aarch64: add test_run_code

Signed-off-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Diana Popa <dpopa@amazon.com>

src/ioctls/vcpu.rs

@@ -1192,7 +1192,6 @@ impl AsRawFd for VcpuFd {
 mod tests {
     extern crate byteorder;
 
-    #[cfg(target_arch = "x86_64")]
     use super::*;
     use ioctls::system::Kvm;
     #[cfg(any(
@@ -1205,7 +1204,6 @@ mod tests {
 
     // Helper function for memory mapping `size` bytes of anonymous memory.
     // Panics if the mmap fails.
-    #[cfg(target_arch = "x86_64")]
     fn mmap_anonymous(size: usize) -> *mut u8 {
         use std::ptr::null_mut;
 
@@ -1430,6 +1428,101 @@ mod tests {
         }
     }
 
+    #[cfg(target_arch = "aarch64")]
+    #[test]
+    fn test_run_code() {
+        use std::io::Write;
+
+        let kvm = Kvm::new().unwrap();
+        let vm = kvm.create_vm().unwrap();
+        #[rustfmt::skip]
+        let code = [
+            0x40, 0x20, 0x80, 0x52, /* mov w0, #0x102 */
+            0x00, 0x01, 0x00, 0xb9, /* str w0, [x8]; test physical memory write */
+            0x81, 0x60, 0x80, 0x52, /* mov w1, #0x304 */
+            0x02, 0x00, 0x80, 0x52, /* mov w2, #0x0 */
+            0x20, 0x01, 0x40, 0xb9, /* ldr w0, [x9]; test MMIO read */
+            0x1f, 0x18, 0x14, 0x71, /* cmp w0, #0x506 */
+            0x20, 0x00, 0x82, 0x1a, /* csel w0, w1, w2, eq */
+            0x20, 0x01, 0x00, 0xb9, /* str w0, [x9]; test MMIO write */
+            0x00, 0x00, 0x00, 0x14, /* b <this address>; shouldn't get here, but if so loop forever */
+        ];
+
+        let mem_size = 0x20000;
+        let load_addr = mmap_anonymous(mem_size);
+        let guest_addr: u64 = 0x10000;
+        let slot: u32 = 0;
+        let mem_region = kvm_userspace_memory_region {
+            slot,
+            guest_phys_addr: guest_addr,
+            memory_size: mem_size as u64,
+            userspace_addr: load_addr as u64,
+            flags: KVM_MEM_LOG_DIRTY_PAGES,
+        };
+        unsafe {
+            vm.set_user_memory_region(mem_region).unwrap();
+        }
+
+        unsafe {
+            // Get a mutable slice of `mem_size` from `load_addr`.
+            // This is safe because we mapped it before.
+            let mut slice = std::slice::from_raw_parts_mut(load_addr, mem_size);
+            slice.write(&code).unwrap();
+        }
+
+        let vcpu_fd = vm.create_vcpu(0).unwrap();
+        let mut kvi = kvm_bindings::kvm_vcpu_init::default();
+        vm.get_preferred_target(&mut kvi).unwrap();
+        vcpu_fd.vcpu_init(&kvi).unwrap();
+
+        let core_reg_base: u64 = 0x6030_0000_0010_0000;
+        let mmio_addr: u64 = guest_addr + mem_size as u64;
+
+        // Set the PC to the guest address where we loaded the code.
+        vcpu_fd
+            .set_one_reg(core_reg_base + 2 * 32, guest_addr)
+            .unwrap();
+
+        // Set x8 and x9 to the addresses the guest test code needs
+        vcpu_fd
+            .set_one_reg(core_reg_base + 2 * 8, guest_addr + 0x10000)
+            .unwrap();
+        vcpu_fd
+            .set_one_reg(core_reg_base + 2 * 9, mmio_addr)
+            .unwrap();
+
+        loop {
+            match vcpu_fd.run().expect("run failed") {
+                VcpuExit::MmioRead(addr, data) => {
+                    assert_eq!(addr, mmio_addr);
+                    assert_eq!(data.len(), 4);
+                    data[3] = 0x0;
+                    data[2] = 0x0;
+                    data[1] = 0x5;
+                    data[0] = 0x6;
+                }
+                VcpuExit::MmioWrite(addr, data) => {
+                    assert_eq!(addr, mmio_addr);
+                    assert_eq!(data.len(), 4);
+                    assert_eq!(data[3], 0x0);
+                    assert_eq!(data[2], 0x0);
+                    assert_eq!(data[1], 0x3);
+                    assert_eq!(data[0], 0x4);
+                    // The code snippet dirties one page at guest_addr + 0x10000.
+                    // The code page should not be dirty, as it's not written by the guest.
+                    let dirty_pages_bitmap = vm.get_dirty_log(slot, mem_size).unwrap();
+                    let dirty_pages = dirty_pages_bitmap
+                        .into_iter()
+                        .map(|page| page.count_ones())
+                        .fold(0, |dirty_page_count, i| dirty_page_count + i);
+                    assert_eq!(dirty_pages, 1);
+                    break;
+                }
+                r => panic!("unexpected exit reason: {:?}", r),
+            }
+        }
+    }
+
     #[cfg(target_arch = "x86_64")]
     #[test]
     fn test_run_code() {