openvmm: add basic gdbstub support for aarch64

Plumb aarch64 support, using the `gdbstub_arch` crate to provide the register definitions. Only register reads and memory access are supported. Register updates and breakpoints are not.
microsoft · Nov 13, 2024 · a4658b5 · a4658b5
1 parent c113573
commit a4658b5
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Showing 17 changed files with 393 additions and 103 deletions.
diff --git a/Cargo.lock b/Cargo.lock
@@ -876,10 +876,12 @@ version = "0.0.0"
 name = "debug_worker"
 version = "0.0.0"
 dependencies = [
+ "aarch64defs",
  "anyhow",
  "debug_worker_defs",
  "futures",
  "gdbstub",
+ "gdbstub_arch",
  "inspect",
  "mesh",
  "mesh_worker",
@@ -2032,6 +2034,16 @@ dependencies = [
  "paste",
 ]
 
+[[package]]
+name = "gdbstub_arch"
+version = "0.2.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "eecb536c55c43593a00dde9074dbbdb0e81ce5f20dbca921400f8779c21dea9c"
+dependencies = [
+ "gdbstub",
+ "num-traits",
+]
+
 [[package]]
 name = "gdma"
 version = "0.0.0"
@@ -7992,6 +8004,7 @@ dependencies = [
  "thiserror 2.0.0",
  "tracing",
  "virt",
+ "virt_support_aarch64emu",
  "virt_support_x86emu",
  "vm_resource",
  "vm_topology",

diff --git a/Cargo.toml b/Cargo.toml
@@ -399,6 +399,7 @@ futures-core = "0.3"
 futures-channel = "0.3"
 futures-io = "0.3"
 gdbstub = "0.6"
+gdbstub_arch = "0.2"
 getrandom = "0.2"
 glob = "0.3"
 gptman = "1.0"

diff --git a/openvmm/hvlite_entry/src/lib.rs b/openvmm/hvlite_entry/src/lib.rs
@@ -1744,6 +1744,11 @@ async fn run_control(driver: &DefaultDriver, mesh: &VmmMesh, opt: Options) -> an
                         listener,
                         req_chan: req_tx,
                         vp_count: vm_config.processor_topology.proc_count,
+                        target_arch: if cfg!(guest_arch = "x86_64") {
+                            debug_worker_defs::TargetArch::X86_64
+                        } else {
+                            debug_worker_defs::TargetArch::Aarch64
+                        },
                     },
                 )
                 .await

diff --git a/vmm_core/Cargo.toml b/vmm_core/Cargo.toml
@@ -7,10 +7,11 @@ edition = "2021"
 rust-version.workspace = true
 
 [features]
-gdb = ["iced-x86", "virt_support_x86emu"]
+gdb = ["iced-x86", "virt_support_aarch64emu", "virt_support_x86emu"]
 
 [dependencies]
 virt.workspace = true
+virt_support_aarch64emu = { workspace = true, optional = true }
 virt_support_x86emu = { workspace = true, optional = true }
 state_unit.workspace = true
 vmm_core_defs.workspace = true

diff --git a/vmm_core/src/partition_unit.rs b/vmm_core/src/partition_unit.rs
@@ -78,7 +78,7 @@ struct PartitionUnitRunner {
     topology: ProcessorTopology,
     initial_regs: Option<Arc<InitialRegs>>,
 
-    #[cfg(all(feature = "gdb", guest_arch = "x86_64"))]
+    #[cfg(feature = "gdb")]
     debugger_state: debug::DebuggerState,
 }
 
@@ -204,7 +204,7 @@ impl PartitionUnit {
             req_recv,
             topology: params.processor_topology.clone(),
             initial_regs: None,
-            #[cfg(all(feature = "gdb", guest_arch = "x86_64"))]
+            #[cfg(feature = "gdb")]
             debugger_state: debug::DebuggerState::new(
                 params.vtl_guest_memory[0]
                     .ok_or(Error::MissingGuestMemory)?
@@ -280,25 +280,25 @@ impl PartitionUnitRunner {
                 State(Option<StateRequest>),
                 Halt(InternalHaltReason),
                 Request(PartitionRequest),
-                #[cfg(all(feature = "gdb", guest_arch = "x86_64"))]
+                #[cfg(feature = "gdb")]
                 Debug(vmm_core_defs::debug_rpc::DebugRequest),
             }
 
-            #[cfg(all(feature = "gdb", guest_arch = "x86_64"))]
+            #[cfg(feature = "gdb")]
             let debug = self.debugger_state.wait_rpc();
-            #[cfg(not(all(feature = "gdb", guest_arch = "x86_64")))]
+            #[cfg(not(feature = "gdb"))]
             let debug = std::future::pending();
 
             let event = futures::select! {  // merge semantics
                 request = recv.next() => Event::State(request),
                 request = self.halt_request_recv.select_next_some() => Event::Halt(request),
                 request = self.req_recv.select_next_some() => Event::Request(request),
                 request = debug.fuse() => {
-                    #[cfg(all(feature = "gdb", guest_arch = "x86_64"))]
+                    #[cfg(feature = "gdb")]
                     {
                         Event::Debug(request)
                     }
-                    #[cfg(not(all(feature = "gdb", guest_arch = "x86_64")))]
+                    #[cfg(not(feature = "gdb"))]
                     {
                         let _: std::convert::Infallible = request;
                         unreachable!()
@@ -334,7 +334,7 @@ impl PartitionUnitRunner {
                             .await
                     }
                 },
-                #[cfg(all(feature = "gdb", guest_arch = "x86_64"))]
+                #[cfg(feature = "gdb")]
                 Event::Debug(request) => {
                     self.handle_gdb(request).await;
                 }
@@ -356,9 +356,9 @@ impl PartitionUnitRunner {
                     self.halt_reason = Some(reason.clone());
 
                     // Report the halt to the debugger.
-                    #[cfg(all(feature = "gdb", guest_arch = "x86_64"))]
+                    #[cfg(feature = "gdb")]
                     let reported = self.debugger_state.report_halt_to_debugger(&reason);
-                    #[cfg(not(all(feature = "gdb", guest_arch = "x86_64")))]
+                    #[cfg(not(feature = "gdb"))]
                     let reported = false;
 
                     // If the debugger is not attached, then report the halt

diff --git a/vmm_core/src/partition_unit/debug.rs b/vmm_core/src/partition_unit/debug.rs
@@ -1,7 +1,7 @@
 // Copyright (c) Microsoft Corporation.
 // Licensed under the MIT License.
 
-#![cfg(all(feature = "gdb", guest_arch = "x86_64"))]
+#![cfg(feature = "gdb")]
 
 //! Implements debugging support for [`PartitionUnitRunner`]. This is a separate
 //! module because it is cfg gated on the `gdb` feature.