firmware/snp: Update PlatformStatus bitflag fields

Initially, byte 0x3 of STRUCT_PLATFORM_STATUS only used bit 0 to
indicate if the RMP was initialized. Updates were made to include
bitfields to indicate if alias detection has completed since the
last system reset and there are no aliasing addresses (bit 1), as well
as if SEV-TIO is enabled (bit 3).

Signed-off-by: Tyler Fanelli <[email protected]>

src/firmware/host/types/snp.rs

@@ -225,6 +225,24 @@ pub struct Build {
     pub build: u32,
 }
 
+bitflags::bitflags! {
+    /// Various platform initialization configuration data. Byte 0x3 in SEV-SNP's
+    /// STRUCT_PLATFORM_STATUS.
+    #[derive(Default)]
+    pub struct PlatformInit: u8 {
+        /// Indicates if RMP is initialized.
+        const IS_RMP_INIT           = 1 << 0;
+        /// Indicates that alias detection has completed since the last system reset
+        /// and there are no aliasing addresses. Resets to 0.
+        /// Added in firmware version:
+        ///     Milan family: 1.55.22
+        ///     Genoa family: 1.55.38
+        const ALIAS_CHECK_COMPLETE  = 1 << 1;
+        /// Indicates TIO is enabled. Present if SevTio feature bit is set.
+        const IS_TIO_EN             = 1 << 3;
+    }
+}
+
 /// Query the SEV-SNP platform status.
 ///
 /// (Chapter 8.3; Table 38)
@@ -238,7 +256,7 @@ pub struct SnpPlatformStatus {
     pub state: u8,
 
     /// IsRmpInitiailzied
-    pub is_rmp_init: u8,
+    pub is_rmp_init: PlatformInit,
 
     /// The platform build ID.
     pub build_id: u32,