From cd7f36a7138b00c2b7381f87cdc7a86d526316c8 Mon Sep 17 00:00:00 2001
From: Michael Zhao <michael.zhao@arm.com>
Date: Thu, 28 Jul 2022 14:06:25 +0800
Subject: [PATCH] hypervisor: Remove `get/set_reg()` on AArch64

`Vcpu::get/set_reg()` were only invoked in Vcpu itself.

Signed-off-by: Michael Zhao <michael.zhao@arm.com>
---
 hypervisor/src/cpu.rs     | 10 ----------
 hypervisor/src/kvm/mod.rs | 35 ++++++++++-------------------------
 vmm/src/cpu.rs            |  5 -----
 3 files changed, 10 insertions(+), 40 deletions(-)

diff --git a/hypervisor/src/cpu.rs b/hypervisor/src/cpu.rs
index 1eba6b53a..89bea2718 100644
--- a/hypervisor/src/cpu.rs
+++ b/hypervisor/src/cpu.rs
@@ -360,16 +360,6 @@ pub trait Vcpu: Send + Sync {
     #[cfg(target_arch = "aarch64")]
     fn vcpu_init(&self, kvi: &VcpuInit) -> Result<()>;
     ///
-    /// Sets the value of one register for this vCPU.
-    ///
-    #[cfg(target_arch = "aarch64")]
-    fn set_reg(&self, reg_id: u64, data: u64) -> Result<()>;
-    ///
-    /// Sets the value of one register for this vCPU.
-    ///
-    #[cfg(target_arch = "aarch64")]
-    fn get_reg(&self, reg_id: u64) -> Result<u64>;
-    ///
     /// Gets a list of the guest registers that are supported for the
     /// KVM_GET_ONE_REG/KVM_SET_ONE_REG calls.
     ///
diff --git a/hypervisor/src/kvm/mod.rs b/hypervisor/src/kvm/mod.rs
index 7fd1667e9..e0c50877c 100644
--- a/hypervisor/src/kvm/mod.rs
+++ b/hypervisor/src/kvm/mod.rs
@@ -1626,24 +1626,6 @@ impl cpu::Vcpu for KvmVcpu {
             .map_err(|e| cpu::HypervisorCpuError::VcpuInit(e.into()))
     }
     ///
-    /// Sets the value of one register for this vCPU.
-    ///
-    #[cfg(target_arch = "aarch64")]
-    fn set_reg(&self, reg_id: u64, data: u64) -> cpu::Result<()> {
-        self.fd
-            .set_one_reg(reg_id, data)
-            .map_err(|e| cpu::HypervisorCpuError::SetRegister(e.into()))
-    }
-    ///
-    /// Gets the value of one register for this vCPU.
-    ///
-    #[cfg(target_arch = "aarch64")]
-    fn get_reg(&self, reg_id: u64) -> cpu::Result<u64> {
-        self.fd
-            .get_one_reg(reg_id)
-            .map_err(|e| cpu::HypervisorCpuError::GetRegister(e.into()))
-    }
-    ///
     /// Gets a list of the guest registers that are supported for the
     /// KVM_GET_ONE_REG/KVM_SET_ONE_REG calls.
     ///
@@ -1683,17 +1665,19 @@ impl cpu::Vcpu for KvmVcpu {
 
         // Get the register index of the PSTATE (Processor State) register.
         let pstate = offset__of!(user_pt_regs, pstate) + kreg_off;
-        self.set_reg(
-            arm64_core_reg_id!(KVM_REG_SIZE_U64, pstate),
-            PSTATE_FAULT_BITS_64,
-        )
-        .map_err(|e| cpu::HypervisorCpuError::SetCoreRegister(e.into()))?;
+        self.fd
+            .set_one_reg(
+                arm64_core_reg_id!(KVM_REG_SIZE_U64, pstate),
+                PSTATE_FAULT_BITS_64,
+            )
+            .map_err(|e| cpu::HypervisorCpuError::SetCoreRegister(e.into()))?;
 
         // Other vCPUs are powered off initially awaiting PSCI wakeup.
         if cpu_id == 0 {
             // Setting the PC (Processor Counter) to the current program address (kernel address).
             let pc = offset__of!(user_pt_regs, pc) + kreg_off;
-            self.set_reg(arm64_core_reg_id!(KVM_REG_SIZE_U64, pc), boot_ip as u64)
+            self.fd
+                .set_one_reg(arm64_core_reg_id!(KVM_REG_SIZE_U64, pc), boot_ip as u64)
                 .map_err(|e| cpu::HypervisorCpuError::SetCoreRegister(e.into()))?;
 
             // Last mandatory thing to set -> the address pointing to the FDT (also called DTB).
@@ -1701,7 +1685,8 @@ impl cpu::Vcpu for KvmVcpu {
             // not exceed 2 megabytes in size." -> https://www.kernel.org/doc/Documentation/arm64/booting.txt.
             // We are choosing to place it the end of DRAM. See `get_fdt_addr`.
             let regs0 = offset__of!(user_pt_regs, regs) + kreg_off;
-            self.set_reg(arm64_core_reg_id!(KVM_REG_SIZE_U64, regs0), fdt_start)
+            self.fd
+                .set_one_reg(arm64_core_reg_id!(KVM_REG_SIZE_U64, regs0), fdt_start)
                 .map_err(|e| cpu::HypervisorCpuError::SetCoreRegister(e.into()))?;
         }
         Ok(())
diff --git a/vmm/src/cpu.rs b/vmm/src/cpu.rs
index 8302b2ea3..6942c2d5e 100644
--- a/vmm/src/cpu.rs
+++ b/vmm/src/cpu.rs
@@ -2491,11 +2491,6 @@ mod tests {
         assert_eq!(state.regs.pstate, 0x3C5);
 
         assert!(vcpu.set_regs(&state).is_ok());
-        let off = offset__of!(user_pt_regs, pstate);
-        let pstate = vcpu
-            .get_reg(arm64_core_reg_id!(KVM_REG_SIZE_U64, off))
-            .expect("Failed to call kvm get one reg");
-        assert_eq!(state.regs.pstate, pstate);
     }
 
     #[test]