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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [PATCH v3 12/24] xen/console: introduce console_{get,set}_owner()
From: Denis Mukhin <dmukhin@xxxxxxxx>
Switch console_owner address spaces from integers mapped to domain IDs to
straight domain IDs, which simplifies console focus handling code.
console_set_owner() is introduced for setting the new console owner. This is a
public API to Xen console driver (it will be used in the follow on code
change).
console_get_owner() is another public API used for retrieving current console
owner domain ID.
After the change, console_{get,put}_domain() do not need to be public console
APIs.
Signed-off-by: Denis Mukhin <dmukhin@xxxxxxxx>
---
xen/arch/arm/vpl011.c | 5 +--
xen/drivers/char/console.c | 101 +++++++++++++++++++++------------------------
xen/include/xen/console.h | 4 +-
3 files changed, 51 insertions(+), 59 deletions(-)
diff --git a/xen/arch/arm/vpl011.c b/xen/arch/arm/vpl011.c
index
236fd70d0847f375070dfff314bb8dd08d6ad166..efe77c13007716d0e0d70ab5ccf5f94268d5b693
100644
--- a/xen/arch/arm/vpl011.c
+++ b/xen/arch/arm/vpl011.c
@@ -81,12 +81,11 @@ static void vpl011_write_data_xen(struct domain *d, uint8_t
data)
unsigned long flags;
struct vpl011 *vpl011 = &d->arch.vpl011;
struct vpl011_xen_backend *intf = vpl011->backend.xen;
- struct domain *input = console_get_domain();
VPL011_LOCK(d, flags);
intf->out[intf->out_prod++] = data;
- if ( d == input )
+ if ( d->domain_id == console_get_owner() )
{
if ( intf->out_prod == 1 )
{
@@ -126,8 +125,6 @@ static void vpl011_write_data_xen(struct domain *d, uint8_t
data)
vpl011_update_interrupt_status(d);
VPL011_UNLOCK(d, flags);
-
- console_put_domain(input);
}
/*
diff --git a/xen/drivers/char/console.c b/xen/drivers/char/console.c
index
8d68116991ba9e2c5a36840b4d973f8cafe95488..f5ff3ebd830d631fa5d8fb5db1cf68adafcd02b4
100644
--- a/xen/drivers/char/console.c
+++ b/xen/drivers/char/console.c
@@ -461,17 +461,15 @@ static void cf_check dump_console_ring_key(unsigned char
key)
/*
* CTRL-<switch_char> changes input direction, rotating among Xen, Dom0,
- * and the DomUs started from Xen at boot.
+ * and the DomUs.
*/
#define switch_code (opt_conswitch[0]-'a'+1)
-/*
- * console_owner=0 => input to xen
- * console_owner=1 => input to dom0 (or the sole shim domain)
- * console_owner=N => input to dom(N-1)
- */
-static unsigned int __read_mostly console_owner = 0;
-#define max_console_rx (max_init_domid + 1)
+/*
+ * Current console owner domain ID: either Xen or domain w/ d->is_console ==
+ * true.
+ */
+static domid_t __read_mostly console_owner = DOMID_XEN;
static struct domain *console_get_domain_by_id(domid_t domid)
{
@@ -488,14 +486,12 @@ static struct domain *console_get_domain_by_id(domid_t
domid)
return NULL;
}
-struct domain *console_get_domain(void)
+static struct domain *console_get_domain(void)
{
- if ( console_owner == 0 )
- return NULL;
- return console_get_domain_by_id(console_owner - 1);
+ return console_get_domain_by_id(console_owner);
}
-void console_put_domain(struct domain *d)
+static void console_put_domain(struct domain *d)
{
if ( d )
rcu_unlock_domain(d);
@@ -510,42 +506,49 @@ static bool console_owner_possible(domid_t domid)
return !!d;
}
-static void console_switch_input(void)
+int console_set_owner(domid_t domid)
{
- unsigned int next_rx = console_owner;
+ if ( domid == DOMID_XEN )
+ printk("*** Serial input to Xen");
+ else if ( console_owner_possible(domid) )
+ printk("*** Serial input to DOM%u", domid);
+ else
+ return -ENOENT;
- /*
- * Rotate among Xen, dom0 and boot-time created domUs while skipping
- * switching serial input to non existing domains.
- */
- for ( ; ; )
- {
- domid_t domid;
-
- if ( next_rx++ >= max_console_rx )
- {
- console_owner = 0;
- printk("*** Serial input to Xen");
- break;
- }
-
- if ( consoled_is_enabled() && next_rx == 1 )
- domid = get_initial_domain_id();
- else
- domid = next_rx - 1;
-
- if ( console_owner_possible(domid) )
- {
- console_owner = next_rx;
- printk("*** Serial input to DOM%u", domid);
- break;
- }
- }
+ console_owner = domid;
if ( switch_code )
printk(" (type 'CTRL-%c' three times to switch input)",
opt_conswitch[0]);
printk("\n");
+
+ return 0;
+}
+
+domid_t console_get_owner(void)
+{
+ return console_owner;
+}
+
+/*
+ * Switch console input focus.
+ * Rotates input focus among Xen, dom0 and boot-time created domUs while
+ * skipping switching serial input to non existing domains.
+ */
+static void console_switch_input(void)
+{
+ domid_t i, n = max_init_domid + 1;
+
+ if ( console_owner == DOMID_XEN )
+ i = get_initial_domain_id();
+ else
+ i = console_owner + 1;
+
+ for ( ; i < n; i++ )
+ if ( !console_set_owner(i) )
+ break;
+ if ( i == n )
+ console_set_owner(DOMID_XEN);
}
static void __serial_rx(char c)
@@ -553,7 +556,7 @@ static void __serial_rx(char c)
struct domain *d;
int rc = 0;
- if ( console_owner == 0 )
+ if ( console_owner == DOMID_XEN )
return handle_keypress(c, false);
d = console_get_domain();
@@ -1132,14 +1135,6 @@ void __init console_endboot(void)
video_endboot();
- /*
- * If user specifies so, we fool the switch routine to redirect input
- * straight back to Xen. I use this convoluted method so we still print
- * a useful 'how to switch' message.
- */
- if ( opt_conswitch[1] == 'x' )
- console_owner = max_console_rx;
-
register_keyhandler('w', dump_console_ring_key,
"synchronously dump console ring buffer (dmesg)", 0);
register_irq_keyhandler('+', &do_inc_thresh,
@@ -1149,8 +1144,8 @@ void __init console_endboot(void)
register_irq_keyhandler('G', &do_toggle_guest,
"toggle host/guest log level adjustment", 0);
- /* Serial input is directed to DOM0 by default. */
- console_switch_input();
+ if ( opt_conswitch[1] != 'x' )
+ console_set_owner( get_initial_domain_id() );
}
int __init console_has(const char *device)
diff --git a/xen/include/xen/console.h b/xen/include/xen/console.h
index
8631fd279bfe1aba42b61d76fbdb45016c2859f9..c03028ad690fa6359105a174ecc77a30f2731948
100644
--- a/xen/include/xen/console.h
+++ b/xen/include/xen/console.h
@@ -31,8 +31,8 @@ void console_end_sync(void);
void console_start_log_everything(void);
void console_end_log_everything(void);
-struct domain *console_get_domain(void);
-void console_put_domain(struct domain *d);
+int console_set_owner(domid_t domid);
+domid_t console_get_owner(void);
/*
* Steal output from the console. Returns +ve identifier, else -ve error.
--
2.34.1
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