Re: [kvm-unit-tests PATCH 5/5] arch/run: unify accelerator detection

["Radim Krčmář" <rkrcmar@redhat.com>]

2017-06-29 14:45+0200, Radim Krčmář:
> 2017-06-28 22:48+0200, Paolo Bonzini:
> > On 28/06/2017 22:08, Radim Krčmář wrote:
> > > -if [ "$ACCEL" = "kvm" ] && [ "$kvm_available" != "yes" ]; then
> > > -	echo "KVM is needed, but not available on this host"
> > > +ACCEL=$(get_accel '([ "$HOST" = "arm" ] && [ "$ARCH" = "arm" ]) || [ "$HOST" = "aarch64" ]') ||
> > >  	exit 2
> > 
> > Should x86 do the same as ARM (follow-up patch)?
> 
> Yeah, I'll prepare it when we've agreed on the format.
> 
> > And maybe the test could move from an argument of get_accel to a
> > function "arch_kvm_available" that returns 0 if available and 1 if not?
> 
> Right, the arm condition needs to be fixed as
> 
>   ([ "$HOST" = "arm" ] && [ "$ARCH" = "arm" ]) ||
>   ([ "$HOST" = "aarch64" ] && [ "$ARCH" = arm -o "$ARCH" = arm64 ])
> 
> and it would look even worse in the argument ...
> 
> Would it be ok like this?

No, we can make a better use of the $HOST variable:

diff --git a/arm/run b/arm/run
index f2e71eca022d..1245d42edae7 100755
--- a/arm/run
+++ b/arm/run
@@ -10,7 +10,7 @@ if [ -z "$STANDALONE" ]; then
 fi
 processor="$PROCESSOR"
 
-ACCEL=$(get_accel '([ "$HOST" = "arm" ] && [ "$ARCH" = "arm" ]) || [ "$HOST" = "aarch64" ]') ||
+ACCEL=$(get_accel) ||
 	exit 2
 
 qemu=$(search_qemu_binary) ||
diff --git a/powerpc/run b/powerpc/run
index 55b987c5efc5..58921e81eb8f 100755
--- a/powerpc/run
+++ b/powerpc/run
@@ -9,7 +9,7 @@ if [ -z "$STANDALONE" ]; then
 	source scripts/arch-run.bash
 fi
 
-ACCEL=$(get_accel '[ "$HOST" = "ppc64" ] && [ "$ARCH" = "ppc64" ]') ||
+ACCEL=$(get_accel) ||
 	exit 2
 
 qemu=$(search_qemu_binary) ||
diff --git a/s390x/run b/s390x/run
index 67d6e88ea7e4..2242ebb79fbc 100755
--- a/s390x/run
+++ b/s390x/run
@@ -9,7 +9,7 @@ if [ -z "$STANDALONE" ]; then
 	source scripts/arch-run.bash
 fi
 
-ACCEL=$(get_accel '[ "$HOST" = "s390x" ] && [ "$ARCH" = "s390x" ]') ||
+ACCEL=$(get_accel) ||
 	exit 2
 
 qemu=$(search_qemu_binary) ||
diff --git a/scripts/arch-run.bash b/scripts/arch-run.bash
index a696652c61b1..77071216ff99 100644
--- a/scripts/arch-run.bash
+++ b/scripts/arch-run.bash
@@ -273,22 +273,26 @@ trap_exit_push ()
 	trap -- "$1; $old_exit" EXIT
 }
 
+kvm_available ()
+{
+	[ -c /dev/kvm ] ||
+		return 1
+
+	[ "$HOST" = "$ARCH_NAME" ] ||
+		[ "$HOST" = aarch64 -a "$ARCH" = arm ] ||
+		[ "$HOST" = x86_64 -a "$ARCH" = i386 ]
+}
+
 get_accel ()
 {
-	local kvm_available
-
-	if [ -c /dev/kvm ] && eval "$@"; then
-		kvm_available=yes
-	fi
-
-	if [ "$ACCEL" = "kvm" ] && [ "$kvm_available" != "yes" ]; then
+	if [ "$ACCEL" = "kvm" ] && ! kvm_available; then
 		echo "KVM is needed, but not available on this host" >&2
 		return 2
 	fi
 
 	if [ "$ACCEL" ]; then
 		echo $ACCEL
-	elif [ "$kvm_available" = "yes" ]; then
+	elif kvm_available; then
 		echo kvm
 	else
 		echo tcg