From: Peter Zijlstra <peterz@infradead.org>
To: Dave Hansen <dave.hansen@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>,
Adam Dunlap <acdunlap@google.com>,
linux-kernel@vger.kernel.org, x86@kernel.org,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
"H. Peter Anvin" <hpa@zytor.com>,
David Hildenbrand <david@redhat.com>,
Mike Rapoport <rppt@kernel.org>,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
Nikunj A Dadhania <nikunj@amd.com>,
Dionna Glaze <dionnaglaze@google.com>,
Joerg Roedel <jroedel@suse.de>, Jacob Xu <jacobhxu@google.com>
Subject: Re: [PATCH] x86/sev-es: Do not use copy_from_kernel_nofault in early #VC handler
Date: Fri, 8 Sep 2023 17:13:33 +0200 [thread overview]
Message-ID: <20230908151333.GL19320@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <cc90c896-7581-62b5-4836-971e9ca8fac0@intel.com>
On Fri, Sep 08, 2023 at 07:48:58AM -0700, Dave Hansen wrote:
> On 9/8/23 06:13, Tom Lendacky wrote:
> > On 9/7/23 14:12, Dave Hansen wrote:
> >> But seriously, is it even *possible* to spin up a SEV-SNP VM what
> >> doesn't have NX?
> >
> > It is a common path, so while an SEV guest would have NX support, you
> > would first have to determine that it is an SEV guest. That would take
> > issuing a CPUID instruction in order to determine if a particular MSR
> > can be read...
>
> I was thinking more along the lines of telling folks that if they want
> to turn SEV-SNP support on, they also have to give up on running on a
> !NX system. That would be a _bit_ nicer than just refusing to boot on
> all !NX systems.
I think there were a very limited amount of !NX P4 class x86_64 systems.
I vote in favour of dropping them into the museum bucket, they get to
run an old kernel.
Andrew and me looked at this a few months ago, but I forgot all details
again :/
prev parent reply other threads:[~2023-09-08 15:14 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-06 22:45 [PATCH] x86/sev-es: Do not use copy_from_kernel_nofault in early #VC handler Adam Dunlap
2023-09-06 23:01 ` Dave Hansen
2023-09-06 23:25 ` Adam Dunlap
2023-09-07 17:04 ` Dave Hansen
2023-09-07 18:03 ` Adam Dunlap
2023-09-07 19:12 ` Dave Hansen
2023-09-07 22:30 ` Adam Dunlap
2023-09-07 22:45 ` Dave Hansen
2023-09-08 13:13 ` Tom Lendacky
2023-09-08 14:48 ` Dave Hansen
2023-09-08 15:13 ` Peter Zijlstra [this message]
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