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From: "Yang, Sheng" <sheng.yang@intel.com>
To: Marcelo Tosatti <mtosatti@redhat.com>
Cc: "kvm-devel" <kvm@vger.kernel.org>
Subject: Re: assigned dev msi int handling
Date: Fri, 27 Feb 2009 12:26:44 +0800	[thread overview]
Message-ID: <200902271226.44756.sheng.yang@intel.com> (raw)
In-Reply-To: <20090226235927.GA4270@amt.cnet>

On Friday 27 February 2009 07:59:27 Marcelo Tosatti wrote:
> Hi Sheng,
>
> So for guest INTX interrupts the host interrupt is reenabled on ack from
> the guest, which is nice. Now for guest MSI interrupts it keeps reenabling
> the interrupt as fast as the work handler can run.
>
> Can you explain why it works this way? Why not disable interrupts
> on the host in all cases and only reenable on ack?
>

Sorry for I didn't think it over... The direct reason is ack_irq binding with 
kvm_set_irq() which is unnecessary for MSI/MSI-X. But enable(msi) after EOI 
seems more proper here, though more changes are needed for MSI-X(seems we need 
one ack notifier for one vector in MSI-X).

-- 
regards
Yang, Sheng


      reply	other threads:[~2009-02-27  4:26 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-02-26 23:59 assigned dev msi int handling Marcelo Tosatti
2009-02-27  4:26 ` Yang, Sheng [this message]

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