linux-kernel - Re: [PATCH v9 6/8] block: set FOLL_PCI_P2PDMA in bio_map_user

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <7b0df76d-a920-90a1-2e1e-044671c386fc@nvidia.com>
Date:   Mon, 5 Sep 2022 17:54:13 -0700
From:   John Hubbard <jhubbard@...dia.com>
To:     Logan Gunthorpe <logang@...tatee.com>,
        linux-kernel@...r.kernel.org, linux-nvme@...ts.infradead.org,
        linux-block@...r.kernel.org, linux-pci@...r.kernel.org,
        linux-mm@...ck.org
Cc:     Christoph Hellwig <hch@....de>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Dan Williams <dan.j.williams@...el.com>,
        Jason Gunthorpe <jgg@...pe.ca>,
        Christian König <christian.koenig@....com>,
        Don Dutile <ddutile@...hat.com>,
        Matthew Wilcox <willy@...radead.org>,
        Daniel Vetter <daniel.vetter@...ll.ch>,
        Minturn Dave B <dave.b.minturn@...el.com>,
        Jason Ekstrand <jason@...kstrand.net>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        Xiong Jianxin <jianxin.xiong@...el.com>,
        Bjorn Helgaas <helgaas@...nel.org>,
        Ira Weiny <ira.weiny@...el.com>,
        Robin Murphy <robin.murphy@....com>,
        Martin Oliveira <martin.oliveira@...eticom.com>,
        Chaitanya Kulkarni <ckulkarnilinux@...il.com>,
        Ralph Campbell <rcampbell@...dia.com>,
        Stephen Bates <sbates@...thlin.com>
Subject: Re: [PATCH v9 6/8] block: set FOLL_PCI_P2PDMA in bio_map_user_iov()

On 8/25/22 08:24, Logan Gunthorpe wrote:
> When a bio's queue supports PCI P2PDMA, set FOLL_PCI_P2PDMA for
> iov_iter_get_pages_flags(). This allows PCI P2PDMA pages to be
> passed from userspace and enables the NVMe passthru requests to
> use P2PDMA pages.
> 
> Signed-off-by: Logan Gunthorpe <logang@...tatee.com>
> ---
>  block/blk-map.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/block/blk-map.c b/block/blk-map.c
> index 7196a6b64c80..1378f49ca5ca 100644
> --- a/block/blk-map.c
> +++ b/block/blk-map.c
> @@ -236,6 +236,7 @@ static int bio_map_user_iov(struct request *rq, struct iov_iter *iter,
>  {
>  	unsigned int max_sectors = queue_max_hw_sectors(rq->q);
>  	unsigned int nr_vecs = iov_iter_npages(iter, BIO_MAX_VECS);
> +	unsigned int flags = 0;

A small thing, but I'd also like to name that one gup_flags, instead of flags.

>  	struct bio *bio;
>  	int ret;
>  	int j;
> @@ -248,13 +249,17 @@ static int bio_map_user_iov(struct request *rq, struct iov_iter *iter,
>  		return -ENOMEM;
>  	bio_init(bio, NULL, bio->bi_inline_vecs, nr_vecs, req_op(rq));
>  
> +	if (blk_queue_pci_p2pdma(rq->q))
> +		flags |= FOLL_PCI_P2PDMA;
> +
>  	while (iov_iter_count(iter)) {
>  		struct page **pages;
>  		ssize_t bytes;
>  		size_t offs, added = 0;
>  		int npages;
>  
> -		bytes = iov_iter_get_pages_alloc2(iter, &pages, LONG_MAX, &offs);
> +		bytes = iov_iter_get_pages_alloc_flags(iter, &pages, LONG_MAX,
> +						       &offs, flags);
>  		if (unlikely(bytes <= 0)) {
>  			ret = bytes ? bytes : -EFAULT;
>  			goto out_unmap;

Looks good, please feel free to add:

Reviewed-by: John Hubbard <jhubbard@...dia.com>


thanks,

-- 
John Hubbard
NVIDIA