1 files changed, 8 insertions, 0 deletions

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 986aea55366..ca6f72ab4c3 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -3602,6 +3602,14 @@ static bool detect_write_misaligned(struct kvm_mmu_page *sp, gpa_t gpa,
 
         offset = offset_in_page(gpa);
         pte_size = sp->role.cr4_pae ? 8 : 4;
+
+        /*
+         * Sometimes, the OS only writes the last one bytes to update status
+         * bits, for example, in linux, andb instruction is used in clear_bit().
+         */
+        if (!(offset & (pte_size - 1)) && bytes == 1)
+                return false;
+
         misaligned = (offset ^ (offset + bytes - 1)) & ~(pte_size - 1);
         misaligned |= bytes < 4;