Lock should be held till all the mmap operations are done. This is to
avoid the mmap failure when multiple guests are created concurrently.
For example consider the following case in which vm1 and vm2 are
created by acrnd concurrently:
- vm1 is created with 4G+2M memory.
- 4G+2M memory is reserved in hugetlb now and vm1 continues to
allocate memory for the lowmem without lock held.
- 2G memory is allocated by vm1 for its lowmem, and 2G+2M memory
is available in hugetlb.
- At this time vm2 is created with 1G+2M memory. It finds that enough
memory is reserved (2G+2M), so it does not try to reserve more
memory.
- vm2 allocates some memory for its lowmem/highmem/ovmf.
- vm1 tries to allocate memory for its highmem/ovmf, the allocation
will fail. vm1 creation failed in this case.
Tracked-On: #3947
Signed-off-by: Jian Jun Chen <jian.jun.chen@intel.com>
Reviewed-by: Yin Fengwei <fengwei.yin@intel.com>
Acked-by: Yu Wang <yu1.wang@intel.com>
46b157008c