From: Avi Kivity <avi@redhat.com>
To: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
Marcelo Tosatti <mtosatti@redhat.com>,
liu ping fan <qemulist@gmail.com>,
Anthony Liguori <anthony@codemonkey.ws>,
"qemu-devel@nongnu.org" <qemu-devel@nongnu.org>
Subject: Re: [Qemu-devel] [PATCH V3 10/11] vcpu: introduce lockmap
Date: Tue, 11 Sep 2012 14:03:39 +0300 [thread overview]
Message-ID: <504F1A8B.3080604@redhat.com> (raw)
In-Reply-To: <504F0CA5.5030405@siemens.com>
On 09/11/2012 01:04 PM, Jan Kiszka wrote:
>> DMA is inherently asynchronous, so we already drop the lock between
>> initiation and completion; we need to find a way to make it easy to use
>> the API without taking the lock while the transfer takes place.
>
> We will have to review/rework device models that want to use the new
> locking scheme in a way that they can drop their own lock while issuing
> DMA. But that is surely non-trivial.
Most DMA today happens without the big qemu lock. We only need to
convert the paths that actually access memory, these are the block and
network layers (for the respective devices).
> The other option is to keep DMA requests issued by devices synchronous
> but let them fail if we are about to lock up. Still requires changes,
> but is probably more comprehensible for device model developers.
How do you handle failures?
--
error compiling committee.c: too many arguments to function
next prev parent reply other threads:[~2012-09-11 11:03 UTC|newest]
Thread overview: 72+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-11 7:51 [Qemu-devel] [PATCH V3 0/10] prepare unplug out of protection of global lock Liu Ping Fan
2012-09-11 7:51 ` [Qemu-devel] [PATCH V3 01/11] atomic: introduce atomic operations Liu Ping Fan
2012-09-11 8:04 ` Avi Kivity
2012-09-13 6:54 ` liu ping fan
2012-09-13 8:14 ` Avi Kivity
2012-09-13 8:19 ` Paolo Bonzini
2012-09-13 8:23 ` Avi Kivity
2012-09-13 8:29 ` Paolo Bonzini
2012-09-13 8:45 ` liu ping fan
2012-09-19 13:16 ` Jamie Lokier
2012-09-19 13:32 ` Jamie Lokier
2012-09-19 14:12 ` Peter Maydell
2012-09-19 15:53 ` Jamie Lokier
2012-09-11 8:15 ` Peter Maydell
2012-09-13 6:53 ` liu ping fan
2012-09-11 7:51 ` [Qemu-devel] [PATCH V3 02/11] qom: apply atomic on object's refcount Liu Ping Fan
2012-09-11 7:51 ` [Qemu-devel] [PATCH V3 03/11] hotplug: introduce qdev_unplug_complete() to remove device from views Liu Ping Fan
2012-09-11 7:51 ` [Qemu-devel] [PATCH V3 04/11] pci: remove pci device from mem view when unplug Liu Ping Fan
2012-09-11 7:51 ` [Qemu-devel] [PATCH V3 05/11] memory: introduce ref, unref interface for MemoryRegionOps Liu Ping Fan
2012-09-11 8:08 ` Avi Kivity
2012-09-11 7:51 ` [Qemu-devel] [PATCH V3 06/11] memory: make mmio dispatch able to be out of biglock Liu Ping Fan
2012-09-11 8:25 ` Avi Kivity
2012-09-11 8:47 ` Avi Kivity
2012-09-11 7:51 ` [Qemu-devel] [PATCH V3 07/11] memory: implement e1000's MemoryRegionOps ref/unref Liu Ping Fan
2012-09-11 8:37 ` Avi Kivity
2012-09-11 7:51 ` [Qemu-devel] [PATCH V3 08/11] qom: introduce reclaimer to release obj in async Liu Ping Fan
2012-09-11 8:32 ` Avi Kivity
2012-09-11 9:32 ` liu ping fan
2012-09-11 9:37 ` Avi Kivity
2012-09-13 6:54 ` liu ping fan
2012-09-13 8:45 ` Avi Kivity
2012-09-13 9:59 ` liu ping fan
2012-09-13 10:09 ` Avi Kivity
2012-09-11 7:51 ` [Qemu-devel] [PATCH V3 09/11] vcpu: make QemuThread as tls to store thread-self info Liu Ping Fan
2012-09-11 7:51 ` [Qemu-devel] [PATCH V3 10/11] vcpu: introduce lockmap Liu Ping Fan
2012-09-11 8:35 ` Avi Kivity
2012-09-11 9:44 ` liu ping fan
2012-09-11 9:54 ` Avi Kivity
2012-09-11 10:04 ` Jan Kiszka
2012-09-11 11:03 ` Avi Kivity [this message]
2012-09-11 11:08 ` Jan Kiszka
2012-09-11 12:20 ` Avi Kivity
2012-09-11 12:25 ` Jan Kiszka
2012-09-11 12:30 ` Avi Kivity
2012-09-11 12:35 ` Jan Kiszka
2012-09-11 12:39 ` Avi Kivity
2012-09-19 4:25 ` Peter Crosthwaite
2012-09-19 4:32 ` Edgar E. Iglesias
2012-09-19 4:40 ` Peter Crosthwaite
2012-09-19 7:55 ` Avi Kivity
2012-09-19 11:46 ` Edgar E. Iglesias
2012-09-19 12:12 ` Avi Kivity
2012-09-19 12:17 ` Edgar E. Iglesias
2012-09-19 13:01 ` Igor Mitsyanko
2012-09-19 13:03 ` Avi Kivity
2012-09-19 7:57 ` Jan Kiszka
2012-09-19 13:07 ` Igor Mitsyanko
2012-09-11 9:57 ` Jan Kiszka
2012-09-11 12:24 ` Avi Kivity
2012-09-11 12:41 ` Avi Kivity
2012-09-11 14:54 ` Marcelo Tosatti
2012-09-13 6:55 ` liu ping fan
2012-09-13 6:55 ` liu ping fan
2012-09-13 8:19 ` Avi Kivity
2012-09-17 2:24 ` liu ping fan
2012-09-19 8:01 ` Avi Kivity
2012-09-19 8:36 ` liu ping fan
2012-09-19 9:05 ` Avi Kivity
2012-09-20 7:51 ` liu ping fan
2012-09-20 9:15 ` Avi Kivity
2012-09-21 7:27 ` liu ping fan
2012-09-11 7:51 ` [Qemu-devel] [PATCH V3 11/11] vcpu: push mmio dispatcher out of big lock Liu Ping Fan
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