[PATCH 2/2] svm: Add VMLOAD/VMSAVE latency test

[Joerg Roedel <joerg.roedel@xxxxxxx>]

This patch adds a test to measure the latency of the VMLOAD
and VMSAVE instructions.

Signed-off-by: Joerg Roedel <joerg.roedel@xxxxxxx>
---
 x86/svm.c |   52 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 52 insertions(+), 0 deletions(-)

diff --git a/x86/svm.c b/x86/svm.c
index babd77d..26bf566 100644
--- a/x86/svm.c
+++ b/x86/svm.c
@@ -19,10 +19,15 @@ u64 tsc_start;
 u64 tsc_end;
 
 u64 vmrun_sum, vmexit_sum;
+u64 vmsave_sum, vmload_sum;
 u64 latvmrun_max;
 u64 latvmrun_min;
 u64 latvmexit_max;
 u64 latvmexit_min;
+u64 latvmload_max;
+u64 latvmload_min;
+u64 latvmsave_max;
+u64 latvmsave_min;
 u64 runs;
 
 static bool npt_supported(void)
@@ -661,6 +666,51 @@ static bool latency_check(struct test *test)
     return true;
 }
 
+static void load_save_prepare(struct test *test)
+{
+    default_prepare(test);
+    runs = LATENCY_RUNS;
+    latvmload_min = latvmsave_min = -1ULL;
+    latvmload_max = latvmsave_max = 0;
+    vmload_sum = vmsave_sum = 0;
+}
+
+static bool load_save_finished(struct test *test)
+{
+    u64 vmcb_phys = virt_to_phys(test->vmcb);
+    u64 cycles;
+
+    for ( ; runs != 0; runs--) {
+        tsc_start = rdtsc();
+        asm volatile("vmload\n\t" : : "a"(vmcb_phys) : "memory");
+        cycles = rdtsc() - tsc_start;
+        if (cycles > latvmload_max)
+            latvmload_max = cycles;
+        if (cycles < latvmload_min)
+            latvmload_min = cycles;
+        vmload_sum += cycles;
+
+        tsc_start = rdtsc();
+        asm volatile("vmsave\n\t" : : "a"(vmcb_phys) : "memory");
+        cycles = rdtsc() - tsc_start;
+        if (cycles > latvmsave_max)
+            latvmsave_max = cycles;
+        if (cycles < latvmsave_min)
+            latvmsave_min = cycles;
+        vmsave_sum += cycles;
+    }
+
+    return true;
+}
+
+static bool load_save_check(struct test *test)
+{
+    printf("    Latency VMLOAD: max: %d min: %d avg: %d\n", latvmload_max,
+            latvmload_min, vmload_sum / LATENCY_RUNS);
+    printf("    Latency VMSAVE: max: %d min: %d avg: %d\n", latvmsave_max,
+            latvmsave_min, vmsave_sum / LATENCY_RUNS);
+    return true;
+}
 static struct test tests[] = {
     { "null", default_supported, default_prepare, null_test,
       default_finished, null_check },
@@ -695,6 +745,8 @@ static struct test tests[] = {
 	    default_finished, npt_pfwalk_check },
     { "latency_run_exit", default_supported, latency_prepare, latency_test,
       latency_finished, latency_check },
+    { "latency_load_save", default_supported, load_save_prepare, null_test,
+      load_save_finished, load_save_check },
 };
 
 int main(int ac, char **av)
-- 
1.7.0.4


--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html