[PATCH v3 6/6] KVM: MMU: init kvm generation close to mmio wrap-around value

[Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>]

Then it has the chance to trigger mmio generation number wrap-around

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
---
 arch/x86/kvm/mmu.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 1fd2c05..7d50a2d 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -235,7 +235,12 @@ static unsigned int get_mmio_spte_generation(u64 spte)
 
 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 - 13) & MMIO_GEN_MASK;
 }
 
 static void mark_mmio_spte(struct kvm *kvm, u64 *sptep, u64 gfn,
-- 
1.8.1.4