From af261f231ca86c9c3c430a2fad58f95455796741 Mon Sep 17 00:00:00 2001
From: Praveen K Paladugu <prapal@linux.microsoft.com>
Date: Fri, 12 Aug 2022 20:28:04 +0000
Subject: [PATCH] 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           | 25 +++++++++++++++++++++++++
 vmm/src/device_manager.rs | 30 ++++++++++++++++++++++++++++++
 vmm/src/vm.rs             |  4 ++--
 3 files changed, 57 insertions(+), 2 deletions(-)

diff --git a/vmm/src/acpi.rs b/vmm/src/acpi.rs
index 2527af7d1..5ae1fd1fb 100644
--- a/vmm/src/acpi.rs
+++ b/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() {
diff --git a/vmm/src/device_manager.rs b/vmm/src/device_manager.rs
index 794cffabc..410734c9e 100644
--- a/vmm/src/device_manager.rs
+++ b/vmm/src/device_manager.rs
@@ -4167,6 +4167,29 @@ fn numa_node_id_from_memory_zone_id(numa_nodes: &NumaNodes, memory_zone_id: &str
     None
 }
 
+struct TpmDevice {}
+
+impl Aml for TpmDevice {
+    fn to_aml_bytes(&self) -> Vec<u8> {
+        aml::Device::new(
+            "TPM2".into(),
+            vec![
+                &aml::Name::new("_HID".into(), &"MSFT0101"),
+                &aml::Name::new("_STA".into(), &(0xF_usize)),
+                &aml::Name::new(
+                    "_CRS".into(),
+                    &aml::ResourceTemplate::new(vec![&aml::Memory32Fixed::new(
+                        true,
+                        layout::TPM_START.0 as u32,
+                        layout::TPM_SIZE as u32,
+                    )]),
+                ),
+            ],
+        )
+        .to_aml_bytes()
+    }
+}
+
 impl Aml for DeviceManager {
     fn append_aml_bytes(&self, bytes: &mut Vec<u8>) {
         #[cfg(target_arch = "aarch64")]
@@ -4328,6 +4351,13 @@ impl Aml for DeviceManager {
         )
         .append_aml_bytes(bytes);
 
+        if self.config.lock().unwrap().tpm.is_some() {
+            // Add tpm device
+            let tpm_acpi = TpmDevice {};
+            let tpm_dsdt_data = tpm_acpi.to_aml_bytes();
+            bytes.extend_from_slice(tpm_dsdt_data.as_slice());
+        }
+
         self.ged_notification_device
             .as_ref()
             .unwrap()
diff --git a/vmm/src/vm.rs b/vmm/src/vm.rs
index 3813ac371..1bc3e186b 100644
--- a/vmm/src/vm.rs
+++ b/vmm/src/vm.rs
@@ -2048,15 +2048,15 @@ impl Vm {
         if self.config.lock().unwrap().is_tdx_enabled() {
             return None;
         }
-
         let mem = self.memory_manager.lock().unwrap().guest_memory().memory();
-
+        let tpm_enabled = self.config.lock().unwrap().tpm.is_some();
         let rsdp_addr = crate::acpi::create_acpi_tables(
             &mem,
             &self.device_manager,
             &self.cpu_manager,
             &self.memory_manager,
             &self.numa_nodes,
+            tpm_enabled,
         );
         info!("Created ACPI tables: rsdp_addr = 0x{:x}", rsdp_addr.0);