From 33b91a76d2d99a360d7082a23b4707773819e30b Mon Sep 17 00:00:00 2001
From: Alon Levy <alevy@redhat.com>
Date: Tue, 19 Jul 2011 09:05:24 -0300
Subject: [RHEL6 qemu-kvm PATCH 6/8] virtio-serial-bus: use bh for unthrottling
RH-Author: Alon Levy <alevy@redhat.com>
Message-id: <1311066324-19208-1-git-send-email-alevy@redhat.com>
Patchwork-id: 29990
O-Subject: [PATCH v2 RHEL6.2] virtio-serial-bus: use bh for unthrottling
Bugzilla: 709397
RH-Acked-by: Jes Sorensen <Jes.Sorensen@redhat.com>
RH-Acked-by: Amit Shah <amit.shah@redhat.com>
RH-Acked-by: Gerd Hoffmann <kraxel@redhat.com>
RHBZ: 709397
cherry picked from upstream commit 199646d81522509ac2dba6d28c31e8c7d807bc93.
Instead of calling flush_queued_data when unthrottling, schedule
a bh. That way we can return immediately to the caller, and the
flush uses the same call path as a have_data for callbackee.
No migration change is required because bh are called from vm_stop.
Signed-off-by: Alon Levy <alevy@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
---
hw/virtio-serial-bus.c | 12 ++++++++++--
hw/virtio-serial.h | 5 +++++
2 files changed, 15 insertions(+), 2 deletions(-)
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
---
hw/virtio-serial-bus.c | 12 ++++++++++--
hw/virtio-serial.h | 5 +++++
2 files changed, 15 insertions(+), 2 deletions(-)
diff --git a/hw/virtio-serial-bus.c b/hw/virtio-serial-bus.c
index 7ae2b0d..72ff834 100644
--- a/hw/virtio-serial-bus.c
+++ b/hw/virtio-serial-bus.c
@@ -321,6 +321,13 @@ size_t virtio_serial_guest_ready(VirtIOSerialPort *port)
return 0;
}
+static void flush_queued_data_bh(void *opaque)
+{
+ VirtIOSerialPort *port = opaque;
+
+ flush_queued_data(port);
+}
+
void virtio_serial_throttle_port(VirtIOSerialPort *port, bool throttle)
{
if (!port) {
@@ -331,8 +338,7 @@ void virtio_serial_throttle_port(VirtIOSerialPort *port, bool throttle)
if (throttle) {
return;
}
-
- flush_queued_data(port);
+ qemu_bh_schedule(port->bh);
}
bool virtio_serial_flow_control_enabled(VirtIOSerialPort *port)
@@ -786,6 +792,7 @@ static int virtser_port_qdev_init(DeviceState *qdev, DeviceInfo *base)
bool plugging_port0;
port->vser = bus->vser;
+ port->bh = qemu_bh_new(flush_queued_data_bh, port);
/*
* Is the first console port we're seeing? If so, put it up at
@@ -852,6 +859,7 @@ static int virtser_port_qdev_exit(DeviceState *qdev)
VirtIOSerialPort *port = DO_UPCAST(VirtIOSerialPort, dev, &dev->qdev);
VirtIOSerial *vser = port->vser;
+ qemu_bh_delete(port->bh);
remove_port(port->vser, port->id);
QTAILQ_REMOVE(&vser->ports, port, next);
diff --git a/hw/virtio-serial.h b/hw/virtio-serial.h
index ecba281..e0fdec6 100644
--- a/hw/virtio-serial.h
+++ b/hw/virtio-serial.h
@@ -131,6 +131,11 @@ struct VirtIOSerialPort {
uint32_t iov_idx;
uint64_t iov_offset;
+ /*
+ * When unthrottling we use a bottom-half to call flush_queued_data.
+ */
+ QEMUBH *bh;
+
/* Identify if this is a port that binds with hvc in the guest */
uint8_t is_console;
--
1.7.3.2