[PATCH 2 of 3] [xen-detect] Return 0 if no Xen detected; 1 if running in PV context; and 2 if in HVM context

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

# HG changeset patch
# User konrad@phenom.dumpdata.com
# Date 1261438342 18000
# Node ID fc27db3a2ddb3f0843841748684547f6e2ed1f02
# Parent  402aa73665eddb3f7b3ede0a8894acd24397218d
[xen-detect] Return 0 if no Xen detected; 1 if running in PV context; and 2 if in HVM context.

On top of printing whether we are in HVM or PV context (or none
at all), also return a value.

diff -r 402aa73665ed -r fc27db3a2ddb tools/misc/xen-detect.c
--- a/tools/misc/xen-detect.c	Mon Dec 21 17:50:08 2009 -0500
+++ b/tools/misc/xen-detect.c	Mon Dec 21 18:32:22 2009 -0500
@@ -68,7 +68,8 @@
     cpuid(base + 1, &eax, &ebx, &ecx, &edx, pv_context);
     printf("Running in %s context on Xen v%d.%d.\n",
            pv_context ? "PV" : "HVM", (uint16_t)(eax >> 16), (uint16_t)eax);
-    return 1;
+
+    return pv_context ? 1 : 2;
 }
 
 static jmp_buf sigill_jmp;
@@ -79,9 +80,12 @@
 
 int main(void)
 {
+    /* 0 - no Xen, 1 - PV Xen, 2 - HVM Xen */
+    int rc = 0;
+
     /* Check for execution in HVM context. */
-    if ( check_for_xen(0) )
-        return 0;
+    if ( (rc = check_for_xen(0)) )
+        return rc;
 
     /*
      * Set up a signal handler to test the paravirtualised CPUID instruction.
@@ -90,8 +94,8 @@
      */
     if ( !setjmp(sigill_jmp)
          && (signal(SIGILL, sigill_handler) != SIG_ERR)
-         && check_for_xen(1) )
-        return 0;
+         && (rc = check_for_xen(1)) )
+        return rc;
 
     printf("Not running on Xen.\n");
     return 0;