Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > linux.kernel > #1519501
| From | "Kani, Toshimitsu" <toshi.kani@hpe.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [RFC PATCH v3 02/20] x86: Set the write-protect cache mode for full PAT support |
| Date | 2016-11-11 02:30 +0100 |
| Message-ID | <sC8Pf-5SO-1@gated-at.bofh.it> (permalink) |
| References | <sBVfj-4HF-7@gated-at.bofh.it> <sBXqN-6H1-7@gated-at.bofh.it> <sBXqN-6H1-5@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Thu, 2016-11-10 at 14:14 +0100, Borislav Petkov wrote: > + Toshi. > > On Wed, Nov 09, 2016 at 06:34:48PM -0600, Tom Lendacky wrote: > > > > For processors that support PAT, set the write-protect cache mode > > (_PAGE_CACHE_MODE_WP) entry to the actual write-protect value > > (x05). Using slot 6 may be more cautious (for the same reason slot 7 was used for WT), but I do not have a strong opinion for it. set_page_memtype() cannot track the use of WP type since there is no extra-bit available for WP, but WP is only supported by early_memremap_xx() interfaces in this series. So, I think we should just document that WP is only intended for temporary mappings at boot- time until this issue is resolved. Also, we need to make sure that this early_memremap for WP is only called after pat_init() is done. A nit - please add WP to the function header comment below. "This function initializes PAT MSR and PAT table with an OS-defined value to enable additional cache attributes, WC and WT." Thanks, -Toshi
Back to linux.kernel | Previous | Next — Previous in thread | Find similar | Unroll thread
Re: [RFC PATCH v3 02/20] x86: Set the write-protect cache mode for full PAT support Borislav Petkov <bp@alien8.de> - 2016-11-10 14:20 +0100 Re: [RFC PATCH v3 02/20] x86: Set the write-protect cache mode for full PAT support "Kani, Toshimitsu" <toshi.kani@hpe.com> - 2016-11-11 02:30 +0100
csiph-web