From 27469d29b3caf889ddf81c7d89f0676e45eb551d Mon Sep 17 00:00:00 2001 From: Andrew Honig Date: Thu, 18 Apr 2013 09:38:14 -0700 Subject: [PATCH] KVM: x86: Fix memory leak in vmx.c If userspace creates and destroys multiple VMs within the same process we leak 20k of memory in the userspace process context per VM. This patch frees the memory in kvm_arch_destroy_vm. If the process exits without closing the VM file descriptor or the file descriptor has been shared with another process then we don't free the memory. It's still possible for a user space process to leak memory if the last process to close the fd for the VM is not the process that created it. However, this is an unexpected case that's only caused by a user space process that's misbehaving. Signed-off-by: Andrew Honig Signed-off-by: Gleb Natapov --- arch/x86/kvm/x86.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index cbe16b4cad5c..e730a462ed05 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -6859,6 +6859,23 @@ void kvm_arch_sync_events(struct kvm *kvm) void kvm_arch_destroy_vm(struct kvm *kvm) { + if (current->mm == kvm->mm) { + /* + * Free memory regions allocated on behalf of userspace, + * unless the the memory map has changed due to process exit + * or fd copying. + */ + struct kvm_userspace_memory_region mem; + memset(&mem, 0, sizeof(mem)); + mem.slot = APIC_ACCESS_PAGE_PRIVATE_MEMSLOT; + kvm_set_memory_region(kvm, &mem); + + mem.slot = IDENTITY_PAGETABLE_PRIVATE_MEMSLOT; + kvm_set_memory_region(kvm, &mem); + + mem.slot = TSS_PRIVATE_MEMSLOT; + kvm_set_memory_region(kvm, &mem); + } kvm_iommu_unmap_guest(kvm); kfree(kvm->arch.vpic); kfree(kvm->arch.vioapic); -- 2.30.2