Re: [PATCH 2/2] tests: migration-test: Add dirty ring test

[Peter Xu]

On Thu, Jun 10, 2021 at 08:01:44PM +0100, Dr. David Alan Gilbert wrote:
> > +#include <linux/kvm.h>
> 
> Does that get you the system headers, which may or may not have
> KVM_CAP_DIRTY_LOG_RING if you're on an old host, or does it get you
> qemu's linux-headers which definitely does?

I tested it and it's using the linux-headers/ file even if I also got the other
/usr/include one.  So I think the qemu one just has higher priority in the "-I"
paths.

Btw, IIUC quotting with <> or "" should be the same here for headers, so I'm
thinking maybe I should switch to "" like the rest headers.

> 
> What happens on a BSD or the like?

Ah, good point..

How about I squash this into the patch?

---8<---
diff --git a/tests/qtest/migration-test.c b/tests/qtest/migration-test.c
index cc6e396d1a2..9ef6b471353 100644
--- a/tests/qtest/migration-test.c
+++ b/tests/qtest/migration-test.c
@@ -12,7 +12,6 @@
 
 #include "qemu/osdep.h"
 
-#include <linux/kvm.h>
 #include "libqos/libqtest.h"
 #include "qapi/error.h"
 #include "qapi/qmp/qdict.h"
@@ -28,6 +27,10 @@
 #include "migration-helpers.h"
 #include "tests/migration/migration-test.h"
 
+#if defined(__linux__)
+#include "linux/kvm.h"
+#endif
+
 /* TODO actually test the results and get rid of this */
 #define qtest_qmp_discard_response(...) qobject_unref(qtest_qmp(__VA_ARGS__))
 
@@ -1392,6 +1395,7 @@ static void test_multifd_tcp_cancel(void)
 
 static bool kvm_dirty_ring_supported(void)
 {
+#if defined(__linux__)
     int ret, kvm_fd = open("/dev/kvm", O_RDONLY);
 
     if (kvm_fd < 0) {
@@ -1407,6 +1411,9 @@ static bool kvm_dirty_ring_supported(void)
     }
 
     return true;
+#else
+    return false;
+#endif
 }
 
 int main(int argc, char **argv)
---8<---

Thanks!

-- 
Peter Xu