From: Dan Williams <dan.j.williams@intel.com>
To: Naveen N Rao <naveen@kernel.org>,
Dan Williams <dan.j.williams@intel.com>
Cc: <dave.hansen@linux.intel.com>, Ingo Molnar <mingo@kernel.org>,
<linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2 1/3] x86/devmem: Remove duplicate range_is_allowed() definition
Date: Thu, 17 Apr 2025 11:27:02 -0700 [thread overview]
Message-ID: <680147f6b6411_130fd294c2@dwillia2-mobl3.amr.corp.intel.com.notmuch> (raw)
In-Reply-To: <ucdjz2mytjsndtkoroadd7r7grsi4hwpqd47v752zwo6rn5bg7@a7pq6ah4tdai>
Naveen N Rao wrote:
[..]
> > The pat_enabled check was originally added as a *bypass* of additional
> > logic in phys_mem_access_prot_allowed() [1] to validate that /dev/mem was
> > establishing compatible mappings of "System-RAM" via /dev/mem. This
> > patch maintains that expectation that phys_mem_access_prot_allowed()
> > returns immediately when there is no potential cache conflict.
>
> Thanks for the background, that makes sense.
>
> Do we also no longer need the devmem_is_allowed() checks in pat.c if PAT
> is enabled and !CONFIG_STRICT_DEVMEM?
The only one that is left is the one in phys_mem_access_prot_allowed()
and that one properly compiles away to nothing in the
!CONFIG_STRICT_DEVMEM case.
next prev parent reply other threads:[~2025-04-17 18:27 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-04-11 1:22 [PATCH v2 0/3] Restrict devmem for confidential VMs Dan Williams
2025-04-11 1:22 ` [PATCH v2 1/3] x86/devmem: Remove duplicate range_is_allowed() definition Dan Williams
2025-04-14 18:17 ` Naveen N Rao
2025-04-16 21:25 ` Dan Williams
2025-04-17 7:28 ` Naveen N Rao
2025-04-17 18:27 ` Dan Williams [this message]
2025-04-19 9:09 ` Naveen N Rao
2025-04-11 1:22 ` [PATCH v2 2/3] devmem: Block mmap access when read/write access is restricted Dan Williams
2025-04-11 2:32 ` Kees Cook
2025-04-11 4:59 ` Dan Williams
2025-04-11 15:38 ` Dave Hansen
2025-04-11 21:48 ` Dan Williams
2025-04-11 1:22 ` [PATCH v2 3/3] x86/devmem: Restrict /dev/mem access for potentially unaccepted memory by default Dan Williams
2025-04-14 18:22 ` Naveen N Rao
2025-04-16 21:30 ` Dan Williams
2025-04-14 10:56 ` [PATCH v2 0/3] Restrict devmem for confidential VMs Nikolay Borisov
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