virtio-devices: add or adjust comments for impl ByteValued

Signed-off-by: Wei Liu <liuwe@microsoft.com>

virtio-devices/src/balloon.rs

@@ -100,7 +100,7 @@ pub struct VirtioBalloonConfig {
 const CONFIG_ACTUAL_OFFSET: u64 = 4;
 const CONFIG_ACTUAL_SIZE: usize = 4;
 
-// Safe because it only has data and has no implicit padding.
+// SAFETY: it only has data and has no implicit padding.
 unsafe impl ByteValued for VirtioBalloonConfig {}
 
 struct VirtioBalloonResizeReceiver {

virtio-devices/src/console.rs

@@ -69,7 +69,7 @@ impl Default for VirtioConsoleConfig {
     }
 }
 
-// Safe because it only has data and has no implicit padding.
+// SAFETY: it only has data and has no implicit padding.
 unsafe impl ByteValued for VirtioConsoleConfig {}
 
 struct ConsoleEpollHandler {

virtio-devices/src/iommu.rs

@@ -79,8 +79,6 @@ struct VirtioIommuRange32 {
     end: u32,
 }
 
-unsafe impl ByteValued for VirtioIommuRange32 {}
-
 #[derive(Copy, Clone, Debug, Default)]
 #[repr(packed)]
 #[allow(dead_code)]
@@ -89,8 +87,6 @@ struct VirtioIommuRange64 {
     end: u64,
 }
 
-unsafe impl ByteValued for VirtioIommuRange64 {}
-
 #[derive(Copy, Clone, Debug, Default)]
 #[repr(packed)]
 #[allow(dead_code)]
@@ -103,8 +99,6 @@ struct VirtioIommuConfig {
     _reserved: [u8; 7],
 }
 
-unsafe impl ByteValued for VirtioIommuConfig {}
-
 /// Virtio IOMMU request type
 const VIRTIO_IOMMU_T_ATTACH: u8 = 1;
 const VIRTIO_IOMMU_T_DETACH: u8 = 2;
@@ -119,8 +113,6 @@ struct VirtioIommuReqHead {
     _reserved: [u8; 3],
 }
 
-unsafe impl ByteValued for VirtioIommuReqHead {}
-
 /// Virtio IOMMU request status
 const VIRTIO_IOMMU_S_OK: u8 = 0;
 #[allow(unused)]
@@ -148,8 +140,6 @@ struct VirtioIommuReqTail {
     _reserved: [u8; 3],
 }
 
-unsafe impl ByteValued for VirtioIommuReqTail {}
-
 /// ATTACH request
 #[derive(Copy, Clone, Debug, Default)]
 #[repr(packed)]
@@ -159,8 +149,6 @@ struct VirtioIommuReqAttach {
     _reserved: [u8; 8],
 }
 
-unsafe impl ByteValued for VirtioIommuReqAttach {}
-
 /// DETACH request
 #[derive(Copy, Clone, Debug, Default)]
 #[repr(packed)]
@@ -170,8 +158,6 @@ struct VirtioIommuReqDetach {
     _reserved: [u8; 8],
 }
 
-unsafe impl ByteValued for VirtioIommuReqDetach {}
-
 /// Virtio IOMMU request MAP flags
 #[allow(unused)]
 const VIRTIO_IOMMU_MAP_F_READ: u32 = 1;
@@ -194,8 +180,6 @@ struct VirtioIommuReqMap {
     _flags: u32,
 }
 
-unsafe impl ByteValued for VirtioIommuReqMap {}
-
 /// UNMAP request
 #[derive(Copy, Clone, Debug, Default)]
 #[repr(packed)]
@@ -206,8 +190,6 @@ struct VirtioIommuReqUnmap {
     _reserved: [u8; 4],
 }
 
-unsafe impl ByteValued for VirtioIommuReqUnmap {}
-
 /// Virtio IOMMU request PROBE types
 #[allow(unused)]
 const VIRTIO_IOMMU_PROBE_T_NONE: u16 = 0;
@@ -224,8 +206,6 @@ struct VirtioIommuReqProbe {
     _reserved: [u64; 8],
 }
 
-unsafe impl ByteValued for VirtioIommuReqProbe {}
-
 #[derive(Copy, Clone, Debug, Default)]
 #[repr(packed)]
 #[allow(dead_code)]
@@ -234,8 +214,6 @@ struct VirtioIommuProbeProperty {
     length: u16,
 }
 
-unsafe impl ByteValued for VirtioIommuProbeProperty {}
-
 /// Virtio IOMMU request PROBE property RESV_MEM subtypes
 #[allow(unused)]
 const VIRTIO_IOMMU_RESV_MEM_T_RESERVED: u8 = 0;
@@ -251,8 +229,6 @@ struct VirtioIommuProbeResvMem {
     end: u64,
 }
 
-unsafe impl ByteValued for VirtioIommuProbeResvMem {}
-
 /// Virtio IOMMU fault flags
 #[allow(unused)]
 const VIRTIO_IOMMU_FAULT_F_READ: u32 = 1;
@@ -284,6 +260,19 @@ struct VirtioIommuFault {
     address: u64,
 }
 
+// SAFETY: these data structures only contain integers and have no implicit padding
+unsafe impl ByteValued for VirtioIommuRange32 {}
+unsafe impl ByteValued for VirtioIommuRange64 {}
+unsafe impl ByteValued for VirtioIommuConfig {}
+unsafe impl ByteValued for VirtioIommuReqHead {}
+unsafe impl ByteValued for VirtioIommuReqTail {}
+unsafe impl ByteValued for VirtioIommuReqAttach {}
+unsafe impl ByteValued for VirtioIommuReqDetach {}
+unsafe impl ByteValued for VirtioIommuReqMap {}
+unsafe impl ByteValued for VirtioIommuReqUnmap {}
+unsafe impl ByteValued for VirtioIommuReqProbe {}
+unsafe impl ByteValued for VirtioIommuProbeProperty {}
+unsafe impl ByteValued for VirtioIommuProbeResvMem {}
 unsafe impl ByteValued for VirtioIommuFault {}
 
 #[derive(Debug)]

virtio-devices/src/mem.rs

@@ -149,7 +149,7 @@ struct VirtioMemReq {
     padding_1: [u16; 3],
 }
 
-// Safe because it only has data and has no implicit padding.
+// SAFETY: it only has data and has no implicit padding.
 unsafe impl ByteValued for VirtioMemReq {}
 
 #[repr(C)]
@@ -160,7 +160,7 @@ struct VirtioMemResp {
     state: u16,
 }
 
-// Safe because it only has data and has no implicit padding.
+// SAFETY: it only has data and has no implicit padding.
 unsafe impl ByteValued for VirtioMemResp {}
 
 #[repr(C)]
@@ -186,7 +186,7 @@ pub struct VirtioMemConfig {
     requested_size: u64,
 }
 
-// Safe because it only has data and has no implicit padding.
+// SAFETY: it only has data and has no implicit padding.
 unsafe impl ByteValued for VirtioMemConfig {}
 
 impl VirtioMemConfig {

virtio-devices/src/pmem.rs

@@ -50,7 +50,7 @@ struct VirtioPmemConfig {
     size: u64,
 }
 
-// Safe because it only has data and has no implicit padding.
+// SAFETY: it only has data and has no implicit padding.
 unsafe impl ByteValued for VirtioPmemConfig {}
 
 #[derive(Copy, Clone, Debug, Default)]
@@ -59,7 +59,7 @@ struct VirtioPmemReq {
     type_: u32,
 }
 
-// Safe because it only has data and has no implicit padding.
+// SAFETY: it only has data and has no implicit padding.
 unsafe impl ByteValued for VirtioPmemReq {}
 
 #[derive(Copy, Clone, Debug, Default)]
@@ -68,7 +68,7 @@ struct VirtioPmemResp {
     ret: u32,
 }
 
-// Safe because it only has data and has no implicit padding.
+// SAFETY: it only has data and has no implicit padding.
 unsafe impl ByteValued for VirtioPmemResp {}
 
 #[derive(Debug)]

virtio-devices/src/transport/pci_device.rs

@@ -75,7 +75,7 @@ struct VirtioPciCap {
     offset: Le32,     // Offset within bar.
     length: Le32,     // Length of the structure, in bytes.
 }
-// It is safe to implement ByteValued. All members are simple numbers and any value is valid.
+// SAFETY: All members are simple numbers and any value is valid.
 unsafe impl ByteValued for VirtioPciCap {}
 
 impl PciCapability for VirtioPciCap {
@@ -111,7 +111,7 @@ struct VirtioPciNotifyCap {
     cap: VirtioPciCap,
     notify_off_multiplier: Le32,
 }
-// It is safe to implement ByteValued. All members are simple numbers and any value is valid.
+// SAFETY: All members are simple numbers and any value is valid.
 unsafe impl ByteValued for VirtioPciNotifyCap {}
 
 impl PciCapability for VirtioPciNotifyCap {
@@ -156,7 +156,7 @@ struct VirtioPciCap64 {
     offset_hi: Le32,
     length_hi: Le32,
 }
-// It is safe to implement ByteValued. All members are simple numbers and any value is valid.
+// SAFETY: All members are simple numbers and any value is valid.
 unsafe impl ByteValued for VirtioPciCap64 {}
 
 impl PciCapability for VirtioPciCap64 {
@@ -194,7 +194,7 @@ struct VirtioPciCfgCap {
     cap: VirtioPciCap,
     pci_cfg_data: [u8; 4],
 }
-// It is safe to implement ByteValued. All members are simple numbers and any value is valid.
+// SAFETY: All members are simple numbers and any value is valid.
 unsafe impl ByteValued for VirtioPciCfgCap {}
 
 impl PciCapability for VirtioPciCfgCap {