From d7b0a238f6c4b0c907f40be2c43979f63cd65727 Mon Sep 17 00:00:00 2001 From: Amit Shah Date: Fri, 4 Feb 2011 08:20:40 -0200 Subject: [RHEL6 qemu-kvm PATCH 09/27] virtio-serial: Let virtio-serial-bus know if all data was consumed RH-Author: Amit Shah Message-id: <48e0eae25a7ae045e630d25b01a9e61dc6dd4b3d.1296806194.git.amit.shah@redhat.com> Patchwork-id: 17710 O-Subject: [RHEL6.1 qemu PATCH v5 09/19] virtio-serial: Let virtio-serial-bus know if all data was consumed Bugzilla: 588916 RH-Acked-by: Alon Levy RH-Acked-by: Juan Quintela RH-Acked-by: Jes Sorensen RH-Acked-by: Michael S. Tsirkin The have_data() API to hand off guest data to apps using virtio-serial so far assumed all the data was consumed. Relax this assumption. Future commits will allow for incomplete writes. Signed-off-by: Amit Shah (cherry picked from commit e300ac275bbf19b31cf5968b8de8abe52c26e163) Signed-off-by: Amit Shah --- hw/virtio-console.c | 4 ++-- hw/virtio-serial.h | 7 ++++--- 2 files changed, 6 insertions(+), 5 deletions(-) Signed-off-by: Eduardo Habkost --- hw/virtio-console.c | 4 ++-- hw/virtio-serial.h | 7 ++++--- 2 files changed, 6 insertions(+), 5 deletions(-) diff --git a/hw/virtio-console.c b/hw/virtio-console.c index 1bb6f8e..22cf28c 100644 --- a/hw/virtio-console.c +++ b/hw/virtio-console.c @@ -20,11 +20,11 @@ typedef struct VirtConsole { /* Callback function that's called when the guest sends us data */ -static void flush_buf(VirtIOSerialPort *port, const uint8_t *buf, size_t len) +static ssize_t flush_buf(VirtIOSerialPort *port, const uint8_t *buf, size_t len) { VirtConsole *vcon = DO_UPCAST(VirtConsole, port, port); - qemu_chr_write(vcon->chr, buf, len); + return qemu_chr_write(vcon->chr, buf, len); } /* Readiness of the guest to accept data on a port */ diff --git a/hw/virtio-serial.h b/hw/virtio-serial.h index 4e64c44..89078d9 100644 --- a/hw/virtio-serial.h +++ b/hw/virtio-serial.h @@ -142,10 +142,11 @@ struct VirtIOSerialPortInfo { /* * Guest wrote some data to the port. This data is handed over to - * the app via this callback. The app is supposed to consume all - * the data that is presented to it. + * the app via this callback. The app can return a size less than + * 'len'. In this case, throttling will be enabled for this port. */ - void (*have_data)(VirtIOSerialPort *port, const uint8_t *buf, size_t len); + ssize_t (*have_data)(VirtIOSerialPort *port, const uint8_t *buf, + size_t len); }; /* Interface to the virtio-serial bus */ -- 1.7.3.2