From cdc14815be70b93e453490b7d15eadbf946fd00b Mon Sep 17 00:00:00 2001
From: Sebastien Boeuf <sebastien.boeuf@intel.com>
Date: Fri, 17 Dec 2021 14:28:12 +0100
Subject: [PATCH] vmm: tdx: Only create ACPI tables if not running TDX

In case of TDX, we don't want to create the ACPI tables the same way we
do for all the other use cases. That's because the ACPI tables don't
need to be written to guest memory at a specific address, instead they
are passed directly through the HOB.

Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
---
 vmm/src/vm.rs | 43 ++++++++++++++++++++++++++++---------------
 1 file changed, 28 insertions(+), 15 deletions(-)

diff --git a/vmm/src/vm.rs b/vmm/src/vm.rs
index b270b27be..d74d22d84 100644
--- a/vmm/src/vm.rs
+++ b/vmm/src/vm.rs
@@ -1918,6 +1918,30 @@ impl Vm {
         Ok(())
     }
 
+    // Creates ACPI tables
+    // In case of TDX being used, this is a no-op since the tables will be
+    // created and passed when populating the HOB.
+    #[cfg(feature = "acpi")]
+    fn create_acpi_tables(&self) -> Option<GuestAddress> {
+        #[cfg(feature = "tdx")]
+        if self.config.lock().unwrap().tdx.is_some() {
+            return None;
+        }
+
+        let mem = self.memory_manager.lock().unwrap().guest_memory().memory();
+
+        let rsdp_addr = crate::acpi::create_acpi_tables(
+            &mem,
+            &self.device_manager,
+            &self.cpu_manager,
+            &self.memory_manager,
+            &self.numa_nodes,
+        );
+        info!("Created ACPI tables: rsdp_addr = 0x{:x}", rsdp_addr.0);
+
+        Some(rsdp_addr)
+    }
+
     pub fn boot(&mut self) -> Result<()> {
         info!("Booting VM");
         event!("vm", "booting");
@@ -1958,20 +1982,7 @@ impl Vm {
         };
 
         #[cfg(feature = "acpi")]
-        let rsdp_addr = {
-            let mem = self.memory_manager.lock().unwrap().guest_memory().memory();
-
-            let rsdp_addr = crate::acpi::create_acpi_tables(
-                &mem,
-                &self.device_manager,
-                &self.cpu_manager,
-                &self.memory_manager,
-                &self.numa_nodes,
-            );
-            info!("Created ACPI tables: rsdp_addr = 0x{:x}", rsdp_addr.0);
-
-            rsdp_addr
-        };
+        let rsdp_addr = self.create_acpi_tables();
 
         // Configuring the TDX regions requires that the vCPUs are created.
         #[cfg(feature = "tdx")]
@@ -1985,9 +1996,11 @@ impl Vm {
         // Configure shared state based on loaded kernel
         entry_point
             .map(|_| {
+                // Safe to unwrap rsdp_addr as we know it can't be None when
+                // the entry_point is Some.
                 self.configure_system(
                     #[cfg(feature = "acpi")]
-                    rsdp_addr,
+                    rsdp_addr.unwrap(),
                 )
             })
             .transpose()?;