xref: /aosp_15_r20/external/crosvm/kvm/tests/real_run_adder.rs (revision bb4ee6a4ae7042d18b07a98463b9c8b875e44b39)
1 // Copyright 2017 The ChromiumOS Authors
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 #![cfg(any(target_os = "android", target_os = "linux"))]
6 #![cfg(target_arch = "x86_64")]
7 
8 use kvm::*;
9 use kvm_sys::kvm_regs;
10 use vm_memory::GuestAddress;
11 use vm_memory::GuestMemory;
12 
13 #[test]
test_run()14 fn test_run() {
15     // This example based on https://lwn.net/Articles/658511/
16     let code = [
17         0xba, 0xf8, 0x03, /* mov $0x3f8, %dx */
18         0x00, 0xd8, /* add %bl, %al */
19         0x04, b'0', /* add $'0', %al */
20         0xee, /* out %al, (%dx) */
21         0xb0, b'\n', /* mov $'\n', %al */
22         0xee,  /* out %al, (%dx) */
23         0x2e, 0xc6, 0x06, 0xf1, 0x10, 0x13, /* movb $0x13, %cs:0xf1 */
24         0xf4, /* hlt */
25     ];
26 
27     let mem_size = 0x1000;
28     let load_addr = GuestAddress(0x1000);
29     let mem = GuestMemory::new(&[(load_addr, mem_size)]).unwrap();
30 
31     let kvm = Kvm::new().expect("new kvm failed");
32     let vm = Vm::new(&kvm, mem).expect("new vm failed");
33     let vcpu = Vcpu::new(0, &kvm, &vm).expect("new vcpu failed");
34 
35     vm.get_memory()
36         .write_at_addr(&code, load_addr)
37         .expect("Writing code to memory failed.");
38 
39     let mut vcpu_sregs = vcpu.get_sregs().expect("get sregs failed");
40     assert_ne!(vcpu_sregs.cs.base, 0);
41     assert_ne!(vcpu_sregs.cs.selector, 0);
42     vcpu_sregs.cs.base = 0;
43     vcpu_sregs.cs.selector = 0;
44     vcpu.set_sregs(&vcpu_sregs).expect("set sregs failed");
45 
46     // SAFETY: trivially safe
47     let mut vcpu_regs: kvm_regs = unsafe { std::mem::zeroed() };
48     vcpu_regs.rip = 0x1000;
49     vcpu_regs.rax = 2;
50     vcpu_regs.rbx = 7;
51     vcpu_regs.rflags = 2;
52     vcpu.set_regs(&vcpu_regs).expect("set regs failed");
53 
54     let mut out = String::new();
55     let runnable_vcpu = vcpu.to_runnable(None).unwrap();
56     loop {
57         match runnable_vcpu.run().expect("run failed") {
58             VcpuExit::IoOut {
59                 port: 0x3f8,
60                 size,
61                 data,
62             } => {
63                 assert_eq!(size, 1);
64                 out.push(data[0] as char);
65             }
66             VcpuExit::Hlt => break,
67             r => panic!("unexpected exit reason: {:?}", r),
68         }
69     }
70 
71     assert_eq!(out, "9\n");
72     let result: u8 = vm
73         .get_memory()
74         .read_obj_from_addr(load_addr.checked_add(0xf1).unwrap())
75         .expect("Error reading the result.");
76     assert_eq!(result, 0x13);
77 }
78