linux-kernel - Re: [PATCH RFC 0/5] mm/gup: Introduce exclusive GUP pinning

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]

Date: Tue, 18 Jun 2024 17:11:00 -0700
From: Elliot Berman <quic_eberman@...cinc.com>
To: Andrew Morton <akpm@...ux-foundation.org>, Shuah Khan <shuah@...nel.org>,
        David Hildenbrand <david@...hat.com>,
        Matthew Wilcox <willy@...radead.org>, <maz@...nel.org>
CC: <kvm@...r.kernel.org>, <linux-arm-msm@...r.kernel.org>,
        <linux-mm@...ck.org>, <linux-kernel@...r.kernel.org>,
        <linux-kselftest@...r.kernel.org>, <pbonzini@...hat.com>,
        Fuad Tabba
	<tabba@...gle.com>, <chenhuacai@...nel.org>,
        <mpe@...erman.id.au>, <anup@...infault.org>,
        <paul.walmsley@...ive.com>, <palmer@...belt.com>,
        <aou@...s.berkeley.edu>, <seanjc@...gle.com>,
        <viro@...iv.linux.org.uk>, <brauner@...nel.org>, <willy@...radead.org>,
        <akpm@...ux-foundation.org>, <xiaoyao.li@...el.com>,
        <yilun.xu@...el.com>, <chao.p.peng@...ux.intel.com>,
        <jarkko@...nel.org>, <amoorthy@...gle.com>, <dmatlack@...gle.com>,
        <yu.c.zhang@...ux.intel.com>, <isaku.yamahata@...el.com>,
        <mic@...ikod.net>, <vbabka@...e.cz>, <vannapurve@...gle.com>,
        <ackerleytng@...gle.com>, <mail@...iej.szmigiero.name>,
        <david@...hat.com>, <michael.roth@....com>, <wei.w.wang@...el.com>,
        <liam.merwick@...cle.com>, <isaku.yamahata@...il.com>,
        <kirill.shutemov@...ux.intel.com>, <suzuki.poulose@....com>,
        <steven.price@....com>, <quic_eberman@...cinc.com>,
        <quic_mnalajal@...cinc.com>, <quic_tsoni@...cinc.com>,
        <quic_svaddagi@...cinc.com>, <quic_cvanscha@...cinc.com>,
        <quic_pderrin@...cinc.com>, <quic_pheragu@...cinc.com>,
        <catalin.marinas@....com>, <james.morse@....com>,
        <yuzenghui@...wei.com>, <oliver.upton@...ux.dev>, <maz@...nel.org>,
        <will@...nel.org>, <qperret@...gle.com>, <keirf@...gle.com>
Subject: Re: [PATCH RFC 0/5] mm/gup: Introduce exclusive GUP pinning

b4 wasn't happy with my copy/paste of the CC list from Fuad's series
[1]. CC'ing them here.

[1]: https://lore.kernel.org/all/20240222161047.402609-1-tabba@google.com/

On Tue, Jun 18, 2024 at 05:05:06PM -0700, Elliot Berman wrote:
> In arm64 pKVM and QuIC's Gunyah protected VM model, we want to support
> grabbing shmem user pages instead of using KVM's guestmemfd. These
> hypervisors provide a different isolation model than the CoCo
> implementations from x86. KVM's guest_memfd is focused on providing
> memory that is more isolated than AVF requires. Some specific examples
> include ability to pre-load data onto guest-private pages, dynamically
> sharing/isolating guest pages without copy, and (future) migrating
> guest-private pages.  In sum of those differences after a discussion in
> [1] and at PUCK, we want to try to stick with existing shmem and extend
> GUP to support the isolation needs for arm64 pKVM and Gunyah. To that
> end, we introduce the concept of "exclusive GUP pinning", which enforces
> that only one pin of any kind is allowed when using the FOLL_EXCLUSIVE
> flag is set. This behavior doesn't affect FOLL_GET or any other folio
> refcount operations that don't go through the FOLL_PIN path.
> 
> [1]: https://lore.kernel.org/all/20240319143119.GA2736@willie-the-truck/
> 
> Tree with patches at:
> https://git.codelinaro.org/clo/linux-kernel/gunyah-linux/-/tree/sent/exclusive-gup-v1
> 
> 
> Signed-off-by: Elliot Berman <quic_eberman@...cinc.com>
> ---
> Elliot Berman (2):
>       mm/gup-test: Verify exclusive pinned
>       mm/gup_test: Verify GUP grabs same pages twice
> 
> Fuad Tabba (3):
>       mm/gup: Move GUP_PIN_COUNTING_BIAS to page_ref.h
>       mm/gup: Add an option for obtaining an exclusive pin
>       mm/gup: Add support for re-pinning a normal pinned page as exclusive
> 
>  include/linux/mm.h                    |  57 ++++----
>  include/linux/mm_types.h              |   2 +
>  include/linux/page_ref.h              |  74 ++++++++++
>  mm/Kconfig                            |   5 +
>  mm/gup.c                              | 265 ++++++++++++++++++++++++++++++----
>  mm/gup_test.c                         | 108 ++++++++++++++
>  mm/gup_test.h                         |   1 +
>  tools/testing/selftests/mm/gup_test.c |   5 +-
>  8 files changed, 457 insertions(+), 60 deletions(-)
> ---
> base-commit: 6ba59ff4227927d3a8530fc2973b80e94b54d58f
> change-id: 20240509-exclusive-gup-66259138bbff
> 
> Best regards,
> -- 
> Elliot Berman <quic_eberman@...cinc.com>
>