On 2021/4/26 21:01, Vitaly Kuznetsov wrote:
After commit 4fc096a99e01 ("KVM: Raise the maximum number of user memslots")
set_memory_region_test may take too long, reports are that the default
timeout value we have (120s) may not be enough even on a physical host.
Speed things up a bit by throwing away vm_userspace_mem_region_add() usage
from test_add_max_memory_regions(), we don't really need to do the majority
of the stuff it does for the sake of this test.
On my AMD EPYC 7401P, # time ./set_memory_region_test
pre-patch:
Testing KVM_RUN with zero added memory regions
Allowed number of memory slots: 32764
Adding slots 0..32763, each memory region with 2048K size
Testing MOVE of in-use region, 10 loops
Testing DELETE of in-use region, 10 loops
real 0m44.917s
user 0m7.416s
sys 0m34.601s
post-patch:
Testing KVM_RUN with zero added memory regions
Allowed number of memory slots: 32764
Adding slots 0..32763, each memory region with 2048K size
Testing MOVE of in-use region, 10 loops
Testing DELETE of in-use region, 10 loops
real 0m20.714s
user 0m0.109s
sys 0m18.359s
Reported-by: kernel test robot <oliver.sang@xxxxxxxxx>
Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
I've seen the failure on my arm64 server, # ./set_memory_region_test
Allowed number of memory slots: 32767
Adding slots 0..32766, each memory region with 2048K size
==== Test Assertion Failure ====
set_memory_region_test.c:391: ret == 0
pid=42696 tid=42696 errno=22 - Invalid argument
1 0x00000000004015a7: test_add_max_memory_regions at
set_memory_region_test.c:389
2 (inlined by) main at set_memory_region_test.c:426
3 0x0000ffffb7c63bdf: ?? ??:0
4 0x00000000004016db: _start at :?
KVM_SET_USER_MEMORY_REGION IOCTL failed,
rc: -1 errno: 22 slot: 2624
+ mem = mmap(NULL, MEM_REGION_SIZE * max_mem_slots + alignment,
The problem is that max_mem_slots is declared as uint32_t, the result
of (MEM_REGION_SIZE * max_mem_slots) is unexpectedly truncated to be
0xffe00000.
+ PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+ TEST_ASSERT(mem != MAP_FAILED, "Failed to mmap() host");
+ mem_aligned = (void *)(((size_t) mem + alignment - 1) & ~(alignment - 1));
+
for (slot = 0; slot < max_mem_slots; slot++) {
- vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS,
- guest_addr, slot, mem_reg_npages,
- 0);
- guest_addr += MEM_REGION_SIZE;
+ ret = test_memory_region_add(vm, mem_aligned +
+ ((uint64_t)slot * MEM_REGION_SIZE),
These unmapped VAs got caught by access_ok() checker in
__kvm_set_memory_region() as they happen to go beyond the task's
address space on arm64. Casting max_mem_slots to size_t in both
mmap() and munmap() fixes the issue for me.
Thanks,
Zenghui
