vmm: Add required acpi entries for vtpm device

Add an TPM2 entry to DSDT ACPI table. Add a TPM2 table to guest's ACPI.

Signed-off-by: Praveen K Paladugu <prapal@linux.microsoft.com>
Co-authored-by: Sean Yoo <t-seanyoo@microsoft.com>

vmm/src/acpi.rs

@@ -264,6 +264,18 @@ fn create_mcfg_table(pci_segments: &[PciSegment]) -> Sdt {
     mcfg
 }
 
+fn create_tpm2_table() -> Sdt {
+    let mut tpm = Sdt::new(*b"TPM2", 52, 3, *b"CLOUDH", *b"CHTPM2  ", 1);
+
+    tpm.write(36, 0_u16); //Platform Class
+    tpm.write(38, 0_u16); // Reserved Space
+    tpm.write(40, 0xfed4_0040_u64); // Address of Control Area
+    tpm.write(48, 7_u32); //Start Method
+
+    tpm.update_checksum();
+    tpm
+}
+
 fn create_srat_table(numa_nodes: &NumaNodes) -> Sdt {
     let mut srat = Sdt::new(*b"SRAT", 36, 3, *b"CLOUDH", *b"CHSRAT  ", 1);
     // SRAT reserved 12 bytes
@@ -609,6 +621,7 @@ pub fn create_acpi_tables(
     cpu_manager: &Arc<Mutex<CpuManager>>,
     memory_manager: &Arc<Mutex<MemoryManager>>,
     numa_nodes: &NumaNodes,
+    tpm_enabled: bool,
 ) -> GuestAddress {
     trace_scoped!("create_acpi_tables");
 
@@ -723,6 +736,18 @@ pub fn create_acpi_tables(
         prev_tbl_off = dbg2_offset;
     }
 
+    if tpm_enabled {
+        // TPM2 Table
+        let tpm2 = create_tpm2_table();
+        let tpm2_offset = prev_tbl_off.checked_add(prev_tbl_len).unwrap();
+        guest_mem
+            .write_slice(tpm2.as_slice(), tpm2_offset)
+            .expect("Error writing TPM2 table");
+        tables.push(tpm2_offset.0);
+
+        prev_tbl_len = tpm2.len() as u64;
+        prev_tbl_off = tpm2_offset;
+    }
     // SRAT and SLIT
     // Only created if the NUMA nodes list is not empty.
     if !numa_nodes.is_empty() {