From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Jan Beulich" Subject: Re: [PATCH 0 of 6] Fix kexec in Xen (take 3) Date: Wed, 25 May 2011 17:14:49 +0100 Message-ID: <4DDD47190200007800043890@vpn.id2.novell.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: Content-Disposition: inline List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Andrew Cooper Cc: xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org >>> On 25.05.11 at 16:32, Andrew Cooper wrote: > This set of patches is designed to get the kexec path working again on = Xen=20 > 4.x >=20 > kdump kernels can't boot if x2apic mode is enabled and the ACPI tables = dont=20 > state this fact. They also cant boot at all with interrupt remapping=20 > enabled. >=20 > These patches cause xen to track the BSP local APIC boot state and = return to=20 > it before kexec'ing to a new kernel. It also makes sure to disable = IO=20 > virtualisation. I was about to reply to the individual patches, but they just seem too inconsistent to me (comments not matching code, without it being clear whether code or comment is wrong; functions introduced that have no callers). Can you work on getting them into a state suitable for reviewing? Further I don't buy your pseudo-quoting of the MP spec saying that secondary CPUs' local APICs have to be disabled. Keir already pointed out on your previous submission that in order for them to receive the INIT and Startup IPIs they must be enabled. Jan > One area which is problematic is disabling interrupt remapping. =20 > lapic_suspend() calls iommu_disable_x2apic_IR() which in a previous = thread=20 > was deemed to be Intel specific and only works by chance on AMD boxes = by=20 > effectivly being a NOP. As lapic_suspend() is generic code, does this = mean=20 > that we can't/don't ever disable interrupt remapping on AMD boxes? >=20 > Signed-off-by: Andrew Cooper >=20 > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xensource.com=20 > http://lists.xensource.com/xen-devel=20