devices: gic: Introduce VgicConfig and Gic::create_default_config()

VgicConfig structure will be used for initializing the Vgic.
Gic::create_default_config will be used everywhere we currently compute
redist/msi registers.

Signed-off-by: Nuno Das Neves <nudasnev@microsoft.com>

devices/src/gic.rs

@@ -6,14 +6,17 @@ use super::interrupt_controller::{Error, InterruptController};
 extern crate arch;
 use anyhow::anyhow;
 use arch::layout;
-use hypervisor::{arch::aarch64::gic::Vgic, CpuState};
+use hypervisor::{
+    arch::aarch64::gic::{Vgic, VgicConfig},
+    CpuState,
+};
 use std::result;
 use std::sync::{Arc, Mutex};
 use vm_device::interrupt::{
     InterruptIndex, InterruptManager, InterruptSourceConfig, InterruptSourceGroup,
     LegacyIrqSourceConfig, MsiIrqGroupConfig,
 };
-use vm_memory::Address;
+use vm_memory::address::Address;
 use vm_migration::{Migratable, MigratableError, Pausable, Snapshot, Snapshottable, Transportable};
 use vmm_sys_util::eventfd::EventFd;
 
@@ -52,6 +55,22 @@ impl Gic {
         })
     }
 
+    /// Default config implied by arch::layout
+    pub fn create_default_config(vcpu_count: u64) -> VgicConfig {
+        let redists_size = layout::GIC_V3_REDIST_SIZE * vcpu_count;
+        let redists_addr = layout::GIC_V3_DIST_START.raw_value() - redists_size;
+        VgicConfig {
+            vcpu_count,
+            dist_addr: layout::GIC_V3_DIST_START.raw_value(),
+            dist_size: layout::GIC_V3_DIST_SIZE,
+            redists_addr,
+            redists_size,
+            msi_addr: redists_addr - layout::GIC_V3_ITS_SIZE,
+            msi_size: layout::GIC_V3_ITS_SIZE,
+            nr_irqs: layout::IRQ_NUM,
+        }
+    }
+
     pub fn create_vgic(
         &mut self,
         vm: &Arc<dyn hypervisor::Vm>,

hypervisor/src/arch/aarch64/gic.rs

@@ -16,6 +16,18 @@ pub enum Error {
 }
 pub type Result<T> = result::Result<T, Error>;
 
+#[derive(Debug)]
+pub struct VgicConfig {
+    pub vcpu_count: u64,
+    pub dist_addr: u64,
+    pub dist_size: u64,
+    pub redists_addr: u64,
+    pub redists_size: u64,
+    pub msi_addr: u64,
+    pub msi_size: u64,
+    pub nr_irqs: u32,
+}
+
 /// Hypervisor agnostic interface for a virtualized GIC
 pub trait Vgic: Send + Sync {
     /// Returns the fdt compatibility property of the device