linux-kernel - Re: [PATCH] swiotlb-xen: override common mmap and get

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: Windows password security audit tool. GUI, reports in PDF.

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

Message-ID: <fbaeaad5-ea8a-ff2d-2e62-d27b4d234e8e@oracle.com>
Date:   Mon, 14 Jun 2021 11:45:46 -0400
From:   Boris Ostrovsky <boris.ostrovsky@...cle.com>
To:     Roman Skakun <rm.skakun@...il.com>
Cc:     Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>,
        Juergen Gross <jgross@...e.com>,
        Stefano Stabellini <sstabellini@...nel.org>,
        xen-devel@...ts.xenproject.org, iommu@...ts.linux-foundation.org,
        linux-kernel@...r.kernel.org,
        Oleksandr Tyshchenko <oleksandr_tyshchenko@...m.com>,
        Oleksandr Andrushchenko <oleksandr_andrushchenko@...m.com>,
        Volodymyr Babchuk <volodymyr_babchuk@...m.com>,
        Roman Skakun <roman_skakun@...m.com>,
        Andrii Anisov <andrii_anisov@...m.com>
Subject: Re: [PATCH] swiotlb-xen: override common mmap and get_sgtable dma ops


On 6/14/21 8:47 AM, Roman Skakun wrote:
> Hey, Boris!
> Thanks for the review.
>
> I have an additional question about current implementation that disturbed me.
> I think, that we can have cases when mapped memory can not be
> physically contiguous.
> In order to proceed this correctly need to apply some additional steps
> to current implementation as well.
>
> In mmap() :
> 1. Is the memory region physically contiguous?
> 2. Remap multiple ranges if it is not.
>
> In get_sgtable() :
> 1. Is the memory region physically contiguous?
> 2. Create sgt that will be included multiple contiguous ranges if it is not.
>
> What do you think about it?


We make sure that we allocate contiguous memory in xen_swiotlb_alloc_coherent().


-boris