acpipm: implement suspend and resume mechanism

For suspend request from VM, will write suspend event and notify
crosvm main process to pause VCPUs.

For resume request, it is not from VM itself but by the resume
command through crosvm socket. Resume request will notify the PM
device to fill its wakeup registers with wakeup event so that
when VCPUs start to run, VM can know there is wakeup from outside.

BUG=chromium:1018674
TEST=cargo test -p devices

Change-Id: I4724ffee10150065a62bf520076c16cbc70b7749
Signed-off-by: Chuanxiao Dong <chuanxiao.dong@intel.corp-partner.google.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/2035169
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Tomasz Jeznach <tjeznach@chromium.org>

1 files changed, 22 insertions, 0 deletions

diff --git a/src/linux.rs b/src/linux.rs
index ab6c64c..0f8a848 100644
--- a/src/linux.rs
+++ b/src/linux.rs
@@ -1638,6 +1638,7 @@ fn run_control(
     #[derive(PollToken)]
     enum Token {
         Exit,
+        Suspend,
         ChildSignal,
         CheckAvailableMemory,
         LowMemory,
@@ -1652,6 +1653,7 @@ fn run_control(
 
     let poll_ctx = PollContext::build_with(&[
         (&linux.exit_evt, Token::Exit),
+        (&linux.suspend_evt, Token::Suspend),
         (&sigchld_fd, Token::ChildSignal),
     ])
     .map_err(Error::PollContextAdd)?;
@@ -1744,6 +1746,14 @@ fn run_control(
                     info!("vcpu requested shutdown");
                     break 'poll;
                 }
+                Token::Suspend => {
+                    info!("VM requested suspend");
+                    linux.suspend_evt.read().unwrap();
+                    run_mode_arc.set_and_notify(VmRunMode::Suspending);
+                    for handle in &vcpu_handles {
+                        let _ = handle.kill(SIGRTMIN() + 0);
+                    }
+                }
                 Token::ChildSignal => {
                     // Print all available siginfo structs, then exit the loop.
                     while let Some(siginfo) = sigchld_fd.read().map_err(Error::SignalFd)? {
@@ -1879,6 +1889,17 @@ fn run_control(
                                             VmRunMode::Exiting => {
                                                 break 'poll;
                                             }
+                                            VmRunMode::Running => {
+                                                if let VmRunMode::Suspending =
+                                                    *run_mode_arc.mtx.lock()
+                                                {
+                                                    linux.io_bus.notify_resume();
+                                                }
+                                                run_mode_arc.set_and_notify(VmRunMode::Running);
+                                                for handle in &vcpu_handles {
+                                                    let _ = handle.kill(SIGRTMIN() + 0);
+                                                }
+                                            }
                                             other => {
                                                 run_mode_arc.set_and_notify(other);
                                                 for handle in &vcpu_handles {
@@ -1937,6 +1958,7 @@ fn run_control(
         for event in events.iter_hungup() {
             match event.token() {
                 Token::Exit => {}
+                Token::Suspend => {}
                 Token::ChildSignal => {}
                 Token::CheckAvailableMemory => {}
                 Token::LowMemory => {}