freebsd-skq/sys/dev/xen/console/xencons_ring.c
Roger Pau Monné 2382778f40 xen: Dom0 console fixes
Minor fixes to make the Xen Dom0 console work. This includes always
returning there's pending input in xencons_has_input, because on Dom0
there's no shared ring and we cannot test the indexes. The second
fix is to use the CONSOLEIO_read hypercall in order to read input
data from the Xen console.

Sponsored by: Citrix Systems R&D

dev/xen/console/xencons_ring.c:
 - Always return true in xencons_has_input for Dom0.
 - Implement Dom0 console support for xencons_handle_input.
2014-08-04 09:02:49 +00:00

202 lines
3.6 KiB
C

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/module.h>
#include <sys/systm.h>
#include <sys/consio.h>
#include <sys/proc.h>
#include <sys/uio.h>
#include <sys/tty.h>
#include <sys/systm.h>
#include <sys/taskqueue.h>
#include <sys/conf.h>
#include <sys/kernel.h>
#include <sys/bus.h>
#include <sys/cons.h>
#include <machine/stdarg.h>
#include <xen/xen-os.h>
#include <xen/hypervisor.h>
#include <xen/xen_intr.h>
#include <sys/cons.h>
#include <xen/xen_intr.h>
#include <xen/evtchn.h>
#include <xen/interface/io/console.h>
#include <dev/xen/console/xencons_ring.h>
#include <xen/evtchn.h>
#include <xen/interface/io/console.h>
#define console_evtchn console.domU.evtchn
xen_intr_handle_t console_handle;
extern struct mtx cn_mtx;
extern device_t xencons_dev;
extern bool cnsl_evt_reg;
#define DOM0_BUFFER_SIZE 16
static inline struct xencons_interface *
xencons_interface(void)
{
return (struct xencons_interface *)console_page;
}
int
xencons_has_input(void)
{
struct xencons_interface *intf;
if (xen_initial_domain()) {
/*
* Since the Dom0 console works with hypercalls
* there's no way to know if there's input unless
* we actually try to retrieve it, so always return
* like there's pending data. Then if the hypercall
* returns no input, we can handle it without problems
* in xencons_handle_input().
*/
return 1;
}
intf = xencons_interface();
return (intf->in_cons != intf->in_prod);
}
int
xencons_ring_send(const char *data, unsigned len)
{
struct xencons_interface *intf;
XENCONS_RING_IDX cons, prod;
int sent;
struct evtchn_send send = {
.port = HYPERVISOR_start_info->console_evtchn
};
intf = xencons_interface();
cons = intf->out_cons;
prod = intf->out_prod;
sent = 0;
mb();
KASSERT((prod - cons) <= sizeof(intf->out),
("console send ring inconsistent"));
while ((sent < len) && ((prod - cons) < sizeof(intf->out)))
intf->out[MASK_XENCONS_IDX(prod++, intf->out)] = data[sent++];
wmb();
intf->out_prod = prod;
if (cnsl_evt_reg)
xen_intr_signal(console_handle);
else
HYPERVISOR_event_channel_op(EVTCHNOP_send, &send);
return sent;
}
static xencons_receiver_func *xencons_receiver;
void
xencons_handle_input(void *unused)
{
struct xencons_interface *intf;
XENCONS_RING_IDX cons, prod;
CN_LOCK(cn_mtx);
if (xen_initial_domain()) {
static char rbuf[DOM0_BUFFER_SIZE];
int l;
while ((l = HYPERVISOR_console_io(CONSOLEIO_read,
DOM0_BUFFER_SIZE, rbuf)) > 0)
xencons_rx(rbuf, l);
CN_UNLOCK(cn_mtx);
return;
}
intf = xencons_interface();
cons = intf->in_cons;
prod = intf->in_prod;
CN_UNLOCK(cn_mtx);
/* XXX needs locking */
while (cons != prod) {
xencons_rx(intf->in + MASK_XENCONS_IDX(cons, intf->in), 1);
cons++;
}
mb();
intf->in_cons = cons;
CN_LOCK(cn_mtx);
xen_intr_signal(console_handle);
xencons_tx();
CN_UNLOCK(cn_mtx);
}
void
xencons_ring_register_receiver(xencons_receiver_func *f)
{
xencons_receiver = f;
}
int
xencons_ring_init(void)
{
int err;
if (HYPERVISOR_start_info->console_evtchn == 0)
return 0;
err = xen_intr_bind_local_port(xencons_dev,
HYPERVISOR_start_info->console_evtchn, NULL, xencons_handle_input, NULL,
INTR_TYPE_MISC | INTR_MPSAFE, &console_handle);
if (err) {
return err;
}
return 0;
}
extern void xencons_suspend(void);
extern void xencons_resume(void);
void
xencons_suspend(void)
{
if (HYPERVISOR_start_info->console_evtchn == 0)
return;
xen_intr_unbind(&console_handle);
}
void
xencons_resume(void)
{
(void)xencons_ring_init();
}
/*
* Local variables:
* mode: C
* c-set-style: "BSD"
* c-basic-offset: 8
* tab-width: 4
* indent-tabs-mode: t
* End:
*/