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Subject: Re: [Xen-devel] Can't boot as Xen dom0 due to commit fe055896
To: Jan Beulich <JBeulich@suse.com>, Borislav Petkov <bp@suse.de>
References: <73a4d64b-b139-6579-a560-92311641d6c7@suse.com>
 <20161215164635.thm7ruio2ddnxszw@pd.tnic>
 <5852D8A20200007800129CC6@prv-mh.provo.novell.com>
CC: Juergen Gross <JGross@suse.com>,
        xen-devel <xen-devel@lists.xenproject.org>,
        Boris Ostrovsky <boris.ostrovsky@oracle.com>,
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From: Andrew Cooper <andrew.cooper3@citrix.com>
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Date: Thu, 15 Dec 2016 16:59:49 +0000
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On 15/12/16 16:53, Jan Beulich wrote:
>>>> On 15.12.16 at 17:46, <bp@suse.de> wrote:
>> On Thu, Dec 15, 2016 at 05:12:04PM +0100, Juergen Gross wrote:
>>> with today's kernel the system isn't coming up when booted as Xen dom0:
>> Remind me again pls, is dom0 even supposed to load microcode? Isn't the
>> hypervisor supposed to apply microcode?
> Yes, it's the hypervisor. Dom0 can at best hand the blob to it via
> hypercall, but iirc upstream Linux doesn't make use of that.

Xen has the same logic as Linux does to look for an uncompressed
microcode blob in the initrd and apply it early in boot.

If dom0 goes looking, it should see the same microcode version as it has
in its initrd.

~Andrew