From: Dave Hansen <dave.hansen@intel.com>
To: "Thomas Hellström (VMware)" <thomas_os@shipmail.org>,
linux-kernel@vger.kernel.org, x86@kernel.org,
pv-drivers@vmware.com
Cc: "Thomas Hellstrom" <thellstrom@vmware.com>,
"Dave Hansen" <dave.hansen@linux.intel.com>,
"Andy Lutomirski" <luto@kernel.org>,
"Peter Zijlstra" <peterz@infradead.org>,
"Thomas Gleixner" <tglx@linutronix.de>,
"Ingo Molnar" <mingo@redhat.com>,
"Borislav Petkov" <bp@alien8.de>,
"H. Peter Anvin" <hpa@zytor.com>,
"Christoph Hellwig" <hch@infradead.org>,
"Christian König" <christian.koenig@amd.com>,
"Marek Szyprowski" <m.szyprowski@samsung.com>,
"Tom Lendacky" <thomas.lendacky@amd.com>
Subject: Re: [RFC PATCH 1/2] x86: Don't let pgprot_modify() change the page encryption bit
Date: Thu, 5 Sep 2019 07:15:07 -0700 [thread overview]
Message-ID: <608bbec6-448e-f9d5-b29a-1984225eb078@intel.com> (raw)
In-Reply-To: <20190905103541.4161-2-thomas_os@shipmail.org>
Hi Thomas,
Thanks for the second batch of patches! These look much improved on all
fronts.
On 9/5/19 3:35 AM, Thomas Hellström (VMware) wrote:
> -/* mprotect needs to preserve PAT bits when updating vm_page_prot */
> +/*
> + * mprotect needs to preserve PAT and encryption bits when updating
> + * vm_page_prot
> + */
> #define pgprot_modify pgprot_modify
> static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot)
> {
> - pgprotval_t preservebits = pgprot_val(oldprot) & _PAGE_CHG_MASK;
> - pgprotval_t addbits = pgprot_val(newprot);
> + pgprotval_t preservebits = pgprot_val(oldprot) &
> + (_PAGE_CHG_MASK | sme_me_mask);
> + pgprotval_t addbits = pgprot_val(newprot) & ~sme_me_mask;
> return __pgprot(preservebits | addbits);
> }
_PAGE_CHG_MASK is claiming similar functionality about preserving bits
when changing PTEs:
> /*
> * Set of bits not changed in pte_modify. The pte's
> * protection key is treated like _PAGE_RW, for
> * instance, and is *not* included in this mask since
> * pte_modify() does modify it.
> */
> #define _PAGE_CHG_MASK (PTE_PFN_MASK | _PAGE_PCD | _PAGE_PWT | \
> _PAGE_SPECIAL | _PAGE_ACCESSED | _PAGE_DIRTY | \
> _PAGE_SOFT_DIRTY | _PAGE_DEVMAP)
This makes me wonder if we should be including sme_me_mask in
_PAGE_CHG_MASK (logically).
next prev parent reply other threads:[~2019-09-05 14:15 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-05 10:35 [RFC PATCH 0/2] Fix SEV user-space mapping of unencrypted coherent memory Thomas Hellström (VMware)
2019-09-05 10:35 ` [RFC PATCH 1/2] x86: Don't let pgprot_modify() change the page encryption bit Thomas Hellström (VMware)
2019-09-05 14:15 ` Dave Hansen [this message]
2019-09-05 15:21 ` Thomas Hellström (VMware)
2019-09-05 15:24 ` Christoph Hellwig
2019-09-05 16:40 ` Thomas Hellström (VMware)
2019-09-05 17:05 ` dma_mmap_fault discussion Thomas Hellström (VMware)
2019-09-06 6:32 ` Christoph Hellwig
2019-09-06 7:10 ` Thomas Hellström (VMware)
2019-09-06 7:20 ` Christoph Hellwig
2019-09-10 8:37 ` Thomas Hellström (VMware)
2019-09-10 16:11 ` [RFC PATCH 1/2] x86: Don't let pgprot_modify() change the page encryption bit Andy Lutomirski
2019-09-10 19:26 ` Thomas Hellström (VMware)
2019-09-11 4:18 ` Andy Lutomirski
2019-09-11 7:49 ` Thomas Hellström (VMware)
2019-09-11 18:03 ` Andy Lutomirski
2019-09-12 8:29 ` Thomas Hellström (VMware)
2019-09-11 9:08 ` Koenig, Christian
2019-09-11 10:10 ` TTM huge page-faults WAS: " Thomas Hellström (VMware)
2019-09-11 14:06 ` Koenig, Christian
2019-09-11 15:08 ` Thomas Hellström (VMware)
2019-09-24 12:03 ` Koenig, Christian
2019-09-05 15:59 ` Dave Hansen
2019-09-05 16:29 ` Thomas Hellström (VMware)
2019-09-05 10:35 ` [RFC PATCH 2/2] dma-mapping: Fix dma_pgprot() for unencrypted coherent pages Thomas Hellström (VMware)
2019-09-05 11:23 ` [RFC PATCH 0/2] Fix SEV user-space mapping of unencrypted coherent memory Christoph Hellwig
2019-09-10 6:11 ` Christoph Hellwig
2019-09-10 6:25 ` Thomas Hellström (VMware)
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=608bbec6-448e-f9d5-b29a-1984225eb078@intel.com \
--to=dave.hansen@intel.com \
--cc=bp@alien8.de \
--cc=christian.koenig@amd.com \
--cc=dave.hansen@linux.intel.com \
--cc=hch@infradead.org \
--cc=hpa@zytor.com \
--cc=linux-kernel@vger.kernel.org \
--cc=luto@kernel.org \
--cc=m.szyprowski@samsung.com \
--cc=mingo@redhat.com \
--cc=peterz@infradead.org \
--cc=pv-drivers@vmware.com \
--cc=tglx@linutronix.de \
--cc=thellstrom@vmware.com \
--cc=thomas.lendacky@amd.com \
--cc=thomas_os@shipmail.org \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).