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From: Peter Xu <peterx@redhat.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>,
	qemu-devel@nongnu.org, "Igor Mammedov" <imammedo@redhat.com>,
	"Richard Henderson" <rth@twiddle.net>,
	"Eduardo Habkost" <ehabkost@redhat.com>,
	"Michael S. Tsirkin" <mst@redhat.com>
Subject: Re: [Qemu-devel] [PATCH 5/5] intel_iommu: do not allow EIM without KVM support
Date: Fri, 23 Sep 2016 18:02:07 +0800	[thread overview]
Message-ID: <20160923100207.GD29144@pxdev.xzpeter.org> (raw)
In-Reply-To: <eab44f91-4d9f-1425-2e77-927dd3a5c144@redhat.com>

On Fri, Sep 23, 2016 at 11:27:09AM +0200, Paolo Bonzini wrote:
> Since the whole IOMMU feature is new and somewhat experimental, I think
> it's okay to just make EIM the default for >=2.8 machine types if KVM is
> on (using DEFINE_PROP_ON_OFF_AUTO; auto means true if KVM is on and
> false otherwise, and pc-2.7 would set eim=off). It means requiring
> kernel 4.8 by default, but I don't think it's a big deal.

I think the problem is, even we have KVM support for x2apic, we are
still losing QEMU part. And guests with cluster x2apic and >8 vcpus
will not working properly on device interrupts, which can be very
confusing to people (it can boot, but some devices just don't work
properly, and they won't see useful information in guest dmesg).

Thanks,

-- peterx

  reply	other threads:[~2016-09-23 10:02 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-09-22 21:04 [Qemu-devel] [PATCH 0/5] intel_iommu: fix EIM Radim Krčmář
2016-09-22 21:04 ` [Qemu-devel] [PATCH 1/5] apic: add global apic_get_class() Radim Krčmář
2016-09-23  9:17   ` Peter Xu
2016-09-27 13:28     ` Radim Krčmář
2016-09-22 21:04 ` [Qemu-devel] [PATCH 2/5] apic: add send_msi() to APICCommonClass Radim Krčmář
2016-09-23  9:35   ` Peter Xu
2016-09-26 12:38   ` Igor Mammedov
2016-09-27 13:55     ` Radim Krčmář
2016-09-22 21:04 ` [Qemu-devel] [PATCH 3/5] intel_iommu: pass whole remapped addresses to apic Radim Krčmář
2016-09-23  9:41   ` Peter Xu
2016-09-27 13:56     ` Radim Krčmář
2016-09-27 13:57   ` Igor Mammedov
2016-09-22 21:04 ` [Qemu-devel] [PATCH 4/5] intel_iommu: add "eim" property Radim Krčmář
2016-09-22 21:04 ` [Qemu-devel] [PATCH 5/5] intel_iommu: do not allow EIM without KVM support Radim Krčmář
2016-09-23  9:27   ` Paolo Bonzini
2016-09-23 10:02     ` Peter Xu [this message]
2016-09-23 10:03       ` Paolo Bonzini
2016-09-23 10:12         ` Peter Xu
2016-09-23 10:39           ` Paolo Bonzini
2016-09-23 10:52             ` Peter Xu
2016-09-27 14:01     ` Radim Krčmář
2016-09-27 21:30       ` Paolo Bonzini
2016-09-27 13:07   ` Igor Mammedov

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