Added MaskID bitfield

Signed-off-by: DGonzalezVillal <Diego.GonzalezVillalobos@amd.com>

src/firmware/host/types/snp.rs

@@ -12,6 +12,8 @@ use std::{
     fmt::Display,
 };
 
+use bitfield::bitfield;
+
 use bitflags;
 
 use serde::{Deserialize, Serialize};
@@ -200,7 +202,7 @@ pub struct Config {
 
     /// Indicates that the CHIP_ID field in the attestation report will always
     /// be zero.
-    pub mask_id: u32,
+    pub mask_id: MaskId,
 
     /// Reserved. Must be zero.
     reserved: [u8; 52],
@@ -218,7 +220,7 @@ impl Default for Config {
 
 impl Config {
     /// Used to create a new Config
-    pub fn new(reported_tcb: TcbVersion, mask_id: u32) -> Self {
+    pub fn new(reported_tcb: TcbVersion, mask_id: MaskId) -> Self {
         Self {
             reported_tcb,
             mask_id,
@@ -302,3 +304,35 @@ impl TcbVersion {
         }
     }
 }
+
+bitfield! {
+    /// Mask ID values that would go into an SNP CONFIG
+    ///
+    /// | Bit(s) | Name | Description |
+    /// |--------|------|-------------|
+    /// |0|MASK_CHIP_ID|Indicates that the CHIP_ID field in the attestation report will alwaysbe zero.|
+    /// |1|MASK_CHIP_KEY|Indicates that the VCEK is not used in attestation and guest key derivation.|
+    #[repr(C)]
+    #[derive(Default, Copy, Clone, PartialEq, Eq, Serialize, Deserialize)]
+    pub struct MaskId(u32);
+    impl Debug;
+    /// Indicates that the CHIP_ID field in the attestation report will alwaysbe zero.
+    pub mask_chip_id, _: 0, 0;
+    /// Indicates that the VCEK is not used in attestation and guest key derivation.
+    pub mask_chip_key, _: 1, 1;
+}
+
+impl Display for MaskId {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(
+            f,
+            r#"
+    MaskID ({}):
+    Mask Chip ID: {}
+    ABI Chip Key: {}"#,
+            self.0,
+            self.mask_chip_id(),
+            self.mask_chip_key(),
+        )
+    }
+}

src/firmware/linux/host/types/snp.rs

@@ -216,7 +216,9 @@ impl CertTableEntry {
 #[cfg(feature = "snp")]
 #[derive(Copy, Clone, Debug, PartialEq, Eq, Default)]
 #[repr(C, packed)]
-pub struct SnpCommit(u32);
+pub struct SnpCommit {
+    pub buffer: u32,
+}
 
 /// Sets the system wide configuration values for SNP.
 #[cfg(feature = "snp")]
@@ -229,7 +231,7 @@ pub struct SnpSetConfig {
     /// mask_id [0] : whether chip id is present in attestation reports or not  
     /// mask_id [1]: whether attestation reports are signed or not
     /// rsvd [2:31]: reserved
-    pub mask_id: u32,
+    pub mask_id: UAPI::MaskId,
 
     /// Reserved. Must be zero.
     reserved: [u8; 52],

tests/api.rs

@@ -121,7 +121,7 @@ mod sev {
 
 #[cfg(feature = "snp")]
 mod snp {
-    use sev::firmware::host::{Config, Firmware, SnpPlatformStatus, TcbVersion};
+    use sev::firmware::host::{Config, Firmware, MaskId, SnpPlatformStatus, TcbVersion};
 
     use serial_test::serial;
 
@@ -182,7 +182,7 @@ mod snp {
     #[serial]
     fn set_config() {
         let mut fw: Firmware = Firmware::open().unwrap();
-        let new_config = Config::new(TcbVersion::new(1, 0, 1, 1), 31);
+        let new_config = Config::new(TcbVersion::new(1, 0, 1, 1), MaskId(31));
         fw.snp_set_config(new_config).unwrap();
     }
 }