From: Gleb Natapov <gleb@redhat.com>
To: Avi Kivity <avi@redhat.com>
Cc: kvm@vger.kernel.org
Subject: Re: [PATCH 08/10] Move IO APIC to its own lock.
Date: Sun, 9 Aug 2009 17:57:39 +0300 [thread overview]
Message-ID: <20090809145739.GS4764@redhat.com> (raw)
In-Reply-To: <4A7EE326.9050300@redhat.com>
On Sun, Aug 09, 2009 at 05:54:30PM +0300, Avi Kivity wrote:
> On 08/09/2009 03:41 PM, Gleb Natapov wrote:
>> Introduce new function kvm_notifier_set_irq() that should be used
>> to change irq line level from irq notifiers. When irq notifier
>> change irq line level it calls into irq chip code recursively. The
>> function avoids taking a lock recursively.
>>
>
> This looks really horrible. I don't have an alternative yet, but I'll
> think of one.
I agree this is not nice. This is needed only for device assignment
case. That explains why I don't like device assignment :) The problem
is that the only communication channel from guest to assigned device that
goes through the host is interrupt injection/acknowledgement, so we try to
do things (lowering IRQ) on this path that usually are done somewhere else.
--
Gleb.
next prev parent reply other threads:[~2009-08-09 14:57 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-08-09 12:41 [PATCH 00/10] make interrupt injection lockless (almost) Gleb Natapov
2009-08-09 12:41 ` [PATCH 01/10] Change irq routing table to use gsi indexed array Gleb Natapov
2009-08-09 14:25 ` Avi Kivity
2009-08-09 12:41 ` [PATCH 02/10] Move irq routing data structure to rcu locking Gleb Natapov
2009-08-09 12:41 ` [PATCH 03/10] Move irq ack notifier list to arch independent code Gleb Natapov
2009-08-09 12:41 ` [PATCH 04/10] Convert irq notifiers lists to RCU locking Gleb Natapov
2009-08-09 12:41 ` [PATCH 05/10] Protect irq_sources_bitmap by kvm->lock instead of kvm->irq_lock Gleb Natapov
2009-08-09 12:41 ` [PATCH 06/10] Move irq routing to its own locking Gleb Natapov
2009-08-09 14:52 ` Avi Kivity
2009-08-09 12:41 ` [PATCH 07/10] Move irq notifiers lists " Gleb Natapov
2009-08-09 14:52 ` Avi Kivity
2009-08-09 14:49 ` Gleb Natapov
2009-08-09 14:57 ` Avi Kivity
2009-08-09 12:41 ` [PATCH 08/10] Move IO APIC to its own lock Gleb Natapov
2009-08-09 14:54 ` Avi Kivity
2009-08-09 14:57 ` Gleb Natapov [this message]
2009-08-09 15:10 ` Avi Kivity
2009-08-09 15:09 ` Gleb Natapov
2009-08-09 12:41 ` [PATCH 09/10] Drop kvm->irq_lock lock Gleb Natapov
2009-08-09 12:41 ` [PATCH 10/10] Introduce MSI message sending interface that bypass IRQ routing Gleb Natapov
2009-08-09 14:56 ` Avi Kivity
2009-08-09 14:52 ` Gleb Natapov
2009-08-09 15:01 ` Avi Kivity
2009-08-09 15:07 ` Gleb Natapov
2009-08-09 15:14 ` Avi Kivity
2009-08-09 15:14 ` Gleb Natapov
2009-08-09 15:22 ` Avi Kivity
-- strict thread matches above, loose matches on Subject: below --
2009-07-14 14:30 [PATCH 0/10] [RFC] more fine grained locking for IRQ injection Gleb Natapov
2009-07-14 14:30 ` [PATCH 08/10] Move IO APIC to its own lock Gleb Natapov
2009-07-15 17:57 ` Marcelo Tosatti
2009-07-15 20:48 ` Gleb Natapov
2009-07-15 21:38 ` Marcelo Tosatti
2009-07-16 7:51 ` Gleb Natapov
2009-07-16 18:09 ` Marcelo Tosatti
2009-07-16 20:49 ` Gleb Natapov
2009-07-17 15:19 ` Marcelo Tosatti
2009-07-17 17:32 ` Gleb Natapov
2009-07-17 20:09 ` Marcelo Tosatti
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