RE: [PATCH v9 3/7] mce: fix set_mce_nospec to always unmap the whole page

From: "Luck, Tony" <tony.luck@intel.com>
To: Borislav Petkov <bp@alien8.de>,
	"Williams, Dan J" <dan.j.williams@intel.com>
Cc: Jane Chu <jane.chu@oracle.com>,
	Christoph Hellwig <hch@infradead.org>,
	"Hansen, Dave" <dave.hansen@intel.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Andy Lutomirski <luto@kernel.org>, david <david@fromorbit.com>,
	"Darrick J. Wong" <djwong@kernel.org>,
	linux-fsdevel <linux-fsdevel@vger.kernel.org>,
	Linux NVDIMM <nvdimm@lists.linux.dev>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	X86 ML <x86@kernel.org>,
	"Verma, Vishal L" <vishal.l.verma@intel.com>,
	"Jiang, Dave" <dave.jiang@intel.com>,
	Alasdair Kergon <agk@redhat.com>,
	Mike Snitzer <snitzer@redhat.com>,
	device-mapper development <dm-devel@redhat.com>,
	"Weiny, Ira" <ira.weiny@intel.com>,
	Matthew Wilcox <willy@infradead.org>,
	Vivek Goyal <vgoyal@redhat.com>, Jue Wang <juew@google.com>
Subject: RE: [PATCH v9 3/7] mce: fix set_mce_nospec to always unmap the whole page
Date: Wed, 11 May 2022 17:17:21 +0000	[thread overview]
Message-ID: <5aa1c9aacc5a4086a904440641062669@intel.com> (raw)
In-Reply-To: <Ynt3WlpcJwuqffDX@zn.tnic>

> I - just like you - am waiting for Tony to say whether he still needs
> this whole_page() thing. I already suggested removing it so I'm fine
> with this patch.

IIRC this new patch effectively reverts back to the original behavior that
I implemented back at the dawn of time. I.e. just always mark the whole
page "not present" and don't try to mess with UC mappings to allow
partial (but non-speculative) access to the not-poisoned parts of the
page.

If that is the case ... then Acked-by: Tony Luck <tony.luck@intel.com>

If I've misunderstood ... then please explain what it is doing.

Thanks

-Tony