From: Wei Wang2 <wei.wang2@amd.com>
To: xen-devel@lists.xensource.com
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Subject: Re: [PATCH 0 of 6] Fix kexec in Xen (take 3)
Date: Wed, 25 May 2011 17:01:40 +0200 [thread overview]
Message-ID: <201105251701.40933.wei.wang2@amd.com> (raw)
In-Reply-To: <patchbomb.1306333922@andrewcoop>
On Wednesday 25 May 2011 16:32:02 Andrew Cooper wrote:
> This set of patches is designed to get the kexec path working again on Xen
> 4.x
>
> kdump kernels can't boot if x2apic mode is enabled and the ACPI tables dont
> state this fact. They also cant boot at all with interrupt remapping
> enabled.
>
> These patches cause xen to track the BSP local APIC boot state and return
> to it before kexec'ing to a new kernel. It also makes sure to disable IO
> virtualisation.
>
> One area which is problematic is disabling interrupt remapping.
> lapic_suspend() calls iommu_disable_x2apic_IR() which in a previous thread
> was deemed to be Intel specific and only works by chance on AMD boxes by
> effectivly being a NOP. As lapic_suspend() is generic code, does this mean
> that we can't/don't ever disable interrupt remapping on AMD boxes?
Yes, there is no explicit way to disable amd iommu like disable_intremap() for
vtd. The reason is that interrupt remapping is enabled per device and there
is no global flag to disable it. We need to visit every device entry and then
disable per device, but it still sounds doable... Maybe we could make
disable_intremap() generic for both Intel and AMD?
Thanks,
Wei
> Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xensource.com
> http://lists.xensource.com/xen-devel
next prev parent reply other threads:[~2011-05-25 15:01 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-25 14:32 [PATCH 0 of 6] Fix kexec in Xen (take 3) Andrew Cooper
2011-05-25 14:32 ` [PATCH 1 of 6] APIC: record local APIC state on boot Andrew Cooper
2011-05-25 14:32 ` [PATCH 2 of 6] APIC: remove 'enabled_via_apicbase' variable Andrew Cooper
2011-05-25 14:32 ` [PATCH 3 of 6] APIC: add crash_disable_local_APIC Andrew Cooper
2011-05-25 14:32 ` [PATCH 4 of 6] IOMMU: Sanitise some of our pointer work Andrew Cooper
2011-05-25 17:28 ` Konrad Rzeszutek Wilk
2011-05-25 14:32 ` [PATCH 5 of 6] IOMMU: add crash_shutdown iommu_op Andrew Cooper
2011-05-25 14:32 ` [PATCH 6 of 6] KEXEC: disable iommu jumping into the kdump kernel Andrew Cooper
2011-05-25 15:01 ` Wei Wang2 [this message]
2011-05-25 16:14 ` [PATCH 0 of 6] Fix kexec in Xen (take 3) Jan Beulich
2011-05-25 16:30 ` Andrew Cooper
2011-05-25 21:35 ` Keir Fraser
2011-05-26 9:12 ` Andrew Cooper
2011-05-26 9:19 ` Keir Fraser
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