trait Pause for device pause and resume

alioth/src/board/board.rs

@@ -39,14 +39,14 @@ use crate::arch::layout::{
     PCIE_MMIO_32_NON_PREFETCHABLE_START, PCIE_MMIO_32_PREFETCHABLE_END,
     PCIE_MMIO_32_PREFETCHABLE_START, RAM_32_SIZE,
 };
+use crate::device::MmioDev;
 #[cfg(target_arch = "x86_64")]
 use crate::device::fw_cfg::FwCfg;
 use crate::errors::{DebugTrace, trace_error};
 use crate::hv::{Coco, Vcpu, Vm, VmEntry, VmExit};
 #[cfg(target_arch = "x86_64")]
 use crate::loader::xen;
 use crate::loader::{Executable, InitState, Payload, linux};
-use crate::mem::emulated::Mmio;
 use crate::mem::mapped::ArcMemPages;
 use crate::mem::{MemBackend, MemConfig, MemRegion, MemRegionType, Memory};
 use crate::pci::bus::PciBus;
@@ -210,9 +210,9 @@ where
     pub arch: ArchBoard<V>,
     pub config: BoardConfig,
     pub payload: RwLock<Option<Payload>>,
-    pub io_devs: RwLock<Vec<(u16, Arc<dyn Mmio>)>>,
+    pub io_devs: RwLock<Vec<(u16, Arc<dyn MmioDev>)>>,
     #[cfg(target_arch = "aarch64")]
-    pub mmio_devs: RwLock<Vec<(u64, Arc<MemRegion>)>>,
+    pub mmio_devs: RwLock<Vec<(u64, Arc<dyn MmioDev>)>>,
     pub pci_bus: PciBus,
     #[cfg(target_arch = "x86_64")]
     pub fw_cfg: Mutex<Option<Arc<Mutex<FwCfg>>>>,
@@ -419,7 +419,7 @@ where
             }
             #[cfg(target_arch = "aarch64")]
             for (addr, dev) in self.mmio_devs.read().iter() {
-                self.memory.add_region(*addr, dev.clone())?;
+                self.memory.add_mmio_dev(*addr, dev.clone())?;
             }
             self.add_pci_devs()?;
             let init_state = self.load_payload()?;

alioth/src/device/device.rs

@@ -12,6 +12,12 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+use alioth_macros::trace_error;
+use snafu::Snafu;
+
+use crate::errors::DebugTrace;
+use crate::mem::emulated::Mmio;
+
 pub mod console;
 #[cfg(target_arch = "x86_64")]
 #[path = "fw_cfg/fw_cfg.rs"]
@@ -21,6 +27,26 @@ pub mod net;
 pub mod pl011;
 #[cfg(target_arch = "aarch64")]
 pub mod pl031;
-pub mod pvpanic;
 #[cfg(target_arch = "x86_64")]
 pub mod serial;
+
+#[trace_error]
+#[derive(Snafu, DebugTrace)]
+#[snafu(module, visibility(pub(crate)), context(suffix(false)))]
+pub enum Error {
+    #[snafu(display("Device is not pausable"))]
+    NotPausable,
+}
+
+pub type Result<T, E = Error> = std::result::Result<T, E>;
+
+pub trait Pause {
+    fn pause(&self) -> Result<()> {
+        error::NotPausable.fail()
+    }
+    fn resume(&self) -> Result<()> {
+        error::NotPausable.fail()
+    }
+}
+
+pub trait MmioDev: Mmio + Pause {}

alioth/src/device/fw_cfg/fw_cfg.rs

@@ -39,6 +39,7 @@ use zerocopy::{FromBytes, Immutable, IntoBytes};
 use crate::arch::layout::{
     PORT_FW_CFG_DATA, PORT_FW_CFG_DMA_HI, PORT_FW_CFG_DMA_LO, PORT_FW_CFG_SELECTOR,
 };
+use crate::device::{self, MmioDev, Pause};
 #[cfg(target_arch = "x86_64")]
 use crate::firmware::acpi::AcpiTable;
 #[cfg(target_arch = "x86_64")]
@@ -512,6 +513,18 @@ impl Mmio for Mutex<FwCfg> {
     }
 }
 
+impl Pause for Mutex<FwCfg> {
+    fn pause(&self) -> device::Result<()> {
+        Ok(())
+    }
+
+    fn resume(&self) -> device::Result<()> {
+        Ok(())
+    }
+}
+
+impl MmioDev for Mutex<FwCfg> {}
+
 #[derive(Debug, PartialEq, Eq, Deserialize, Help)]
 pub enum FwCfgContentParam {
     /// Path to a file with binary contents.

alioth/src/device/pl011.rs

@@ -20,6 +20,7 @@ use bitflags::bitflags;
 use parking_lot::Mutex;
 
 use crate::device::console::{Console, UartRecv};
+use crate::device::{self, MmioDev, Pause};
 use crate::hv::IrqSender;
 use crate::mem::emulated::{Action, Mmio};
 use crate::{hv, mem};
@@ -258,6 +259,21 @@ where
     }
 }
 
+impl<I> Pause for Pl011<I>
+where
+    I: IrqSender,
+{
+    fn pause(&self) -> device::Result<()> {
+        Ok(())
+    }
+
+    fn resume(&self) -> device::Result<()> {
+        Ok(())
+    }
+}
+
+impl<I> MmioDev for Pl011<I> where I: IrqSender {}
+
 struct Pl011Recv<I: IrqSender> {
     irq_line: Arc<I>,
     reg: Arc<Mutex<Pl011Reg>>,

alioth/src/device/pl031.rs

@@ -20,6 +20,7 @@ use std::time::{SystemTime, UNIX_EPOCH};
 use bitflags::bitflags;
 use parking_lot::Mutex;
 
+use crate::device::{self, MmioDev, Pause};
 use crate::mem;
 use crate::mem::emulated::{Action, Mmio};
 
@@ -141,3 +142,15 @@ impl Mmio for Pl031 {
         Ok(Action::None)
     }
 }
+
+impl Pause for Pl031 {
+    fn pause(&self) -> device::Result<()> {
+        Ok(())
+    }
+
+    fn resume(&self) -> device::Result<()> {
+        Ok(())
+    }
+}
+
+impl MmioDev for Pl031 {}

alioth/src/device/serial.rs

@@ -21,6 +21,7 @@ use bitflags::bitflags;
 use parking_lot::Mutex;
 
 use crate::device::console::{Console, UartRecv};
+use crate::device::{self, MmioDev, Pause};
 use crate::hv::IrqSender;
 use crate::mem;
 use crate::mem::emulated::{Action, Mmio};
@@ -191,7 +192,7 @@ pub struct Serial<I> {
 
 impl<I> Mmio for Serial<I>
 where
-    I: IrqSender + Sync + Send + 'static,
+    I: IrqSender,
 {
     fn size(&self) -> u64 {
         8
@@ -282,6 +283,21 @@ where
     }
 }
 
+impl<I> Pause for Serial<I>
+where
+    I: IrqSender,
+{
+    fn pause(&self) -> device::Result<()> {
+        Ok(())
+    }
+
+    fn resume(&self) -> device::Result<()> {
+        Ok(())
+    }
+}
+
+impl<I> MmioDev for Serial<I> where I: IrqSender {}
+
 struct SerialRecv<I: IrqSender> {
     pub name: Arc<str>,
     pub irq_sender: Arc<I>,

alioth/src/mem/emulated.rs

@@ -43,9 +43,7 @@ pub trait Mmio: Debug + Send + Sync + 'static {
     fn size(&self) -> u64;
 }
 
-pub type MmioRange = Arc<dyn Mmio>;
-
-impl Mmio for MmioRange {
+impl Mmio for Arc<dyn Mmio> {
     fn read(&self, offset: u64, size: u8) -> Result<u64> {
         Mmio::read(self.as_ref(), offset, size)
     }
@@ -59,7 +57,7 @@ impl Mmio for MmioRange {
     }
 }
 
-impl SlotBackend for MmioRange {
+impl SlotBackend for Arc<dyn Mmio> {
     fn size(&self) -> u64 {
         Mmio::size(self.as_ref())
     }
@@ -120,7 +118,7 @@ macro_rules! impl_mmio_for_zerocopy {
 }
 
 #[derive(Debug)]
-pub struct MmioBus<R = MmioRange>
+pub struct MmioBus<R = Arc<dyn Mmio>>
 where
     R: Debug + SlotBackend,
 {

alioth/src/mem/mem.rs

@@ -31,7 +31,7 @@ use crate::errors::{DebugTrace, trace_error};
 use crate::hv::{MemMapOption, VmEntry, VmMemory};
 
 use self::addressable::{Addressable, SlotBackend};
-use self::emulated::{Action, MmioBus, MmioRange};
+use self::emulated::{Action, Mmio, MmioBus};
 use self::mapped::{ArcMemPages, Ram, RamBus};
 
 #[trace_error]
@@ -125,15 +125,15 @@ impl MemConfig {
 pub enum MemRange {
     Ram(ArcMemPages),
     DevMem(ArcMemPages),
-    Emulated(MmioRange),
+    Emulated(Arc<dyn Mmio>),
     Span(u64),
 }
 
 impl MemRange {
     pub fn size(&self) -> u64 {
         match self {
             MemRange::Ram(pages) | MemRange::DevMem(pages) => pages.size(),
-            MemRange::Emulated(range) => range.size(),
+            MemRange::Emulated(range) => Mmio::size(range),
             MemRange::Span(size) => *size,
         }
     }
@@ -192,8 +192,8 @@ impl MemRegion {
         }
     }
 
-    pub fn with_emulated(range: MmioRange, type_: MemRegionType) -> MemRegion {
-        let size = range.size();
+    pub fn with_emulated(range: Arc<dyn Mmio>, type_: MemRegionType) -> MemRegion {
+        let size = Mmio::size(&range);
         MemRegion {
             ranges: vec![MemRange::Emulated(range)],
             entries: vec![MemRegionEntry { type_, size }],
@@ -223,12 +223,12 @@ impl SlotBackend for Arc<MemRegion> {
 
 #[derive(Debug)]
 pub struct IoRegion {
-    pub range: MmioRange,
+    pub range: Arc<dyn Mmio>,
     pub callbacks: Mutex<Vec<Box<dyn MemRegionCallback>>>,
 }
 
 impl IoRegion {
-    pub fn new(range: MmioRange) -> IoRegion {
+    pub fn new(range: Arc<dyn Mmio>) -> IoRegion {
         IoRegion {
             range,
             callbacks: Mutex::new(vec![]),
@@ -238,7 +238,7 @@ impl IoRegion {
 
 impl SlotBackend for Arc<IoRegion> {
     fn size(&self) -> u64 {
-        self.range.size()
+        Mmio::size(self.range.as_ref())
     }
 }
 
@@ -339,6 +339,11 @@ impl Memory {
         Ok(())
     }
 
+    pub fn add_mmio_dev(&self, addr: u64, dev: Arc<dyn Mmio>) -> Result<()> {
+        let region = MemRegion::with_emulated(dev, MemRegionType::Hidden);
+        self.add_region(addr, Arc::new(region))
+    }
+
     pub fn add_region(&self, addr: u64, region: Arc<MemRegion>) -> Result<()> {
         region.validate()?;
         let mut regions = self.regions.lock();
@@ -460,7 +465,7 @@ impl Memory {
         entries
     }
 
-    pub fn add_io_dev(&self, port: u16, dev: MmioRange) -> Result<()> {
+    pub fn add_io_dev(&self, port: u16, dev: Arc<dyn Mmio>) -> Result<()> {
         self.add_io_region(port, Arc::new(IoRegion::new(dev)))
     }
 

alioth/src/pci/bus_test.rs

@@ -17,11 +17,11 @@ use std::sync::atomic::AtomicU32;
 
 use assert_matches::assert_matches;
 
-use crate::device::pvpanic::{PVPANIC_DEVICE_ID, PVPANIC_VENDOR_ID, PvPanic};
 use crate::mem::emulated::{Action, Mmio};
 use crate::pci::Bdf;
 use crate::pci::bus::{Address, PciBus, PciIoBus};
 use crate::pci::config::{BAR_MEM64, BAR_PREFETCHABLE, CommonHeader, offset_bar};
+use crate::pci::pvpanic::{PVPANIC_DEVICE_ID, PVPANIC_VENDOR_ID, PvPanic};
 use crate::pci::segment::PciSegment;
 
 #[test]

alioth/src/pci/host_bridge.rs

@@ -12,6 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+use crate::device::{self, Pause};
 use crate::pci;
 use crate::pci::cap::PciCapList;
 use crate::pci::config::{CommonHeader, DeviceHeader, EmulatedConfig, HeaderType, PciConfig};
@@ -47,6 +48,16 @@ impl HostBridge {
     }
 }
 
+impl Pause for HostBridge {
+    fn pause(&self) -> device::Result<()> {
+        Ok(())
+    }
+
+    fn resume(&self) -> device::Result<()> {
+        Ok(())
+    }
+}
+
 impl Pci for HostBridge {
     fn name(&self) -> &str {
         "host_bridge"

alioth/src/pci/pci.rs

@@ -16,6 +16,7 @@ pub mod bus;
 pub mod cap;
 pub mod config;
 pub mod host_bridge;
+pub mod pvpanic;
 pub mod segment;
 
 use std::fmt::{Debug, Display, Formatter};
@@ -24,6 +25,7 @@ use std::sync::Arc;
 use bitfield::bitfield;
 use snafu::Snafu;
 
+use crate::device::Pause;
 use crate::errors::{DebugTrace, trace_error};
 use crate::mem::{IoRegion, MemRegion};
 
@@ -59,7 +61,7 @@ pub enum Error {
 
 pub type Result<T, E = Error> = std::result::Result<T, E>;
 
-pub trait Pci: Debug + Send + Sync + 'static {
+pub trait Pci: Debug + Send + Sync + Pause + 'static {
     fn name(&self) -> &str;
     fn config(&self) -> &dyn PciConfig;
     fn reset(&self) -> Result<()>;

alioth/src/device/pvpanic.rs → alioth/src/pci/pvpanic.rs

@@ -16,6 +16,7 @@ use std::sync::Arc;
 
 use bitflags::bitflags;
 
+use crate::device::{self, Pause};
 use crate::mem::emulated::{Action, Mmio};
 use crate::mem::{self, MemRegion};
 use crate::pci::cap::PciCapList;
@@ -92,6 +93,16 @@ impl Default for PvPanic {
     }
 }
 
+impl Pause for PvPanic {
+    fn pause(&self) -> device::Result<()> {
+        Ok(())
+    }
+
+    fn resume(&self) -> device::Result<()> {
+        Ok(())
+    }
+}
+
 impl Pci for PvPanic {
     fn name(&self) -> &str {
         "pvpanic"