[Qemu-commits] [COMMIT 168ccc1] kvm: Improve upgrade notes when facing unsupportedkernels

[Anthony Liguori]

From: Jan Kiszka <address@hidden>

Users complained that it is not obvious what to do when kvm refuses to
build or run due to an unsupported host kernel, so let's improve the
hints.

Signed-off-by: Jan Kiszka <address@hidden>

diff --git a/configure b/configure
index 3a34e00..89e7f53 100755
--- a/configure
+++ b/configure
@@ -1158,7 +1158,9 @@ EOF
        | grep "error: " \
        | awk -F "error: " '{if (NR>1) printf(", "); printf("%s",$2);}'`
       if test "$kvmerr" != "" ; then
-        kvm="no - (${kvmerr})"
+        kvm="no - (${kvmerr})\n\
+    NOTE: To enable KVM support, update your kernel to 2.6.29+ or install \
+recent kvm-kmod from http://sourceforge.net/projects/kvm.";
       fi
     fi
   fi
@@ -1377,7 +1379,7 @@ echo "vde support       $vde"
 echo "AIO support       $aio"
 echo "IO thread         $io_thread"
 echo "Install blobs     $blobs"
-echo "KVM support       $kvm"
+echo -e "KVM support       $kvm"
 echo "fdt support       $fdt"
 echo "preadv support    $preadv"
 
diff --git a/kvm-all.c b/kvm-all.c
index c89e3b1..b24d876 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -404,6 +404,9 @@ static void kvm_reset_vcpus(void *opaque)
 
 int kvm_init(int smp_cpus)
 {
+    static const char upgrade_note[] =
+        "Please upgrade to at least kernel 2.6.29 or recent kvm-kmod\n"
+        "(see http://sourceforge.net/projects/kvm).\n";
     KVMState *s;
     int ret;
     int i;
@@ -454,7 +457,8 @@ int kvm_init(int smp_cpus)
      */
     if (!kvm_check_extension(s, KVM_CAP_USER_MEMORY)) {
         ret = -EINVAL;
-        fprintf(stderr, "kvm does not support KVM_CAP_USER_MEMORY\n");
+        fprintf(stderr, "kvm does not support KVM_CAP_USER_MEMORY\n%s",
+                upgrade_note);
         goto err;
     }
 
@@ -465,8 +469,8 @@ int kvm_init(int smp_cpus)
         ret = -EINVAL;
 
         fprintf(stderr,
-                "KVM kernel module broken (DESTROY_MEMORY_REGION)\n"
-                "Please upgrade to at least kvm-81.\n");
+                "KVM kernel module broken (DESTROY_MEMORY_REGION).\n%s",
+                upgrade_note);
         goto err;
     }