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From: "Luck, Tony" <tony.luck@intel.com>
To: Borislav Petkov <bp@alien8.de>,
	"Williams, Dan J" <dan.j.williams@intel.com>
Cc: Linux NVDIMM <nvdimm@lists.linux.dev>,
	Jane Chu <jane.chu@oracle.com>,
	Luis Chamberlain <mcgrof@suse.com>
Subject: RE: [RFT PATCH] x86/pat: Fix set_mce_nospec() for pmem
Date: Thu, 30 Sep 2021 17:28:12 +0000	[thread overview]
Message-ID: <3b3266266835447aa668a244ae4e1baf@intel.com> (raw)
In-Reply-To: <YVXxr3e3shdFqOox@zn.tnic>

> Question is, can we even access a hwpoisoned page to retrieve that data
> or are we completely in the wrong weeds here? Tony?

Hardware scope for poison is a cache line (64 bytes for DDR, may be larger
for the internals of 3D-Xpoint memory).

So you can access the other lines in the page. You just need to be careful
not to access the poison. Setting the cache mode for the page to uncacheable
ensures that h/w prefetchers and speculative access don't accidently touch
the poison while accessing nearby cache lines.

-Tony

  reply	other threads:[~2021-09-30 17:28 UTC|newest]

Thread overview: 48+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-07  1:01 [RFT PATCH] x86/pat: Fix set_mce_nospec() for pmem Dan Williams
2021-08-26 19:08 ` Dan Williams
2021-08-27  7:12   ` Jane Chu
2021-09-13 10:29 ` Borislav Petkov
2021-09-14 18:08   ` Dan Williams
2021-09-15 10:41     ` Borislav Petkov
2021-09-16 20:33       ` Dan Williams
2021-09-17 11:30         ` Borislav Petkov
2021-09-21  2:04           ` Dan Williams
2021-09-30 17:19             ` Borislav Petkov
2021-09-30 17:28               ` Luck, Tony [this message]
2021-09-30 19:30                 ` Borislav Petkov
2021-09-30 19:41                   ` Dan Williams
2021-09-30 19:44                   ` Luck, Tony
2021-09-30 20:01                     ` Borislav Petkov
2021-09-30 20:15                       ` Luck, Tony
2021-09-30 20:32                         ` Borislav Petkov
2021-09-30 20:39                           ` Dan Williams
2021-09-30 20:54                             ` Borislav Petkov
2021-09-30 21:05                               ` Dan Williams
2021-09-30 21:20                                 ` Borislav Petkov
2021-09-30 21:41                                   ` Dan Williams
2021-09-30 22:35                                     ` Borislav Petkov
2021-09-30 22:44                                       ` Dan Williams
2021-10-01 10:41                                         ` Borislav Petkov
2021-10-01  0:43                                       ` Jane Chu
2021-10-01  2:02                                         ` Dan Williams
2021-10-01 10:50                                           ` Borislav Petkov
2021-10-01 16:52                                             ` Dan Williams
2021-10-01 18:11                                               ` Borislav Petkov
2021-10-01 18:29                                                 ` Dan Williams
2021-10-02 10:17                                                   ` Borislav Petkov
2021-11-11  0:06                                                     ` Jane Chu
2021-11-12  0:30                                                       ` Jane Chu
2021-11-12  0:51                                                         ` Dan Williams
2021-11-12 17:57                                                           ` Jane Chu
2021-11-12 19:24                                                             ` Dan Williams
2021-11-12 22:35                                                               ` Jane Chu
2021-11-12 22:50                                                                 ` Jane Chu
2021-11-12 23:08                                                                 ` Dan Williams
2021-11-13  5:50                                                                   ` Jane Chu
2021-11-13 20:47                                                                     ` Dan Williams
2021-11-18 19:03                                                                       ` Jane Chu
2021-11-25  0:16                                                                         ` Dan Williams
2021-11-30 23:00                                                                           ` Jane Chu
2021-09-30 18:15         ` Jane Chu
2021-09-30 19:11           ` Dan Williams
2021-09-30 21:23             ` Jane Chu

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