> -----Original Message----- > From: Alex Williamson [mailto:alex.williamson@xxxxxxxxxx] > Sent: Saturday, October 03, 2015 4:16 AM > To: Bhushan Bharat-R65777 <Bharat.Bhushan@xxxxxxxxxxxxx> > Cc: kvmarm@xxxxxxxxxxxxxxxxxxxxx; kvm@xxxxxxxxxxxxxxx; > christoffer.dall@xxxxxxxxxx; eric.auger@xxxxxxxxxx; pranavkumar@xxxxxxxxxx; > marc.zyngier@xxxxxxx; will.deacon@xxxxxxx > 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 <Bharat.Bhushan@xxxxxxxxxxxxx> > > --- > > 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 ��.n��������+%������w��{.n�����o�^n�r������&��z�ޗ�zf���h���~����������_��+v���)ߣ�
