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 need to free the memory.
Signed-off-by: Andrew Honig <ahonig@xxxxxxxxxx>
---
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 e172132..e93e16b 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6811,6 +6811,23 @@ 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, 0);
+
+ mem.slot = IDENTITY_PAGETABLE_PRIVATE_MEMSLOT;
+ kvm_set_memory_region(kvm, &mem, 0);
+
+ mem.slot = TSS_PRIVATE_MEMSLOT;
+ kvm_set_memory_region(kvm, &mem, 0);
+ }
kvm_iommu_unmap_guest(kvm);
kfree(kvm->arch.vpic);
kfree(kvm->arch.vioapic);
--
1.7.10.4
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