From: Sjur Brændeland <[email protected]> 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 <[email protected]> cc: Rusty Russell <[email protected]> cc: Michael S. Tsirkin <[email protected]> cc: [email protected] cc: Ohad Ben-Cohen <[email protected]> cc: Linus Walleij <[email protected]> --- 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 _______________________________________________ Virtualization mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/virtualization
