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author | 2011-03-22 16:28:41 +0100 | |
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committer | 2011-07-21 15:19:02 -0500 | |
commit | 4d2c1d53b9ca086ea9c583581684a84b889e6469 (patch) | |
tree | 68be2ebe2a8e8dbb5288869f3f259e1b5a22b715 | |
parent | spice-chardev: listen to frontend guest open / close (diff) | |
download | qemu-kvm-4d2c1d53b9ca086ea9c583581684a84b889e6469.tar.gz qemu-kvm-4d2c1d53b9ca086ea9c583581684a84b889e6469.tar.bz2 qemu-kvm-4d2c1d53b9ca086ea9c583581684a84b889e6469.zip |
spice-qemu-char: Fix flow control in client -> guest direction
In the old spice-vmc device we used to have:
last_out = virtio_serial_write(&svc->port, p, MIN(len, VMC_MAX_HOST_WRITE));
if (last_out > 0)
...
Now in the chardev backend we have:
last_out = MIN(len, VMC_MAX_HOST_WRITE);
qemu_chr_read(scd->chr, p, last_out);
if (last_out > 0) {
...
Which causes us to no longer detect if the virtio port is not ready
to receive data from us. chardev actually has a mechanism to detect this,
but it requires a separate call to qemu_chr_can_read, before calling
qemu_chr_read (which return void).
This patch uses qemu_chr_can_read to fix the flow control from client to
guest.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
-rw-r--r-- | spice-qemu-char.c | 11 |
1 files changed, 5 insertions, 6 deletions
diff --git a/spice-qemu-char.c b/spice-qemu-char.c index 343146cc8..def713a60 100644 --- a/spice-qemu-char.c +++ b/spice-qemu-char.c @@ -38,14 +38,13 @@ static int vmc_write(SpiceCharDeviceInstance *sin, const uint8_t *buf, int len) while (len > 0) { last_out = MIN(len, VMC_MAX_HOST_WRITE); - qemu_chr_read(scd->chr, p, last_out); - if (last_out > 0) { - out += last_out; - len -= last_out; - p += last_out; - } else { + if (qemu_chr_can_read(scd->chr) < last_out) { break; } + qemu_chr_read(scd->chr, p, last_out); + out += last_out; + len -= last_out; + p += last_out; } dprintf(scd, 3, "%s: %lu/%zd\n", __func__, out, len + out); |