Support to shrinking aliases complicates kernel code unnecessarily,
while userspace can do the same with two operations, delete an alias,
and create a new alias.
Signed-off-by: Marcelo Tosatti <mtosatti@xxxxxxxxxx>
Index: kvm-pending/arch/x86/kvm/x86.c
===================================================================
--- kvm-pending.orig/arch/x86/kvm/x86.c
+++ kvm-pending/arch/x86/kvm/x86.c
@@ -1669,6 +1669,7 @@ static int kvm_vm_ioctl_set_memory_alias
{
int r, n;
struct kvm_mem_alias *p;
+ unsigned long npages;
r = -EINVAL;
/* General sanity checks */
@@ -1690,9 +1691,12 @@ static int kvm_vm_ioctl_set_memory_alias
p = &kvm->arch.aliases[alias->slot];
- /* FIXME: either disallow shrinking alias slots or disable
- * size changes as done with memslots
- */
+ /* Disallow changing an alias slot's size. */
+ npages = alias->memory_size >> PAGE_SHIFT;
+ r = -EINVAL;
+ if (npages && p->npages && npages != p->npages)
+ goto out_unlock;
+
if (!alias->memory_size) {
r = -EBUSY;
if (kvm_root_gfn_in_range(kvm, p->base_gfn,
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
