From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36161) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dKpyz-0005wL-1o for qemu-devel@nongnu.org; Tue, 13 Jun 2017 13:52:02 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dKpyu-0002mH-5z for qemu-devel@nongnu.org; Tue, 13 Jun 2017 13:52:01 -0400 Received: from mx1.redhat.com ([209.132.183.28]:36922) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dKpyt-0002ke-St for qemu-devel@nongnu.org; Tue, 13 Jun 2017 13:51:56 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id B353E7E9F0 for ; Tue, 13 Jun 2017 17:51:54 +0000 (UTC) Date: Tue, 13 Jun 2017 18:51:48 +0100 From: "Dr. David Alan Gilbert" Message-ID: <20170613175147.GB2463@work-vm> References: <20170613095432.11623-1-quintela@redhat.com> <20170613095432.11623-2-quintela@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170613095432.11623-2-quintela@redhat.com> Subject: Re: [Qemu-devel] [PATCH 1/2] migration: Test for disabled features on reception List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Juan Quintela Cc: qemu-devel@nongnu.org, lvivier@redhat.com, peterx@redhat.com * Juan Quintela (quintela@redhat.com) wrote: > Right now, if we receive a compressed page while this features are > disabled, Bad Things (TM) can happen. Just add a test for them. > > Signed-off-by: Juan Quintela > Reviewed-by: Dr. David Alan Gilbert Yes, my R-b stands, there could be someone somewhere driving this by hand who might get caught out, but seems saner this way. > -- > > I had XBZRLE here also, but it don't need extra resources on > destination, only on source. Additionally libvirt don't enable it on > destination, so don't put it here. > --- > migration/ram.c | 16 +++++++++++++++- > 1 file changed, 15 insertions(+), 1 deletion(-) > > diff --git a/migration/ram.c b/migration/ram.c > index f35d65a..f2d1bce 100644 > --- a/migration/ram.c > +++ b/migration/ram.c > @@ -2477,7 +2477,7 @@ 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; > /* > @@ -2494,6 +2494,11 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id) > ret = -EINVAL; > } > > + invalid_flags = 0; why didn't you use = 0 in the declaration like the rest of the flags? (Only minor) Dave > + > + if (!migrate_use_compression()) { > + invalid_flags |= RAM_SAVE_FLAG_COMPRESS_PAGE; > + } > /* This RCU critical section can be very long running. > * When RCU reclaims in the code start to become numerous, > * it will be necessary to reduce the granularity of this > @@ -2514,6 +2519,15 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id) > flags = addr & ~TARGET_PAGE_MASK; > addr &= TARGET_PAGE_MASK; > > + if (flags & invalid_flags) { > + if (flags & invalid_flags & RAM_SAVE_FLAG_COMPRESS_PAGE) { > + error_report("Received an unexpected compressed page"); > + } > + > + ret = -EINVAL; > + break; > + } > + > if (flags & (RAM_SAVE_FLAG_ZERO | RAM_SAVE_FLAG_PAGE | > RAM_SAVE_FLAG_COMPRESS_PAGE | RAM_SAVE_FLAG_XBZRLE)) { > RAMBlock *block = ram_block_from_stream(f, flags); > -- > 2.9.4 > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK