From: Sjur Brændeland <sjur.brandel...@stericsson.com>
Add the feature VIRTIO_CONSOLE_F_NO_HVC. With this bit set
only port-devices are created. The console port and
port control virtio-queues are not created.
The console port is not suited for communicating
to a remote processor because of it's blocking behavior.
But the port-device supports efficient non-blocking IO
to a remote processor.
Signed-off-by: Sjur Brændeland <sjur.brandel...@stericsson.com>
cc: Rusty Russell <ru...@rustcorp.com.au>
cc: Michael S. Tsirkin <m...@redhat.com>
cc: virtualizat...@lists.linux-foundation.org
cc: Ohad Ben-Cohen <o...@wizery.com>
cc: Linus Walleij <linus.wall...@linaro.org>
---
drivers/char/virtio_console.c | 5 ++++-
include/linux/virtio_console.h | 1 +
2 files changed, 5 insertions(+), 1 deletions(-)
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index 6bfbd09..81546e9 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -1246,7 +1246,9 @@ static int add_port(struct ports_device *portdev, u32 id)
/*
* If we're not using multiport support, this has to be a console port
*/
- if (!use_multiport(port->portdev)) {
+ if (virtio_has_feature(port->portdev->vdev, VIRTIO_CONSOLE_F_NO_HVC))
+ port->host_connected = true;
+ else if (!use_multiport(port->portdev)) {
err = init_port_console(port);
if (err)
goto free_inbufs;
@@ -1882,6 +1884,7 @@ static unsigned int features[] = {
VIRTIO_CONSOLE_F_SIZE,
VIRTIO_CONSOLE_F_MULTIPORT,
VIRTIO_CONSOLE_F_DMA_MEM,
+ VIRTIO_CONSOLE_F_NO_HVC,
};
#ifdef CONFIG_PM
diff --git a/include/linux/virtio_console.h b/include/linux/virtio_console.h
index b27f7fa..a7c8974 100644
--- a/include/linux/virtio_console.h
+++ b/include/linux/virtio_console.h
@@ -39,6 +39,7 @@
#define VIRTIO_CONSOLE_F_SIZE 0 /* Does host provide console size? */
#define VIRTIO_CONSOLE_F_MULTIPORT 1 /* Does host provide multiple ports? */
#define VIRTIO_CONSOLE_F_DMA_MEM 2 /* Use DMA memory in vrings */
+#define VIRTIO_CONSOLE_F_NO_HVC 3 /* Disable use of HVC */
#define VIRTIO_CONSOLE_BAD_ID (~(u32)0)
--
1.7.5.4
--
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