From: Peter Zijlstra <peterz@infradead.org>
To: Joerg Roedel <jroedel@suse.de>
Cc: David Rientjes <rientjes@google.com>,
Borislav Petkov <bp@alien8.de>, Andy Lutomirski <luto@kernel.org>,
Sean Christopherson <seanjc@google.com>,
Andrew Morton <akpm@linux-foundation.org>,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
Andi Kleen <ak@linux.intel.com>,
Brijesh Singh <brijesh.singh@amd.com>,
Tom Lendacky <thomas.lendacky@amd.com>,
Jon Grimm <jon.grimm@amd.com>,
Thomas Gleixner <tglx@linutronix.de>,
Christoph Hellwig <hch@lst.de>,
Paolo Bonzini <pbonzini@redhat.com>,
Ingo Molnar <mingo@redhat.com>,
x86@kernel.org, linux-mm@kvack.org
Subject: Re: AMD SEV-SNP/Intel TDX: validation of memory pages
Date: Fri, 12 Feb 2021 16:19:22 +0100 [thread overview]
Message-ID: <YCacenGvoQsTmVcy@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20210212145318.GK5453@suse.de>
On Fri, Feb 12, 2021 at 03:53:18PM +0100, Joerg Roedel wrote:
> On Fri, Feb 12, 2021 at 03:17:57PM +0100, Peter Zijlstra wrote:
> > On Fri, Feb 12, 2021 at 02:19:07PM +0100, Joerg Roedel wrote:
> > > - Then we can pass this information up the boot process by
> > > extending struct boot_params. The bootloader can pass which
> > > E820 usable memory it validated, same for the kernel
> > > decompressor. The text+data (but not bss) of the running
> > > kernel image is per definition validated by the decompressor
> > > and does not need to be added explicitly to boot_params.
> >
> > Even if all text+data is prevalidated, we'll probably still need some
> > prevalidated bss and certainly some prevalidated percpu data (like the
> > various stacks, but also crud like the percpu variable we store the DR7
> > shadow in etc..).
>
> The kernel sets up early exception handling in head_64.S, right after
> setting MSR_GS_BASE. So per-cpu data can probably be be on-demand. For
> bss you might be right.
That's the thing, we don't want #VE to happen in noinstr code *ever*.
noinstr covers the whole entry code, things like the syscall gap and nmi
recursion setup. Getting a #VE there is fail.
So most per-cpu data can be on-demand, but some of it must absolutely
not be.
next prev parent reply other threads:[~2021-02-12 15:19 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-02 1:51 AMD SEV-SNP/Intel TDX: validation of memory pages David Rientjes
2021-02-02 13:17 ` Matthew Wilcox
2021-02-02 16:02 ` Kirill A. Shutemov
2021-02-03 0:16 ` Brijesh Singh
2021-02-11 17:46 ` Sean Christopherson
2021-02-02 22:37 ` Andi Kleen
2021-02-11 20:46 ` Peter Zijlstra
2021-02-12 13:19 ` Joerg Roedel
2021-02-12 14:17 ` Peter Zijlstra
2021-02-12 14:53 ` Joerg Roedel
2021-02-12 15:19 ` Peter Zijlstra [this message]
2021-02-12 15:28 ` Joerg Roedel
2021-02-12 16:12 ` Peter Zijlstra
2021-02-12 16:18 ` Joerg Roedel
2021-02-12 16:45 ` Peter Zijlstra
2021-02-12 17:48 ` Dave Hansen
2021-02-12 18:22 ` Sean Christopherson
2021-02-12 18:38 ` Andy Lutomirski
2021-02-12 18:43 ` Sean Christopherson
2021-02-12 18:46 ` Dave Hansen
2021-02-12 19:24 ` Sean Christopherson
2021-02-16 10:00 ` Joerg Roedel
2021-02-16 14:27 ` Andi Kleen
2021-02-16 14:46 ` Peter Zijlstra
2021-02-16 15:59 ` Paolo Bonzini
2021-02-16 16:25 ` Joerg Roedel
2021-02-16 16:48 ` Paolo Bonzini
2021-02-16 18:26 ` Joerg Roedel
2021-02-16 18:33 ` Paolo Bonzini
2021-02-16 16:47 ` Peter Zijlstra
2021-02-16 16:57 ` Andy Lutomirski
2021-02-16 17:05 ` Paolo Bonzini
2021-02-16 16:55 ` Andi Kleen
2021-02-12 21:42 ` Andi Kleen
2021-02-12 21:58 ` Peter Zijlstra
2021-02-12 22:39 ` Andi Kleen
2021-02-12 22:46 ` Andy Lutomirski
2021-02-13 9:38 ` Peter Zijlstra
2021-02-12 23:51 ` Paolo Bonzini
2021-03-23 9:33 ` Joerg Roedel
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=YCacenGvoQsTmVcy@hirez.programming.kicks-ass.net \
--to=peterz@infradead.org \
--cc=ak@linux.intel.com \
--cc=akpm@linux-foundation.org \
--cc=bp@alien8.de \
--cc=brijesh.singh@amd.com \
--cc=hch@lst.de \
--cc=jon.grimm@amd.com \
--cc=jroedel@suse.de \
--cc=kirill.shutemov@linux.intel.com \
--cc=linux-mm@kvack.org \
--cc=luto@kernel.org \
--cc=mingo@redhat.com \
--cc=pbonzini@redhat.com \
--cc=rientjes@google.com \
--cc=seanjc@google.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).