console: buffer and show origin of guest PV writes

Guests other than domain 0 using the console output have previously been
controlled by the VERBOSE #define, but with no designation of which
guest's output was on the console. This patch converts the HVM output
buffering to be used by all domains except the hardware domain (dom0):
stripping non-printable characters, line buffering the output, and
prefixing it with the domain ID. This is especially useful for debugging
stub domains during early boot.

Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Acked-by: Keir Fraser <keir@xen.org>

3 files changed, 8 insertions, 6 deletions

diff --git a/xen/include/asm-x86/hvm/domain.h b/xen/include/asm-x86/hvm/domain.h
index 27b3de50dc..b1e31871cc 100644
--- a/xen/include/asm-x86/hvm/domain.h
+++ b/xen/include/asm-x86/hvm/domain.h
@@ -62,12 +62,6 @@ struct hvm_domain {
     /* emulated irq to pirq */
     struct radix_tree_root emuirq_pirq;
 
-    /* hvm_print_line() logging. */
-#define HVM_PBUF_SIZE 80
-    char                  *pbuf;
-    int                    pbuf_idx;
-    spinlock_t             pbuf_lock;
-
     uint64_t              *params;
 
     /* Memory ranges with pinned cache attributes. */
diff --git a/xen/include/xen/lib.h b/xen/include/xen/lib.h
index 74b34eb932..4768b0e1dc 100644
--- a/xen/include/xen/lib.h
+++ b/xen/include/xen/lib.h
@@ -83,6 +83,8 @@ extern void debugtrace_printk(const char *fmt, ...);
 #define _p(_x) ((void *)(unsigned long)(_x))
 extern void printk(const char *format, ...)
     __attribute__ ((format (printf, 1, 2)));
+extern void guest_printk(const struct domain *d, const char *format, ...)
+    __attribute__ ((format (printf, 2, 3)));
 extern void panic(const char *format, ...)
     __attribute__ ((format (printf, 1, 2)));
 extern long vm_assist(struct domain *, unsigned int, unsigned int);
diff --git a/xen/include/xen/sched.h b/xen/include/xen/sched.h
index ae6a3b843b..0013a8d8ce 100644
--- a/xen/include/xen/sched.h
+++ b/xen/include/xen/sched.h
@@ -341,6 +341,12 @@ struct domain
     /* Control-plane tools handle for this domain. */
     xen_domain_handle_t handle;
 
+    /* hvm_print_line() and guest_console_write() logging. */
+#define DOMAIN_PBUF_SIZE 80
+    char       *pbuf;
+    unsigned    pbuf_idx;
+    spinlock_t  pbuf_lock;
+
     /* OProfile support. */
     struct xenoprof *xenoprof;
     int32_t time_offset_seconds;