Generic Linux architectural discussions
 help / color / mirror / Atom feed
From: Jason Gunthorpe <jgg@ziepe.ca>
To: Yu Zhang <zhangyu1@linux.microsoft.com>
Cc: Jacob Pan <jacob.pan@linux.microsoft.com>,
	linux-kernel@vger.kernel.org, linux-hyperv@vger.kernel.org,
	iommu@lists.linux.dev, linux-pci@vger.kernel.org,
	linux-arch@vger.kernel.org, x86@kernel.org, wei.liu@kernel.org,
	kys@microsoft.com, haiyangz@microsoft.com, decui@microsoft.com,
	longli@microsoft.com, joro@8bytes.org, will@kernel.org,
	robin.murphy@arm.com, bhelgaas@google.com,
	kwilczynski@kernel.org, lpieralisi@kernel.org, mani@kernel.org,
	robh@kernel.org, arnd@arndb.de, mhklinux@outlook.com,
	tgopinath@linux.microsoft.com,
	easwar.hariharan@linux.microsoft.com,
	mrathor@linux.microsoft.com, baolu.lu@linux.intel.com,
	suravee.suthikulpanit@amd.com, vasant.hegde@amd.com
Subject: Re: [PATCH v3 4/5] iommu/hyperv: Add para-virtualized IOMMU support for Hyper-V guest
Date: Mon, 17 Aug 2026 14:35:52 -0300	[thread overview]
Message-ID: <20260817173552.GA1418894@ziepe.ca> (raw)
In-Reply-To: <aiioa6ospojivued3djhwadyfpit5temyvrgm3xxzhzt6aqbiv@hqz6q5bqnl6w>

On Tue, Aug 18, 2026 at 01:22:03AM +0800, Yu Zhang wrote:

> So we could
> - either keep the duplicate check in hv_iommu_blocking_attach_dev();
> - or add code in our common helper, hv_iommu_attach_dev(), to treat
>   HV_STATUS_DEVICE_ALREADY_IN_DOMAIN also as successful explicitly. 
> 
> And since normal paging-domain attaches do not have this duplicate
> case, I'd prefer the first choice, to keep current check in
> hv_iommu_blocking_attach_dev().

I think everything can technically be re-attached and must not fail,
you have to handle that possibility everywhere.

So accepting that code as success seems like it might be needed anyhow?

Jason

  reply	other threads:[~2026-08-17 17:35 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-08-11 15:50 [PATCH v3 0/5] Hyper-V: Add para-virtualized IOMMU support for Linux guests Yu Zhang
2026-08-11 15:50 ` [PATCH v3 1/5] hyperv: Introduce new hypercall interfaces used by Hyper-V guest IOMMU Yu Zhang
2026-08-12 18:08   ` Jacob Pan
2026-08-14  1:31   ` Mukesh R
2026-08-14 10:04     ` Yu Zhang
2026-08-14 15:31   ` Michael Kelley
2026-08-17  2:33     ` Yu Zhang
2026-08-11 15:50 ` [PATCH v3 2/5] Drivers: hv: Add logical device ID registry for vPCI devices Yu Zhang
2026-08-14 15:31   ` Michael Kelley
2026-08-17 10:37     ` Yu Zhang
2026-08-17 17:27       ` Michael Kelley
2026-08-11 15:50 ` [PATCH v3 3/5] iommu/x86: Share the architectural MSI reserved range Yu Zhang
2026-08-11 16:21   ` Jason Gunthorpe
2026-08-12  8:58     ` Yu Zhang
2026-08-12 12:30       ` Jason Gunthorpe
2026-08-11 15:50 ` [PATCH v3 4/5] iommu/hyperv: Add para-virtualized IOMMU support for Hyper-V guest Yu Zhang
2026-08-13 13:49   ` Jason Gunthorpe
2026-08-14  9:47     ` Yu Zhang
2026-08-13 18:02   ` Easwar Hariharan
2026-08-14 12:49     ` Yu Zhang
2026-08-13 22:29   ` Jacob Pan
2026-08-13 22:46     ` Jason Gunthorpe
2026-08-14  9:37       ` Yu Zhang
2026-08-17 12:22         ` Jason Gunthorpe
2026-08-17 16:01           ` Yu Zhang
2026-08-17 17:22             ` Yu Zhang
2026-08-17 17:35               ` Jason Gunthorpe [this message]
2026-08-11 15:50 ` [PATCH v3 5/5] iommu/hyperv: Add page-selective IOTLB flush support Yu Zhang
2026-08-13 23:07   ` Jacob Pan
2026-08-14 12:07     ` Yu Zhang

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=20260817173552.GA1418894@ziepe.ca \
    --to=jgg@ziepe.ca \
    --cc=arnd@arndb.de \
    --cc=baolu.lu@linux.intel.com \
    --cc=bhelgaas@google.com \
    --cc=decui@microsoft.com \
    --cc=easwar.hariharan@linux.microsoft.com \
    --cc=haiyangz@microsoft.com \
    --cc=iommu@lists.linux.dev \
    --cc=jacob.pan@linux.microsoft.com \
    --cc=joro@8bytes.org \
    --cc=kwilczynski@kernel.org \
    --cc=kys@microsoft.com \
    --cc=linux-arch@vger.kernel.org \
    --cc=linux-hyperv@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-pci@vger.kernel.org \
    --cc=longli@microsoft.com \
    --cc=lpieralisi@kernel.org \
    --cc=mani@kernel.org \
    --cc=mhklinux@outlook.com \
    --cc=mrathor@linux.microsoft.com \
    --cc=robh@kernel.org \
    --cc=robin.murphy@arm.com \
    --cc=suravee.suthikulpanit@amd.com \
    --cc=tgopinath@linux.microsoft.com \
    --cc=vasant.hegde@amd.com \
    --cc=wei.liu@kernel.org \
    --cc=will@kernel.org \
    --cc=x86@kernel.org \
    --cc=zhangyu1@linux.microsoft.com \
    /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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox