vmm: cpu: Only include hotplug/unplug related AML code if dynamic

This will significantly reduce the size of the DSDT and the effort
required to parse them if there is no requirement to support
hotplug/unplug.

Signed-off-by: Rob Bradford <robert.bradford@intel.com>

vmm/src/cpu.rs

@@ -1463,6 +1463,7 @@ impl CpuManager {
 struct Cpu {
     cpu_id: u8,
     proximity_domain: u32,
+    dynamic: bool,
 }
 
 #[cfg(all(target_arch = "x86_64", feature = "acpi"))]
@@ -1493,7 +1494,8 @@ impl Aml for Cpu {
     fn append_aml_bytes(&self, bytes: &mut Vec<u8>) {
         #[cfg(target_arch = "x86_64")]
         let mat_data: Vec<u8> = self.generate_mat();
-
+        #[allow(clippy::if_same_then_else)]
+        if self.dynamic {
             aml::Device::new(
                 format!("C{:03}", self.cpu_id).as_str().into(),
                 vec![
@@ -1542,7 +1544,36 @@ impl Aml for Cpu {
                     ),
                 ],
             )
-        .append_aml_bytes(bytes)
+            .append_aml_bytes(bytes);
+        } else {
+            aml::Device::new(
+                format!("C{:03}", self.cpu_id).as_str().into(),
+                vec![
+                    &aml::Name::new("_HID".into(), &"ACPI0007"),
+                    &aml::Name::new("_UID".into(), &self.cpu_id),
+                    #[cfg(target_arch = "x86_64")]
+                    &aml::Method::new(
+                        "_STA".into(),
+                        0,
+                        false,
+                        // Mark CPU present see CSTA implementation
+                        vec![&aml::Return::new(&0xfu8)],
+                    ),
+                    &aml::Method::new(
+                        "_PXM".into(),
+                        0,
+                        false,
+                        vec![&aml::Return::new(&self.proximity_domain)],
+                    ),
+                    // The Linux kernel expects every CPU device to have a _MAT entry
+                    // containing the LAPIC for this processor with the enabled bit set
+                    // even it if is disabled in the MADT (non-boot CPU)
+                    #[cfg(target_arch = "x86_64")]
+                    &aml::Name::new("_MAT".into(), &aml::Buffer::new(mat_data)),
+                ],
+            )
+            .append_aml_bytes(bytes);
+        }
     }
 }
 
@@ -1566,11 +1597,13 @@ impl Aml for CpuNotify {
 #[cfg(feature = "acpi")]
 struct CpuMethods {
     max_vcpus: u8,
+    dynamic: bool,
 }
 
 #[cfg(feature = "acpi")]
 impl Aml for CpuMethods {
     fn append_aml_bytes(&self, bytes: &mut Vec<u8>) {
+        if self.dynamic {
             // CPU status method
             aml::Method::new(
                 "CSTA".into(),
@@ -1645,7 +1678,10 @@ impl Aml for CpuMethods {
                                         vec![&aml::Local(0), &aml::ONE],
                                     ),
                                     // Reset CINS bit
-                                &aml::Store::new(&aml::Path::new("\\_SB_.PRES.CINS"), &aml::ONE),
+                                    &aml::Store::new(
+                                        &aml::Path::new("\\_SB_.PRES.CINS"),
+                                        &aml::ONE,
+                                    ),
                                 ],
                             ),
                             // Check if CRMV bit is set
@@ -1653,9 +1689,15 @@ impl Aml for CpuMethods {
                                 &aml::Equal::new(&aml::Path::new("\\_SB_.PRES.CRMV"), &aml::ONE),
                                 // Notify device if it is (with the eject constant 0x3)
                                 vec![
-                                &aml::MethodCall::new("CTFY".into(), vec![&aml::Local(0), &3u8]),
+                                    &aml::MethodCall::new(
+                                        "CTFY".into(),
+                                        vec![&aml::Local(0), &3u8],
+                                    ),
                                     // Reset CRMV bit
-                                &aml::Store::new(&aml::Path::new("\\_SB_.PRES.CRMV"), &aml::ONE),
+                                    &aml::Store::new(
+                                        &aml::Path::new("\\_SB_.PRES.CRMV"),
+                                        &aml::ONE,
+                                    ),
                                 ],
                             ),
                             &aml::Add::new(&aml::Local(0), &aml::Local(0), &aml::ONE),
@@ -1666,12 +1708,16 @@ impl Aml for CpuMethods {
                 ],
             )
             .append_aml_bytes(bytes)
+        } else {
+            aml::Method::new("CSCN".into(), 0, true, vec![]).append_aml_bytes(bytes)
+        }
     }
 }
 
 #[cfg(feature = "acpi")]
 impl Aml for CpuManager {
     fn append_aml_bytes(&self, bytes: &mut Vec<u8>) {
+        if self.dynamic {
             // CPU hotplug controller
             #[cfg(target_arch = "x86_64")]
             aml::Device::new(
@@ -1724,6 +1770,7 @@ impl Aml for CpuManager {
                 ],
             )
             .append_aml_bytes(bytes);
+        }
 
         // CPU devices
         let hid = aml::Name::new("_HID".into(), &"ACPI0010");
@@ -1731,6 +1778,7 @@ impl Aml for CpuManager {
         // Bundle methods together under a common object
         let methods = CpuMethods {
             max_vcpus: self.config.max_vcpus,
+            dynamic: self.dynamic,
         };
         let mut cpu_data_inner: Vec<&dyn aml::Aml> = vec![&hid, &uid, &methods];
 
@@ -1740,6 +1788,7 @@ impl Aml for CpuManager {
             let cpu_device = Cpu {
                 cpu_id,
                 proximity_domain,
+                dynamic: self.dynamic,
             };
 
             cpu_devices.push(cpu_device);