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From: "Jan Beulich" <JBeulich@novell.com>
To: "xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>
Subject: iommu=0 leading to panic when system defaults to using x2apic
Date: Fri, 10 Dec 2010 09:12:21 +0000	[thread overview]
Message-ID: <4D01FD050200007800027296@vpn.id2.novell.com> (raw)

Why wouldn't iommu=0 imply not using the x2apic, if use of the
iommu indeed is a prerequisite (which by itself seems questionable
as long as APIC IDs aren't wider than 8 bits)?

Looking further at enable_bsp_x2apic(), I also wonder whether
the pre-enabled case, when specifying iommu=0 and x2apic=0,
can actually work if iommu=0 is a prerequisite (intremap_enabled()
would return 1 in that case afaics, so the early check doesn't help).

Thanks, Jan

             reply	other threads:[~2010-12-10  9:12 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-12-10  9:12 Jan Beulich [this message]
2010-12-10 10:06 ` iommu=0 leading to panic when system defaults to using x2apic Keir Fraser
2010-12-10 10:58   ` Jan Beulich
2010-12-10 11:47     ` Keir Fraser
2010-12-10 12:02       ` Jan Beulich
2010-12-10 15:00         ` Zhang, Yang Z
2010-12-10 15:39           ` Jan Beulich
2010-12-10 18:26             ` Kay, Allen M
2010-12-10 18:49               ` Keir Fraser
2010-12-11  0:07                 ` Kay, Allen M
2010-12-13  8:15                   ` Jan Beulich
2010-12-13  9:03                     ` Keir Fraser
2010-12-14  2:25                       ` Kay, Allen M
2010-12-14  7:44                         ` Keir Fraser
2010-12-14  7:59                           ` Keir Fraser
2010-12-15  2:35                           ` Kay, Allen M
2010-12-14  8:21               ` Jan Beulich
2010-12-14  8:46                 ` Weidong Han
2010-12-14  9:12                   ` Jan Beulich
2010-12-14 16:53                 ` Kay, Allen M
2010-12-14 17:06                   ` Jan Beulich
2010-12-14 17:08                   ` Jan Beulich
2010-12-14 17:52                     ` Yinghai Lu
2010-12-14 18:18                       ` Keir Fraser
2010-12-15  7:53                         ` Jan Beulich

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