From 8155be2e6b80e3d8c9eca4e21a2b48e968d519b0 Mon Sep 17 00:00:00 2001
From: Wei Liu <liuwe@microsoft.com>
Date: Fri, 14 Jan 2022 18:21:08 +0000
Subject: [PATCH] arch: aarch64: vm_memory is not required when configuring
 vcpu

Drop the unused parameter throughout the code base.

Also take the chance to drop a needless clone.

No functional change intended.

Signed-off-by: Wei Liu <liuwe@microsoft.com>
---
 arch/src/aarch64/mod.rs  | 14 +++-----------
 arch/src/aarch64/regs.rs |  8 +-------
 vmm/src/cpu.rs           | 19 ++++++-------------
 3 files changed, 10 insertions(+), 31 deletions(-)

diff --git a/arch/src/aarch64/mod.rs b/arch/src/aarch64/mod.rs
index 0a915d423..2d9caa353 100644
--- a/arch/src/aarch64/mod.rs
+++ b/arch/src/aarch64/mod.rs
@@ -21,9 +21,7 @@ use std::collections::HashMap;
 use std::convert::TryInto;
 use std::fmt::Debug;
 use std::sync::Arc;
-use vm_memory::{
-    Address, GuestAddress, GuestAddressSpace, GuestMemory, GuestMemoryAtomic, GuestUsize,
-};
+use vm_memory::{Address, GuestAddress, GuestMemory, GuestUsize};
 
 /// Errors thrown while configuring aarch64 system.
 #[derive(Debug)]
@@ -66,16 +64,10 @@ pub fn configure_vcpu(
     fd: &Arc<dyn hypervisor::Vcpu>,
     id: u8,
     kernel_entry_point: Option<EntryPoint>,
-    vm_memory: &GuestMemoryAtomic<GuestMemoryMmap>,
 ) -> super::Result<u64> {
     if let Some(kernel_entry_point) = kernel_entry_point {
-        regs::setup_regs(
-            fd,
-            id,
-            kernel_entry_point.entry_addr.raw_value(),
-            &vm_memory.memory(),
-        )
-        .map_err(Error::RegsConfiguration)?;
+        regs::setup_regs(fd, id, kernel_entry_point.entry_addr.raw_value())
+            .map_err(Error::RegsConfiguration)?;
     }
 
     let mpidr = fd.read_mpidr().map_err(Error::VcpuRegMpidr)?;
diff --git a/arch/src/aarch64/regs.rs b/arch/src/aarch64/regs.rs
index 628fd977d..bc9e449fa 100644
--- a/arch/src/aarch64/regs.rs
+++ b/arch/src/aarch64/regs.rs
@@ -6,7 +6,6 @@
 // found in the THIRD-PARTY file.
 
 use super::get_fdt_addr;
-use crate::GuestMemoryMmap;
 use hypervisor::kvm::kvm_bindings::{
     kvm_regs, user_pt_regs, KVM_REG_ARM64, KVM_REG_ARM_CORE, KVM_REG_SIZE_U64,
 };
@@ -43,12 +42,7 @@ const PSTATE_FAULT_BITS_64: u64 = PSR_MODE_EL1h | PSR_A_BIT | PSR_F_BIT | PSR_I_
 /// * `cpu_id` - Index of current vcpu.
 /// * `boot_ip` - Starting instruction pointer.
 /// * `mem` - Reserved DRAM for current VM.
-pub fn setup_regs(
-    vcpu: &Arc<dyn hypervisor::Vcpu>,
-    cpu_id: u8,
-    boot_ip: u64,
-    _mem: &GuestMemoryMmap,
-) -> Result<()> {
+pub fn setup_regs(vcpu: &Arc<dyn hypervisor::Vcpu>, cpu_id: u8, boot_ip: u64) -> Result<()> {
     let kreg_off = offset__of!(kvm_regs, regs);
 
     // Get the register index of the PSTATE (Processor State) register.
diff --git a/vmm/src/cpu.rs b/vmm/src/cpu.rs
index df21d05c5..579ca28d6 100644
--- a/vmm/src/cpu.rs
+++ b/vmm/src/cpu.rs
@@ -265,14 +265,14 @@ impl Vcpu {
         &mut self,
         #[cfg(target_arch = "aarch64")] vm: &Arc<dyn hypervisor::Vm>,
         kernel_entry_point: Option<EntryPoint>,
-        vm_memory: &GuestMemoryAtomic<GuestMemoryMmap>,
+        #[cfg(target_arch = "x86_64")] vm_memory: &GuestMemoryAtomic<GuestMemoryMmap>,
         #[cfg(target_arch = "x86_64")] cpuid: CpuId,
         #[cfg(target_arch = "x86_64")] kvm_hyperv: bool,
     ) -> Result<()> {
         #[cfg(target_arch = "aarch64")]
         {
             self.init(vm)?;
-            self.mpidr = arch::configure_vcpu(&self.vcpu, self.id, kernel_entry_point, vm_memory)
+            self.mpidr = arch::configure_vcpu(&self.vcpu, self.id, kernel_entry_point)
                 .map_err(Error::VcpuConfiguration)?;
         }
         info!("Configuring vCPU: cpu_id = {}", self.id);
@@ -656,19 +656,17 @@ impl CpuManager {
 
             vcpu.restore(snapshot).expect("Failed to restore vCPU");
         } else {
-            let vm_memory = self.vm_memory.clone();
-
             #[cfg(target_arch = "x86_64")]
             vcpu.configure(
                 entry_point,
-                &vm_memory,
+                &self.vm_memory,
                 self.cpuid.clone(),
                 self.config.kvm_hyperv,
             )
             .expect("Failed to configure vCPU");
 
             #[cfg(target_arch = "aarch64")]
-            vcpu.configure(&self.vm, entry_point, &vm_memory)
+            vcpu.configure(&self.vm, entry_point)
                 .expect("Failed to configure vCPU");
         }
 
@@ -1757,13 +1755,8 @@ mod tests {
         let hv = hypervisor::new().unwrap();
         let vm = hv.create_vm().unwrap();
         let vcpu = vm.create_vcpu(0, None).unwrap();
-        let regions = vec![(
-            GuestAddress(layout::RAM_64BIT_START),
-            (layout::FDT_MAX_SIZE + 0x1000) as usize,
-        )];
-        let mem = GuestMemoryMmap::from_ranges(&regions).expect("Cannot initialize memory");
 
-        let res = setup_regs(&vcpu, 0, 0x0, &mem);
+        let res = setup_regs(&vcpu, 0, 0x0);
         // Must fail when vcpu is not initialized yet.
         assert!(res.is_err());
 
@@ -1771,7 +1764,7 @@ mod tests {
         vm.get_preferred_target(&mut kvi).unwrap();
         vcpu.vcpu_init(&kvi).unwrap();
 
-        assert!(setup_regs(&vcpu, 0, 0x0, &mem).is_ok());
+        assert!(setup_regs(&vcpu, 0, 0x0).is_ok());
     }
 
     #[test]