Our QE team reported test failure on access_tracking_perf_test:
Testing guest mode: PA-bits:ANY, VA-bits:48, 4K pages
guest physical test memory offset: 0x3fffbffff000
Populating memory : 0.684014577s
Writing to populated memory : 0.006230175s
Reading from populated memory : 0.004557805s
==== Test Assertion Failure ====
lib/kvm_util.c:1411: false
pid=125806 tid=125809 errno=4 - Interrupted system call
1 0x0000000000402f7c: addr_gpa2hva at kvm_util.c:1411
2 (inlined by) addr_gpa2hva at kvm_util.c:1405
3 0x0000000000401f52: lookup_pfn at access_tracking_perf_test.c:98
4 (inlined by) mark_vcpu_memory_idle at access_tracking_perf_test.c:152
5 (inlined by) vcpu_thread_main at access_tracking_perf_test.c:232
6 0x00007fefe9ff81ce: ?? ??:0
7 0x00007fefe9c64d82: ?? ??:0
No vm physical memory at 0xffbffff000
And I can easily reproduce it with a Intel(R) Xeon(R) CPU E5-2630 with 46
bits PA.
It turns out that the address translation for clearing idle page tracking
returned wrong result, in which addr_gva2gpa()'s last step should have
treated "pte[index[0]].pfn" to be a 32bit value. In above case the GPA
address 0x3fffbffff000 got cut-off into 0xffbffff000, then it caused
further lookup failure in the gpa2hva mapping.
I didn't yet check any other test that may fail too on some hosts, but
logically any test using addr_gva2gpa() could suffer.
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2075036
Signed-off-by: Peter Xu <peterx@xxxxxxxxxx>
---
tools/testing/selftests/kvm/lib/x86_64/processor.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c
index 9f000dfb5594..6c356fb4a9bf 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/processor.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c
@@ -587,7 +587,7 @@ vm_paddr_t addr_gva2gpa(struct kvm_vm *vm, vm_vaddr_t gva)
if (!pte[index[0]].present)
goto unmapped_gva;
- return (pte[index[0]].pfn * vm->page_size) + (gva & 0xfffu);
+ return ((vm_paddr_t)pte[index[0]].pfn * vm->page_size) + (gva & 0xfffu);
unmapped_gva:
TEST_FAIL("No mapping for vm virtual address, gva: 0x%lx", gva);
--
2.32.0
