| Message ID | 20250318233617.849903-8-dmukhin@ford.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | xen/console: cleanup console input switch logic | expand |
On Tuesday, March 18th, 2025 at 4:37 PM, dmkhn@proton.me <dmkhn@proton.me> wrote: > > > Switch console_focus address space from integers mapped to domain IDs to > direct domain IDs, simplifying the console input switching code. > > Introduce console_set_focus() to set the console owner domain identifier. > > Signed-off-by: Denis Mukhin dmukhin@ford.com > > --- > xen/drivers/char/console.c | 81 ++++++++++++++++---------------------- > 1 file changed, 34 insertions(+), 47 deletions(-) > > diff --git a/xen/drivers/char/console.c b/xen/drivers/char/console.c > index 3d538510f4..0e2349a868 100644 > --- a/xen/drivers/char/console.c > +++ b/xen/drivers/char/console.c > @@ -462,14 +462,12 @@ 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 domain identifier. / > -static unsigned int __read_mostly console_focus = 0; > - > -#define max_console_rx (domid_top + 1) > +static domid_t __read_mostly console_focus = DOMID_XEN; > > static struct domain console_get_domain_by_id(domid_t domid) > { > @@ -488,9 +486,7 @@ static struct domain console_get_domain_by_id(domid_t domid) > > struct domain console_get_domain(void) > { > - if ( console_focus == 0 ) > - return NULL; > - return console_get_domain_by_id(console_focus - 1); > + return console_get_domain_by_id(console_focus); > } > > void console_put_domain(struct domain d) > @@ -508,42 +504,41 @@ static bool console_check_focus_by_id(domid_t domid) > return !!d; > } > > -static void console_switch_focus(void) > +static int console_set_focus(domid_t domid) > { > - unsigned int next_rx = console_focus; > + if ( domid == DOMID_XEN ) > + printk(" Serial input to Xen"); > + else if ( console_check_focus_by_id(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_focus = 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_check_focus_by_id(domid) ) > - { > - console_focus = next_rx; > - printk("*** Serial input to DOM%u", domid); > - break; > - } > - } > + console_focus = domid; > > if ( switch_code ) > printk(" (type 'CTRL-%c' three times to switch input)", > opt_conswitch[0]); > printk("\n"); > + > + return 0; > +} > + > +/* > + * Switch console 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_focus(void) > +{ > + const domid_t n = domid_top + 1; > + domid_t i = ( console_focus == DOMID_XEN ) > + ? get_initial_domain_id() : console_focus + 1; > + > + for ( ; i < n; i++ ) > + if ( !console_set_focus(i) ) > + return; > + > + console_set_focus(DOMID_XEN); > } > > static void __serial_rx(char c) > @@ -551,7 +546,7 @@ static void __serial_rx(char c) > struct domain d; > int rc = 0; > > - if ( console_focus == 0 ) > + if ( console_focus == DOMID_XEN ) > return handle_keypress(c, false); > > d = console_get_domain(); > @@ -1141,14 +1136,6 @@ 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_focus = max_console_rx; > - > register_keyhandler('w', dump_console_ring_key, > "synchronously dump console ring buffer (dmesg)", 0); > register_irq_keyhandler('+', &do_inc_thresh, > @@ -1158,8 +1145,8 @@ 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_focus(); > + if ( opt_conswitch[1] != 'x' ) > + console_set_focus( get_initial_domain_id() ); Forgot to drop extra spaces around the function parameter. > } > > int __init console_has(const char *device) > -- > 2.34.1
diff --git a/xen/drivers/char/console.c b/xen/drivers/char/console.c index 3d538510f4..0e2349a868 100644 --- a/xen/drivers/char/console.c +++ b/xen/drivers/char/console.c @@ -462,14 +462,12 @@ 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 domain identifier. */ -static unsigned int __read_mostly console_focus = 0; - -#define max_console_rx (domid_top + 1) +static domid_t __read_mostly console_focus = DOMID_XEN; static struct domain *console_get_domain_by_id(domid_t domid) { @@ -488,9 +486,7 @@ static struct domain *console_get_domain_by_id(domid_t domid) struct domain *console_get_domain(void) { - if ( console_focus == 0 ) - return NULL; - return console_get_domain_by_id(console_focus - 1); + return console_get_domain_by_id(console_focus); } void console_put_domain(struct domain *d) @@ -508,42 +504,41 @@ static bool console_check_focus_by_id(domid_t domid) return !!d; } -static void console_switch_focus(void) +static int console_set_focus(domid_t domid) { - unsigned int next_rx = console_focus; + if ( domid == DOMID_XEN ) + printk("*** Serial input to Xen"); + else if ( console_check_focus_by_id(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_focus = 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_check_focus_by_id(domid) ) - { - console_focus = next_rx; - printk("*** Serial input to DOM%u", domid); - break; - } - } + console_focus = domid; if ( switch_code ) printk(" (type 'CTRL-%c' three times to switch input)", opt_conswitch[0]); printk("\n"); + + return 0; +} + +/* + * Switch console 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_focus(void) +{ + const domid_t n = domid_top + 1; + domid_t i = ( console_focus == DOMID_XEN ) + ? get_initial_domain_id() : console_focus + 1; + + for ( ; i < n; i++ ) + if ( !console_set_focus(i) ) + return; + + console_set_focus(DOMID_XEN); } static void __serial_rx(char c) @@ -551,7 +546,7 @@ static void __serial_rx(char c) struct domain *d; int rc = 0; - if ( console_focus == 0 ) + if ( console_focus == DOMID_XEN ) return handle_keypress(c, false); d = console_get_domain(); @@ -1141,14 +1136,6 @@ 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_focus = max_console_rx; - register_keyhandler('w', dump_console_ring_key, "synchronously dump console ring buffer (dmesg)", 0); register_irq_keyhandler('+', &do_inc_thresh, @@ -1158,8 +1145,8 @@ 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_focus(); + if ( opt_conswitch[1] != 'x' ) + console_set_focus( get_initial_domain_id() ); } int __init console_has(const char *device)
Switch console_focus address space from integers mapped to domain IDs to direct domain IDs, simplifying the console input switching code. Introduce console_set_focus() to set the console owner domain identifier. Signed-off-by: Denis Mukhin <dmukhin@ford.com> --- xen/drivers/char/console.c | 81 ++++++++++++++++---------------------- 1 file changed, 34 insertions(+), 47 deletions(-)