From d8becc742cc53770f0b2ea889f6c25ae0e8ae6f5 Mon Sep 17 00:00:00 2001
From: Wei Liu <liuwe@microsoft.com>
Date: Wed, 17 Nov 2021 13:33:13 +0000
Subject: [PATCH] vfio_user: add safety comments for `impl ByteValued`

Signed-off-by: Wei Liu <liuwe@microsoft.com>
---
 vfio_user/src/lib.rs | 27 ++++++++++-----------------
 1 file changed, 10 insertions(+), 17 deletions(-)

diff --git a/vfio_user/src/lib.rs b/vfio_user/src/lib.rs
index 2b5ab4162..8dae052ba 100644
--- a/vfio_user/src/lib.rs
+++ b/vfio_user/src/lib.rs
@@ -73,8 +73,6 @@ struct Header {
     error: u32,
 }
 
-unsafe impl ByteValued for Header {}
-
 #[repr(C)]
 #[derive(Default, Clone, Copy, Debug)]
 struct Version {
@@ -82,7 +80,6 @@ struct Version {
     major: u16,
     minor: u16,
 }
-unsafe impl ByteValued for Version {}
 
 #[derive(Serialize, Deserialize, Debug)]
 struct MigrationCapabilities {
@@ -128,8 +125,6 @@ struct DmaMap {
     size: u64,
 }
 
-unsafe impl ByteValued for DmaMap {}
-
 #[repr(C)]
 #[derive(Default, Clone, Copy, Debug)]
 struct DmaUnmap {
@@ -140,8 +135,6 @@ struct DmaUnmap {
     size: u64,
 }
 
-unsafe impl ByteValued for DmaUnmap {}
-
 #[repr(C)]
 #[derive(Default, Clone, Copy, Debug)]
 struct DeviceGetInfo {
@@ -152,8 +145,6 @@ struct DeviceGetInfo {
     num_irqs: u32,
 }
 
-unsafe impl ByteValued for DeviceGetInfo {}
-
 #[repr(C)]
 #[derive(Default, Clone, Copy, Debug)]
 struct DeviceGetRegionInfo {
@@ -161,8 +152,6 @@ struct DeviceGetRegionInfo {
     region_info: vfio_region_info,
 }
 
-unsafe impl ByteValued for DeviceGetRegionInfo {}
-
 #[repr(C)]
 #[derive(Default, Clone, Copy, Debug)]
 struct RegionAccess {
@@ -172,8 +161,6 @@ struct RegionAccess {
     count: u32,
 }
 
-unsafe impl ByteValued for RegionAccess {}
-
 #[repr(C)]
 #[derive(Default, Clone, Copy, Debug)]
 struct GetIrqInfo {
@@ -184,8 +171,6 @@ struct GetIrqInfo {
     count: u32,
 }
 
-unsafe impl ByteValued for GetIrqInfo {}
-
 #[repr(C)]
 #[derive(Default, Clone, Copy, Debug)]
 struct SetIrqs {
@@ -197,14 +182,22 @@ struct SetIrqs {
     count: u32,
 }
 
-unsafe impl ByteValued for SetIrqs {}
-
 #[repr(C)]
 #[derive(Default, Clone, Copy, Debug)]
 struct DeviceReset {
     header: Header,
 }
 
+// SAFETY: these data structures only contain a sereis of integers
+unsafe impl ByteValued for Header {}
+unsafe impl ByteValued for Version {}
+unsafe impl ByteValued for DmaMap {}
+unsafe impl ByteValued for DmaUnmap {}
+unsafe impl ByteValued for DeviceGetInfo {}
+unsafe impl ByteValued for DeviceGetRegionInfo {}
+unsafe impl ByteValued for RegionAccess {}
+unsafe impl ByteValued for GetIrqInfo {}
+unsafe impl ByteValued for SetIrqs {}
 unsafe impl ByteValued for DeviceReset {}
 
 #[derive(Serialize, Deserialize, Debug)]