From fe24a7a24f07eb90d485130a11e95128cfadd261 Mon Sep 17 00:00:00 2001
From: Wei Liu <liuwe@microsoft.com>
Date: Thu, 2 Jan 2025 20:02:25 +0000
Subject: [PATCH] hypervisor: introduce an mshv_emulator feature

This will become useful when we build the fuzzing target for the
instruction emulator, because there is no need to pull in the rest of
the hypervisor crate in that situation.

Signed-off-by: Wei Liu <liuwe@microsoft.com>
---
 hypervisor/Cargo.toml          | 3 ++-
 hypervisor/src/arch/x86/mod.rs | 2 +-
 hypervisor/src/lib.rs          | 9 ++++++---
 3 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/hypervisor/Cargo.toml b/hypervisor/Cargo.toml
index 05d4c9947..1729dd90a 100644
--- a/hypervisor/Cargo.toml
+++ b/hypervisor/Cargo.toml
@@ -7,7 +7,8 @@ version = "0.1.0"
 
 [features]
 kvm = ["kvm-bindings", "kvm-ioctls", "vfio-ioctls/kvm"]
-mshv = ["iced-x86", "mshv-bindings", "mshv-ioctls", "vfio-ioctls/mshv"]
+mshv = ["mshv-bindings", "mshv-ioctls", "mshv_emulator", "vfio-ioctls/mshv"]
+mshv_emulator = ["iced-x86", "mshv-bindings"]
 sev_snp = ["igvm", "igvm_defs"]
 tdx = []
 
diff --git a/hypervisor/src/arch/x86/mod.rs b/hypervisor/src/arch/x86/mod.rs
index eb3db34a2..6dc195b49 100644
--- a/hypervisor/src/arch/x86/mod.rs
+++ b/hypervisor/src/arch/x86/mod.rs
@@ -11,7 +11,7 @@
 // Copyright © 2020, Microsoft Corporation
 //
 
-#[cfg(all(feature = "mshv", target_arch = "x86_64"))]
+#[cfg(all(feature = "mshv_emulator", target_arch = "x86_64"))]
 pub mod emulator;
 pub mod gdt;
 #[allow(non_camel_case_types)]
diff --git a/hypervisor/src/lib.rs b/hypervisor/src/lib.rs
index ea3bb77df..7fd16ee0c 100644
--- a/hypervisor/src/lib.rs
+++ b/hypervisor/src/lib.rs
@@ -202,7 +202,10 @@ pub enum StandardRegisters {
     Kvm(kvm_bindings::kvm_regs),
     #[cfg(all(feature = "kvm", target_arch = "riscv64"))]
     Kvm(kvm_bindings::kvm_riscv_core),
-    #[cfg(all(feature = "mshv", target_arch = "x86_64"))]
+    #[cfg(all(
+        any(feature = "mshv", feature = "mshv_emulator"),
+        target_arch = "x86_64"
+    ))]
     Mshv(mshv_bindings::StandardRegisters),
 }
 
@@ -215,7 +218,7 @@ macro_rules! set_x86_64_reg {
                     match self {
                         #[cfg(feature = "kvm")]
                         StandardRegisters::Kvm(s) => s.$reg_name = val,
-                        #[cfg(feature = "mshv")]
+                        #[cfg(any(feature = "mshv", feature = "mshv_emulator"))]
                         StandardRegisters::Mshv(s) => s.$reg_name = val,
                     }
                 }
@@ -233,7 +236,7 @@ macro_rules! get_x86_64_reg {
                     match self {
                         #[cfg(feature = "kvm")]
                         StandardRegisters::Kvm(s) => s.$reg_name,
-                        #[cfg(feature = "mshv")]
+                        #[cfg(any(feature = "mshv", feature = "mshv_emulator"))]
                         StandardRegisters::Mshv(s) => s.$reg_name,
                     }
                 }