From 5049415db63478eb0182a50a920df9c2668681c7 Mon Sep 17 00:00:00 2001
From: Jason White <jasonwhite@meta.com>
Date: Fri, 21 Oct 2022 12:09:36 -0700
Subject: [PATCH] Get main `reverie` crate compiling on aarch64

Reviewed By: wangbj

Differential Revision: D40577288

fbshipit-source-id: 0cf76ef1fdae1a5bcd0aaf046ec59ed7b7478d91
---
 reverie/src/lib.rs   |  2 ++
 reverie/src/rdtsc.rs |  3 ++-
 reverie/src/tool.rs  | 26 ++++++++++++++++----------
 3 files changed, 20 insertions(+), 11 deletions(-)

diff --git a/reverie/src/lib.rs b/reverie/src/lib.rs
index db1da4b..564ecdd 100644
--- a/reverie/src/lib.rs
+++ b/reverie/src/lib.rs
@@ -21,6 +21,7 @@ mod auxv;
 mod backtrace;
 mod error;
 mod guest;
+#[cfg(target_arch = "x86_64")]
 mod rdtsc;
 mod stack;
 mod subscription;
@@ -33,6 +34,7 @@ pub use error::*;
 pub use guest::*;
 pub use process::ExitStatus;
 pub use process::Pid;
+#[cfg(target_arch = "x86_64")]
 pub use rdtsc::*;
 pub use reverie_process as process;
 pub use stack::*;
diff --git a/reverie/src/rdtsc.rs b/reverie/src/rdtsc.rs
index cf69bba..85d992d 100644
--- a/reverie/src/rdtsc.rs
+++ b/reverie/src/rdtsc.rs
@@ -7,7 +7,8 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-//! rdtsc/rdtscp helpers
+//! rdtsc/rdtscp helpers. This only makes sense on x86_64 as it is the only
+//! architecture where we can intercept these instructions.
 
 use core::arch::x86_64::__rdtscp;
 use core::arch::x86_64::_rdtsc;
diff --git a/reverie/src/tool.rs b/reverie/src/tool.rs
index 37e7b59..d492b3d 100644
--- a/reverie/src/tool.rs
+++ b/reverie/src/tool.rs
@@ -14,8 +14,6 @@
 //! same process.
 
 use async_trait::async_trait;
-use raw_cpuid::cpuid;
-use raw_cpuid::CpuIdResult;
 use reverie_syscalls::Syscall;
 use serde::de::DeserializeOwned;
 use serde::Serialize;
@@ -23,7 +21,9 @@ use serde::Serialize;
 use crate::error::Errno;
 use crate::error::Error;
 use crate::guest::Guest;
+#[cfg(target_arch = "x86_64")]
 use crate::rdtsc::Rdtsc;
+#[cfg(target_arch = "x86_64")]
 use crate::rdtsc::RdtscResult;
 use crate::ExitStatus;
 use crate::Pid;
@@ -238,25 +238,31 @@ pub trait Tool: Serialize + DeserializeOwned + Send + Sync + Default {
         guest.tail_inject(c).await
     }
 
-    /// CPUID is trapped, the tool should implement this function to return [eax,
-    /// ebx, ecx, edx]
+    /// CPUID is trapped, the tool should implement this function to return
+    /// `[eax, ebx, ecx, edx]`.
     ///
-    /// NOTE: This is never called by default unless cpuid events are subscribed
-    /// to.
+    /// NOTE:
+    ///  * This is never called by default unless cpuid events are subscribed
+    ///    to.
+    ///  * This is only available on x86_64.
+    #[cfg(target_arch = "x86_64")]
     async fn handle_cpuid_event<T: Guest<Self>>(
         &self,
         _guest: &mut T,
         eax: u32,
         ecx: u32,
-    ) -> Result<CpuIdResult, Errno> {
-        Ok(cpuid!(eax, ecx))
+    ) -> Result<raw_cpuid::CpuIdResult, Errno> {
+        Ok(raw_cpuid::cpuid!(eax, ecx))
     }
 
     /// rdtsc/rdtscp is trapped, the tool should implement this function to
     /// return the counter.
     ///
-    /// NOTE: This is never called by default unless rdtsc events are subscribed
-    /// to.
+    /// NOTE:
+    ///  * This is never called by default unless rdtsc events are subscribed
+    ///    to.
+    ///  * This is only available on x86_64.
+    #[cfg(target_arch = "x86_64")]
     async fn handle_rdtsc_event<T: Guest<Self>>(
         &self,
         _guest: &mut T,