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authorKeqian Zhu <zhukeqian1@huawei.com>2020-12-17 09:49:41 +0800
committerPaolo Bonzini <pbonzini@redhat.com>2021-03-06 11:41:54 +0100
commit3920552846e881bafa9f9aad0bb1a6eef874d7fb (patch)
tree3a4db98b6d2e568fbfb396ab426a66128e760265 /accel/kvm/kvm-all.c
parente0a8f99355c32b48c9ef867127075b5267ae23d8 (diff)
downloadfocaccia-qemu-3920552846e881bafa9f9aad0bb1a6eef874d7fb.tar.gz
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accel: kvm: Add aligment assert for kvm_log_clear_one_slot
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 assert to avoid future breaking.

Signed-off-by: Keqian Zhu <zhukeqian1@huawei.com>
Acked-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Message-Id: <20201217014941.22872-3-zhukeqian1@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'accel/kvm/kvm-all.c')
-rw-r--r--accel/kvm/kvm-all.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index ffce83f1a7..f88a52393f 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -673,6 +673,10 @@ out:
 #define KVM_CLEAR_LOG_ALIGN  (qemu_real_host_page_size << KVM_CLEAR_LOG_SHIFT)
 #define KVM_CLEAR_LOG_MASK   (-KVM_CLEAR_LOG_ALIGN)
 
+/*
+ * As the granule of kvm dirty log is qemu_real_host_page_size,
+ * @start and @size are expected and restricted to align to it.
+ */
 static int kvm_log_clear_one_slot(KVMSlot *mem, int as_id, uint64_t start,
                                   uint64_t size)
 {
@@ -682,6 +686,9 @@ 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 qemu_real_host_page_size aligned */
+    assert(QEMU_IS_ALIGNED(start | size, psize));
+
     /*
      * We need to extend either the start or the size or both to
      * satisfy the KVM interface requirement.  Firstly, do the start