vfio: Integrate VFIO device into pci device model

Create VFIO device and VFIO PCI device in create_devices() function, and
intergrate it into PciRootBridge, so guest could see this vfio device.

Add a vfio config parameter, this config point to passthrough or mdev
device sysfs path.

For passthrough case, first user unbind host device from its driver,
then bind host device to vfio-pci. Like:
echo 0000:00:02.0 > /sys/bus/pci/devices/0000:00:02.0/driver/unbind
ech0 8086 1912 > /sys/bus/pci/drivers/vfio-pci/new_id
Finally pass the sysfs to crosvm through
--vfio=/sys/bus/pci/devices/0000:00:02.0

For mdev case, user create a mdev device through
echo $UUID > mdev_type/create, then pass this mdev device to crosvm like
--vfio=/sys/bus/pci/devices/0000:00:02.0/$UUID

BUG=chromium:992270
TEST=none

Change-Id: I0f59d6e93f62f9ab0727ad3a867d204f4ff6ad2d
Signed-off-by: Xiong Zhang <xiong.y.zhang@intel.corp-partner.google.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/1581140
Reviewed-by: Daniel Verkamp <dverkamp@chromium.org>
Reviewed-by: Zach Reizner <zachr@chromium.org>
Tested-by: kokoro <noreply+kokoro@google.com>
Commit-Queue: Daniel Verkamp <dverkamp@chromium.org>

1 files changed, 16 insertions, 1 deletions

diff --git a/devices/src/vfio.rs b/devices/src/vfio.rs
index b08414a..6a8c3ea 100644
--- a/devices/src/vfio.rs
+++ b/devices/src/vfio.rs
@@ -111,6 +111,7 @@ impl AsRawFd for VfioContainer {
 
 struct VfioGroup {
     group: File,
+    container: VfioContainer,
 }
 
 impl VfioGroup {
@@ -163,7 +164,10 @@ impl VfioGroup {
 
         Self::kvm_device_add_group(vm, &group_file)?;
 
-        Ok(VfioGroup { group: group_file })
+        Ok(VfioGroup {
+            group: group_file,
+            container,
+        })
     }
 
     fn kvm_device_add_group(vm: &Vm, group: &File) -> Result<File, VfioError> {
@@ -230,6 +234,7 @@ struct VfioRegion {
 /// Vfio device for exposing regions which could be read/write to kernel vfio device.
 pub struct VfioDevice {
     dev: File,
+    group: VfioGroup,
     regions: Vec<VfioRegion>,
 }
 
@@ -254,6 +259,7 @@ impl VfioDevice {
 
         Ok(VfioDevice {
             dev: new_dev,
+            group,
             regions: dev_regions,
         })
     }
@@ -368,6 +374,15 @@ impl VfioDevice {
             );
         }
     }
+
+    /// get vfio device's fds which are passed into minijail process
+    pub fn keep_fds(&self) -> Vec<RawFd> {
+        let mut fds = Vec::new();
+        fds.push(self.as_raw_fd());
+        fds.push(self.group.as_raw_fd());
+        fds.push(self.group.container.as_raw_fd());
+        fds
+    }
 }
 
 impl AsRawFd for VfioDevice {