kvm: add dirty log support

This add safe support for KVM's KVM_GET_DIRTY_LOG ioctl.

TEST=./build_test
BUG=None

Change-Id: I3d0f996927844a33addd072f2bfc62361f8b7fe0
Reviewed-on: https://chromium-review.googlesource.com/848019
Commit-Ready: Zach Reizner <zachr@chromium.org>
Tested-by: Zach Reizner <zachr@chromium.org>
Reviewed-by: Zach Reizner <zachr@chromium.org>

1 files changed, 70 insertions, 0 deletions

diff --git a/kvm/tests/dirty_log.rs b/kvm/tests/dirty_log.rs
new file mode 100644
index 0000000..94f854e
--- /dev/null
+++ b/kvm/tests/dirty_log.rs
@@ -0,0 +1,70 @@
+// Copyright 2017 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#![cfg(any(target_arch = "x86", target_arch = "x86_64"))]
+
+extern crate sys_util;
+extern crate kvm_sys;
+extern crate kvm;
+
+use kvm::*;
+use kvm_sys::kvm_regs;
+use sys_util::{GuestAddress, GuestMemory, SharedMemory, MemoryMapping};
+
+#[test]
+fn test_run() {
+    /*
+    0000  881C mov [si],bl
+    0002  F4   hlt
+    */
+    let code = [0x88, 0x1c, 0xf4];
+    let mem_size = 0x10000;
+    let load_addr = GuestAddress(0x1000);
+    let guest_mem = GuestMemory::new(&[]).unwrap();
+    let mut mem = SharedMemory::new(None).expect("failed to create shared memory");
+    mem.set_size(mem_size)
+        .expect("failed to set shared memory size");
+    let mmap = MemoryMapping::from_fd(&mem, mem_size as usize)
+        .expect("failed to create memory mapping");
+
+    mmap.write_slice(&code[..], load_addr.offset())
+        .expect("Writing code to memory failed.");
+
+    let kvm = Kvm::new().expect("new kvm failed");
+    let mut vm = Vm::new(&kvm, guest_mem).expect("new vm failed");
+    let vcpu = Vcpu::new(0, &kvm, &vm).expect("new vcpu failed");
+    let mut vcpu_sregs = vcpu.get_sregs().expect("get sregs failed");
+    vcpu_sregs.cs.base = 0;
+    vcpu_sregs.cs.selector = 0;
+    vcpu.set_sregs(&vcpu_sregs).expect("set sregs failed");
+
+    let mut vcpu_regs: kvm_regs = unsafe { std::mem::zeroed() };
+    vcpu_regs.rip = load_addr.offset() as u64;
+    vcpu_regs.rflags = 2;
+    // Write 0x12 to the beginning of the 9th page.
+    vcpu_regs.rsi = 0x8000;
+    vcpu_regs.rbx = 0x12;
+    vcpu.set_regs(&vcpu_regs).expect("set regs failed");
+    let slot = vm.add_device_memory(GuestAddress(0),
+        MemoryMapping::from_fd(&mem, mem_size as usize)
+            .expect("failed to create memory mapping"),
+        true)
+        .expect("failed to register memory");
+
+
+    loop {
+        match vcpu.run().expect("run failed") {
+            VcpuExit::Hlt => break,
+            r => panic!("unexpected exit reason: {:?}", r),
+        }
+    }
+
+    let mut dirty_log = [0x0, 0x0];
+    vm.get_dirty_log(slot, &mut dirty_log[..])
+        .expect("failed to get dirty log");
+    // Tests the 9th page was written to.
+    assert_eq!(dirty_log[1], 0x1);
+    assert_eq!(mmap.read_obj::<u64>(vcpu_regs.rsi as usize).unwrap(),
+               vcpu_regs.rbx);
+}