devices: implement dedicated Interrupt struct for virtio Worker

The code to inject interrupt to the guest can be generic to all
virtio devices. This patch:

- move those guest interrupt related fields out of Worker structure and
  put in a separate file, making the worker code cleaner.
- remove redandant functions across virtio devices: signal_used_queue(),
  signal_config_changed(), etc.

BUG=chromium:854765
TEST=sanity test on eve and Linux
TEST=cargo test -p devices

Change-Id: I8e9f760f2057f192fdc74d16a59fea2e6b08c194
Signed-off-by: Zide Chen <zide.chen@intel.corp-partner.google.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/1869553
Reviewed-by: Daniel Verkamp <dverkamp@chromium.org>
Tested-by: Daniel Verkamp <dverkamp@chromium.org>
Tested-by: kokoro <noreply+kokoro@google.com>
Commit-Queue: Daniel Verkamp <dverkamp@chromium.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/devices/src/virtio/mod.rs b/devices/src/virtio/mod.rs
index 49f4355..ca3511f 100644
--- a/devices/src/virtio/mod.rs
+++ b/devices/src/virtio/mod.rs
@@ -10,6 +10,7 @@ mod descriptor_utils;
 #[cfg(feature = "gpu")]
 mod gpu;
 mod input;
+mod interrupt;
 mod net;
 mod p9;
 mod pmem;
@@ -32,6 +33,7 @@ pub use self::descriptor_utils::*;
 #[cfg(feature = "gpu")]
 pub use self::gpu::*;
 pub use self::input::*;
+pub use self::interrupt::*;
 pub use self::net::*;
 pub use self::p9::*;
 pub use self::pmem::*;