From a40f520f7b94d2a5de04c7ca3a7513a99c84e9ef Mon Sep 17 00:00:00 2001
From: Justin M. Forbes <jforbes@redhat.com>
Date: Thu, 1 Oct 2009 16:13:56 -0500
Subject: [PATCH] Improve error reporting on file access

By making the error reporting include strerror(errno), it gives the user
a bit more indication as to why qemu failed.  This is particularly
important for people running qemu as a non root user.

Signed-off-by: Justin M. Forbes <jforbes@redhat.com>
---
 hw/pc.c |   12 ++++++------
 vl.c    |   20 ++++++++++----------
 2 files changed, 16 insertions(+), 16 deletions(-)

diff --git a/hw/pc.c b/hw/pc.c
index 3b226f4..7a184cd 100644
--- a/hw/pc.c
+++ b/hw/pc.c
@@ -841,8 +841,8 @@ static void load_linux(void *fw_cfg,
     if (!f || !(kernel_size = get_file_size(f)) ||
 	fread(header, 1, MIN(ARRAY_SIZE(header), kernel_size), f) !=
 	MIN(ARRAY_SIZE(header), kernel_size)) {
-	fprintf(stderr, "qemu: could not load kernel '%s'\n",
-		kernel_filename);
+	fprintf(stderr, "qemu: could not load kernel '%s': %s\n",
+		kernel_filename, strerror(errno));
 	exit(1);
     }

@@ -947,8 +947,8 @@ static void load_linux(void *fw_cfg,

 	fi = fopen(initrd_filename, "rb");
 	if (!fi) {
-	    fprintf(stderr, "qemu: could not load initial ram disk '%s'\n",
-		    initrd_filename);
+	    fprintf(stderr, "qemu: could not load initial ram disk '%s': %s\n",
+		    initrd_filename, strerror(errno));
 	    exit(1);
 	}

@@ -956,8 +956,8 @@ static void load_linux(void *fw_cfg,
 	initrd_addr = (initrd_max-initrd_size) & ~4095;

 	if (!fread_targphys_ok(initrd_addr, initrd_size, fi)) {
-	    fprintf(stderr, "qemu: read error on initial ram disk '%s'\n",
-		    initrd_filename);
+	    fprintf(stderr, "qemu: read error on initial ram disk '%s': %s\n",
+		    initrd_filename, strerror(errno));
 	    exit(1);
 	}
 	fclose(fi);
diff --git a/vl.c b/vl.c
index d7c7ab1..9182d89 100644
--- a/vl.c
+++ b/vl.c
@@ -2379,8 +2379,8 @@ int drive_init(struct drive_opt *arg, int snapshot, void *opaque)
     else if (cache == 2) /* write-back */
         bdrv_flags |= BDRV_O_CACHE_WB;
     if (bdrv_open2(bdrv, file, bdrv_flags, drv) < 0) {
-        fprintf(stderr, "qemu: could not open disk image %s\n",
-                        file);
+        fprintf(stderr, "qemu: could not open disk image %s: %s\n",
+                        file, strerror(errno));
         return -1;
     }
     if (bdrv_key_required(bdrv))
@@ -5799,7 +5799,7 @@ int main(int argc, char **argv, char **envp)
             if (len != 1)
                 exit(1);
             else if (status == 1) {
-                fprintf(stderr, "Could not acquire pidfile\n");
+                fprintf(stderr, "Could not acquire pidfile: %s\n", strerror(errno));
                 exit(1);
             } else
                 exit(0);
@@ -5826,7 +5826,7 @@ int main(int argc, char **argv, char **envp)
             uint8_t status = 1;
             write(fds[1], &status, 1);
         } else
-            fprintf(stderr, "Could not acquire pid file\n");
+            fprintf(stderr, "Could not acquire pid file: %s\n", strerror(errno));
         exit(1);
     }
 #endif
@@ -6031,8 +6031,8 @@ int main(int argc, char **argv, char **envp)
             snprintf(label, sizeof(label), "serial%d", i);
             serial_hds[i] = qemu_chr_open(label, devname, NULL);
             if (!serial_hds[i]) {
-                fprintf(stderr, "qemu: could not open serial device '%s'\n",
-                        devname);
+                fprintf(stderr, "qemu: could not open serial device '%s': %s\n",
+                        devname, strerror(errno));
                 exit(1);
             }
         }
@@ -6045,8 +6045,8 @@ int main(int argc, char **argv, char **envp)
             snprintf(label, sizeof(label), "parallel%d", i);
             parallel_hds[i] = qemu_chr_open(label, devname, NULL);
             if (!parallel_hds[i]) {
-                fprintf(stderr, "qemu: could not open parallel device '%s'\n",
-                        devname);
+                fprintf(stderr, "qemu: could not open parallel device '%s': %s\n",
+                        devname, strerror(errno));
                 exit(1);
             }
         }
@@ -6059,8 +6059,8 @@ int main(int argc, char **argv, char **envp)
             snprintf(label, sizeof(label), "virtcon%d", i);
             virtcon_hds[i] = qemu_chr_open(label, devname, NULL);
             if (!virtcon_hds[i]) {
-                fprintf(stderr, "qemu: could not open virtio console '%s'\n",
-                        devname);
+                fprintf(stderr, "qemu: could not open virtio console '%s': %s\n",
+                        devname, strerror(errno));
                 exit(1);
             }
         }
-- 
1.6.2.5