pci: add virtio-pci transport implementation

Add a VirtIO PCI transport implementation. Nothing uses it at the
moment. This requires a few changes in our vended pci and vm-device
crates.

Add a couple of tests that ensure that PCI configuration space is what
expected. We read common fields and make sure the BAR we allocate for
the VirtIO device is what expected.

Signed-off-by: Babis Chalios <[email protected]>

Author: bchalios

Cargo.lock

@@ -17,11 +17,13 @@ gdb = ["arrayvec", "gdbstub", "gdbstub_arch"]
 
 acpi_tables = { path = "../acpi-tables" }
 aes-gcm = { version = "0.10.1", default-features = false, features = ["aes"] }
+anyhow = "1.0.98"
 arrayvec = { version = "0.7.6", optional = true }
 aws-lc-rs = { version = "1.13.1", features = ["bindgen"] }
 base64 = "0.22.1"
 bincode = { version = "2.0.1", features = ["serde"] }
 bitflags = "2.9.1"
+byteorder = "1.5.0"
 crc64 = "2.0.0"
 derive_more = { version = "2.0.1", default-features = false, features = [
   "from",

src/vmm/Cargo.toml

@@ -148,7 +148,7 @@ pub trait VirtioDevice: AsAny + Send {
 
     /// Optionally deactivates this device and returns ownership of the guest memory map, interrupt
     /// event, and queue events.
-    fn reset(&mut self) -> Option<(EventFd, Vec<EventFd>)> {
+    fn reset(&mut self) -> Option<(Arc<dyn VirtioInterrupt>, Vec<EventFd>)> {
         None
     }
 

src/vmm/src/devices/virtio/device.rs

@@ -712,6 +712,19 @@ impl Queue {
 
         new - used_event - Wrapping(1) < new - old
     }
+
+    /// Resets the Virtio Queue
+    pub(crate) fn reset(&mut self) {
+        self.ready = false;
+        self.size = self.max_size;
+        self.desc_table_address = GuestAddress(0);
+        self.avail_ring_address = GuestAddress(0);
+        self.used_ring_address = GuestAddress(0);
+        self.next_avail = Wrapping(0);
+        self.next_used = Wrapping(0);
+        self.num_added = Wrapping(0);
+        self.uses_notif_suppression = false;
+    }
 }
 
 #[cfg(kani)]

src/vmm/src/devices/virtio/queue.rs

@@ -8,6 +8,8 @@ use vmm_sys_util::eventfd::EventFd;
 
 /// MMIO transport for VirtIO devices
 pub mod mmio;
+/// PCI transport for VirtIO devices
+pub mod pci;
 
 /// Represents the types of interrupts used by VirtIO devices
 #[derive(Debug, Clone)]