From: Borislav Petkov <bp@suse.de>
To: Brijesh Singh <brijesh.singh@amd.com>
Cc: x86@kernel.org, linux-kernel@vger.kernel.org,
kvm@vger.kernel.org, "Tom Lendacky" <thomas.lendacky@amd.com>,
"Thomas Gleixner" <tglx@linutronix.de>,
"H. Peter Anvin" <hpa@zytor.com>,
"Paolo Bonzini" <pbonzini@redhat.com>,
"Sean Christopherson" <sean.j.christopherson@intel.com>,
"Radim Krčmář" <rkrcmar@redhat.com>
Subject: Re: [PATCH v6 4/5] x86/kvm: use __decrypted attribute in shared variables
Date: Mon, 10 Sep 2018 14:04:16 +0200 [thread overview]
Message-ID: <20180910120416.GD21815@zn.tnic> (raw)
In-Reply-To: <1536343050-18532-5-git-send-email-brijesh.singh@amd.com>
On Fri, Sep 07, 2018 at 12:57:29PM -0500, Brijesh Singh wrote:
> Commit: 368a540e0232 (x86/kvmclock: Remove memblock dependency)
> caused SEV guest regression.
When mentioning a commit in the commit message, put it on a separate
line, like this:
"Commit
368a540e0232 (x86/kvmclock: Remove memblock dependency)
caused a SEV guest regression."
> When SEV is active, we map the shared
Use passive tone in your commit message: no "we", etc...
> variables (wall_clock and hv_clock_boot) with C=0 to ensure that both
> the guest and the hypervisor are able to access the data. To map the
> variables we use kernel_physical_mapping_init() to split the large pages,
"... to potentially split large pages used for that mapping... "
> but splitting large pages requires allocating a new PMD, which fails now
> that kvmclock initialization is called early during boot.
"... before the memblock allocator is initialized."
> Recently we added a special .data..decrypted section to hold the shared
> variables.
You don't really need that sentence.
> This section is mapped with C=0 early during boot. Use
> __decrypted attribute to put the wall_clock and hv_clock_boot in
> .data..decrypted section so that they are mapped with C=0.
"... so that they're mapped decrypted." Readers don't care about C=0
- they simply wanna know what C=0 represents, i.e., memory is not
encrypted.
With that:
Reviewed-by: Borislav Petkov <bp@suse.de>
--
Regards/Gruss,
Boris.
SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg)
--
next prev parent reply other threads:[~2018-09-10 12:04 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-07 17:57 [PATCH v6 0/5] x86: Fix SEV guest regression Brijesh Singh
2018-09-07 17:57 ` [PATCH v6 1/5] x86/mm: Restructure sme_encrypt_kernel() Brijesh Singh
2018-09-10 11:32 ` Borislav Petkov
2018-09-07 17:57 ` [PATCH v6 2/5] x86/mm: fix sme_populate_pgd() to update page flags Brijesh Singh
2018-09-10 11:36 ` Borislav Petkov
2018-09-10 12:28 ` Brijesh Singh
2018-09-10 12:32 ` Borislav Petkov
2018-09-07 17:57 ` [PATCH v6 3/5] x86/mm: add .data..decrypted section to hold shared variables Brijesh Singh
2018-09-10 11:54 ` Borislav Petkov
2018-09-10 12:33 ` Brijesh Singh
2018-09-07 17:57 ` [PATCH v6 4/5] x86/kvm: use __decrypted attribute in " Brijesh Singh
2018-09-10 12:04 ` Borislav Petkov [this message]
2018-09-10 13:15 ` Sean Christopherson
2018-09-10 13:29 ` Thomas Gleixner
2018-09-10 15:34 ` Borislav Petkov
2018-09-10 12:29 ` Paolo Bonzini
2018-09-10 12:33 ` Borislav Petkov
2018-09-10 12:46 ` Paolo Bonzini
2018-09-07 17:57 ` [PATCH v6 5/5] x86/kvm: Avoid dynamic allocation of pvclock data when SEV is active Brijesh Singh
2018-09-10 12:27 ` Borislav Petkov
2018-09-10 13:15 ` Brijesh Singh
2018-09-10 13:29 ` Sean Christopherson
2018-09-10 15:10 ` Brijesh Singh
2018-09-10 15:28 ` Sean Christopherson
2018-09-10 15:30 ` Brijesh Singh
2018-09-10 16:48 ` Borislav Petkov
2018-09-11 9:26 ` Paolo Bonzini
2018-09-11 10:01 ` Borislav Petkov
2018-09-11 10:19 ` Paolo Bonzini
2018-09-11 10:25 ` Borislav Petkov
2018-09-11 11:07 ` Paolo Bonzini
2018-09-11 13:55 ` Borislav Petkov
2018-09-11 14:00 ` Paolo Bonzini
2018-09-10 15:53 ` Borislav Petkov
2018-09-10 16:13 ` Sean Christopherson
2018-09-10 16:14 ` Brijesh Singh
2018-09-10 12:28 ` Paolo Bonzini
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=20180910120416.GD21815@zn.tnic \
--to=bp@suse.de \
--cc=brijesh.singh@amd.com \
--cc=hpa@zytor.com \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=pbonzini@redhat.com \
--cc=rkrcmar@redhat.com \
--cc=sean.j.christopherson@intel.com \
--cc=tglx@linutronix.de \
--cc=thomas.lendacky@amd.com \
--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).