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From: Chao Gao <chao.gao@intel.com>
To: Jim Mattson <jmattson@google.com>, <pawan.kumar.gupta@intel.com>,
	<chen.zhang@intel.com>
Cc: kvm list <kvm@vger.kernel.org>
Subject: Re: BHB-clearing on VM-exit
Date: Wed, 31 Aug 2022 16:22:03 +0800	[thread overview]
Message-ID: <Yw8aK9O2C+38ShCC@gao-cwp> (raw)
In-Reply-To: <CALMp9eRp-cH6=trNby3EY6+ynD6F-AWiThBHiSF8_sgL2UWnkA@mail.gmail.com>

On Tue, Aug 30, 2022 at 04:42:19PM -0700, Jim Mattson wrote:
>Don't we need a software BHB-clearing sequence on VM-exit for Intel
>parts that don't report IA32_ARCH_CAPABILITIES.BHI_NO? What am I
>missing?

I think we need the software mitigation on parts that don't support/enable
BHI_DIS_S of IA32_SPEC_CTRL MSR and don't enumerate BHI_NO.

Pawan, any idea?

>
>https://www.intel.com/content/www/us/en/developer/articles/technical/software-security-guidance/technical-documentation/branch-history-injection.html

  reply	other threads:[~2022-08-31  8:23 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-08-30 23:42 BHB-clearing on VM-exit Jim Mattson
2022-08-31  8:22 ` Chao Gao [this message]
2022-09-01 17:46   ` Pawan Gupta
2022-09-01 18:35     ` Jim Mattson
2022-09-02 19:14       ` Pawan Gupta
2022-09-02 19:35         ` Jim Mattson
2022-09-03  2:08           ` Pawan Gupta

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