From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linutronix.de (193.142.43.55:993) by crypto-ml.lab.linutronix.de with IMAP4-SSL for ; 01 Oct 2019 18:32:05 -0000 Received: from mga02.intel.com ([134.134.136.20]) by Galois.linutronix.de with esmtps (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1iFMwN-00028R-R5 for speck@linutronix.de; Tue, 01 Oct 2019 20:32:04 +0200 Date: Tue, 1 Oct 2019 11:26:25 -0700 From: Pawan Gupta Subject: [MODERATED] Re: [PATCH v4 05/10] TAAv4 5 Message-ID: <20191001182618.GA7734@guptapadev.amr> References: =?utf-8?q?=3Cea74109d0d0662fcad3a60f002690b19340bd73b=2E1567543894=2Egi?= =?utf-8?q?t=2Epawan=2Ekumar=2Egupta=40linux=2Eintel=2Ecom=3E?= MIME-Version: 1.0 In-Reply-To: =?utf-8?q?=3Cea74109d0d0662fcad3a60f002690b19340bd73b=2E15675?= =?utf-8?q?43894=2Egit=2Epawan=2Ekumar=2Egupta=40linux=2Eintel=2Ecom=3E?= Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit To: speck@linutronix.de List-ID: On Tue, Sep 03, 2019 at 02:15:33PM -0700, speck for Pawan Gupta wrote: > From: Pawan Gupta > Subject: [PATCH v4 05/10] x86/speculation/mds: Rename MDS buffer clear > functions > > In preparation for reusing the MDS cpu buffer clear functions and static > keys by the following commits, rename them from mds_* --> verw_* to make > them more generic. VERW is a legacy cpu instruction which was > overloaded to clear the CPU buffers for MDS. > > Signed-off-by: Pawan Gupta > --- > Documentation/x86/mds.rst | 6 +++--- > arch/x86/entry/common.c | 2 +- > arch/x86/include/asm/irqflags.h | 4 ++-- > arch/x86/include/asm/mwait.h | 4 ++-- > arch/x86/include/asm/nospec-branch.h | 24 ++++++++++++------------ > arch/x86/kernel/cpu/bugs.c | 22 +++++++++++----------- > arch/x86/kernel/nmi.c | 2 +- > arch/x86/kvm/vmx/vmx.c | 4 ++-- > 8 files changed, 34 insertions(+), 34 deletions(-) This patch (s/mds/verw/) doesn't add much value compared to the amount of changes needed. It also doesn't bring any functional change. Dropping this patch in favor of below comment. taa_select_mitigation() { [...] /* * TSX is enabled, select alternate mitigation for TAA which is * same as MDS. Enable MDS static branch to clear CPU buffers. * * For guests that can't determine whether the correct microcode is * present on host, enable the mitigation for UCODE_NEEDED as well. */ static_branch_enable(&mds_user_clear); Thanks, Pawan