[PATCH 2/2] accel: kvm: Add aligment check for kvm_log_clear_one_slot

[Keqian Zhu <zhukeqian1@huawei.com>]

The parameters start and size are transfered from QEMU memory
emulation layer. It can promise that they are TARGET_PAGE_SIZE
aligned. However, KVM needs they are qemu_real_page_size aligned.

Though no caller breaks this aligned requirement currently, we'd
better add an explicit check to avoid future breaking.

Signed-off-by: Keqian Zhu <zhukeqian1@huawei.com>
---
 accel/kvm/kvm-all.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index c5e06288eb..3d0e3aa872 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -701,6 +701,11 @@ static int kvm_log_clear_one_slot(KVMSlot *mem, int as_id, uint64_t start,
     unsigned long *bmap_clear = NULL, psize = qemu_real_host_page_size;
     int ret;
 
+    /* Make sure start and size are psize aligned */
+    if (!QEMU_IS_ALIGNED(start, psize) || !QEMU_IS_ALIGNED(size, psize)) {
+        return -EINVAL;
+    }
+
     /*
      * We need to extend either the start or the size or both to
      * satisfy the KVM interface requirement.  Firstly, do the start
-- 
2.23.0