From: "Jan Beulich" <JBeulich@suse.com>
To: "Daniel Kiper" <daniel.kiper@oracle.com>
Cc: "Andrew Cooper" <andrew.cooper3@citrix.com>,
"x86@kernel.org" <x86@kernel.org>,
"tglx@linutronix.de" <tglx@linutronix.de>,
"kexec@lists.infradead.org" <kexec@lists.infradead.org>,
"virtualization@lists.linux-foundation.org"
<virtualization@lists.linux-foundation.org>,
"xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>,
"konrad.wilk@oracle.com" <konrad.wilk@oracle.com>,
"mingo@redhat.com" <mingo@redhat.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"Eric W. Biederman" <ebiederm@xmission.com>,
"H. Peter Anvin" <hpa@zytor.com>
Subject: Re: [PATCH v2 01/11] kexec: introduce kexec_ops struct
Date: Fri, 23 Nov 2012 10:51:55 +0000 [thread overview]
Message-ID: <50AF635B02000078000AAD0C@nat28.tlf.novell.com> (raw)
In-Reply-To: <20121123103726.GB2921@host-192-168-1-59.local.net-space.pl>
>>> On 23.11.12 at 11:37, Daniel Kiper <daniel.kiper@oracle.com> wrote:
> On Fri, Nov 23, 2012 at 09:53:37AM +0000, Jan Beulich wrote:
>> >>> On 23.11.12 at 02:56, Andrew Cooper <andrew.cooper3@citrix.com> wrote:
>> > On 23/11/2012 01:38, H. Peter Anvin wrote:
>> >> I still don't really get why it can't be isolated from dom0, which would
>> > make more sense to me, even for a Xen crash.
>> >>
>> >
>> > The crash region (as specified by crashkernel= on the Xen command line)
>> > is isolated from dom0.
>> >
>> > dom0 (using the kexec utility etc) has the task of locating the Xen
>> > crash notes (using the kexec hypercall interface), constructing a binary
>> > blob containing kernel, initram and gubbins, and asking Xen to put this
>> > blob in the crash region (again, using the kexec hypercall interface).
>> >
>> > I do not see how this is very much different from the native case
>> > currently (although please correct me if I am misinformed). Linux has
>> > extra work to do by populating /proc/iomem with the Xen crash regions
>> > boot (so the kexec utility can reference their physical addresses when
>> > constructing the blob), and should just act as a conduit between the
>> > kexec system call and the kexec hypercall to load the blob.
>>
>> But all of this _could_ be done completely independent of the
>> Dom0 kernel's kexec infrastructure (i.e. fully from user space,
>> invoking the necessary hypercalls through the privcmd driver).
>
> No, this is impossible. kexec/kdump image lives in dom0 kernel memory
> until execution. That is why privcmd driver itself is not a solution
> in this case.
Even if so, there's no fundamental reason why that kernel image
can't be put into Xen controlled space instead.
Jan
next prev parent reply other threads:[~2012-11-23 10:51 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-11-20 15:04 [PATCH v2 00/11] xen: Initial kexec/kdump implementation Daniel Kiper
2012-11-20 15:04 ` [PATCH v2 01/11] kexec: introduce kexec_ops struct Daniel Kiper
2012-11-20 15:04 ` [PATCH v2 02/11] x86/kexec: Add extra pointers to transition page table PGD, PUD, PMD and PTE Daniel Kiper
2012-11-20 15:04 ` [PATCH v2 03/11] xen: Introduce architecture independent data for kexec/kdump Daniel Kiper
2012-11-20 15:04 ` [PATCH v2 04/11] x86/xen: Introduce architecture dependent " Daniel Kiper
2012-11-20 15:04 ` [PATCH v2 05/11] x86/xen: Register resources required by kexec-tools Daniel Kiper
2012-11-20 15:04 ` [PATCH v2 06/11] x86/xen: Add i386 kexec/kdump implementation Daniel Kiper
2012-11-20 15:04 ` [PATCH v2 07/11] x86/xen: Add x86_64 " Daniel Kiper
2012-11-20 15:04 ` [PATCH v2 08/11] x86/xen: Add kexec/kdump makefile rules Daniel Kiper
2012-11-20 15:04 ` [PATCH v2 09/11] x86/xen/enlighten: Add init and crash kexec/kdump hooks Daniel Kiper
2012-11-20 15:04 ` [PATCH v2 10/11] drivers/xen: Export vmcoreinfo through sysfs Daniel Kiper
2012-11-20 15:04 ` [PATCH v2 11/11] x86: Add Xen kexec control code size check to linker script Daniel Kiper
2012-11-20 15:52 ` [PATCH v2 02/11] x86/kexec: Add extra pointers to transition page table PGD, PUD, PMD and PTE Jan Beulich
2012-11-20 16:40 ` [PATCH v2 01/11] kexec: introduce kexec_ops struct Eric W. Biederman
2012-11-21 10:52 ` Daniel Kiper
2012-11-22 12:15 ` Eric W. Biederman
2012-11-22 17:37 ` H. Peter Anvin
2012-11-23 9:56 ` Jan Beulich
2012-11-23 10:53 ` [Xen-devel] " Ian Campbell
2012-11-22 17:47 ` H. Peter Anvin
2012-11-22 18:07 ` Andrew Cooper
2012-11-22 22:26 ` H. Peter Anvin
2014-03-31 10:50 ` Petr Tesarik
2012-11-23 0:12 ` Andrew Cooper
2012-11-23 1:34 ` H. Peter Anvin
2012-11-23 1:38 ` H. Peter Anvin
2012-11-23 1:56 ` Andrew Cooper
2012-11-23 9:53 ` Jan Beulich
2012-11-23 10:37 ` Daniel Kiper
2012-11-23 10:51 ` [Xen-devel] " Ian Campbell
2012-11-23 11:13 ` Daniel Kiper
2012-11-23 10:51 ` Jan Beulich [this message]
2012-11-23 11:08 ` Daniel Kiper
2012-11-23 9:47 ` Daniel Kiper
2012-11-23 20:24 ` Eric W. Biederman
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