From: Nicolin Chen <nicolinc@nvidia.com>
To: "Tian, Kevin" <kevin.tian@intel.com>
Cc: Will Deacon <will@kernel.org>, Jason Gunthorpe <jgg@nvidia.com>,
Lu Baolu <baolu.lu@linux.intel.com>,
Robin Murphy <robin.murphy@arm.com>,
"joro@8bytes.org" <joro@8bytes.org>,
David Woodhouse <dwmw2@infradead.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"iommu@lists.linux.dev" <iommu@lists.linux.dev>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v1 1/5] iommu/arm-smmu-v3-iommufd: Reject unsupported bits in invalidation commands
Date: Fri, 3 Jul 2026 01:00:27 -0700 [thread overview]
Message-ID: <akdsG46/j21yzEkU@nvidia.com> (raw)
In-Reply-To: <CO1PR11MB4835A412EADC0D56A8BDBBFC8CF42@CO1PR11MB4835.namprd11.prod.outlook.com>
On Fri, Jul 03, 2026 at 06:20:37AM +0000, Tian, Kevin wrote:
> > From: Nicolin Chen <nicolinc@nvidia.com>
> > + case CMDQ_OP_ATC_INV:
> > + /*
> > + * Exclude the Global bit: it makes the SMMU ignore the SID
> > and
> > + * invalidate the ATC of every device, not just the guest's.
> > + */
>
> I suppose the Global bit in vcmdq is guaranteed by HW to be contained within
> the vcmdq, then the SMMU will convert it into multiple INV cmds sent to
> devices associated with the vcmdq?
Actually, this piece is wrong. I double-checked the spec, the
Global bit isn't about SID but SSID (should be provided too).
So, the Global bit should be allowed. I need to fix it..
Similarly for VCMDQ, it is allowed. HW only validates whether
the given SID/BDF is programmed into the VINTF or not.
Thanks (for the question)!
Nicolin
next prev parent reply other threads:[~2026-07-03 8:01 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-29 21:15 [PATCH v1 0/5] iommufd: Iterate the cache invalidation array in the core Nicolin Chen
2026-06-29 21:15 ` [PATCH v1 1/5] iommu/arm-smmu-v3-iommufd: Reject unsupported bits in invalidation commands Nicolin Chen
2026-07-03 6:20 ` Tian, Kevin
2026-07-03 8:00 ` Nicolin Chen [this message]
2026-07-06 17:16 ` Jason Gunthorpe
2026-07-06 17:46 ` Nicolin Chen
2026-06-29 21:15 ` [PATCH v1 2/5] iommufd: Iterate the cache invalidation array in the core Nicolin Chen
2026-07-03 6:21 ` Tian, Kevin
2026-06-29 21:15 ` [PATCH v1 3/5] iommufd/selftest: Convert cache invalidation mocks to the core array loop Nicolin Chen
2026-07-03 6:22 ` Tian, Kevin
2026-06-29 21:15 ` [PATCH v1 4/5] iommu/arm-smmu-v3-iommufd: Convert cache invalidation " Nicolin Chen
2026-07-03 6:30 ` Tian, Kevin
2026-06-29 21:15 ` [PATCH v1 5/5] iommu/vt-d: Convert nested " Nicolin Chen
2026-07-03 6:31 ` Tian, Kevin
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=akdsG46/j21yzEkU@nvidia.com \
--to=nicolinc@nvidia.com \
--cc=baolu.lu@linux.intel.com \
--cc=dwmw2@infradead.org \
--cc=iommu@lists.linux.dev \
--cc=jgg@nvidia.com \
--cc=joro@8bytes.org \
--cc=kevin.tian@intel.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=robin.murphy@arm.com \
--cc=will@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.