From: David Vrabel <david.vrabel@citrix.com>
To: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: <xen-devel@lists.xenproject.org>, <linux-kernel@vger.kernel.org>,
<x86@kernel.org>, Stefano Stabellini <sstabellini@kernel.org>,
"Boris Ostrovsky" <boris.ostrovsky@oracle.com>,
Juergen Gross <jgross@suse.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
Julien Grall <julien.grall@citrix.com>
Subject: Re: [PATCH linux 0/8] xen: pvhvm: support bootup on secondary vCPUs
Date: Wed, 29 Jun 2016 13:36:47 +0100 [thread overview]
Message-ID: <5773C0DF.3090905@citrix.com> (raw)
In-Reply-To: <871t3gwe0o.fsf@vitty.brq.redhat.com>
On 29/06/16 10:16, Vitaly Kuznetsov wrote:
> David Vrabel <david.vrabel@citrix.com> writes:
>
>> On 28/06/16 17:47, Vitaly Kuznetsov wrote:
>>> It may happen that Xen's and Linux's ideas of vCPU id diverge. In
>>> particular, when we crash on a secondary vCPU we may want to do kdump
>>> and unlike plain kexec where we do migrate_to_reboot_cpu() we try booting
>>> on the vCPU which crashed. This doesn't work very well for PVHVM guests as
>>> we have a number of hypercalls where we pass vCPU id as a parameter. These
>>> hypercalls either fail or do something unexpected. To solve the issue we
>>> need to have a mapping between Linux's and Xen's vCPU ids.
>>
>> Could the soft-reboot hypercall (optionally) return on vcpu 0?
>>
>
> In theory, yes, I think we can re-arrange vCPUs inside the hypervisor so
> Linux will get them in the natural order after soft reset.
The series is straight forwards and the concept of the guest having to
map its idea of CPU to VCPU is fine, so unless you think a hypervisor
based solution is better we can take this series once it's fixed up.
David
next prev parent reply other threads:[~2016-06-29 12:37 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-28 16:47 [PATCH linux 0/8] xen: pvhvm: support bootup on secondary vCPUs Vitaly Kuznetsov
2016-06-28 16:47 ` [PATCH linux 1/8] x86/xen: update cpuid.h from Xen-4.7 Vitaly Kuznetsov
2016-06-28 16:47 ` [PATCH linux 2/8] xen: introduce xen_vcpu_id mapping Vitaly Kuznetsov
2016-06-28 17:28 ` [Xen-devel] " Andrew Cooper
2016-06-29 12:16 ` Vitaly Kuznetsov
2016-06-29 12:30 ` Andrew Cooper
2016-06-29 12:50 ` Vitaly Kuznetsov
2016-06-29 16:19 ` Vitaly Kuznetsov
[not found] ` <5040c916-279f-c350-383a-583ec1700686@citrix.com>
2016-06-30 9:10 ` Jan Beulich
2016-07-01 12:06 ` Vitaly Kuznetsov
2016-07-01 13:33 ` Jan Beulich
2016-07-05 15:34 ` Konrad Rzeszutek Wilk
2016-07-05 15:44 ` Jan Beulich
2016-07-07 10:15 ` Joao Martins
2016-06-28 16:47 ` [PATCH linux 3/8] x86/xen: use xen_vcpu_id mapping for HYPERVISOR_vcpu_op Vitaly Kuznetsov
2016-06-29 12:26 ` [Xen-devel] " David Vrabel
2016-06-28 16:47 ` [PATCH linux 4/8] x86/xen: use xen_vcpu_id mapping when pointing vcpu_info to the shared_info page Vitaly Kuznetsov
2016-06-29 12:32 ` [Xen-devel] " David Vrabel
2016-06-28 16:47 ` [PATCH linux 5/8] xen/events: use xen_vcpu_id mapping in events_base Vitaly Kuznetsov
2016-06-28 16:47 ` [PATCH linux 6/8] xen/events: fifo: use xen_vcpu_id mapping Vitaly Kuznetsov
2016-06-28 16:47 ` [PATCH linux 7/8] xen/evtchn: " Vitaly Kuznetsov
2016-06-28 16:47 ` [PATCH linux 8/8] xen/pvhvm: run xen_vcpu_setup() for the boot CPU Vitaly Kuznetsov
2016-06-28 17:32 ` [PATCH linux 0/8] xen: pvhvm: support bootup on secondary vCPUs David Vrabel
2016-06-29 9:16 ` Vitaly Kuznetsov
2016-06-29 12:36 ` David Vrabel [this message]
2016-07-01 9:24 ` Vitaly Kuznetsov
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