[PATCH v2 05/10] rust: add bindings for memattrs

[Zhao Liu <zhao1.liu@intel.com>]

The MemTxAttrs structure contains bitfield members, and bindgen is
unable to generate an equivalent macro definition for
MEMTXATTRS_UNSPECIFIED.

Therefore, manually define a global constant variable
MEMTXATTRS_UNSPECIFIED to support calls from Rust code.

Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
---
Changes since RFC:
 * With a boolean type unspecified field, no need to add once_cell.
 * Merge memattrs binding to memory.rs.
---
 rust/qemu-api/src/memory.rs   | 16 ++++++++++++++--
 rust/qemu-api/src/zeroable.rs |  1 +
 rust/wrapper.h                |  1 +
 3 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/rust/qemu-api/src/memory.rs b/rust/qemu-api/src/memory.rs
index 963d689c27d4..fff92508c68f 100644
--- a/rust/qemu-api/src/memory.rs
+++ b/rust/qemu-api/src/memory.rs
@@ -2,7 +2,7 @@
 // Author(s): Paolo Bonzini <pbonzini@redhat.com>
 // SPDX-License-Identifier: GPL-2.0-or-later
 
-//! Bindings for `MemoryRegion` and `MemoryRegionOps`
+//! Bindings for `MemoryRegion`, `MemoryRegionOps` and `MemTxAttrs`
 
 use std::{
     ffi::{CStr, CString},
@@ -11,7 +11,7 @@
     ptr::addr_of,
 };
 
-pub use bindings::hwaddr;
+pub use bindings::{hwaddr, MemTxAttrs};
 
 use crate::{
     bindings::{self, device_endian, memory_region_init_io},
@@ -189,3 +189,15 @@ unsafe impl ObjectType for MemoryRegion {
         unsafe { CStr::from_bytes_with_nul_unchecked(bindings::TYPE_MEMORY_REGION) };
 }
 qom_isa!(MemoryRegion: Object);
+
+/// A special `MemTxAttrs` constant, used to indicate that no memary
+/// attributes are specified.
+///
+/// Bus masters which don't specify any attributes will get this,
+/// which has all attribute bits clear except the topmost one
+/// (so that we can distinguish "all attributes deliberately clear"
+/// from "didn't specify" if necessary).
+pub const MEMTXATTRS_UNSPECIFIED: MemTxAttrs = MemTxAttrs {
+    unspecified: true,
+    ..Zeroable::ZERO
+};
diff --git a/rust/qemu-api/src/zeroable.rs b/rust/qemu-api/src/zeroable.rs
index 304ad6698360..53dc90da31a1 100644
--- a/rust/qemu-api/src/zeroable.rs
+++ b/rust/qemu-api/src/zeroable.rs
@@ -103,3 +103,4 @@ fn default() -> Self {
 impl_zeroable!(crate::bindings::MemoryRegionOps__bindgen_ty_1);
 impl_zeroable!(crate::bindings::MemoryRegionOps__bindgen_ty_2);
 impl_zeroable!(crate::bindings::MemoryRegionOps);
+impl_zeroable!(crate::bindings::MemTxAttrs);
diff --git a/rust/wrapper.h b/rust/wrapper.h
index a9bc67af0d5f..54839ce0f510 100644
--- a/rust/wrapper.h
+++ b/rust/wrapper.h
@@ -62,3 +62,4 @@ typedef enum memory_order {
 #include "qapi/error.h"
 #include "migration/vmstate.h"
 #include "chardev/char-serial.h"
+#include "exec/memattrs.h"
-- 
2.34.1