linux-kernel - Re: [PATCH] x86/sev: Fix host kdump support for SNP

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <ZtCKqD_gc6wnqu-P@google.com>
Date: Thu, 29 Aug 2024 07:50:16 -0700
From: Sean Christopherson <seanjc@...gle.com>
To: Borislav Petkov <bp@...en8.de>
Cc: Ashish Kalra <Ashish.Kalra@....com>, pbonzini@...hat.com, dave.hansen@...ux.intel.com, 
	tglx@...utronix.de, mingo@...hat.com, x86@...nel.org, hpa@...or.com, 
	peterz@...radead.org, linux-kernel@...r.kernel.org, kvm@...r.kernel.org, 
	thomas.lendacky@....com, michael.roth@....com, kexec@...ts.infradead.org, 
	linux-coco@...ts.linux.dev
Subject: Re: [PATCH] x86/sev: Fix host kdump support for SNP

On Thu, Aug 29, 2024, Borislav Petkov wrote:
> On August 27, 2024 10:38:04 PM GMT+02:00, Ashish Kalra <Ashish.Kalra@....com> wrote:
> >From: Ashish Kalra <ashish.kalra@....com>
> >
> >With active SNP VMs, SNP_SHUTDOWN_EX invoked during panic notifiers causes
> >crashkernel boot failure with the following signature:
> 
> Why would SNP_SHUTDOWN be allowed *at all* if there are active SNP guests and
> there's potential to lose guest data in the process?!

Because if the host is panicking, guests are hosed regardless.  Unless I'm
misreading things, the goal here is to ensure the crashkernel can actually capture
a kdump.