KVM: MMU: init kvm generation close to mmio wrap-around value
Then it has the chance to trigger mmio generation number wrap-around
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
[Change from MMIO_MAX_GEN - 13 to MMIO_MAX_GEN - 150, because 13 is
very close to the number of calls to KVM_SET_USER_MEMORY_REGION
before the guest is started and there is any chance to create any
spte. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 417f36b..c212101 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -235,7 +235,12 @@
static unsigned int kvm_current_mmio_generation(struct kvm *kvm)
{
- return kvm_memslots(kvm)->generation & MMIO_GEN_MASK;
+ /*
+ * Init kvm generation close to MMIO_MAX_GEN to easily test the
+ * code of handling generation number wrap-around.
+ */
+ return (kvm_memslots(kvm)->generation +
+ MMIO_MAX_GEN - 150) & MMIO_GEN_MASK;
}
static void mark_mmio_spte(struct kvm *kvm, u64 *sptep, u64 gfn,