From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:35719)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <pbonzini@redhat.com>) id 1WFnLV-0000fG-TT
	for qemu-devel@nongnu.org; Tue, 18 Feb 2014 11:16:39 -0500
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <pbonzini@redhat.com>) id 1WFnLP-0007Bb-Tb
	for qemu-devel@nongnu.org; Tue, 18 Feb 2014 11:16:33 -0500
Received: from mx1.redhat.com ([209.132.183.28]:54176)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <pbonzini@redhat.com>) id 1WFnLP-0007BR-M2
	for qemu-devel@nongnu.org; Tue, 18 Feb 2014 11:16:27 -0500
Message-ID: <53038754.7000304@redhat.com>
Date: Tue, 18 Feb 2014 17:16:20 +0100
From: Paolo Bonzini <pbonzini@redhat.com>
MIME-Version: 1.0
References: <1392726818-14606-1-git-send-email-vincent.kherbache@inria.fr>
In-Reply-To: <1392726818-14606-1-git-send-email-vincent.kherbache@inria.fr>
Content-Type: text/plain; charset=ISO-8859-15; format=flowed
Content-Transfer-Encoding: 7bit
Subject: Re: [Qemu-devel] [PATCH] kvm: fix kvm_set_migration_log() behavior
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: Vincent KHERBACHE <vincent.kherbache@inria.fr>, qemu-devel@nongnu.org
Cc: gleb@redhat.com

Il 18/02/2014 13:33, Vincent KHERBACHE ha scritto:
> diff --git a/kvm-all.c b/kvm-all.c
> index 2ca9143..f104f87 100644
> --- a/kvm-all.c
> +++ b/kvm-all.c
> @@ -355,7 +355,7 @@ static int kvm_set_migration_log(int enable)
>  {
>      KVMState *s = kvm_state;
>      KVMSlot *mem;
> -    int i, err;
> +    int i, err = 0;
>
>      s->migration_log = enable;
>
> @@ -365,15 +365,9 @@ static int kvm_set_migration_log(int enable)
>          if (!mem->memory_size) {
>              continue;
>          }
> -        if (!!(mem->flags & KVM_MEM_LOG_DIRTY_PAGES) == enable) {
> -            continue;
> -        }
> -        err = kvm_set_user_memory_region(s, mem);
> -        if (err) {
> -            return err;
> -        }
> +        err = kvm_slot_dirty_pages_log_change(mem, (bool)enable);
>      }
> -    return 0;
> +    return err;
>  }

This patch is not correct, because it introduces another one: if dirty 
logging was enabled on the memory region (kvm_dirty_pages_log_change), 
it will be disabled after migration.

Can you explain better the problem?  I cannot see anything wrong in the 
code, though it is not the clearest.  Note that the effects of 
kvm_set_migration_log and kvm_dirty_pages_log_change should be logically 
ORed.

Paolo