[kvm-unit-tests PATCH v6 11/13] arm/run: Allow Migration tests

[Eric Auger <eric.auger@redhat.com>]

Let's link getchar.o to use puts and getchar from the
tests.

Then allow tests belonging to the migration group to
trigger the migration from the test code by putting
"migrate" into the uart. Then the code can wait for the
migration completion by using getchar().

The __getchar implement is minimalist as it just reads the
data register. It is just meant to read the single character
emitted at the end of the migration by the runner script.

It is not meant to read more data (FIFOs are not enabled).

Signed-off-by: Eric Auger <eric.auger@redhat.com>

---

v3 -> v4:
- remove space around Elvis operator
- rename ___getchar into do_getchar

v2 -> v3:
- take the lock
- assert if more than 16 chars
- removed Thomas' R-b
---
 arm/Makefile.common |  2 +-
 arm/run             |  2 +-
 lib/arm/io.c        | 28 ++++++++++++++++++++++++++++
 3 files changed, 30 insertions(+), 2 deletions(-)

diff --git a/arm/Makefile.common b/arm/Makefile.common
index b8988f2..a123e85 100644
--- a/arm/Makefile.common
+++ b/arm/Makefile.common
@@ -32,7 +32,7 @@ CFLAGS += -I $(SRCDIR)/lib -I $(SRCDIR)/lib/libfdt -I lib
 asm-offsets = lib/$(ARCH)/asm-offsets.h
 include $(SRCDIR)/scripts/asm-offsets.mak
 
-cflatobjs += lib/util.o
+cflatobjs += lib/util.o lib/getchar.o
 cflatobjs += lib/alloc_phys.o
 cflatobjs += lib/alloc_page.o
 cflatobjs += lib/vmalloc.o
diff --git a/arm/run b/arm/run
index 277db9b..a390ca5 100755
--- a/arm/run
+++ b/arm/run
@@ -61,6 +61,6 @@ fi
 M+=",accel=$ACCEL"
 command="$qemu -nodefaults $M -cpu $processor $chr_testdev $pci_testdev"
 command+=" -display none -serial stdio -kernel"
-command="$(timeout_cmd) $command"
+command="$(migration_cmd) $(timeout_cmd) $command"
 
 run_qemu $command "$@"
diff --git a/lib/arm/io.c b/lib/arm/io.c
index 99fd315..343e108 100644
--- a/lib/arm/io.c
+++ b/lib/arm/io.c
@@ -87,6 +87,34 @@ void puts(const char *s)
 	spin_unlock(&uart_lock);
 }
 
+static int do_getchar(void)
+{
+	int c;
+
+	spin_lock(&uart_lock);
+	c = readb(uart0_base);
+	spin_unlock(&uart_lock);
+
+	return c ?: -1;
+}
+
+/*
+ * Minimalist implementation for migration completion detection.
+ * Without FIFOs enabled on the QEMU UART device we just read
+ * the data register: we cannot read more than 16 characters.
+ */
+int __getchar(void)
+{
+	int c = do_getchar();
+	static int count;
+
+	if (c != -1)
+		++count;
+
+	assert(count < 16);
+
+	return c;
+}
 
 /*
  * Defining halt to take 'code' as an argument guarantees that it will
-- 
2.20.1