From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46282) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1X6yyG-00059Z-On for qemu-devel@nongnu.org; Tue, 15 Jul 2014 05:24:30 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1X6yyA-000529-K1 for qemu-devel@nongnu.org; Tue, 15 Jul 2014 05:24:24 -0400 Received: from mx1.redhat.com ([209.132.183.28]:30335) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1X6yyA-00051i-D4 for qemu-devel@nongnu.org; Tue, 15 Jul 2014 05:24:18 -0400 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s6F9OHYA018061 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Tue, 15 Jul 2014 05:24:17 -0400 From: Amit Shah Date: Tue, 15 Jul 2014 14:53:26 +0530 Message-Id: <965a31ed0c51f30c4e3a3a9df5db9c4892ec914e.1405416206.git.amit.shah@redhat.com> Subject: [Qemu-devel] [PATCH for-2.1 1/1] virtio-serial-bus: keep port 0 reserved for virtconsole even on unplug List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu list Cc: Amit Shah , Amos Kong We keep port 0 reserved for compat with older guests, where only virtio-console was expected. Even if a system is started without a virtio-console port, port #0 is kept aside. However, after a virtconsole port is unplugged, port id 0 became available, and the next hotplug of a virtserialport caused failure due to it not being a console port. Steps to reproduce: $ ./x86_64-softmmu/qemu-system-x86_64 -m 512 -cpu host -enable-kvm -device virtio-serial-pci -monitor stdio -vnc :1 QEMU 2.0.91 monitor - type 'help' for more information (qemu) device_add virtconsole,id=p1 (qemu) device_del p1 (qemu) device_add virtserialport,id=p1 Port number 0 on virtio-serial devices reserved for virtconsole devices for backward compatibility. Device 'virtserialport' could not be initialized (qemu) quit Reported-by: dengmin Signed-off-by: Amit Shah --- hw/char/virtio-serial-bus.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/hw/char/virtio-serial-bus.c b/hw/char/virtio-serial-bus.c index 07bebc0..e1808b0 100644 --- a/hw/char/virtio-serial-bus.c +++ b/hw/char/virtio-serial-bus.c @@ -800,7 +800,14 @@ static void remove_port(VirtIOSerial *vser, uint32_t port_id) unsigned int i; i = port_id / 32; - vser->ports_map[i] &= ~(1U << (port_id % 32)); + if (port_id) { + /* + * Don't mark port 0 removed -- we explicitly reserve it for + * backward compat with older guests, and a device unplug of + * virtconsole removes the reservation. + */ + vser->ports_map[i] &= ~(1U << (port_id % 32)); + } port = find_port_by_id(vser, port_id); /* -- 1.9.3