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Subject: Re: [PATCH linux 0/8] xen: pvhvm: support bootup on secondary vCPUs
To: Vitaly Kuznetsov <vkuznets@redhat.com>, <xen-devel@lists.xenproject.org>
References: <1467132449-1030-1-git-send-email-vkuznets@redhat.com>
CC: <linux-kernel@vger.kernel.org>, <x86@kernel.org>,
        Stefano Stabellini <sstabellini@kernel.org>,
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        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>
From: David Vrabel <david.vrabel@citrix.com>
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Date: Tue, 28 Jun 2016 18:32:50 +0100
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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?

David