Re: [PATCH v4 03/18] PCI/P2PDMA: Restrict the p2pmem search to pool backed providers

[Logan Gunthorpe]

On 2026-08-21 13:38, Leon Romanovsky wrote:
> From: Leon Romanovsky <leonro@xxxxxxxxxx>
> 
> pci_p2pmem_find_many() exists to pick a provider that the caller will
> then allocate from with pci_alloc_p2pmem(), which goes straight to the
> gen_pool:
> 
> 	ret = (void *)gen_pool_alloc_owner(p2pdma->pool, size, (void **) &ref);
> 
> pci_has_p2pmem() does not ask for that pool, only for the published flag.
> The two used to be equivalent, because a provider could only exist by way
> of pci_p2pdma_add_resource(), which always creates the pool.
> 
> pcim_p2pdma_init() broke that. It registers a provider for the DMABUF
> path and never creates a pool, so pdev->p2pdma is set while
> p2pdma->pool stays NULL. Nothing publishes such a provider today, so the
> search cannot return one yet, but the flag alone no longer says what the
> caller needs.
> 
> Ask for the pool as well, so the search covers the providers its result
> is used for. A later patch documents the pdev->p2pdma lifetime and RCU
> rules.
> 
> Tested-by: Tushar Dave <tdave@xxxxxxxxxx>
> Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxx>

Makes sense to me:

Reviewed-by: Logan Gunthorpe <logang@xxxxxxxxxxxx>