virtio_sys: add virtio_fs bindings

Replace the hand-written bindings in the virtio-fs device with
automatically generated bindings from bindgen.

BUG=None
TEST=./virtio_sys/bindgen.sh

Change-Id: Ia11a2d97f3546515196a41764107e7aaece8ad82
Reviewed-on: https://chromium-review.googlesource.com/c/crosvm/crosvm/+/4103907
Reviewed-by: Alexandre Courbot <acourbot@chromium.org>
Commit-Queue: Daniel Verkamp <dverkamp@chromium.org>

devices/src/virtio/fs/mod.rs

@@ -22,6 +22,8 @@ use remain::sorted;
 use resources::Alloc;
 use sync::Mutex;
 use thiserror::Error;
+use virtio_sys::virtio_fs::virtio_fs_config;
+use virtio_sys::virtio_fs::VIRTIO_FS_SHMCAP_ID_CACHE;
 use vm_control::FsMappingRequest;
 use vm_control::VmResponse;
 use vm_memory::GuestMemory;
@@ -59,25 +61,9 @@ const FS_BAR_NUM: u8 = 4;
 const FS_BAR_OFFSET: u64 = 0;
 const FS_BAR_SIZE: u64 = 1 << 33;
 
-/// Defined in kernel/include/uapi/linux/virtio_fs.h.
-const VIRTIO_FS_SHMCAP_ID_CACHE: u8 = 0;
-
 /// The maximum allowable length of the tag used to identify a specific virtio-fs device.
 pub const FS_MAX_TAG_LEN: usize = 36;
 
-/// kernel/include/uapi/linux/virtio_fs.h
-#[repr(C, packed)]
-#[derive(Clone, Copy)]
-pub struct virtio_fs_config {
-    /// Filesystem name (UTF-8, not NUL-terminated, padded with NULs)
-    pub tag: [u8; FS_MAX_TAG_LEN],
-    /// Number of request queues
-    pub num_request_queues: Le32,
-}
-
-// Safe because all members are plain old data and any value is valid.
-unsafe impl DataInit for virtio_fs_config {}
-
 /// Errors that may occur during the creation or operation of an Fs device.
 #[sorted]
 #[derive(Error, Debug)]
@@ -353,7 +339,7 @@ impl VirtioDevice for Fs {
             FS_BAR_NUM,
             FS_BAR_OFFSET,
             FS_BAR_SIZE,
-            VIRTIO_FS_SHMCAP_ID_CACHE,
+            VIRTIO_FS_SHMCAP_ID_CACHE as u8,
         ))]
     }
 }

devices/src/virtio/vhost/user/device/fs.rs

@@ -27,6 +27,7 @@ use futures::future::Abortable;
 use hypervisor::ProtectionType;
 use sync::Mutex;
 pub use sys::start_device as run_fs_device;
+use virtio_sys::virtio_fs::virtio_fs_config;
 use vm_memory::GuestMemory;
 use vmm_vhost::message::VhostUserProtocolFeatures;
 use vmm_vhost::message::VhostUserVirtioFeatures;
@@ -35,7 +36,6 @@ use crate::virtio;
 use crate::virtio::copy_config;
 use crate::virtio::fs::passthrough::PassthroughFs;
 use crate::virtio::fs::process_fs_queue;
-use crate::virtio::fs::virtio_fs_config;
 use crate::virtio::fs::FS_MAX_TAG_LEN;
 use crate::virtio::vhost::user::device::handler::sys::Doorbell;
 use crate::virtio::vhost::user::device::handler::VhostUserBackend;

devices/src/virtio/vhost/user/vmm/fs.rs

@@ -4,9 +4,9 @@
 
 use data_model::DataInit;
 use data_model::Le32;
+use virtio_sys::virtio_fs::virtio_fs_config;
 use vmm_vhost::message::VhostUserProtocolFeatures;
 
-use crate::virtio::fs::virtio_fs_config;
 use crate::virtio::fs::FS_MAX_TAG_LEN;
 use crate::virtio::fs::QUEUE_SIZE;
 use crate::virtio::vhost::user::vmm::Connection;

virtio_sys/bindgen.sh

@@ -35,6 +35,24 @@ bindgen_generate \
     | replace_linux_int_types \
     > virtio_sys/src/virtio_config.rs
 
+VIRTIO_FS_EXTRA="// Added by virtio_sys/bindgen.sh
+use data_model::DataInit;
+use data_model::Le32;
+
+// Safe because all members are plain old data and any value is valid.
+unsafe impl DataInit for virtio_fs_config {}"
+
+bindgen_generate \
+    --raw-line "${VIRTIO_FS_EXTRA}" \
+    --allowlist-var='VIRTIO_FS_.*' \
+    --allowlist-type='virtio_fs_.*' \
+    "${BINDGEN_LINUX_X86_HEADERS}/include/linux/virtio_fs.h" \
+    -- \
+    -isystem "${BINDGEN_LINUX_X86_HEADERS}/include" \
+    | replace_linux_int_types \
+    | replace_linux_endian_types \
+    > virtio_sys/src/virtio_fs.rs
+
 VIRTIO_IDS_EXTRAS="
 //! This file defines virtio device IDs. IDs with large values (counting down
 //! from 63) are nonstandard and not defined by the virtio specification.

virtio_sys/src/lib.rs

@@ -15,6 +15,7 @@ use base::ioctl_iowr_nr;
 
 pub mod vhost;
 pub mod virtio_config;
+pub mod virtio_fs;
 pub mod virtio_ids;
 pub mod virtio_mmio;
 pub mod virtio_net;

virtio_sys/src/virtio_fs.rs

@@ -0,0 +1,32 @@
+/* automatically generated by tools/bindgen-all-the-things */
+
+#![allow(clippy::missing_safety_doc)]
+#![allow(clippy::upper_case_acronyms)]
+#![allow(non_upper_case_globals)]
+#![allow(non_camel_case_types)]
+#![allow(non_snake_case)]
+#![allow(dead_code)]
+
+// Added by virtio_sys/bindgen.sh
+use data_model::DataInit;
+use data_model::Le32;
+
+// Safe because all members are plain old data and any value is valid.
+unsafe impl DataInit for virtio_fs_config {}
+
+pub const VIRTIO_FS_SHMCAP_ID_CACHE: u32 = 0;
+#[repr(C, packed)]
+#[derive(Debug, Copy, Clone)]
+pub struct virtio_fs_config {
+    pub tag: [u8; 36usize],
+    pub num_request_queues: Le32,
+}
+impl Default for virtio_fs_config {
+    fn default() -> Self {
+        let mut s = ::std::mem::MaybeUninit::<Self>::uninit();
+        unsafe {
+            ::std::ptr::write_bytes(s.as_mut_ptr(), 0, 1);
+            s.assume_init()
+        }
+    }
+}