[PATCH v4 09/10] xen: make hvc_xen console work for dom0.

From: stefano . stabellini
Date: Tue Oct 19 2010 - 07:18:34 EST


From: Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>

Use the console hypercalls for dom0 console.

[ Impact: Add Xen dom0 console ]
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>
Signed-off-by: Juan Quintela <quintela@xxxxxxxxxx>
Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
---
drivers/char/hvc_xen.c | 98 ++++++++++++++++++++++++++++++++----------------
drivers/xen/events.c | 2 +-
include/xen/events.h | 1 +
3 files changed, 67 insertions(+), 34 deletions(-)

diff --git a/drivers/char/hvc_xen.c b/drivers/char/hvc_xen.c
index 60446f8..1f7e13a 100644
--- a/drivers/char/hvc_xen.c
+++ b/drivers/char/hvc_xen.c
@@ -78,7 +78,7 @@ static int __write_console(const char *data, int len)
return sent;
}

-static int write_console(uint32_t vtermno, const char *data, int len)
+static int domU_write_console(uint32_t vtermno, const char *data, int len)
{
int ret = len;

@@ -101,7 +101,7 @@ static int write_console(uint32_t vtermno, const char *data, int len)
return ret;
}

-static int read_console(uint32_t vtermno, char *buf, int len)
+static int domU_read_console(uint32_t vtermno, char *buf, int len)
{
struct xencons_interface *intf = xencons_interface();
XENCONS_RING_IDX cons, prod;
@@ -122,28 +122,62 @@ static int read_console(uint32_t vtermno, char *buf, int len)
return recv;
}

-static const struct hv_ops hvc_ops = {
- .get_chars = read_console,
- .put_chars = write_console,
+static struct hv_ops domU_hvc_ops = {
+ .get_chars = domU_read_console,
+ .put_chars = domU_write_console,
.notifier_add = notifier_add_irq,
.notifier_del = notifier_del_irq,
.notifier_hangup = notifier_hangup_irq,
};

-static int __init xen_init(void)
+static int dom0_read_console(uint32_t vtermno, char *buf, int len)
+{
+ return HYPERVISOR_console_io(CONSOLEIO_read, len, buf);
+}
+
+/*
+ * Either for a dom0 to write to the system console, or a domU with a
+ * debug version of Xen
+ */
+static int dom0_write_console(uint32_t vtermno, const char *str, int len)
+{
+ int rc = HYPERVISOR_console_io(CONSOLEIO_write, len, (char *)str);
+ if (rc < 0)
+ return 0;
+
+ return len;
+}
+
+static struct hv_ops dom0_hvc_ops = {
+ .get_chars = dom0_read_console,
+ .put_chars = dom0_write_console,
+ .notifier_add = notifier_add_irq,
+ .notifier_del = notifier_del_irq,
+ .notifier_hangup = notifier_hangup_irq,
+};
+
+static int __init xen_hvc_init(void)
{
struct hvc_struct *hp;
+ struct hv_ops *ops;

- if (!xen_pv_domain() ||
- xen_initial_domain() ||
- !xen_start_info->console.domU.evtchn)
+ if (!xen_pv_domain())
return -ENODEV;

- xencons_irq = bind_evtchn_to_irq(xen_start_info->console.domU.evtchn);
+ if (xen_initial_domain()) {
+ ops = &dom0_hvc_ops;
+ xencons_irq = bind_virq_to_irq(VIRQ_CONSOLE, 0);
+ } else {
+ if (!xen_start_info->console.domU.evtchn)
+ return -ENODEV;
+
+ ops = &domU_hvc_ops;
+ xencons_irq = bind_evtchn_to_irq(xen_start_info->console.domU.evtchn);
+ }
if (xencons_irq < 0)
xencons_irq = 0; /* NO_IRQ */

- hp = hvc_alloc(HVC_COOKIE, xencons_irq, &hvc_ops, 256);
+ hp = hvc_alloc(HVC_COOKIE, xencons_irq, ops, 256);
if (IS_ERR(hp))
return PTR_ERR(hp);

@@ -160,7 +194,7 @@ void xen_console_resume(void)
rebind_evtchn_irq(xen_start_info->console.domU.evtchn, xencons_irq);
}

-static void __exit xen_fini(void)
+static void __exit xen_hvc_fini(void)
{
if (hvc)
hvc_remove(hvc);
@@ -168,29 +202,24 @@ static void __exit xen_fini(void)

static int xen_cons_init(void)
{
+ struct hv_ops *ops;
+
if (!xen_pv_domain())
return 0;

- hvc_instantiate(HVC_COOKIE, 0, &hvc_ops);
+ if (xen_initial_domain())
+ ops = &dom0_hvc_ops;
+ else
+ ops = &domU_hvc_ops;
+
+ hvc_instantiate(HVC_COOKIE, 0, ops);
return 0;
}

-module_init(xen_init);
-module_exit(xen_fini);
+module_init(xen_hvc_init);
+module_exit(xen_hvc_fini);
console_initcall(xen_cons_init);

-static void raw_console_write(const char *str, int len)
-{
- while(len > 0) {
- int rc = HYPERVISOR_console_io(CONSOLEIO_write, len, (char *)str);
- if (rc <= 0)
- break;
-
- str += rc;
- len -= rc;
- }
-}
-
#ifdef CONFIG_EARLY_PRINTK
static void xenboot_write_console(struct console *console, const char *string,
unsigned len)
@@ -198,19 +227,22 @@ static void xenboot_write_console(struct console *console, const char *string,
unsigned int linelen, off = 0;
const char *pos;

- raw_console_write(string, len);
+ dom0_write_console(0, string, len);
+
+ if (xen_initial_domain())
+ return;

- write_console(0, "(early) ", 8);
+ domU_write_console(0, "(early) ", 8);
while (off < len && NULL != (pos = strchr(string+off, '\n'))) {
linelen = pos-string+off;
if (off + linelen > len)
break;
- write_console(0, string+off, linelen);
- write_console(0, "\r\n", 2);
+ domU_write_console(0, string+off, linelen);
+ domU_write_console(0, "\r\n", 2);
off += linelen + 1;
}
if (off < len)
- write_console(0, string+off, len-off);
+ domU_write_console(0, string+off, len-off);
}

struct console xenboot_console = {
@@ -222,7 +254,7 @@ struct console xenboot_console = {

void xen_raw_console_write(const char *str)
{
- raw_console_write(str, strlen(str));
+ dom0_write_console(0, str, strlen(str));
}

void xen_raw_printk(const char *fmt, ...)
diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index d59debb..b794034 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -841,7 +841,7 @@ static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu)
}


-static int bind_virq_to_irq(unsigned int virq, unsigned int cpu)
+int bind_virq_to_irq(unsigned int virq, unsigned int cpu)
{
struct evtchn_bind_virq bind_virq;
int evtchn, irq;
diff --git a/include/xen/events.h b/include/xen/events.h
index 8fa27dc..646dd17 100644
--- a/include/xen/events.h
+++ b/include/xen/events.h
@@ -12,6 +12,7 @@ int bind_evtchn_to_irqhandler(unsigned int evtchn,
irq_handler_t handler,
unsigned long irqflags, const char *devname,
void *dev_id);
+int bind_virq_to_irq(unsigned int virq, unsigned int cpu);
int bind_virq_to_irqhandler(unsigned int virq, unsigned int cpu,
irq_handler_t handler,
unsigned long irqflags, const char *devname,
--
1.5.6.5

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