From: Jason Gunthorpe <jgg@nvidia.com>
To: "Zhang, Tina" <tina.zhang@intel.com>
Cc: "Liu, Yi L" <yi.l.liu@intel.com>,
"joro@8bytes.org" <joro@8bytes.org>,
"alex.williamson@redhat.com" <alex.williamson@redhat.com>,
"Tian, Kevin" <kevin.tian@intel.com>,
"robin.murphy@arm.com" <robin.murphy@arm.com>,
"baolu.lu@linux.intel.com" <baolu.lu@linux.intel.com>,
"cohuck@redhat.com" <cohuck@redhat.com>,
"eric.auger@redhat.com" <eric.auger@redhat.com>,
"nicolinc@nvidia.com" <nicolinc@nvidia.com>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
"mjrosato@linux.ibm.com" <mjrosato@linux.ibm.com>,
"chao.p.peng@linux.intel.com" <chao.p.peng@linux.intel.com>,
"yi.y.sun@linux.intel.com" <yi.y.sun@linux.intel.com>,
"peterx@redhat.com" <peterx@redhat.com>,
"jasowang@redhat.com" <jasowang@redhat.com>,
"shameerali.kolothum.thodi@huawei.com"
<shameerali.kolothum.thodi@huawei.com>,
"lulu@redhat.com" <lulu@redhat.com>,
"suravee.suthikulpanit@amd.com" <suravee.suthikulpanit@amd.com>,
"iommu@lists.linux.dev" <iommu@lists.linux.dev>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-kselftest@vger.kernel.org"
<linux-kselftest@vger.kernel.org>,
"Duan, Zhenzhong" <zhenzhong.duan@intel.com>
Subject: Re: [PATCH v3 01/10] iommufd: Add data structure for Intel VT-d stage-1 domain allocation
Date: Mon, 29 May 2023 17:00:14 -0300 [thread overview]
Message-ID: <ZHUETinmrYy8zp/h@nvidia.com> (raw)
In-Reply-To: <MW5PR11MB5881B1B7C7B14F776F0FD3F489469@MW5PR11MB5881.namprd11.prod.outlook.com>
On Thu, May 25, 2023 at 02:28:18AM +0000, Zhang, Tina wrote:
> > +struct iommu_hwpt_intel_vtd {
> > + __u64 flags;
> > + __u64 pgtbl_addr;
> > + __u32 pat;
> > + __u32 emt;
> Do we need the emt field as part of the stage-1 page table info?
> IIUC, according to vt-d spec, the emt field is in stage-2 page table
> entries. Since in nested mode we only expose stage-1 page table to
> guest vt-d driver, I'm curious how does guest vt-d driver populate
> this EMT?
Indeed. The EMT is controlling how the iommu HW parses memory that is
controlled by the kernel - this simply should not be something that
userspace controls.
The S2 itself has to decide if it is populating the EMT bits in the
IOPTE and if so it could enable EMT. Does userspace need to be
involved here?
The seemingly more tricky thing is that it feels like EMT and PAT
would like to be per-iova and we don't have a means for that right
now. (and even if we did, how would qemu decide what to do ?)
So probably drop it.
Jason
next prev parent reply other threads:[~2023-05-29 20:00 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-11 14:51 [PATCH v3 00/10] Add Intel VT-d nested translation Yi Liu
2023-05-11 14:51 ` [PATCH v3 01/10] iommufd: Add data structure for Intel VT-d stage-1 domain allocation Yi Liu
2023-05-24 6:59 ` Tian, Kevin
2023-05-25 2:28 ` Zhang, Tina
2023-05-29 20:00 ` Jason Gunthorpe [this message]
2023-05-29 19:53 ` Jason Gunthorpe
2023-05-11 14:51 ` [PATCH v3 02/10] iommu/vt-d: Extend dmar_domain to support nested domain Yi Liu
2023-05-24 7:02 ` Tian, Kevin
2023-05-26 2:56 ` Baolu Lu
2023-05-11 14:51 ` [PATCH v3 03/10] iommu/vt-d: Add helper for nested domain allocation Yi Liu
2023-05-11 14:51 ` [PATCH v3 04/10] iommu/vt-d: Add helper to setup pasid nested translation Yi Liu
2023-05-24 7:16 ` Tian, Kevin
2023-05-26 4:16 ` Baolu Lu
2023-06-07 8:34 ` Liu, Yi L
2023-06-08 3:32 ` Liu, Yi L
2023-06-08 3:35 ` Liu, Yi L
2023-06-08 3:37 ` Baolu Lu
2023-05-11 14:51 ` [PATCH v3 05/10] iommu/vt-d: Make domain attach helpers to be extern Yi Liu
2023-05-11 14:51 ` [PATCH v3 06/10] iommu/vt-d: Set the nested domain to a device Yi Liu
2023-05-24 7:22 ` Tian, Kevin
2023-05-26 4:24 ` Baolu Lu
2023-05-11 14:51 ` [PATCH v3 07/10] iommu/vt-d: Add iotlb flush for nested domain Yi Liu
2023-05-24 7:33 ` Tian, Kevin
2023-06-08 7:14 ` Liu, Yi L
2023-06-08 8:07 ` Baolu Lu
2023-06-20 6:22 ` Liu, Yi L
2023-05-11 14:51 ` [PATCH v3 08/10] iommu/vt-d: Add nested domain allocation Yi Liu
2023-05-11 14:51 ` [PATCH v3 09/10] iommu/vt-d: Implement hw_info for iommu capability query Yi Liu
2023-05-11 14:51 ` [PATCH v3 10/10] iommu/vt-d: Disallow nesting on domains with read-only mappings Yi Liu
2023-05-24 7:44 ` Tian, Kevin
2023-05-26 4:28 ` Baolu Lu
2023-05-24 8:59 ` [PATCH v3 00/10] Add Intel VT-d nested translation Tian, Kevin
2023-05-25 18:06 ` Alex Williamson
2023-05-26 11:25 ` Tian, Kevin
2023-05-29 18:43 ` Jason Gunthorpe
2023-05-30 0:16 ` Alex Williamson
2023-05-30 16:42 ` Jason Gunthorpe
2023-06-14 8:07 ` Tian, Kevin
2023-06-14 11:52 ` Jason Gunthorpe
2023-06-16 2:29 ` Tian, Kevin
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