Hi Rusty, On 13 May 2013 08:22, Rusty Russell <rusty@xxxxxxxxxxxxxxx> wrote: > Pranavkumar Sawargaonkar <pranavkumar@xxxxxxxxxx> writes: >> Signed-off-by: Pranavkumar Sawargaonkar <pranavkumar@xxxxxxxxxx> >> Signed-off-by: Anup Patel <anup.patel@xxxxxxxxxx> >> --- >> Documentation/virtual/virtio-spec.txt | 8 +++++++- >> 1 file changed, 7 insertions(+), 1 deletion(-) > > OK, I applied this to the lyx master, with three changes: > 1) Changed "filed" to "field". > 2) Added ", or even acknowledging the feature" after "without > initializing virtio queues". > 3) Added an initial point to the Device Initialization section: > > 1. If the VIRTIO_CONSOLE_F_EMERG_WRITE feature is offered, the > emerg_wr field of the configuration can be written at any time. Thus > it should work for very early boot debugging output as well as > catastophic OS failures (eg. virtio ring corruption). Thanks for applying this patch. Have you also applied first patch ([PATCH V2 1/3] virtio: console: Add emergency writeonly register to config space) with this? (https://lkml.org/lkml/2013/5/6/169) > > Thanks, > Rusty. Thanks, Pranav > >> diff --git a/Documentation/virtual/virtio-spec.txt b/Documentation/virtual/virtio-spec.txt >> index 0d6ec85..3ca38f8 100644 >> --- a/Documentation/virtual/virtio-spec.txt >> +++ b/Documentation/virtual/virtio-spec.txt >> @@ -1927,11 +1927,16 @@ Ports 2 onwards only if VIRTIO_CONSOLE_F_MULTIPORT is set >> ports; configuration fields nr_ports and max_nr_ports are >> valid and control virtqueues will be used. >> >> + VIRTIO_CONSOLE_F_EMERG_WRITE(2) Device has support for emergency >> + write. Configuration filed emerg_wr is valid. >> + >> Device configuration layout The size of the console is supplied >> in the configuration space if the VIRTIO_CONSOLE_F_SIZE feature >> is set. Furthermore, if the VIRTIO_CONSOLE_F_MULTIPORT feature >> is set, the maximum number of ports supported by the device can >> - be fetched.struct virtio_console_config { >> + be fetched. If VIRTIO_CONSOLE_F_EMERG_WRITE is set then one can >> + use emergency write to output single character without initializing >> + virtio queues. struct virtio_console_config { >> >> u16 cols; >> >> @@ -1941,6 +1946,7 @@ Ports 2 onwards only if VIRTIO_CONSOLE_F_MULTIPORT is set >> >> u32 max_nr_ports; >> >> + u32 emerg_wr; >> }; >> >> Device Initialization >> -- >> 1.7.9.5 _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/cucslists/listinfo/kvmarm
