protected];
> [email protected]; [email protected]
> Subject: Re: [RFC PATCH 3/6] vfio: Extend iommu-info to return MSIs
> automap state
>
> On Wed, 2015-09-30 at 20:26 +0530, Bharat Bhushan wrote:
> > This patch allows the user-space to know whether msi-pages are
> > automatically mapped with some magic iova or not.
> >
> > Even if the msi-pages are automatically mapped, still user-space wants
> > to over-ride the automatic iova selection for msi-mapping.
> > For this user-space need to know whether it is allowed to change the
> > automatic mapping or not and this API provides this mechanism.
> > Follow up patches will provide how to over-ride this.
> >
> > Signed-off-by: Bharat Bhushan <[email protected]>
> > ---
> > drivers/vfio/vfio_iommu_type1.c | 32
> ++++++++++++++++++++++++++++++++
> > include/uapi/linux/vfio.h | 3 +++
> > 2 files changed, 35 insertions(+)
> >
> > diff --git a/drivers/vfio/vfio_iommu_type1.c
> > b/drivers/vfio/vfio_iommu_type1.c index fa5d3e4..3315fb6 100644
> > --- a/drivers/vfio/vfio_iommu_type1.c
> > +++ b/drivers/vfio/vfio_iommu_type1.c
> > @@ -59,6 +59,7 @@ struct vfio_iommu {
> > struct rb_root dma_list;
> > bool v2;
> > bool nesting;
> > + bool allow_msi_reconfig;
> > struct list_head reserved_iova_list;
> > };
> >
> > @@ -1117,6 +1118,23 @@ static int
> vfio_domains_have_iommu_cache(struct vfio_iommu *iommu)
> > return ret;
> > }
> >
> > +static
> > +int vfio_domains_get_msi_maps(struct vfio_iommu *iommu,
> > + struct iommu_domain_msi_maps *msi_maps) {
> > + struct vfio_domain *d;
> > + int ret;
> > +
> > + mutex_lock(&iommu->lock);
> > + /* All domains have same msi-automap property, pick first */
> > + d = list_first_entry(&iommu->domain_list, struct vfio_domain, next);
> > + ret = iommu_domain_get_attr(d->domain,
> DOMAIN_ATTR_MSI_MAPPING,
> > + msi_maps);
> > + mutex_unlock(&iommu->lock);
> > +
> > + return ret;
> > +}
> > +
> > static long vfio_iommu_type1_ioctl(void *iommu_data,
> > unsigned int cmd, unsigned long arg) { @@
> -1138,6 +1156,8 @@
> > static long vfio_iommu_type1_ioctl(void *iommu_data,
> > }
> > } else if (cmd == VFIO_IOMMU_GET_INFO) {
> > struct vfio_iommu_type1_info info;
> > + struct iommu_domain_msi_maps msi_maps;
> > + int ret;
> >
> > minsz = offsetofend(struct vfio_iommu_type1_info,
> iova_pgsizes);
> >
> > @@ -1149,6 +1169,18 @@ static long vfio_iommu_type1_ioctl(void
> > *iommu_data,
> >
> > info.flags = 0;
> >
> > + ret = vfio_domains_get_msi_maps(iommu, &msi_maps);
> > + if (ret)
> > + return ret;
>
> And now ioctl(VFIO_IOMMU_GET_INFO) no longer works for any IOMMU
> implementing domain_get_attr but not supporting
> DOMAIN_ATTR_MSI_MAPPING.
With this current patch version this will get the default assumed behavior as
you commented on previous patch.
>
> > +
> > + if (msi_maps.override_automap) {
> > + info.flags |=
> VFIO_IOMMU_INFO_MSI_ALLOW_RECONFIG;
> > + iommu->allow_msi_reconfig = true;
> > + }
> > +
> > + if (msi_maps.automap)
> > + info.flags |= VFIO_IOMMU_INFO_MSI_AUTOMAP;
> > +
> > info.iova_pgsizes = vfio_pgsize_bitmap(iommu);
> >
> > return copy_to_user((void __user *)arg, &info, minsz); diff --
> git
> > a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h index
> > 1abd1a9..9998f6e 100644
> > --- a/include/uapi/linux/vfio.h
> > +++ b/include/uapi/linux/vfio.h
> > @@ -391,6 +391,9 @@ struct vfio_iommu_type1_info {
> > __u32 argsz;
> > __u32 flags;
> > #define VFIO_IOMMU_INFO_PGSIZES (1 << 0) /* supported page
> sizes info */
> > +#define VFIO_IOMMU_INFO_MSI_AUTOMAP (1 << 1) /* MSI pages
> are auto-mapped
> > + in iommu */
> > +#define VFIO_IOMMU_INFO_MSI_ALLOW_RECONFIG (1 << 2) /* Allows
> > +reconfig automap*/
> > __u64 iova_pgsizes; /* Bitmap of supported page sizes */
> > };
> >
>
> Once again, exposing interfaces to the user before they actually do anything
> is backwards.
Will change the order.
Thanks
-Bharat
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