Add test for qemu broken -machine option (RHBZ#748266).

Also add this option, if necessary, when testing for virtio-serial
support.

When the workaround is enabled, we specify machine type 'pc'.

1 files changed, 46 insertions, 1 deletions

diff --git a/configure.ac b/configure.ac
index c384c6e7..d1b1c108 100644
--- a/configure.ac
+++ b/configure.ac
@@ -446,8 +446,53 @@ working.
 ])
     fi
 
+    dnl qemu 0.15 was released with broken support for '-machine',
+    dnl requiring you to add the machine type: '-machine pc,[...]'.
+    dnl The problem is that 'pc' is only applicable for PC-like
+    dnl hardware, so we cannot do this as a general solution.  Since
+    dnl qemu 0.15, this problem has been fixed so now the default
+    dnl machine type is chosen (qemu commit 2645c6dcaf6ea2a51a).
+    dnl
+    dnl We need to work out if this qemu is the broken version, so we
+    dnl can add 'pc' just for this broken version.
+    dnl
+    dnl Note that old qemu didn't support the '-machine' option at all.
+    dnl
+    dnl We use the -kernel option for testing this, because this option
+    dnl is processed very late, after qemu has set up the machine.
+    AC_MSG_CHECKING([for broken '-machine accel=tcg' option in $QEMU])
+    LC_ALL=C $QEMU -nographic -machine accel=tcg -kernel /NO_SUCH_FILE \
+             > config1.tmp 2>&1
+    LC_ALL=C $QEMU -nographic -machine pc,accel=tcg -kernel /NO_SUCH_FILE \
+             > config2.tmp 2>&1
+    if cmp -s config1.tmp config2.tmp; then
+        AC_MSG_RESULT([no])
+    else
+        AC_MSG_RESULT([yes])
+        AC_DEFINE([QEMU_MACHINE_TYPE_IS_BROKEN],[1],[qemu -machine accel=tcg option is broken (in qemu 0.15 only)])
+    fi
+    rm config1.tmp config2.tmp
+
+    dnl See if the '-machine [pc,]accel=tcg' option is required in
+    dnl order to run the virtio-serial test below.  This happens when
+    dnl we run qemu-kvm inside a VM without forcing TCG:
+    dnl
+    dnl   Could not access KVM kernel module: No such file or directory
+    dnl   failed to initialize KVM: No such file or directory
+    dnl   No accelerator found!
+    AC_MSG_CHECKING([if -machine @<:@pc,@:>@accel=tcg option is required to test virtio-serial feature])
+    if $QEMU -nographic -device \? >/dev/null 2>&1; then
+        :
+    elif $QEMU -machine accel=tcg -nographic -device \? >/dev/null 2>&1; then
+        QEMU_EXTRA_OPTIONS_FOR_TEST="-machine accel=tcg"
+    elif $QEMU -machine pc,accel=tcg -nographic -device \? >/dev/null 2>&1; then
+        QEMU_EXTRA_OPTIONS_FOR_TEST="-machine pc,accel=tcg"
+    # else nothing ... it'll fail below.
+    fi
+    AC_MSG_RESULT([$QEMU_EXTRA_OPTIONS_FOR_TEST])
+
     AC_MSG_CHECKING([for virtio-serial support in $QEMU])
-    if $QEMU -nographic -device \? 2>&1 | grep -sq virtio-serial; then
+    if $QEMU $QEMU_EXTRA_OPTIONS_FOR_TEST -nographic -device \? 2>&1 | grep -sq virtio-serial; then
         AC_MSG_RESULT([yes])
     else
         AC_MSG_RESULT([no])