[RFCv2 2/2] virtio_console: Add feature to disable console port
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From: <hidden>
Date: 2012-09-07 06:58:33
Also in:
lkml
Subsystem:
char and misc drivers, the rest, virtio console driver, virtio core · Maintainers:
Arnd Bergmann, Greg Kroah-Hartman, Linus Torvalds, Amit Shah, "Michael S. Tsirkin", Jason Wang, Eugenio Pérez
From: Sjur Brændeland <redacted> 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 <redacted> cc: Rusty Russell <redacted> cc: Michael S. Tsirkin <mst@redhat.com> cc: Amit Shah <redacted> cc: Ohad Ben-Cohen <redacted> cc: Linus Walleij <redacted> cc: virtualization@lists.linux-foundation.org cc: linux-kernel@vger.kernel.org --- drivers/char/virtio_console.c | 6 +++++- include/linux/virtio_console.h | 1 + 2 files changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index 469c05f..7408c00 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c@@ -1244,10 +1244,13 @@ static int add_port(struct ports_device *portdev, u32 id) goto free_device; } + /* Don't initialize the port_console if F_NO_HVC is set*/ + if (virtio_has_feature(port->portdev->vdev, VIRTIO_CONSOLE_F_NO_HVC)) + port->host_connected = true; /* * If we're not using multiport support, this has to be a console port */ - if (!use_multiport(port->portdev)) { + else if (!use_multiport(port->portdev)) { err = init_port_console(port); if (err) goto free_inbufs;
@@ -1896,6 +1899,7 @@ static unsigned int features[] = { #if VIRTIO_CONSOLE_HAS_DMA VIRTIO_CONSOLE_F_DMA_MEM, #endif + VIRTIO_CONSOLE_F_NO_HVC, };
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)
--
1.7.9.5
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