From: Peter Zijlstra <peterz@infradead.org>
To: Borislav Petkov <bp@alien8.de>
Cc: X86 ML <x86@kernel.org>, Tom Lendacky <thomas.lendacky@amd.com>,
LKML <linux-kernel@vger.kernel.org>,
Eric Morton <Eric.Morton@amd.com>
Subject: Re: [PATCH 3/3] x86/msr: Add an MSR write callback
Date: Wed, 10 Jun 2020 14:32:26 +0200 [thread overview]
Message-ID: <20200610123226.GC2497@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20200610110037.11853-4-bp@alien8.de>
On Wed, Jun 10, 2020 at 01:00:37PM +0200, Borislav Petkov wrote:
> From: Borislav Petkov <bp@suse.de>
>
> Add a callback which gets executed after a MSR is written from
> userspace. This is needed because in the case of AMD's MSR_AMD64_LS_CFG
> MSR which gets cached in the kernel, the cached value needs to be
> updated after the write, otherwise latter doesn't stick.
We cache a whole bunch of MSRs in kernel. Why is this one special?
If you write using the stupid msr device, you get to keep all pieces.
next prev parent reply other threads:[~2020-06-10 12:32 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-10 11:00 [PATCH 0/3] x86/MSR: Add a MSR write callback Borislav Petkov
2020-06-10 11:00 ` [PATCH 1/3] x86/msr: Pass a single MSR value to __rwmsr_on_cpus() too Borislav Petkov
2020-06-10 11:00 ` [PATCH 2/3] x86/msr: Add wrmsrl_val_on_cpus() Borislav Petkov
2020-06-10 11:00 ` [PATCH 3/3] x86/msr: Add an MSR write callback Borislav Petkov
2020-06-10 12:32 ` Peter Zijlstra [this message]
2020-06-10 13:21 ` Borislav Petkov
2020-06-10 14:01 ` Peter Zijlstra
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