accel/tcg: Introduce page_check_range_empty

Examine the interval tree to validate that a region
has no existing mappings.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230707204054.8792-10-richard.henderson@linaro.org>

1 files changed, 7 insertions, 0 deletions

diff --git a/accel/tcg/user-exec.c b/accel/tcg/user-exec.c
index d95b875a6a..ab684a3ea2 100644
--- a/accel/tcg/user-exec.c
+++ b/accel/tcg/user-exec.c
@@ -598,6 +598,13 @@ int page_check_range(target_ulong start, target_ulong len, int flags)
     return ret;
 }
 
+bool page_check_range_empty(target_ulong start, target_ulong last)
+{
+    assert(last >= start);
+    assert_memory_lock();
+    return pageflags_find(start, last) == NULL;
+}
+
 void page_protect(tb_page_addr_t address)
 {
     PageFlagsNode *p;