From 0acf10d8fbd52926217d3933d196b33fe2468f18 Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Mon, 26 May 2008 23:30:59 +0100 Subject: xen: add raw console write functions for debug Add a couple of functions which can write directly to the Xen console for debugging. This output ends up on the host's dom0 console (assuming it allows the domain to write there). Signed-off-by: Jeremy Fitzhardinge Signed-off-by: Thomas Gleixner --- drivers/char/hvc_xen.c | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) (limited to 'drivers/char/hvc_xen.c') diff --git a/drivers/char/hvc_xen.c b/drivers/char/hvc_xen.c index dd68f8541c2d..e97d9d168325 100644 --- a/drivers/char/hvc_xen.c +++ b/drivers/char/hvc_xen.c @@ -157,3 +157,29 @@ struct console xenboot_console = { .write = xenboot_write_console, .flags = CON_PRINTBUFFER | CON_BOOT, }; + +void xen_raw_console_write(const char *str) +{ + int len = strlen(str); + + while(len > 0) { + int rc = HYPERVISOR_console_io(CONSOLEIO_write, len, (char *)str); + if (rc <= 0) + break; + + str += rc; + len -= rc; + } +} + +void xen_raw_printk(const char *fmt, ...) +{ + static char buf[512]; + va_list ap; + + va_start(ap, fmt); + vsnprintf(buf, sizeof(buf), fmt, ap); + va_end(ap); + + xen_raw_console_write(buf); +} -- cgit v1.2.3 From 0922abdc3982ae54cbe1b24ac5aa91a260eca1bb Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Mon, 26 May 2008 23:31:00 +0100 Subject: xen: make early console also write to debug console When using "earlyprintk=xen", also write the console output to the raw debug console. This will appear on dom0's console if the hypervisor has been compiled to allow it. Signed-off-by: Jeremy Fitzhardinge Signed-off-by: Thomas Gleixner --- drivers/char/hvc_xen.c | 29 ++++++++++++++++++----------- 1 file changed, 18 insertions(+), 11 deletions(-) (limited to 'drivers/char/hvc_xen.c') diff --git a/drivers/char/hvc_xen.c b/drivers/char/hvc_xen.c index e97d9d168325..2413af342a81 100644 --- a/drivers/char/hvc_xen.c +++ b/drivers/char/hvc_xen.c @@ -134,12 +134,27 @@ module_init(xen_init); module_exit(xen_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) { unsigned int linelen, off = 0; const char *pos; + raw_console_write(string, len); + while (off < len && NULL != (pos = strchr(string+off, '\n'))) { linelen = pos-string+off; if (off + linelen > len) @@ -155,21 +170,13 @@ static void xenboot_write_console(struct console *console, const char *string, struct console xenboot_console = { .name = "xenboot", .write = xenboot_write_console, - .flags = CON_PRINTBUFFER | CON_BOOT, + .flags = CON_PRINTBUFFER | CON_BOOT | CON_ANYTIME, }; +#endif /* CONFIG_EARLY_PRINTK */ void xen_raw_console_write(const char *str) { - int len = strlen(str); - - while(len > 0) { - int rc = HYPERVISOR_console_io(CONSOLEIO_write, len, (char *)str); - if (rc <= 0) - break; - - str += rc; - len -= rc; - } + raw_console_write(str, strlen(str)); } void xen_raw_printk(const char *fmt, ...) -- cgit v1.2.3 From 83abc70a4c6e306f4c1672e25884322f797e4fcb Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Mon, 26 May 2008 23:31:12 +0100 Subject: xen: make earlyprintk=xen work again For some perverse reason, if you call add_preferred_console() it prevents setup_early_printk() from successfully enabling the boot console - unless you make it a preferred console too... Also, make xenboot console output distinct from normal console output, since it gets repeated when the console handover happens, and the duplicated output is confusing without disambiguation. Signed-off-by: Jeremy Fitzhardinge Signed-off-by: Thomas Gleixner Cc: Markus Armbruster Cc: Gerd Hoffmann --- arch/x86/xen/enlighten.c | 1 + drivers/char/hvc_xen.c | 1 + 2 files changed, 2 insertions(+) (limited to 'drivers/char/hvc_xen.c') diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index 6cfb708408e9..5c0635a8bffd 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -1257,6 +1257,7 @@ asmlinkage void __init xen_start_kernel(void) boot_params.hdr.ramdisk_size = xen_start_info->mod_len; if (!is_initial_xendomain()) { + add_preferred_console("xenboot", 0, NULL); add_preferred_console("tty", 0, NULL); add_preferred_console("hvc", 0, NULL); } diff --git a/drivers/char/hvc_xen.c b/drivers/char/hvc_xen.c index 2413af342a81..d5fe0a8952fa 100644 --- a/drivers/char/hvc_xen.c +++ b/drivers/char/hvc_xen.c @@ -155,6 +155,7 @@ static void xenboot_write_console(struct console *console, const char *string, raw_console_write(string, len); + write_console(0, "(early) ", 8); while (off < len && NULL != (pos = strchr(string+off, '\n'))) { linelen = pos-string+off; if (off + linelen > len) -- cgit v1.2.3 From 6b9b732d0e396a3f1a95977162a8624aafce38a1 Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Mon, 26 May 2008 23:31:25 +0100 Subject: xen-console: add save/restore Add code to: 1. Deal with the console page being canonicalized. During save, the console's mfn in the start_info structure is canonicalized to a pfn. In order to deal with that, we always use a copy of the pfn and indirect off that all the time. However, we fall back to using the mfn if the pfn hasn't been initialized yet. 2. Restore the console event channel, and rebind it to the existing irq. Signed-off-by: Jeremy Fitzhardinge Signed-off-by: Thomas Gleixner --- drivers/char/hvc_xen.c | 25 +++++++++++++++++++++---- include/xen/hvc-console.h | 2 ++ 2 files changed, 23 insertions(+), 4 deletions(-) (limited to 'drivers/char/hvc_xen.c') diff --git a/drivers/char/hvc_xen.c b/drivers/char/hvc_xen.c index d5fe0a8952fa..db2ae4216279 100644 --- a/drivers/char/hvc_xen.c +++ b/drivers/char/hvc_xen.c @@ -39,9 +39,14 @@ static int xencons_irq; /* ------------------------------------------------------------------ */ +static unsigned long console_pfn = ~0ul; + static inline struct xencons_interface *xencons_interface(void) { - return mfn_to_virt(xen_start_info->console.domU.mfn); + if (console_pfn == ~0ul) + return mfn_to_virt(xen_start_info->console.domU.mfn); + else + return __va(console_pfn << PAGE_SHIFT); } static inline void notify_daemon(void) @@ -101,20 +106,32 @@ static int __init xen_init(void) { struct hvc_struct *hp; - if (!is_running_on_xen()) - return 0; + if (!is_running_on_xen() || + is_initial_xendomain() || + !xen_start_info->console.domU.evtchn) + return -ENODEV; xencons_irq = bind_evtchn_to_irq(xen_start_info->console.domU.evtchn); if (xencons_irq < 0) - xencons_irq = 0 /* NO_IRQ */; + xencons_irq = 0; /* NO_IRQ */ + hp = hvc_alloc(HVC_COOKIE, xencons_irq, &hvc_ops, 256); if (IS_ERR(hp)) return PTR_ERR(hp); hvc = hp; + + console_pfn = mfn_to_pfn(xen_start_info->console.domU.mfn); + return 0; } +void xen_console_resume(void) +{ + if (xencons_irq) + rebind_evtchn_irq(xen_start_info->console.domU.evtchn, xencons_irq); +} + static void __exit xen_fini(void) { if (hvc) diff --git a/include/xen/hvc-console.h b/include/xen/hvc-console.h index efc3237ab990..fd5483a059bb 100644 --- a/include/xen/hvc-console.h +++ b/include/xen/hvc-console.h @@ -3,6 +3,8 @@ extern struct console xenboot_console; +void xen_console_resume(void); + void xen_raw_console_write(const char *str); void xen_raw_printk(const char *fmt, ...); -- cgit v1.2.3