From: Jason Gunthorpe <jgg@nvidia.com>
To: Bjorn Helgaas <helgaas@kernel.org>
Cc: Vivek Kasireddy <vivek.kasireddy@intel.com>,
dri-devel@lists.freedesktop.org, intel-xe@lists.freedesktop.org,
Bjorn Helgaas <bhelgaas@google.com>,
Logan Gunthorpe <logang@deltatee.com>,
linux-pci@vger.kernel.org
Subject: Re: [PATCH v4 1/5] PCI/P2PDMA: Don't enforce ACS check for device functions of Intel GPUs
Date: Tue, 16 Sep 2025 14:59:50 -0300 [thread overview]
Message-ID: <20250916175950.GU1086830@nvidia.com> (raw)
In-Reply-To: <20250916173442.GA1765656@bhelgaas>
On Tue, Sep 16, 2025 at 12:34:42PM -0500, Bjorn Helgaas wrote:
> I know I've asked this before, but I'm still confused about how this
> is related to PCIe r7.0, sec 7.7.12, which says that if an SR-IOV
> device implements internal peer-to-peer transactions, ACS is required,
> and ACS P2P Egress Control must be supported.
Right, certainly for SRIOV Linux has always taken the view that VFs
and PFs have NO internal loopback if there are no ACS caps.
The entire industry has aligned to this because having an hidden
uncontrolled internal loopback where the VF can reach the PF's BAR
would be catastrophically security broken for virtualization.
Virtualization is the main use case for having SRIOV in the first
place, so nobody would build an insecure internal loopback..
Jason
next prev parent reply other threads:[~2025-09-16 17:59 UTC|newest]
Thread overview: 62+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-09-15 7:21 [PATCH v4 0/5] drm/xe/sriov: Don't migrate dmabuf BO to System RAM if P2P check succeeds Vivek Kasireddy
2025-09-15 7:21 ` [PATCH v4 1/5] PCI/P2PDMA: Don't enforce ACS check for device functions of Intel GPUs Vivek Kasireddy
2025-09-15 15:33 ` Logan Gunthorpe
2025-09-16 17:34 ` Bjorn Helgaas
2025-09-16 17:59 ` Jason Gunthorpe [this message]
2025-09-16 17:57 ` Jason Gunthorpe
2025-09-18 6:16 ` Kasireddy, Vivek
2025-09-18 12:04 ` Jason Gunthorpe
2025-09-19 6:22 ` Kasireddy, Vivek
2025-09-19 12:29 ` Jason Gunthorpe
2025-09-22 6:59 ` Kasireddy, Vivek
2025-09-22 11:22 ` Christian König
2025-09-22 12:20 ` Jason Gunthorpe
2025-09-22 12:25 ` Christian König
2025-09-22 12:29 ` Jason Gunthorpe
2025-09-22 13:20 ` Christian König
2025-09-22 13:27 ` Jason Gunthorpe
2025-09-22 13:57 ` Christian König
2025-09-22 14:00 ` Jason Gunthorpe
2025-09-23 5:53 ` Kasireddy, Vivek
2025-09-23 6:25 ` Matthew Brost
2025-09-23 6:44 ` Matthew Brost
2025-09-23 7:52 ` Christian König
2025-09-23 12:15 ` Jason Gunthorpe
2025-09-23 12:45 ` Christian König
2025-09-23 13:12 ` Jason Gunthorpe
2025-09-23 13:28 ` Christian König
2025-09-23 13:38 ` Jason Gunthorpe
2025-09-23 13:48 ` Christian König
2025-09-23 23:02 ` Matthew Brost
2025-09-24 8:29 ` Christian König
2025-09-24 6:50 ` Kasireddy, Vivek
2025-09-24 7:21 ` Christian König
2025-09-25 3:56 ` Kasireddy, Vivek
2025-09-25 10:51 ` Thomas Hellström
2025-09-25 11:28 ` Christian König
2025-09-25 13:11 ` Thomas Hellström
2025-09-25 13:33 ` Jason Gunthorpe
2025-09-25 15:40 ` Thomas Hellström
2025-09-25 15:55 ` Jason Gunthorpe
2025-09-26 6:12 ` Kasireddy, Vivek
2025-09-23 13:36 ` Christoph Hellwig
2025-09-23 6:01 ` Kasireddy, Vivek
2025-09-22 12:12 ` Jason Gunthorpe
2025-09-24 16:13 ` Simon Richter
2025-09-24 17:12 ` Jason Gunthorpe
2025-09-25 4:06 ` Kasireddy, Vivek
2025-09-15 7:21 ` [PATCH v4 2/5] drm/xe/dmabuf: Don't migrate BO to System RAM if P2P check succeeds Vivek Kasireddy
2025-09-16 20:01 ` Thomas Hellström
2025-09-15 7:21 ` [PATCH v4 3/5] drm/xe/pf: Add a helper function to get a VF's backing object in LMEM Vivek Kasireddy
2025-09-16 19:58 ` Matthew Brost
2025-09-16 20:06 ` Thomas Hellström
2025-09-17 7:10 ` Thomas Hellström
2025-09-15 7:21 ` [PATCH v4 4/5] drm/xe/bo: Create new dma_addr array for dmabuf BOs associated with VFs Vivek Kasireddy
2025-09-16 19:08 ` Matthew Brost
2025-09-16 19:44 ` Matthew Brost
2025-09-15 7:21 ` [PATCH v4 5/5] drm/xe/pt: Add an additional check for dmabuf BOs while doing bind Vivek Kasireddy
2025-09-16 19:13 ` Matthew Brost
2025-09-15 7:32 ` ✗ CI.checkpatch: warning for drm/xe/sriov: Don't migrate dmabuf BO to System RAM if P2P check succeeds Patchwork
2025-09-15 7:33 ` ✓ CI.KUnit: success " Patchwork
2025-09-15 8:16 ` ✓ Xe.CI.BAT: " Patchwork
2025-09-15 10:19 ` ✗ Xe.CI.Full: failure " Patchwork
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