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From: Juan Quintela <quintela@redhat.com>
In-Reply-To: <20170124103329.GA2220@work-vm> (David Alan Gilbert's message of
	"Tue, 24 Jan 2017 10:33:29 +0000")
References: <1485207141-1941-1-git-send-email-quintela@redhat.com>
	<1485207141-1941-4-git-send-email-quintela@redhat.com>
	<20170124103329.GA2220@work-vm>
Reply-To: quintela@redhat.com
Date: Thu, 09 Feb 2017 18:12:33 +0100
Message-ID: <87zihvnv9a.fsf@emacs.mitica>
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Subject: Re: [Qemu-devel] [PATCH 03/17] migration: Test for disabled
 features on reception
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To: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: qemu-devel@nongnu.org, amit.shah@redhat.com

"Dr. David Alan Gilbert" <dgilbert@redhat.com> wrote:
> * Juan Quintela (quintela@redhat.com) wrote:
>> Right now, if we receive a compressed page or a xbzrle page while this
>> features are disabled, Bad Things (TM) can happen.  Just add a test for
>> them.
>> 
>> Signed-off-by: Juan Quintela <quintela@redhat.com>
>> ---
>>  migration/ram.c | 23 ++++++++++++++++++++++-
>>  1 file changed, 22 insertions(+), 1 deletion(-)
>> 
>> diff --git a/migration/ram.c b/migration/ram.c
>> index ef8fadf..4ad814a 100644
>> --- a/migration/ram.c
>> +++ b/migration/ram.c
>> @@ -2455,7 +2455,7 @@ static int ram_load_postcopy(QEMUFile *f)
>> 
>>  static int ram_load(QEMUFile *f, void *opaque, int version_id)
>>  {
>> -    int flags = 0, ret = 0;
>> +    int flags = 0, ret = 0, invalid_flags;
>>      static uint64_t seq_iter;
>>      int len = 0;
>>      /*
>> @@ -2470,6 +2470,15 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id)
>>          ret = -EINVAL;
>>      }
>> 
>> +    invalid_flags = 0;
>> +
>> +    if (!migrate_use_xbzrle()) {
>> +        invalid_flags |= RAM_SAVE_FLAG_XBZRLE;
>> +    }
>
> Is that really the case? I thought we used to ignore the flags on the incoming
> side and didn't need to enable xbzrle on the destination?

we don't need infrastructure for xbzrle, but we need it for compression.

Removing xbzrle.