From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40396) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZEazs-0007F1-7I for qemu-devel@nongnu.org; Mon, 13 Jul 2015 06:30:05 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZEazo-0001n0-Vv for qemu-devel@nongnu.org; Mon, 13 Jul 2015 06:30:04 -0400 Received: from mx1.redhat.com ([209.132.183.28]:45905) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZEazo-0001mv-OW for qemu-devel@nongnu.org; Mon, 13 Jul 2015 06:30:00 -0400 From: Juan Quintela In-Reply-To: <1434450415-11339-16-git-send-email-dgilbert@redhat.com> (David Alan Gilbert's message of "Tue, 16 Jun 2015 11:26:28 +0100") References: <1434450415-11339-1-git-send-email-dgilbert@redhat.com> <1434450415-11339-16-git-send-email-dgilbert@redhat.com> Date: Mon, 13 Jul 2015 12:29:57 +0200 Message-ID: <87wpy4l596.fsf@neno.neno> MIME-Version: 1.0 Content-Type: text/plain Subject: Re: [Qemu-devel] [PATCH v7 15/42] Return path: Source handling of return path Reply-To: quintela@redhat.com List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Dr. David Alan Gilbert (git)" Cc: aarcange@redhat.com, yamahata@private.email.ne.jp, liang.z.li@intel.com, qemu-devel@nongnu.org, luis@cs.umu.se, amit.shah@redhat.com, pbonzini@redhat.com, david@gibson.dropbear.id.au "Dr. David Alan Gilbert (git)" wrote: > From: "Dr. David Alan Gilbert" > > Open a return path, and handle messages that are received upon it. > > Signed-off-by: Dr. David Alan Gilbert > +/* > + * Handles messages sent on the return path towards the source VM > + * > + */ > +static void *source_return_path_thread(void *opaque) > +{ > + MigrationState *ms = opaque; > + QEMUFile *rp = ms->rp_state.file; > + uint16_t expected_len, header_len, header_type; > + const int max_len = 512; > + uint8_t buf[max_len]; > + uint32_t tmp32; > + int res; > + > + trace_source_return_path_thread_entry(); > + while (rp && !qemu_file_get_error(rp) && What can make rp == NULL? THinking about that, could you mean *rp here? > + migration_already_active(ms)) { > + trace_source_return_path_thread_loop_top(); > + header_type = qemu_get_be16(rp); > + header_len = qemu_get_be16(rp); > + > + switch (header_type) { > + case MIG_RP_MSG_SHUT: > + case MIG_RP_MSG_PONG: > + expected_len = 4; > + break; > + > + default: > + error_report("RP: Received invalid message 0x%04x length 0x%04x", > + header_type, header_len); > + source_return_path_bad(ms); > + goto out; > + } > > + if (header_len > expected_len) { > + error_report("RP: Received message 0x%04x with" > + "incorrect length %d expecting %d", > + header_type, header_len, > + expected_len); I know this is a big request, but getting an array with messages length and message names to be able to print nice error messages looks ilke good? > + source_return_path_bad(ms); > + goto out; > + } > + > + /* We know we've got a valid header by this point */ > + res = qemu_get_buffer(rp, buf, header_len); > + if (res != header_len) { > + trace_source_return_path_thread_failed_read_cmd_data(); > + source_return_path_bad(ms); > + goto out; > + } > + > + /* OK, we have the message and the data */ > + switch (header_type) { > + case MIG_RP_MSG_SHUT: > + tmp32 = be32_to_cpup((uint32_t *)buf); make local variable and call it sibling_error or whatever you like? > + trace_source_return_path_thread_shut(tmp32); > + if (tmp32) { > + error_report("RP: Sibling indicated error %d", tmp32); > + source_return_path_bad(ms); > + } > + /* > + * We'll let the main thread deal with closing the RP > + * we could do a shutdown(2) on it, but we're the only user > + * anyway, so there's nothing gained. > + */ > + goto out; > + > + case MIG_RP_MSG_PONG: > + tmp32 = be32_to_cpup((uint32_t *)buf); unused? Althought I guess it is used somewhere to make sure that the value is the same that whatever we did the ping. credentials? I can't see with this and previous patch what value is sent here. > + trace_source_return_path_thread_pong(tmp32); > + break; > + > + default: > + break; > + } > + } > + if (rp && qemu_file_get_error(rp)) { > + trace_source_return_path_thread_bad_end(); > + source_return_path_bad(ms); > + } > + > + trace_source_return_path_thread_end(); > +out: > + return NULL; > +} > + > +__attribute__ (( unused )) /* Until later in patch series */ unused_by_know attribute required O:-)