linux-kernel - Re: [PATCHv8 08/17] x86/tdx: Account shared memory

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: <dd3f7acb-4a35-4a87-a664-1d02181fe090@intel.com>
Date: Wed, 28 Feb 2024 12:12:20 +1300
From: "Huang, Kai" <kai.huang@...el.com>
To: "Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>, Thomas Gleixner
	<tglx@...utronix.de>, Ingo Molnar <mingo@...hat.com>, Borislav Petkov
	<bp@...en8.de>, Dave Hansen <dave.hansen@...ux.intel.com>, <x86@...nel.org>
CC: "Rafael J. Wysocki" <rafael@...nel.org>, Peter Zijlstra
	<peterz@...radead.org>, Adrian Hunter <adrian.hunter@...el.com>, "Kuppuswamy
 Sathyanarayanan" <sathyanarayanan.kuppuswamy@...ux.intel.com>, "Elena
 Reshetova" <elena.reshetova@...el.com>, Jun Nakajima
	<jun.nakajima@...el.com>, Rick Edgecombe <rick.p.edgecombe@...el.com>, Tom
 Lendacky <thomas.lendacky@....com>, "Kalra, Ashish" <ashish.kalra@....com>,
	"Sean Christopherson" <seanjc@...gle.com>, Baoquan He <bhe@...hat.com>,
	<kexec@...ts.infradead.org>, <linux-coco@...ts.linux.dev>,
	<linux-kernel@...r.kernel.org>
Subject: Re: [PATCHv8 08/17] x86/tdx: Account shared memory



On 28/02/2024 10:24 am, Kirill A. Shutemov wrote:
> The kernel will convert all shared memory back to private during kexec.
> The direct mapping page tables will provide information on which memory
> is shared.
> 
> It is extremely important to convert all shared memory. If a page is
> missed, it will cause the second kernel to crash when it accesses it.
> 
> Keep track of the number of shared pages. This will allow for
> cross-checking against the shared information in the direct mapping and
> reporting if the shared bit is lost.
> 
> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@...ux.intel.com>

Reviewed-by: Kai Huang <kai.huang@...el.com>