[LTP] [PATCH v3 1/2] tst_is_virt(): Allow checking for any hypervisor

[LTP] [PATCH v3 1/2] tst_is_virt(): Allow checking for any hypervisor

[Martin Doucha]

Add two more valid arguments for tst_is_virt():
- VIRT_ANY: return 1 if any hypervisor is detected
- VIRT_OTHER: return 1 if an unrecognized hypervisor is detected

Also fix bugs in try_systemd_detect_virt() and return -1 on error.

Signed-off-by: Martin Doucha <mdoucha@suse.cz>
---

Changes since v1: New patch

The is_kvm() fallback test pretty much doesn't work anywhere except in our
OpenQA setup. But looking at SystemD sources (yuck), detecting KVM properly
will be a major pain in the ass, never mind any other hypervisor. So I'll
leave any further improvements as an exercise for the reader.

BTW, systemd-detect-virt can't detect the PowerPC LPAR hypervisor.

 include/tst_cpu.h |  2 ++
 lib/tst_virt.c    | 23 +++++++++++++++++------
 2 files changed, 19 insertions(+), 6 deletions(-)

diff --git a/include/tst_cpu.h b/include/tst_cpu.h
index db6138f43..c83a58260 100644
--- a/include/tst_cpu.h
+++ b/include/tst_cpu.h
@@ -9,8 +9,10 @@ long tst_ncpus(void);
 long tst_ncpus_conf(void);
 long tst_ncpus_max(void);
 
+#define VIRT_ANY	0	/* catch-all argument for tst_is_virt() */
 #define VIRT_XEN	1	/* xen dom0/domU */
 #define VIRT_KVM	2	/* only default virtual CPU */
+#define VIRT_OTHER	0xffff	/* unrecognized hypervisor */
 
 int tst_is_virt(int virt_type);
 
diff --git a/lib/tst_virt.c b/lib/tst_virt.c
index 090e6334c..53d33e69c 100644
--- a/lib/tst_virt.c
+++ b/lib/tst_virt.c
@@ -49,7 +49,7 @@ static int is_kvm(void)
 
 static int is_xen(void)
 {
-	char hypervisor_type[3];
+	char hypervisor_type[4];
 
 	if (access("/proc/xen", F_OK) == 0)
 		return 1;
@@ -90,30 +90,41 @@ static int try_systemd_detect_virt(void)
 	 * systemd-detect-virt not found by shell or no virtualization detected
 	 * (systemd-detect-virt returns non-zero)
          */
+	if (ret < 0 || (WIFEXITED(ret) && WEXITSTATUS(ret) == 127))
+		return -1;
+
 	if (ret)
 		return 0;
 
-	if (strncmp("kvm", virt_type, 3))
+	if (!strncmp("kvm", virt_type, 3))
 		return VIRT_KVM;
 
-	if (strncmp("xen", virt_type, 3))
+	if (!strncmp("xen", virt_type, 3))
 		return VIRT_XEN;
 
-	return 0;
+	return VIRT_OTHER;
 }
 
 int tst_is_virt(int virt_type)
 {
 	int ret = try_systemd_detect_virt();
 
-	if (ret)
-		return ret == virt_type;
+	if (ret >= 0) {
+		if (virt_type == VIRT_ANY)
+			return ret != 0;
+		else
+			return ret == virt_type;
+	}
 
 	switch (virt_type) {
+	case VIRT_ANY:
+		return is_xen() || is_kvm();
 	case VIRT_XEN:
 		return is_xen();
 	case VIRT_KVM:
 		return is_kvm();
+	case VIRT_OTHER:
+		return 0;
 	}
 
 	tst_brkm(TBROK, NULL, "invalid virt_type flag: %d", virt_type);
-- 
2.26.0

[LTP] [PATCH v3 2/2] Skip oversleep checks in timer tests under VM

[Martin Doucha]

Timer tests often fail on sleep overrun when LTP is running inside a VM.
The main cause is usually that the VM doesn't get enough CPU time to wake up
the test process in time. Disable oversleep tests if tst_is_virt() detects
any hypervisor.

Signed-off-by: Martin Doucha <mdoucha@suse.cz>
---

Changes since v1: Use tst_is_virt() instead of env variable.
Changes since v2: Fixed comment.

 lib/tst_timer_test.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/lib/tst_timer_test.c b/lib/tst_timer_test.c
index 13e9deff2..196c51272 100644
--- a/lib/tst_timer_test.c
+++ b/lib/tst_timer_test.c
@@ -26,6 +26,7 @@ static long long *samples;
 static unsigned int cur_sample;
 static unsigned int monotonic_resolution;
 static unsigned int timerslack;
+static int virt_env;
 
 static char *print_frequency_plot;
 static char *file_name;
@@ -306,7 +307,10 @@ void do_timer_test(long long usec, unsigned int nsamples)
 		samples[nsamples-1], samples[0], median,
 		1.00 * trunc_mean / keep_samples, discard);
 
-	if (trunc_mean > (nsamples - discard) * usec + threshold) {
+	if (virt_env) {
+		tst_res(TINFO,
+			"Virtualisation detected, skipping oversleep checks");
+	} else if (trunc_mean > (nsamples - discard) * usec + threshold) {
 		tst_res(TFAIL, "%s slept for too long", scall);
 
 		if (!print_frequency_plot)
@@ -343,6 +347,11 @@ static void timer_setup(void)
 	if (setup)
 		setup();
 
+	/*
+	 * Running tests in VM may cause timing issues, disable upper bound
+	 * checks if any hypervisor is detected.
+	 */
+	virt_env = tst_is_virt(VIRT_ANY);
 	tst_clock_getres(CLOCK_MONOTONIC, &t);
 
 	tst_res(TINFO, "CLOCK_MONOTONIC resolution %lins", (long)t.tv_nsec);
-- 
2.26.0

[LTP] [PATCH v3 1/2] tst_is_virt(): Allow checking for any hypervisor

[Li Wang]

Patchset LGTM and:

Tested-by: Li Wang <liwang@redhat.com>

-- 
Regards,
Li Wang
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.linux.it/pipermail/ltp/attachments/20200429/e2c93596/attachment-0001.htm>

[LTP] [PATCH v3 1/2] tst_is_virt(): Allow checking for any hypervisor

[Li Wang]

Pushed, thanks!

-- 
Regards,
Li Wang
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.linux.it/pipermail/ltp/attachments/20200430/e3a90fd7/attachment.htm>