xen: add and enable Xen console for PVH guests

This adds and enables the PV console used on XEN kernels to
GENERIC/XENHVM kernels in order for it to be used on PVH.

Approved by: gibbs
Sponsored by: Citrix Systems R&D

dev/xen/console/console.c:
 - Define console_page.
 - Move xc_printf debug function from i386 XEN code to generic console
   code.
 - Rework xc_printf.
 - Use xen_initial_domain instead of open-coded checks for Dom0.
 - Gate the attach of the PV console to PV(H) guests.

dev/xen/console/xencons_ring.c:
 - Allow the PV Xen console to output earlier by directly signaling
   the event channel in start_info if the event channel is not yet
   initialized.
 - Use HYPERVISOR_start_info instead of xen_start_info.

i386/include/xen/xen-os.h:
 - Remove prototype for xc_printf since it's now declared in global
   xen-os.h

i386/xen/xen_machdep.c:
 - Remove previous version of xc_printf.
 - Remove definition of console_page (now it's defined in the console
   itself).
 - Fix some printf formatting errors.

x86/xen/pv.c:
 - Add some early boot debug messages using xc_printf.
 - Set console_page based on the value passed in start_info.

xen/xen-os.h:
 - Declare console_page and add prototype for xc_printf.

2 files changed, 2 insertions, 20 deletions

diff --git a/sys/i386/include/xen/xen-os.h b/sys/i386/include/xen/xen-os.h
index a8fba61..3d1ef04 100644
--- a/sys/i386/include/xen/xen-os.h
+++ b/sys/i386/include/xen/xen-os.h
@@ -45,7 +45,6 @@ static inline void rep_nop(void)
 #define cpu_relax() rep_nop()
 
 #ifndef XENHVM
-void xc_printf(const char *fmt, ...);
 
 #ifdef SMP
 extern int gdtset;
diff --git a/sys/i386/xen/xen_machdep.c b/sys/i386/xen/xen_machdep.c
index fd575ee..c1e166b 100644
--- a/sys/i386/xen/xen_machdep.c
+++ b/sys/i386/xen/xen_machdep.c
@@ -186,21 +186,6 @@ xen_boothowto(char *envp)
 	return howto;
 }
 
-#define XC_PRINTF_BUFSIZE 1024
-void
-xc_printf(const char *fmt, ...)
-{
-        __va_list ap;
-        int retval;
-        static char buf[XC_PRINTF_BUFSIZE];
-
-        va_start(ap, fmt);
-        retval = vsnprintf(buf, XC_PRINTF_BUFSIZE - 1, fmt, ap);
-        va_end(ap);
-        buf[retval] = 0;
-        (void)HYPERVISOR_console_write(buf, retval);
-}
-
 
 #define XPQUEUE_SIZE 128
 
@@ -745,8 +730,6 @@ void initvalues(start_info_t *startinfo);
 struct xenstore_domain_interface;
 extern struct xenstore_domain_interface *xen_store;
 
-char *console_page;
-
 void *
 bootmem_alloc(unsigned int size) 
 {
@@ -969,7 +952,7 @@ initvalues(start_info_t *startinfo)
 	xc_printf("initvalues(): wooh - availmem=%x,%x\n", avail_space,
 	    cur_space);
 
-	xc_printf("KERNBASE=%x,pt_base=%x, VTOPFN(base)=%x, nr_pt_frames=%x\n",
+	xc_printf("KERNBASE=%x,pt_base=%lx, VTOPFN(base)=%x, nr_pt_frames=%lx\n",
 	    KERNBASE,xen_start_info->pt_base, VTOPFN(xen_start_info->pt_base),
 	    xen_start_info->nr_pt_frames);
 	xendebug_flags = 0; /* 0xffffffff; */
@@ -978,7 +961,7 @@ initvalues(start_info_t *startinfo)
 	shift_phys_machine(xen_phys_machine, xen_start_info->nr_pages);
 #endif
 	XENPRINTF("IdlePTD %p\n", IdlePTD);
-	XENPRINTF("nr_pages: %ld shared_info: 0x%lx flags: 0x%lx pt_base: 0x%lx "
+	XENPRINTF("nr_pages: %ld shared_info: 0x%lx flags: 0x%x pt_base: 0x%lx "
 		  "mod_start: 0x%lx mod_len: 0x%lx\n",
 		  xen_start_info->nr_pages, xen_start_info->shared_info, 
 		  xen_start_info->flags, xen_start_info->pt_base,