devices: virtio: factor out interrupt signal function

This will be used for configuration interrupts as well.

No functional change.

BUG=chromium:854765
TEST=./build_test.py

Change-Id: Iacccfd0a93a5c90783033a8e37598c2683704351
Signed-off-by: Daniel Verkamp <dverkamp@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/1898267
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Zide Chen <zide.chen@intel.corp-partner.google.com>
Reviewed-by: Zach Reizner <zachr@chromium.org>

1 files changed, 8 insertions, 3 deletions

diff --git a/devices/src/virtio/interrupt.rs b/devices/src/virtio/interrupt.rs
index 2715d12..0665b3f 100644
--- a/devices/src/virtio/interrupt.rs
+++ b/devices/src/virtio/interrupt.rs
@@ -35,7 +35,7 @@ impl Interrupt {
     ///
     /// If MSI-X is enabled in this device, MSI-X interrupt is preferred.
     /// Write to the irqfd to VMM to deliver virtual interrupt to the guest
-    pub fn signal_used_queue(&self, vector: u16) {
+    fn signal(&self, vector: u16, interrupt_status_mask: u32) {
         // Don't need to set ISR for MSI-X interrupts
         if let Some(msix_config) = &self.msix_config {
             let mut msix_config = msix_config.lock();
@@ -47,11 +47,11 @@ impl Interrupt {
             }
         }
 
-        // Set BIT0 in ISR and inject the interrupt if it was not already pending.
+        // Set bit in ISR and inject the interrupt if it was not already pending.
         // Don't need to inject the interrupt if the guest hasn't processed it.
         if self
             .interrupt_status
-            .fetch_or(INTERRUPT_STATUS_USED_RING as usize, Ordering::SeqCst)
+            .fetch_or(interrupt_status_mask as usize, Ordering::SeqCst)
             == 0
         {
             // Write to irqfd to inject INTx interrupt
@@ -59,6 +59,11 @@ impl Interrupt {
         }
     }
 
+    /// Notify the driver that buffers have been placed in the used queue.
+    pub fn signal_used_queue(&self, vector: u16) {
+        self.signal(vector, INTERRUPT_STATUS_USED_RING)
+    }
+
     /// Notification of Device Configuration Changes
     /// Set BIT1 in ISR and write to irqfd
     pub fn signal_config_changed(&self) {