On 2012-12-07 20:51, Andrew Honig wrote: > I've noticed a memory leak that occurs in vmx.c. > > In alloc_apic_access_page, it calls __kvm_set_memory_region(kvm, > &kvm_userspace_mem, 0). __kvm_set_memory_region calls > kvm_arch_prepare_memory_region, which because the user_alloc parameter > is 0 will allocate memory for the page with vm_mmap. > > This memory never gets freed. In kvm_arch_destroy_vm it calls > put_page(kvm->arch.apic_access_page), but that only unpins the memory > (necessary due to an earlier call to gfn_to_page), it never actually > frees the memory. The memory is allocated in the current process > context so it's cleaned up when the process exits, but if a process > creates and destroys multiple VMs then this leak starts to become a > problem. > > Similar leaks occur in alloc_identity_pagetable and vmx_set_tss_addr > for a total of 5 pages of memory leak for a VM. The vmx_set_tss_addr > actually leaks each time vmx_set_tss_addr is called so this could also > become a problem if a program had occasion to set the tss addr several > times. Both pages are per-vm. Therefore they are freed in kvm_arch_destroy_vm. But I have to admit that I dug a while as well to find this out. Jan
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