devices: finish the functions to enable MSI-X

- add a new field "vector" to struct Queue, which represents the entry
  number to the MSI-X Table. This can be used to find out the desired irqfd
  to inject MSI-X interrupts to the guest.
- enable MSI-X when MSI-X Enable bit of the Message Control word is
  being set: allocate irqfd per MSI-X vector; register the irqfd to KVM;
  update GSI routing to KVM.
- update GSI routing if the Message Data or Message Addr of individual
  MSI-X table Entry is being changed in run time.

BUG=chromium:854765
TEST=cargo test -p devices

Change-Id: I81533999ab6cd9ec5f111b256caf34077a4a7d1a
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Signed-off-by: Xiong Zhang <xiong.y.zhang@intel.corp-partner.google.com>
Signed-off-by: Zide Chen <zide.chen@intel.corp-partner.google.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/1828338
Reviewed-by: Daniel Verkamp <dverkamp@chromium.org>
Tested-by: Daniel Verkamp <dverkamp@chromium.org>
Commit-Queue: Stephen Barber <smbarber@chromium.org>

1 files changed, 4 insertions, 3 deletions

diff --git a/devices/src/virtio/virtio_pci_common_config.rs b/devices/src/virtio/virtio_pci_common_config.rs
index 977e2c0..d1ea3e8 100644
--- a/devices/src/virtio/virtio_pci_common_config.rs
+++ b/devices/src/virtio/virtio_pci_common_config.rs
@@ -118,10 +118,11 @@ impl VirtioPciCommonConfig {
 
     fn read_common_config_word(&self, offset: u64, queues: &[Queue]) -> u16 {
         match offset {
-            0x10 => 0,                   // TODO msi-x (crbug/854765): self.msix_config,
+            0x10 => self.msix_config,
             0x12 => queues.len() as u16, // num_queues
             0x16 => self.queue_select,
             0x18 => self.with_queue(queues, |q| q.size).unwrap_or(0),
+            0x1a => self.with_queue(queues, |q| q.vector).unwrap_or(0),
             0x1c => {
                 if self.with_queue(queues, |q| q.ready).unwrap_or(false) {
                     1
@@ -136,10 +137,10 @@ impl VirtioPciCommonConfig {
 
     fn write_common_config_word(&mut self, offset: u64, value: u16, queues: &mut [Queue]) {
         match offset {
-            0x10 => (), // TODO msi-x (crbug/854765): self.msix_config = value,
+            0x10 => self.msix_config = value,
             0x16 => self.queue_select = value,
             0x18 => self.with_queue_mut(queues, |q| q.size = value),
-            0x1a => (), // TODO msi-x (crbug/854765): self.with_queue_mut(queues, |q| q.msix_vector = v),
+            0x1a => self.with_queue_mut(queues, |q| q.vector = value),
             0x1c => self.with_queue_mut(queues, |q| q.ready = value == 1),
             _ => {
                 warn!("invalid virtio register word write: 0x{:x}", offset);