Bring back DAX

src/arch/src/aarch64/mod.rs

@@ -42,8 +42,8 @@ pub enum Error {
 
 /// The start of the memory area reserved for MMIO devices.
 pub const MMIO_MEM_START: u64 = layout::MAPPED_IO_START;
-/// The size of the MMIO shared memory area used by virtio-fs DAX.
-pub const MMIO_SHM_SIZE: u64 = 1 << 33;
+/// The size of the MMIO shared memory area used by virtio-fs DAX and virtio-gpu.
+pub const MMIO_SHM_SIZE: u64 = 1 << 34;
 
 pub use self::fdt::DeviceInfoForFDT;
 use crate::DeviceType;

src/arch/src/x86_64/mod.rs

@@ -60,8 +60,8 @@ const FIRST_ADDR_PAST_32BITS: u64 = 1 << 32;
 const MEM_32BIT_GAP_SIZE: u64 = 768 << 20;
 /// The start of the memory area reserved for MMIO devices.
 pub const MMIO_MEM_START: u64 = FIRST_ADDR_PAST_32BITS - MEM_32BIT_GAP_SIZE;
-/// The size of the MMIO shared memory area used by virtio-fs DAX.
-pub const MMIO_SHM_SIZE: u64 = 1 << 33;
+/// The size of the MMIO shared memory area used by virtio-fs DAX and virtio-gpu.
+pub const MMIO_SHM_SIZE: u64 = 1 << 34;
 
 /// Returns a Vec of the valid memory addresses.
 /// These should be used to configure the GuestMemoryMmap structure for the platform.

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

@@ -201,6 +201,7 @@ impl VirtioDevice for Fs {
             mem.clone(),
             self.passthrough_cfg.clone(),
             self.worker_stopfd.try_clone().unwrap(),
+            self.shm_region.clone(),
         );
         self.worker_thread = Some(worker.run());
 

src/devices/src/virtio/fs/worker.rs

@@ -13,6 +13,7 @@ use super::descriptor_utils::{Reader, Writer};
 use super::passthrough::{self, PassthroughFs};
 use super::server::Server;
 use crate::legacy::Gic;
+use crate::virtio::VirtioShmRegion;
 
 pub struct FsWorker {
     queues: Vec<Queue>,
@@ -25,6 +26,7 @@ pub struct FsWorker {
     mem: GuestMemoryMmap,
     server: Server<PassthroughFs>,
     stop_fd: EventFd,
+    shm_region: Option<VirtioShmRegion>,
 }
 
 impl FsWorker {
@@ -39,6 +41,7 @@ impl FsWorker {
         mem: GuestMemoryMmap,
         passthrough_cfg: passthrough::Config,
         stop_fd: EventFd,
+        shm_region: Option<VirtioShmRegion>,
     ) -> Self {
         Self {
             queues,
@@ -51,6 +54,7 @@ impl FsWorker {
             mem,
             server: Server::new(PassthroughFs::new(passthrough_cfg).unwrap()),
             stop_fd,
+            shm_region,
         }
     }
 
@@ -149,7 +153,10 @@ impl FsWorker {
                 .map_err(FsError::QueueWriter)
                 .unwrap();
 
-            if let Err(e) = self.server.handle_message(reader, writer, None) {
+            if let Err(e) = self
+                .server
+                .handle_message(reader, writer, self.shm_region.as_ref())
+            {
                 error!("error handling message: {:?}", e);
             }
 

src/vmm/src/builder.rs

@@ -554,13 +554,27 @@ pub fn build_microvm(
         )?;
     }
 
+    // Use half of the shmem region for virtio-gpu and half for DAX
+    let _shm_region_size = arch_memory_info.shm_size >> 1;
+
     #[cfg(not(feature = "tee"))]
-    let _shm_region = Some(VirtioShmRegion {
+    let dax_shm_region = Some(VirtioShmRegion {
         host_addr: guest_memory
             .get_host_address(GuestAddress(arch_memory_info.shm_start_addr))
             .unwrap() as u64,
         guest_addr: arch_memory_info.shm_start_addr,
-        size: arch_memory_info.shm_size as usize,
+        size: _shm_region_size as usize,
+    });
+
+    #[cfg(feature = "gpu")]
+    let gpu_shm_region = Some(VirtioShmRegion {
+        host_addr: guest_memory
+            .get_host_address(GuestAddress(
+                arch_memory_info.shm_start_addr + _shm_region_size,
+            ))
+            .unwrap() as u64,
+        guest_addr: arch_memory_info.shm_start_addr + _shm_region_size,
+        size: _shm_region_size as usize,
     });
 
     let mut vmm = Vmm {
@@ -591,15 +605,15 @@ pub fn build_microvm(
         attach_gpu_device(
             &mut vmm,
             event_manager,
-            _shm_region,
+            gpu_shm_region,
             intc.clone(),
             virgl_flags,
             #[cfg(target_os = "macos")]
             _map_sender,
         )?;
     }
     #[cfg(not(feature = "tee"))]
-    attach_fs_devices(&mut vmm, &vm_resources.fs, None, intc.clone())?;
+    attach_fs_devices(&mut vmm, &vm_resources.fs, dax_shm_region, intc.clone())?;
     #[cfg(feature = "blk")]
     attach_block_devices(&mut vmm, &vm_resources.block, intc.clone())?;
     if let Some(vsock) = vm_resources.vsock.get() {

src/vmm/src/vmm_config/boot_source.rs

@@ -18,7 +18,7 @@ use std::fmt::{Display, Formatter, Result};
 
 #[cfg(all(target_os = "linux", not(feature = "tee")))]
 pub const DEFAULT_KERNEL_CMDLINE: &str = "reboot=k panic=-1 panic_print=0 nomodule console=hvc0 \
-                                          rootfstype=virtiofs rw quiet no-kvmapf";
+                                          rootflags=dax rootfstype=virtiofs rw quiet no-kvmapf";
 
 #[cfg(feature = "amd-sev")]
 pub const DEFAULT_KERNEL_CMDLINE: &str = "reboot=k panic=-1 panic_print=0 nomodule console=hvc0 \