From: Avi Kivity <avi@xxxxxxxxxx>
This checks the failure that was fixed by kernel commit edde99ce0529
("KVM: Write protect memory after slot swap"). Two threads are used;
a guest thread continuously updates a shared variable, which is also
sampled by a host thread that also checks if dirty logging marked it
as dirty.
It detects about 5 million failures with the fix reverted, and 0 failures
with the fix applied.
Signed-off-by: Avi Kivity <avi@xxxxxxxxxx>
Signed-off-by: Marcelo Tosatti <mtosatti@xxxxxxxxxx>
diff --git a/api/dirty-log.cc b/api/dirty-log.cc
new file mode 100644
index 0000000..1e4ef9e
--- /dev/null
+++ b/api/dirty-log.cc
@@ -0,0 +1,78 @@
+#include "kvmxx.hh"
+#include "memmap.hh"
+#include "identity.hh"
+#include <boost/thread/thread.hpp>
+#include <stdlib.h>
+#include <stdio.h>
+
+namespace {
+
+void delay_loop(unsigned n)
+{
+ for (unsigned i = 0; i < n; ++i) {
+ asm volatile("pause");
+ }
+ }
+
+void write_mem(volatile bool& running, volatile int* shared_var)
+{
+ while (running) {
+ ++*shared_var;
+ delay_loop(1000);
+ }
+}
+
+void check_dirty_log(mem_slot& slot,
+ volatile bool& running,
+ volatile int* shared_var,
+ int& nr_fail)
+{
+ uint64_t shared_var_gpa = reinterpret_cast<uint64_t>(shared_var);
+ slot.set_dirty_logging(true);
+ slot.update_dirty_log();
+ for (int i = 0; i < 10000000; ++i) {
+ int sample1 = *shared_var;
+ delay_loop(600);
+ int sample2 = *shared_var;
+ slot.update_dirty_log();
+ if (!slot.is_dirty(shared_var_gpa) && sample1 != sample2) {
+ ++nr_fail;
+ }
+ }
+ running = false;
+ slot.set_dirty_logging(false);
+}
+
+}
+
+using boost::ref;
+using std::tr1::bind;
+
+int main(int ac, char **av)
+{
+ kvm::system sys;
+ kvm::vm vm(sys);
+ mem_map memmap(vm);
+ void* logged_slot_virt;
+ posix_memalign(&logged_slot_virt, 4096, 4096);
+ int* shared_var = static_cast<int*>(logged_slot_virt);
+ identity::hole hole(logged_slot_virt, 4096);
+ identity::vm ident_vm(vm, memmap, hole);
+ kvm::vcpu vcpu(vm, 0);
+ bool running = true;
+ int nr_fail = 0;
+ mem_slot logged_slot(memmap,
+ reinterpret_cast<uint64_t>(logged_slot_virt),
+ 4096, logged_slot_virt);
+ boost::thread host_poll_thread(check_dirty_log, ref(logged_slot),
+ ref(running),
+ ref(shared_var), ref(nr_fail));
+ identity::vcpu guest_write_thread(vcpu,
+ bind(write_mem,
+ ref(running),
+ ref(shared_var)));
+ vcpu.run();
+ host_poll_thread.join();
+ printf("Dirty bitmap failures: %d\n", nr_fail);
+ return nr_fail == 0 ? 0 : 1;
+}
diff --git a/config-x86-common.mak b/config-x86-common.mak
index ce36cde..b5c49f4 100644
--- a/config-x86-common.mak
+++ b/config-x86-common.mak
@@ -33,6 +33,7 @@ tests-common = $(TEST_DIR)/vmexit.flat $(TEST_DIR)/tsc.flat \
$(TEST_DIR)/kvmclock_test.flat
tests-common += api/api-sample
+tests-common += api/dirty-log
tests_and_config = $(TEST_DIR)/*.flat $(TEST_DIR)/unittests.cfg
@@ -85,10 +86,12 @@ arch_clean:
api/%.o: CFLAGS += -m32
-api/%: LDLIBS += -lstdc++
+api/%: LDLIBS += -lstdc++ -lboost_thread-mt -lpthread
api/%: LDFLAGS += -m32
api/libapi.a: api/kvmxx.o api/identity.o api/exception.o api/memmap.o
$(AR) rcs $@ $^
-api/api-sample: api/api-sample.o api/libapi.a
\ No newline at end of file
+api/api-sample: api/api-sample.o api/libapi.a
+
+api/dirty-log: api/dirty-log.o api/libapi.a
--
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