__kvm_set_memory_region does not use the hva at all, so trying to
catch use-after-delete is pointless and, worse, it fails access_ok
now that we apply it to all memslots including private kernel ones.
This fixes an AVIC regression.
Fixes: 09d952c971a5 ("KVM: check userspace_addr for all memslots", 2020-06-01)
Reported-by: Maxim Levitsky <mlevitsk@xxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
arch/x86/kvm/x86.c | 7 +------
1 file changed, 1 insertion(+), 6 deletions(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 290784ba63e4..00c88c2f34e4 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -9951,13 +9951,8 @@ int __x86_set_memory_region(struct kvm *kvm, int id, gpa_t gpa, u32 size)
if (!slot || !slot->npages)
return 0;
- /*
- * Stuff a non-canonical value to catch use-after-delete. This
- * ends up being 0 on 32-bit KVM, but there's no better
- * alternative.
- */
- hva = (unsigned long)(0xdeadull << 48);
old_npages = slot->npages;
+ hva = 0;
}
for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) {
--
2.26.2
