From: Joerg Roedel <joro@8bytes.org>
To: Borislav Petkov <bp@alien8.de>
Cc: x86@kernel.org, Joerg Roedel <jroedel@suse.de>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
Andy Lutomirski <luto@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Kees Cook <keescook@chromium.org>,
Arvind Sankar <nivedita@alum.mit.edu>,
Martin Radev <martin.b.radev@gmail.com>,
Tom Lendacky <thomas.lendacky@amd.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 3/5] x86/boot/compressed/64: Check SEV encryption in 64-bit boot-path
Date: Wed, 28 Oct 2020 09:38:19 +0100 [thread overview]
Message-ID: <20201028083819.GC18723@8bytes.org> (raw)
In-Reply-To: <20201027110812.GC15580@zn.tnic>
On Tue, Oct 27, 2020 at 12:08:12PM +0100, Borislav Petkov wrote:
> On Wed, Oct 21, 2020 at 02:39:36PM +0200, Joerg Roedel wrote:
> > diff --git a/arch/x86/kernel/sev_verify_cbit.S b/arch/x86/kernel/sev_verify_cbit.S
> > new file mode 100644
> > index 000000000000..5075458ecad0
> > --- /dev/null
> > +++ b/arch/x86/kernel/sev_verify_cbit.S
>
> Why a separate file? You're using it just like verify_cpu.S and this is
> kinda verifying CPU so you could simply add the functionality there...
verify_cpu.S is also used on 32bit and this function is 64bit code. It
can be made working with some #ifdef'fery but I think it is cleaner to
just keep it in a separate file, also given that sev_verify_cbit() is
not needed at every place verify_cpu() is called.
> Yeah, can you please use the callee-clobbered registers in the order as
> they're used by the ABI, see arch/x86/entry/calling.h.
>
> Because I'm looking at this and wondering are rsi, rdx and rcx somehow
> live here and you're avoiding them...
Makes sense, will update the function.
Regards,
Joerg
next prev parent reply other threads:[~2020-10-29 2:12 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-21 12:39 [PATCH v3 0/5] x86/sev-es: Mitigate some HV attack vectors Joerg Roedel
2020-10-21 12:39 ` [PATCH v3 1/5] x86/boot/compressed/64: Introduce sev_status Joerg Roedel
2020-10-26 18:27 ` Borislav Petkov
2020-10-28 8:23 ` Joerg Roedel
2020-10-28 16:50 ` Arvind Sankar
2020-10-28 16:55 ` Joerg Roedel
2020-10-21 12:39 ` [PATCH v3 2/5] x86/boot/compressed/64: Add CPUID sanity check to early #VC handler Joerg Roedel
2020-10-27 10:38 ` Borislav Petkov
2020-10-28 8:31 ` Joerg Roedel
2020-10-21 12:39 ` [PATCH v3 3/5] x86/boot/compressed/64: Check SEV encryption in 64-bit boot-path Joerg Roedel
2020-10-27 11:08 ` Borislav Petkov
2020-10-28 8:38 ` Joerg Roedel [this message]
2020-10-27 11:09 ` Borislav Petkov
2020-10-21 12:39 ` [PATCH v3 4/5] x86/head/64: Check SEV encryption before switching to kernel page-table Joerg Roedel
2020-10-27 11:20 ` Borislav Petkov
2020-10-21 12:39 ` [PATCH v3 5/5] x86/sev-es: Do not support MMIO to/from encrypted memory Joerg Roedel
2020-10-27 11:26 ` Borislav Petkov
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=20201028083819.GC18723@8bytes.org \
--to=joro@8bytes.org \
--cc=bp@alien8.de \
--cc=dave.hansen@linux.intel.com \
--cc=hpa@zytor.com \
--cc=jroedel@suse.de \
--cc=keescook@chromium.org \
--cc=linux-kernel@vger.kernel.org \
--cc=luto@kernel.org \
--cc=martin.b.radev@gmail.com \
--cc=mingo@redhat.com \
--cc=nivedita@alum.mit.edu \
--cc=peterz@infradead.org \
--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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.