From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:58132) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UIwPN-0003Y3-UB for qemu-devel@nongnu.org; Fri, 22 Mar 2013 03:29:03 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UIwPM-0002OH-OU for qemu-devel@nongnu.org; Fri, 22 Mar 2013 03:29:01 -0400 Received: from mx1.redhat.com ([209.132.183.28]:52684) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UIwPM-0002OD-Gv for qemu-devel@nongnu.org; Fri, 22 Mar 2013 03:29:00 -0400 Message-ID: <514C0880.9000005@redhat.com> Date: Fri, 22 Mar 2013 09:30:08 +0200 From: Orit Wasserman MIME-Version: 1.0 References: <1363890878-8161-1-git-send-email-owasserm@redhat.com> <1363890878-8161-3-git-send-email-owasserm@redhat.com> <514B60E5.6090707@redhat.com> In-Reply-To: <514B60E5.6090707@redhat.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v4 2/8] Add socket_writev_buffer function List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eric Blake Cc: pbonzini@redhat.com, quintela@redhat.com, chegu_vinod@hp.com, qemu-devel@nongnu.org, mst@redhat.com On 03/21/2013 09:35 PM, Eric Blake wrote: > On 03/21/2013 12:34 PM, Orit Wasserman wrote: >> Signed-off-by: Orit Wasserman >> --- >> savevm.c | 15 +++++++++++++++ >> 1 file changed, 15 insertions(+) >> >> diff --git a/savevm.c b/savevm.c >> index 35c8d1e..6608b6e 100644 >> --- a/savevm.c >> +++ b/savevm.c >> @@ -39,6 +39,7 @@ >> #include "qmp-commands.h" >> #include "trace.h" >> #include "qemu/bitops.h" >> +#include "qemu/iov.h" >> >> #define SELF_ANNOUNCE_ROUNDS 5 >> >> @@ -171,6 +172,19 @@ static void coroutine_fn yield_until_fd_readable(int fd) >> qemu_coroutine_yield(); >> } >> >> +static int socket_writev_buffer(void *opaque, struct iovec *iov, int iovcnt) > > Returning int... > >> +{ >> + QEMUFileSocket *s = opaque; >> + ssize_t len; >> + ssize_t size = iov_size(iov, iovcnt); >> + >> + len = iov_send(s->fd, iov, iovcnt, 0, size); >> + if (len < size) { >> + len = -socket_error(); >> + } >> + return len; > > ...but len is an ssize_t. If we send an iov with 2 gigabytes of data, > this can wrap around to a negative int even though we send a positive > amount of data. Why not make the callback be typed to return ssize_t > from the beginning (affects patch 1/8)? At the moment it is not an issue but for the future we need to switch to ssize_t instead on int, I will change it. We actually need to replace it all around the migration code but this should be done in a different patch series. Orit >