From mboxrd@z Thu Jan  1 00:00:00 1970
From: =?UTF-8?B?Um9nZXIgUGF1IE1vbm7DqQ==?= <roger.pau@citrix.com>
Subject: Removing the PVH assert in arch/x86/hvm/io.c:87
Date: Thu, 4 Dec 2014 17:35:59 +0100
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To: xen-devel@lists.xenproject.org, Jan Beulich <JBeulich@suse.com>, Mukesh Rathor <mukesh.rathor@oracle.com>, Tim Deegan <tim@xen.org>
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Hello,

I've just stumbled upon this assert while testing PVH on different
hardware. It was added in 7c4870 as a safe belt, but it turns out INS
and OUTS go through handle_mmio. So using this instructions from a PVH
guest basically kills Xen.

I've removed it and everything seems fine, so I'm considering sending a
patch for 4.5 in order to have it removed. I think the path that could
trigger the crash because of the missing vioapic stuff is already
guarded by the other chunk added in the same patch.

Roger.