[PATCH] PCI/P2PDMA: Add Intel 0x6f00 host bridge to the whitelist

[PATCH] PCI/P2PDMA: Add Intel 0x6f00 host bridge to the whitelist

[kai zhang]

For P2P paths routed through a host bridge, the P2PDMA core consults a
whitelist of known-good hardware. Add Intel 8086:6f00 with
REQ_SAME_HOST_BRIDGE so the entry permits peers only below the same host
bridge.

The bridge was tested on a single-socket Intel Xeon E5-2697A v4 system
with two PCIe GPUs below different Root Ports of the same host bridge.
Without the whitelist entry, peer access was rejected before a transfer
was issued. With the entry, 64 MiB peer transfers completed in both
directions with data integrity verified while the IOMMU used translated
mode.

Assisted-by: LLM
Signed-off-by: kai zhang <zhangkai.cool@gmail.com>
---
 drivers/pci/p2pdma.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c
index 9334eb314663..84413920e39b 100644
--- a/drivers/pci/p2pdma.c
+++ b/drivers/pci/p2pdma.c
@@ -542,6 +542,7 @@ static const struct pci_p2pdma_whitelist_entry {
 	/* Intel Xeon E5/Core i7 */
 	{PCI_VENDOR_ID_INTEL,	0x3c00, REQ_SAME_HOST_BRIDGE},
 	{PCI_VENDOR_ID_INTEL,	0x3c01, REQ_SAME_HOST_BRIDGE},
+	{PCI_VENDOR_ID_INTEL,	0x6f00, REQ_SAME_HOST_BRIDGE},
 	/* Intel Xeon E7 v3/Xeon E5 v3/Core i7 */
 	{PCI_VENDOR_ID_INTEL,	0x2f00, REQ_SAME_HOST_BRIDGE},
 	{PCI_VENDOR_ID_INTEL,	0x2f01, REQ_SAME_HOST_BRIDGE},
-- 
2.54.0 (Apple Git-157)

Re: [PATCH] PCI/P2PDMA: Add Intel 0x6f00 host bridge to the whitelist

[Bjorn Helgaas]

On Wed, Oct 07, 2026 at 10:15:58PM +0800, kai zhang wrote:
> For P2P paths routed through a host bridge, the P2PDMA core consults a
> whitelist of known-good hardware. Add Intel 8086:6f00 with
> REQ_SAME_HOST_BRIDGE so the entry permits peers only below the same host
> bridge.
> 
> The bridge was tested on a single-socket Intel Xeon E5-2697A v4 system
> with two PCIe GPUs below different Root Ports of the same host bridge.
> Without the whitelist entry, peer access was rejected before a transfer
> was issued. With the entry, 64 MiB peer transfers completed in both
> directions with data integrity verified while the IOMMU used translated
> mode.
> 
> Assisted-by: LLM
> Signed-off-by: kai zhang <zhangkai.cool@gmail.com>

Applied to pci/p2pdma for v7.4, thanks!

> ---
>  drivers/pci/p2pdma.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c
> index 9334eb314663..84413920e39b 100644
> --- a/drivers/pci/p2pdma.c
> +++ b/drivers/pci/p2pdma.c
> @@ -542,6 +542,7 @@ static const struct pci_p2pdma_whitelist_entry {
>  	/* Intel Xeon E5/Core i7 */
>  	{PCI_VENDOR_ID_INTEL,	0x3c00, REQ_SAME_HOST_BRIDGE},
>  	{PCI_VENDOR_ID_INTEL,	0x3c01, REQ_SAME_HOST_BRIDGE},
> +	{PCI_VENDOR_ID_INTEL,	0x6f00, REQ_SAME_HOST_BRIDGE},
>  	/* Intel Xeon E7 v3/Xeon E5 v3/Core i7 */
>  	{PCI_VENDOR_ID_INTEL,	0x2f00, REQ_SAME_HOST_BRIDGE},
>  	{PCI_VENDOR_ID_INTEL,	0x2f01, REQ_SAME_HOST_BRIDGE},
> -- 
> 2.54.0 (Apple Git-157)
>