From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:40870)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <imammedo@redhat.com>) id 1ePVEa-0007ad-Vm
	for qemu-devel@nongnu.org; Thu, 14 Dec 2017 10:15:41 -0500
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <imammedo@redhat.com>) id 1ePVEY-0002vN-Ab
	for qemu-devel@nongnu.org; Thu, 14 Dec 2017 10:15:40 -0500
Received: from mx1.redhat.com ([209.132.183.28]:51816)
	by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32)
	(Exim 4.71) (envelope-from <imammedo@redhat.com>) id 1ePVEY-0002tQ-4z
	for qemu-devel@nongnu.org; Thu, 14 Dec 2017 10:15:38 -0500
Date: Thu, 14 Dec 2017 16:15:24 +0100
From: Igor Mammedov <imammedo@redhat.com>
Message-ID: <20171214161524.495caede@redhat.com>
In-Reply-To: <20171213180807.7066-4-dgilbert@redhat.com>
References: <20171213180807.7066-1-dgilbert@redhat.com>
	<20171213180807.7066-4-dgilbert@redhat.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Subject: Re: [Qemu-devel] [PATCH v4 3/6] vhost: Add temporary memory
 structure
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel/>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: "Dr. David Alan Gilbert (git)" <dgilbert@redhat.com>
Cc: qemu-devel@nongnu.org, pbonzini@redhat.com, maxime.coquelin@redhat.com, mst@redhat.com, groug@kaod.org

On Wed, 13 Dec 2017 18:08:04 +0000
"Dr. David Alan Gilbert (git)" <dgilbert@redhat.com> wrote:

> From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
> 
> Add a 2nd 'vhost_memory' structure that will be used to build
> the new version as the listener iterates over the address space.
I'd suggest to add temporary 'mem_sections' instead and
create/use/free temporary 'vhost_memory' structure at commit time,
(1 less duplicated data set to keep in memory)

> 
> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> ---
>  hw/virtio/vhost.c         | 3 +++
>  include/hw/virtio/vhost.h | 1 +
>  2 files changed, 4 insertions(+)
> 
> diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
> index c7ce7baf9b..4523f45587 100644
> --- a/hw/virtio/vhost.c
> +++ b/hw/virtio/vhost.c
> @@ -632,6 +632,8 @@ static void vhost_begin(MemoryListener *listener)
>                                           memory_listener);
>      dev->mem_changed_end_addr = 0;
>      dev->mem_changed_start_addr = -1;
> +
> +    dev->tmp_mem = g_malloc0(offsetof(struct vhost_memory, regions));
>  }
>  
>  static void vhost_commit(MemoryListener *listener)
> @@ -641,6 +643,7 @@ static void vhost_commit(MemoryListener *listener)
>      uint64_t log_size;
>      int r;
>  
> +    g_free(dev->tmp_mem);
>      if (!dev->memory_changed) {
>          return;
>      }
> diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
> index 467dc7794b..41f9e569be 100644
> --- a/include/hw/virtio/vhost.h
> +++ b/include/hw/virtio/vhost.h
> @@ -70,6 +70,7 @@ struct vhost_dev {
>      bool memory_changed;
>      hwaddr mem_changed_start_addr;
>      hwaddr mem_changed_end_addr;
> +    struct vhost_memory *tmp_mem;
>      const VhostOps *vhost_ops;
>      void *opaque;
>      struct vhost_log *log;