linux-kernel - Re: [PATCH RFC] virtio-mem: check against memhp_get_pluggable

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: <a1644ce0-427f-7a5c-b90a-547e61341a75@arm.com>
Date:   Mon, 18 Jan 2021 18:51:30 +0530
From:   Anshuman Khandual <anshuman.khandual@....com>
To:     linux-mm@...ck.org, akpm@...ux-foundation.org, david@...hat.com,
        hca@...ux.ibm.com, catalin.marinas@....com
Cc:     Oscar Salvador <osalvador@...e.de>,
        Vasily Gorbik <gor@...ux.ibm.com>,
        Will Deacon <will@...nel.org>,
        Ard Biesheuvel <ardb@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        linux-arm-kernel@...ts.infradead.org, linux-s390@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        "Michael S. Tsirkin" <mst@...hat.com>,
        Jason Wang <jasowang@...hat.com>,
        Pankaj Gupta <pankaj.gupta.linux@...il.com>,
        Michal Hocko <mhocko@...nel.org>,
        Wei Yang <richard.weiyang@...ux.alibaba.com>,
        teawater <teawaterz@...ux.alibaba.com>,
        Pankaj Gupta <pankaj.gupta@...ud.ionos.com>,
        Jonathan Cameron <Jonathan.Cameron@...wei.com>
Subject: Re: [PATCH RFC] virtio-mem: check against memhp_get_pluggable_range()
 which memory we can hotplug



On 1/18/21 6:43 PM, Anshuman Khandual wrote:
> From: David Hildenbrand <david@...hat.com>
> 
> Right now, we only check against MAX_PHYSMEM_BITS - but turns out there
> are more restrictions of which memory we can actually hotplug, especially
> om arm64 or s390x once we support them: we might receive something like
> -E2BIG or -ERANGE from add_memory_driver_managed(), stopping device
> operation.
> 
> So, check right when initializing the device which memory we can add,
> warning the user. Try only adding actually pluggable ranges: in the worst
> case, no memory provided by our device is pluggable.
> 
> In the usual case, we expect all device memory to be pluggable, and in
> corner cases only some memory at the end of the device-managed memory
> region to not be pluggable.
> 
> Cc: "Michael S. Tsirkin" <mst@...hat.com>
> Cc: Jason Wang <jasowang@...hat.com>
> Cc: Pankaj Gupta <pankaj.gupta.linux@...il.com>
> Cc: Michal Hocko <mhocko@...nel.org>
> Cc: Oscar Salvador <osalvador@...e.de>
> Cc: Wei Yang <richard.weiyang@...ux.alibaba.com>
> Cc: Andrew Morton <akpm@...ux-foundation.org>
> Cc: catalin.marinas@....com
> Cc: teawater <teawaterz@...ux.alibaba.com>
> Cc: Anshuman Khandual <anshuman.khandual@....com>
> Cc: Pankaj Gupta <pankaj.gupta@...ud.ionos.com>
> Cc: Jonathan Cameron <Jonathan.Cameron@...wei.com>
> Cc: hca@...ux.ibm.com
> Cc: Vasily Gorbik <gor@...ux.ibm.com>
> Cc: Will Deacon <will@...nel.org>
> Cc: Ard Biesheuvel <ardb@...nel.org>
> Cc: Mark Rutland <mark.rutland@....com>
> Cc: Heiko Carstens <hca@...ux.ibm.com>
> Cc: Michal Hocko <mhocko@...nel.org>
> Signed-off-by: David Hildenbrand <david@...hat.com>
> Signed-off-by: Anshuman Khandual <anshuman.khandual@....com>

Hello David,

As your original patch was in the RFC state, I have just maintained
the same here as well. But once you test this patch along with the
new series, please do let me know if this needs to be converted to
a normal PATCH instead. Thank you.

- Anshuman