linux-kernel - Re: [PATCH v4 1/3] x86/sev: Add new dump_rmp parameter to snp_leak

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: <aMRnxb68UTzId7zz@google.com>
Date: Fri, 12 Sep 2025 11:34:45 -0700
From: Sean Christopherson <seanjc@...gle.com>
To: Borislav Petkov <bp@...en8.de>
Cc: Ashish Kalra <Ashish.Kalra@....com>, tglx@...utronix.de, mingo@...hat.com, 
	dave.hansen@...ux.intel.com, x86@...nel.org, hpa@...or.com, 
	pbonzini@...hat.com, thomas.lendacky@....com, herbert@...dor.apana.org.au, 
	nikunj@....com, davem@...emloft.net, aik@....com, ardb@...nel.org, 
	john.allen@....com, michael.roth@....com, Neeraj.Upadhyay@....com, 
	linux-kernel@...r.kernel.org, kvm@...r.kernel.org, 
	linux-crypto@...r.kernel.org
Subject: Re: [PATCH v4 1/3] x86/sev: Add new dump_rmp parameter to
 snp_leak_pages() API

On Fri, Sep 12, 2025, Borislav Petkov wrote:
> On Wed, Sep 10, 2025 at 10:55:24PM +0000, Ashish Kalra wrote:
> > From: Ashish Kalra <ashish.kalra@....com>
> > 
> > When leaking certain page types, such as Hypervisor Fixed (HV_FIXED)
> > pages, it does not make sense to dump RMP contents for the 2MB range of
> > the page(s) being leaked. In the case of HV_FIXED pages, this is not an
> > error situation where the surrounding 2MB page RMP entries can provide
> > debug information.
> > 
> > Add new __snp_leak_pages() API with dump_rmp bool parameter to support
> > continue adding pages to the snp_leaked_pages_list but not issue
> > dump_rmpentry().
> > 
> > Make snp_leak_pages() a wrapper for the common case which also allows
> > existing users to continue to dump RMP entries.
> > 
> > Suggested-by: Thomas Lendacky <Thomas.Lendacky@....com>
> > Suggested-by: Sean Christopherson <seanjc@...gle.com>
> > Signed-off-by: Ashish Kalra <ashish.kalra@....com>
> > ---
> >  arch/x86/include/asm/sev.h | 8 +++++++-
> >  arch/x86/virt/svm/sev.c    | 7 ++++---
> >  2 files changed, 11 insertions(+), 4 deletions(-)
> 
> Sean, lemme know if I should carry this through tip.

Take them through tip, but the stubs mess in sev.h really needs to be cleaned up
(doesn't have to block this series, but should be done sooner than later).