From: Jason Gunthorpe <jgg@nvidia.com>
To: "Tian, Kevin" <kevin.tian@intel.com>
Cc: LKML <linux-kernel@vger.kernel.org>,
Joerg Roedel <joro@8bytes.org>,
Lu Baolu <baolu.lu@linux.intel.com>,
David Woodhouse <dwmw2@infradead.org>,
"iommu@lists.linux-foundation.org"
<iommu@lists.linux-foundation.org>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
"Alex Williamson (alex.williamson@redhat.com)"
<alex.williamson@redhat.com>, Jason Wang <jasowang@redhat.com>,
Eric Auger <eric.auger@redhat.com>,
Jonathan Corbet <corbet@lwn.net>,
"Raj, Ashok" <ashok.raj@intel.com>,
"Liu, Yi L" <yi.l.liu@intel.com>, "Wu, Hao" <hao.wu@intel.com>,
"Jiang, Dave" <dave.jiang@intel.com>,
Jacob Pan <jacob.jun.pan@linux.intel.com>,
Jean-Philippe Brucker <jean-philippe@linaro.org>,
David Gibson <david@gibson.dropbear.id.au>,
Kirti Wankhede <kwankhede@nvidia.com>,
Robin Murphy <robin.murphy@arm.com>
Subject: Re: [RFC] /dev/ioasid uAPI proposal
Date: Thu, 3 Jun 2021 10:05:19 -0300 [thread overview]
Message-ID: <20210603130519.GY1002214@nvidia.com> (raw)
In-Reply-To: <MWHPR11MB188621A9D1181A414D5491198C3C9@MWHPR11MB1886.namprd11.prod.outlook.com>
On Thu, Jun 03, 2021 at 06:39:30AM +0000, Tian, Kevin wrote:
> > > Two helper functions are provided to support VFIO_ATTACH_IOASID:
> > >
> > > struct attach_info {
> > > u32 ioasid;
> > > // If valid, the PASID to be used physically
> > > u32 pasid;
> > > };
> > > int ioasid_device_attach(struct ioasid_dev *dev,
> > > struct attach_info info);
> > > int ioasid_device_detach(struct ioasid_dev *dev, u32 ioasid);
> >
> > Honestly, I still prefer this to be highly explicit as this is where
> > all device driver authors get invovled:
> >
> > ioasid_pci_device_attach(struct pci_device *pdev, struct ioasid_dev *dev,
> > u32 ioasid);
> > ioasid_pci_device_pasid_attach(struct pci_device *pdev, u32 *physical_pasid,
> > struct ioasid_dev *dev, u32 ioasid);
>
> Then better naming it as pci_device_attach_ioasid since the 1st parameter
> is struct pci_device?
No, the leading tag indicates the API's primary subystem, in this case
it is iommu (and if you prefer list the iommu related arguments first)
> By keeping physical_pasid as a pointer, you want to remove the last helper
> function (ioasid_get_global_pasid) so the global pasid is returned along
> with the attach function?
It is just a thought.. It allows the caller to both specify a fixed
PASID and request an allocation
I still dont have a clear idea how all this PASID complexity should
work, sorry.
> > > The actual policy depends on pdev vs. mdev, and whether ENQCMD is
> > > supported. There are three possible scenarios:
> > >
> > > (Note: /dev/ioasid uAPI is not affected by underlying PASID virtualization
> > > policies.)
> >
> > This has become unclear. I think this should start by identifying the
> > 6 main type of devices and how they can use pPASID/vPASID:
> >
> > 0) Device is a RID and cannot issue PASID
> > 1) Device is a mdev and cannot issue PASID
> > 2) Device is a mdev and programs a single fixed PASID during bind,
> > does not accept PASID from the guest
>
> There are no vPASID per se in above 3 types. So this section only
> focus on the latter 3 types. But I can include them in next version
> if it sets the tone clearer.
I think it helps
> >
> > 3) Device accepts any PASIDs from the guest. No
> > vPASID/pPASID translation is possible. (classic vfio_pci)
> > 4) Device accepts any PASID from the guest and has an
> > internal vPASID/pPASID translation (enhanced vfio_pci)
>
> what is enhanced vfio_pci? In my writing this is for mdev
> which doesn't support ENQCMD
This is a vfio_pci that mediates some element of the device interface
to communicate the vPASID/pPASID table to the device, using Max's
series for vfio_pci drivers to inject itself into VFIO.
For instance a device might send a message through the PF that the VF
has a certain vPASID/pPASID translation table. This would be useful
for devices that cannot use ENQCMD but still want to support migration
and thus need vPASID.
> for 0-2 the device will report no PASID support. Although this may duplicate
> with other information (e.g. PCI PASID cap), this provides a vendor-agnostic
> way for reporting details around IOASID.
We have to consider mdevs too here, so PCI caps are not general enough
> for 3-5 the device will report PASID support. In these cases the user is
> expected to always provide a vPASID.
>
> for 5 in addition the device will report a requirement on CPU PASID
> translation. For such device the user should talk to KVM to setup the PASID
> mapping. This way the user doesn't need to know whether a device is
> pdev or mdev. Just follows what device capability reports.
Something like that. Needs careful documentation
Jason
next prev parent reply other threads:[~2021-06-03 13:05 UTC|newest]
Thread overview: 258+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-27 7:58 [RFC] /dev/ioasid uAPI proposal Tian, Kevin
2021-05-28 2:24 ` Jason Wang
2021-05-28 20:25 ` Jason Gunthorpe
[not found] ` <20210531164118.265789ee@yiliu-dev>
2021-06-01 2:36 ` Jason Wang
2021-06-01 4:27 ` Shenming Lu
2021-06-01 5:10 ` Jason Wang
[not found] ` <20210601113152.6d09e47b@yiliu-dev>
2021-06-01 5:08 ` Jason Wang
2021-06-01 5:23 ` Lu Baolu
2021-06-01 5:29 ` Jason Wang
2021-06-01 5:42 ` Tian, Kevin
2021-06-01 6:07 ` Jason Wang
2021-06-01 6:16 ` Tian, Kevin
2021-06-01 8:47 ` Jason Wang
2021-06-01 17:31 ` Jason Gunthorpe
2021-06-02 8:54 ` Jason Wang
2021-06-02 17:21 ` Jason Gunthorpe
2021-06-07 13:30 ` Enrico Weigelt, metux IT consult
2021-06-07 18:01 ` Jason Gunthorpe
2021-06-08 10:45 ` Enrico Weigelt, metux IT consult
2021-06-10 2:16 ` Jason Wang
2021-06-08 1:10 ` Jason Wang
2021-06-08 13:20 ` Jason Gunthorpe
2021-06-10 2:00 ` Jason Wang
2021-06-10 4:03 ` Jason Wang
2021-06-10 11:47 ` Jason Gunthorpe
2021-06-11 5:43 ` Jason Wang
2021-06-01 17:29 ` Jason Gunthorpe
2021-06-02 8:58 ` Jason Wang
2021-05-28 16:23 ` Jean-Philippe Brucker
2021-05-28 20:16 ` Jason Gunthorpe
2021-06-01 7:50 ` Tian, Kevin
2021-05-28 17:35 ` Jason Gunthorpe
2021-06-01 8:10 ` Tian, Kevin
2021-06-01 17:42 ` Jason Gunthorpe
2021-06-02 1:33 ` Tian, Kevin
2021-06-02 16:09 ` Jason Gunthorpe
2021-06-03 1:29 ` Tian, Kevin
2021-06-03 5:09 ` David Gibson
2021-06-03 6:49 ` Tian, Kevin
2021-06-03 11:47 ` Jason Gunthorpe
2021-06-04 2:15 ` Tian, Kevin
2021-06-08 0:49 ` David Gibson
2021-06-09 2:52 ` Tian, Kevin
2021-06-02 6:32 ` David Gibson
2021-06-02 16:16 ` Jason Gunthorpe
2021-06-03 2:11 ` Tian, Kevin
2021-06-03 5:13 ` David Gibson
2021-06-03 11:52 ` Jason Gunthorpe
2021-06-08 0:53 ` David Gibson
2021-06-08 19:04 ` Jason Gunthorpe
2021-06-17 2:42 ` David Gibson
2021-05-28 19:58 ` Jason Gunthorpe
2021-06-01 8:38 ` Tian, Kevin
2021-06-01 17:56 ` Jason Gunthorpe
2021-06-02 2:00 ` Tian, Kevin
2021-06-02 6:57 ` David Gibson
2021-06-02 16:37 ` Jason Gunthorpe
2021-06-03 5:23 ` David Gibson
2021-06-03 12:28 ` Jason Gunthorpe
2021-06-08 6:04 ` David Gibson
2021-06-08 19:23 ` Jason Gunthorpe
2021-06-02 6:48 ` David Gibson
2021-06-02 16:58 ` Jason Gunthorpe
2021-06-03 2:49 ` Tian, Kevin
2021-06-03 5:48 ` David Gibson
2021-06-03 5:45 ` David Gibson
2021-06-03 12:11 ` Jason Gunthorpe
2021-06-04 6:08 ` Tian, Kevin
2021-06-04 12:33 ` Jason Gunthorpe
2021-06-04 23:20 ` Tian, Kevin
2021-06-08 6:13 ` David Gibson
2021-06-04 10:24 ` Jean-Philippe Brucker
2021-06-04 12:05 ` Jason Gunthorpe
2021-06-04 17:27 ` Jacob Pan
2021-06-04 17:40 ` Jason Gunthorpe
2021-06-08 6:31 ` David Gibson
2021-06-10 16:37 ` Jean-Philippe Brucker
2021-06-17 3:00 ` David Gibson
2021-06-18 17:03 ` Jean-Philippe Brucker
2021-06-18 18:30 ` Jason Gunthorpe
2021-06-23 8:19 ` Tian, Kevin
2021-06-23 7:57 ` Tian, Kevin
2021-06-24 3:49 ` David Gibson
2021-05-28 20:03 ` Jason Gunthorpe
2021-06-01 7:01 ` Tian, Kevin
2021-06-01 20:28 ` Jason Gunthorpe
2021-06-02 1:25 ` Tian, Kevin
2021-06-02 23:27 ` Jason Gunthorpe
2021-06-04 8:17 ` Jean-Philippe Brucker
2021-06-04 8:43 ` Tian, Kevin
2021-06-02 8:52 ` Jason Wang
2021-06-02 16:07 ` Jason Gunthorpe
2021-06-01 22:22 ` Alex Williamson
2021-06-02 2:20 ` Tian, Kevin
2021-06-02 16:01 ` Jason Gunthorpe
2021-06-02 17:11 ` Alex Williamson
2021-06-02 17:35 ` Jason Gunthorpe
2021-06-02 18:01 ` Alex Williamson
2021-06-02 18:09 ` Jason Gunthorpe
2021-06-02 19:00 ` Alex Williamson
2021-06-02 19:54 ` Jason Gunthorpe
2021-06-02 20:37 ` Alex Williamson
2021-06-02 22:45 ` Jason Gunthorpe
2021-06-03 2:50 ` Alex Williamson
2021-06-03 3:22 ` Tian, Kevin
2021-06-03 4:14 ` Alex Williamson
2021-06-03 5:18 ` Tian, Kevin
2021-06-03 12:40 ` Jason Gunthorpe
2021-06-03 20:41 ` Alex Williamson
2021-06-04 9:19 ` Tian, Kevin
2021-06-04 15:37 ` Alex Williamson
2021-06-04 12:13 ` Jason Gunthorpe
2021-06-04 21:45 ` Alex Williamson
2021-06-04 7:33 ` Tian, Kevin
2021-06-03 12:34 ` Jason Gunthorpe
2021-06-03 20:01 ` Alex Williamson
2021-06-03 20:10 ` Jason Gunthorpe
2021-06-03 21:44 ` Alex Williamson
2021-06-04 8:38 ` Tian, Kevin
2021-06-04 12:28 ` Jason Gunthorpe
2021-06-04 15:26 ` Alex Williamson
2021-06-04 15:40 ` Paolo Bonzini
2021-06-04 15:50 ` Jason Gunthorpe
2021-06-04 15:57 ` Paolo Bonzini
2021-06-04 16:03 ` Jason Gunthorpe
2021-06-04 16:10 ` Paolo Bonzini
2021-06-04 17:22 ` Jason Gunthorpe
2021-06-04 21:29 ` Alex Williamson
2021-06-04 23:01 ` Jason Gunthorpe
2021-06-07 15:41 ` Alex Williamson
2021-06-07 18:18 ` Jason Gunthorpe
2021-06-07 18:59 ` Alex Williamson
2021-06-07 19:08 ` Jason Gunthorpe
2021-06-07 19:41 ` Alex Williamson
2021-06-07 23:03 ` Jason Gunthorpe
2021-06-08 0:30 ` Alex Williamson
2021-06-08 1:20 ` Jason Wang
2021-06-30 6:53 ` Christoph Hellwig
2021-06-30 6:49 ` Christoph Hellwig
2021-06-07 3:25 ` Tian, Kevin
2021-06-07 6:51 ` Paolo Bonzini
2021-06-07 18:01 ` Jason Gunthorpe
2021-06-30 6:56 ` Christoph Hellwig
2021-06-05 6:22 ` Paolo Bonzini
2021-06-07 3:50 ` Tian, Kevin
2021-06-07 17:59 ` Jason Gunthorpe
2021-06-08 7:56 ` Paolo Bonzini
2021-06-08 13:15 ` Jason Gunthorpe
2021-06-08 13:44 ` Paolo Bonzini
2021-06-08 18:47 ` Alex Williamson
2021-06-08 19:00 ` Jason Gunthorpe
2021-06-09 8:51 ` Enrico Weigelt, metux IT consult
2021-06-09 9:11 ` Paolo Bonzini
2021-06-09 11:54 ` Jason Gunthorpe
2021-06-09 14:31 ` Alex Williamson
2021-06-09 14:45 ` Jason Gunthorpe
2021-06-09 15:20 ` Paolo Bonzini
2021-10-27 6:18 ` Tian, Kevin
2021-10-27 10:32 ` Paolo Bonzini
2021-10-28 1:50 ` Tian, Kevin
2021-06-09 2:49 ` Tian, Kevin
2021-06-09 11:57 ` Jason Gunthorpe
2021-06-09 12:46 ` Paolo Bonzini
2021-06-09 12:47 ` Jason Gunthorpe
2021-06-09 13:24 ` Paolo Bonzini
2021-06-09 14:32 ` Jason Gunthorpe
2021-06-30 7:01 ` Christoph Hellwig
2021-06-09 18:09 ` Alex Williamson
2021-06-03 2:52 ` Jason Wang
2021-06-03 13:09 ` Jason Gunthorpe
2021-06-04 1:11 ` Jason Wang
2021-06-04 11:58 ` Jason Gunthorpe
2021-06-07 3:18 ` Jason Wang
2021-06-07 14:14 ` Jason Gunthorpe
2021-06-08 1:00 ` Jason Wang
2021-06-08 8:54 ` Enrico Weigelt, metux IT consult
2021-06-08 12:52 ` Jason Gunthorpe
2021-06-30 7:07 ` Christoph Hellwig
2021-06-30 7:05 ` Christoph Hellwig
2021-06-08 2:37 ` David Gibson
2021-06-08 13:17 ` Jason Gunthorpe
2021-06-17 3:47 ` David Gibson
2021-06-23 7:59 ` Tian, Kevin
2021-06-24 3:53 ` David Gibson
2021-05-28 23:36 ` Jason Gunthorpe
2021-05-31 11:31 ` Liu Yi L
2021-05-31 18:09 ` Jason Gunthorpe
2021-06-01 3:08 ` Lu Baolu
2021-06-01 17:24 ` Jason Gunthorpe
2021-06-01 1:25 ` Lu Baolu
2021-06-01 11:09 ` Lu Baolu
2021-06-01 17:26 ` Jason Gunthorpe
2021-06-02 4:01 ` Lu Baolu
2021-06-02 23:23 ` Jason Gunthorpe
2021-06-03 5:49 ` Lu Baolu
2021-06-03 5:54 ` David Gibson
2021-06-03 6:50 ` Lu Baolu
2021-06-03 12:56 ` Jason Gunthorpe
2021-06-02 7:22 ` David Gibson
2021-06-03 6:39 ` Tian, Kevin
2021-06-03 13:05 ` Jason Gunthorpe [this message]
2021-06-04 6:37 ` Tian, Kevin
2021-06-04 12:09 ` Jason Gunthorpe
2021-06-04 23:10 ` Tian, Kevin
2021-06-07 17:54 ` Jason Gunthorpe
2021-06-15 8:59 ` Tian, Kevin
2021-06-15 15:06 ` Jason Gunthorpe
2021-06-15 22:59 ` Tian, Kevin
2021-06-15 23:02 ` Jason Gunthorpe
2021-06-15 23:09 ` Tian, Kevin
2021-06-15 23:40 ` Jason Gunthorpe
2021-06-15 23:56 ` Tian, Kevin
2021-06-15 23:59 ` Jason Gunthorpe
2021-06-16 0:02 ` Tian, Kevin
2021-05-31 17:37 ` Parav Pandit
2021-05-31 18:12 ` Jason Gunthorpe
2021-06-01 12:04 ` Parav Pandit
2021-06-01 17:36 ` Jason Gunthorpe
2021-06-02 8:38 ` Enrico Weigelt, metux IT consult
2021-06-02 12:41 ` Parav Pandit
2021-06-01 4:31 ` Shenming Lu
2021-06-01 5:10 ` Lu Baolu
2021-06-01 7:15 ` Shenming Lu
2021-06-01 12:30 ` Lu Baolu
2021-06-01 13:10 ` Shenming Lu
2021-06-01 17:33 ` Jason Gunthorpe
2021-06-02 4:50 ` Shenming Lu
2021-06-03 18:19 ` Jacob Pan
2021-06-04 1:30 ` Jason Wang
2021-06-04 16:22 ` Jacob Pan
2021-06-04 16:22 ` Jason Gunthorpe
2021-06-04 18:05 ` Jacob Pan
2021-06-04 2:03 ` Shenming Lu
2021-06-07 12:19 ` Liu, Yi L
2021-06-08 1:09 ` Shenming Lu
2021-06-01 17:30 ` Parav Pandit
2021-06-03 20:58 ` Jacob Pan
2021-06-08 6:30 ` Parav Pandit
2021-06-02 6:15 ` David Gibson
2021-06-02 17:19 ` Jason Gunthorpe
2021-06-03 3:02 ` Tian, Kevin
2021-06-03 6:26 ` David Gibson
2021-06-03 12:46 ` Jason Gunthorpe
2021-06-04 6:27 ` Tian, Kevin
2021-06-03 7:17 ` Tian, Kevin
2021-06-03 12:49 ` Jason Gunthorpe
2021-06-08 5:49 ` David Gibson
2021-06-03 8:12 ` Tian, Kevin
2021-06-17 4:07 ` David Gibson
2021-06-23 8:00 ` Tian, Kevin
2021-06-24 3:55 ` David Gibson
2021-06-02 8:56 ` Enrico Weigelt, metux IT consult
2021-06-02 17:24 ` Jason Gunthorpe
2021-06-04 10:44 ` Enrico Weigelt, metux IT consult
2021-06-04 12:30 ` Jason Gunthorpe
2021-06-08 1:15 ` David Gibson
2021-06-08 10:43 ` Enrico Weigelt, metux IT consult
2021-06-08 13:11 ` Jason Gunthorpe
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