From 80b14b5b32cb0a98234283daf9b5a6643e1a1ef3 Mon Sep 17 00:00:00 2001 From: Izik Eidus Date: Thu, 25 Oct 2007 11:54:04 +0200 Subject: [PATCH] KVM: Unmap kernel-allocated memory on slot destruction kvm_vm_ioctl_set_memory_region() is able to remove memory in addition to adding it. Therefore when using kernel swapping support for old userspaces, we need to munmap the memory if the user request to remove it Signed-off-by: Izik Eidus Signed-off-by: Avi Kivity --- drivers/kvm/kvm.h | 1 + drivers/kvm/kvm_main.c | 14 ++++++++++++++ 2 files changed, 15 insertions(+) diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h index f7181a407b..12de42c789 100644 --- a/drivers/kvm/kvm.h +++ b/drivers/kvm/kvm.h @@ -353,6 +353,7 @@ struct kvm_memory_slot { unsigned long *rmap; unsigned long *dirty_bitmap; unsigned long userspace_addr; + int user_alloc; }; struct kvm { diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c index 453e98e251..ab2c77c9ec 100644 --- a/drivers/kvm/kvm_main.c +++ b/drivers/kvm/kvm_main.c @@ -713,6 +713,7 @@ static int kvm_vm_ioctl_set_memory_region(struct kvm *kvm, memset(new.rmap, 0, npages * sizeof(*new.rmap)); + new.user_alloc = user_alloc; if (user_alloc) new.userspace_addr = mem->userspace_addr; else { @@ -727,6 +728,19 @@ static int kvm_vm_ioctl_set_memory_region(struct kvm *kvm, if (IS_ERR((void *)new.userspace_addr)) goto out_unlock; } + } else { + if (!old.user_alloc && old.rmap) { + int ret; + + down_write(¤t->mm->mmap_sem); + ret = do_munmap(current->mm, old.userspace_addr, + old.npages * PAGE_SIZE); + up_write(¤t->mm->mmap_sem); + if (ret < 0) + printk(KERN_WARNING + "kvm_vm_ioctl_set_memory_region: " + "failed to munmap memory\n"); + } } /* Allocate page dirty bitmap if needed */ -- 2.39.5