linux-kernel - Re: [PATCH -mm] kexec jump -v9

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: <1210903686.23707.171.camel@caritas-dev.intel.com>
Date:	Fri, 16 May 2008 10:08:06 +0800
From:	"Huang, Ying" <ying.huang@...el.com>
To:	Vivek Goyal <vgoyal@...hat.com>
CC:	"Eric W. Biederman" <ebiederm@...ssion.com>,
	Pavel Machek <pavel@....cz>, nigel@...el.suspend2.net,
	"Rafael J. Wysocki" <rjw@...k.pl>,
	Andrew Morton <akpm@...ux-foundation.org>,
	linux-kernel@...r.kernel.org, linux-pm@...ts.linux-foundation.org,
	Kexec Mailing List <kexec@...ts.infradead.org>
Subject: Re: [PATCH -mm] kexec jump -v9

On Thu, 2008-05-15 at 21:51 -0400, Vivek Goyal wrote:
> On Fri, May 16, 2008 at 09:48:34AM +0800, Huang, Ying wrote:
> > On Thu, 2008-05-15 at 16:09 -0400, Vivek Goyal wrote:
> > [...]
> > > Ok, You want to make BIOS calls. We already do that using vm86 mode and
> > > use bios real mode interrupts. So why do we need this interface? Or, IOW,
> > > how is this interface better?
> > 
> > It can call code in 32-bit physical mode in addition to real mode. So It
> > can be used to call EFI runtime service, especially call EFI 64 runtime
> > service under 32-bit kernel or vice versa.
> > 
> > The main purpose of kexec jump is for hibernation. But I think if the
> > effort is small, why not support general 32-bit physical mode code call
> > at same time.
> > 
> 
> In general what's the environment requirements for EFI runtime 
> services? I mean, just that processor should be in protected mode with
> paging disabled or one need to stop all other cpus and devices and then make
> the call (as we are doing in this case?). 

Put processor in protected mode with paging disabled is sufficient. In
one of previous kexec jump versions, I provide some option to choose the
state saved (whether stop other cpus, whether stop devices).

I agree that now we should focus on kexec based hibernation. But I think
it is reasonable to keep the possibility with minimal effort.

Best Regards,
Huang Ying

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/