From fa2b5ca12b35b23c9def34e0d03c2050f247451f Mon Sep 17 00:00:00 2001
From: Jinank Jain <jinankjain@microsoft.com>
Date: Mon, 5 May 2025 04:49:15 +0000
Subject: [PATCH] vmm: hypervisor: Add a new interface to setup GICR for vcpus

For MSHV arm64 guest, there is an in-hypervisor GICv2M emulation and for
that to work, it needs to be enlightened with the base address of GIC
redistributor exposed to guest via FDT.

Signed-off-by: Jinank Jain <jinankjain@microsoft.com>
---
 hypervisor/src/cpu.rs      |  8 +++++++-
 hypervisor/src/mshv/mod.rs | 18 ++++++++++++++++++
 vmm/src/cpu.rs             | 21 +++++++++++++++++++++
 vmm/src/vm.rs              | 23 ++++++++++++++++++++++-
 4 files changed, 68 insertions(+), 2 deletions(-)

diff --git a/hypervisor/src/cpu.rs b/hypervisor/src/cpu.rs
index afdc532a5..6059499d1 100644
--- a/hypervisor/src/cpu.rs
+++ b/hypervisor/src/cpu.rs
@@ -590,7 +590,13 @@ pub trait Vcpu: Send + Sync {
     fn set_sev_control_register(&self, _reg: u64) -> Result<()> {
         unimplemented!()
     }
-
+    ///
+    /// Sets the value of GIC redistributor address
+    ///
+    #[cfg(target_arch = "aarch64")]
+    fn set_gic_redistributor_addr(&self, _gicr_base_addr: u64) -> Result<()> {
+        Ok(())
+    }
     #[cfg(target_arch = "x86_64")]
     ///
     /// Trigger NMI interrupt
diff --git a/hypervisor/src/mshv/mod.rs b/hypervisor/src/mshv/mod.rs
index 4f975e7c4..b65fad46e 100644
--- a/hypervisor/src/mshv/mod.rs
+++ b/hypervisor/src/mshv/mod.rs
@@ -1603,6 +1603,24 @@ impl cpu::Vcpu for MshvVcpu {
             .request_virtual_interrupt(&cfg)
             .map_err(|e| cpu::HypervisorCpuError::Nmi(e.into()))
     }
+    ///
+    /// Set the GICR base address for the vcpu.
+    ///
+    #[cfg(target_arch = "aarch64")]
+    fn set_gic_redistributor_addr(&self, gicr_base_addr: u64) -> cpu::Result<()> {
+        debug!(
+            "Setting GICR base address to: {:#x}, for vp_index: {:?}",
+            gicr_base_addr, self.vp_index
+        );
+        let arr_reg_name_value = [(
+            hv_register_name_HV_ARM64_REGISTER_GICR_BASE_GPA,
+            gicr_base_addr,
+        )];
+        set_registers_64!(self.fd, arr_reg_name_value)
+            .map_err(|e| cpu::HypervisorCpuError::SetRegister(e.into()))?;
+
+        Ok(())
+    }
 }
 
 impl MshvVcpu {
diff --git a/vmm/src/cpu.rs b/vmm/src/cpu.rs
index 663119e2d..42952d8a3 100644
--- a/vmm/src/cpu.rs
+++ b/vmm/src/cpu.rs
@@ -147,6 +147,10 @@ pub enum Error {
     #[error("Error finalising vCPU: {0}")]
     VcpuArmFinalize(#[source] hypervisor::HypervisorCpuError),
 
+    #[cfg(target_arch = "aarch64")]
+    #[error("Error initialising GICR base address: {0}")]
+    VcpuSetGicrBaseAddr(#[source] hypervisor::HypervisorCpuError),
+
     #[error("Failed to join on vCPU threads: {0:?}")]
     ThreadCleanup(std::boxed::Box<dyn std::any::Any + std::marker::Send>),
 
@@ -463,6 +467,23 @@ impl Vcpu {
             .set_sev_control_register(vmsa_pfn)
             .map_err(Error::SetSevControlRegister)
     }
+
+    ///
+    /// Sets the vCPU's GIC redistributor base address.
+    ///
+    #[cfg(target_arch = "aarch64")]
+    pub fn set_gic_redistributor_addr(
+        &self,
+        base_redist_addr: u64,
+        redist_size: u64,
+    ) -> Result<()> {
+        let gicr_base = base_redist_addr + (arch::layout::GIC_V3_REDIST_SIZE * self.id as u64);
+        assert!(gicr_base + arch::layout::GIC_V3_REDIST_SIZE <= base_redist_addr + redist_size);
+        self.vcpu
+            .set_gic_redistributor_addr(gicr_base)
+            .map_err(Error::VcpuSetGicrBaseAddr)?;
+        Ok(())
+    }
 }
 
 impl Pausable for Vcpu {}
diff --git a/vmm/src/vm.rs b/vmm/src/vm.rs
index 66eea3390..bda4a76b1 100644
--- a/vmm/src/vm.rs
+++ b/vmm/src/vm.rs
@@ -2203,6 +2203,21 @@ impl Vm {
         #[cfg(feature = "tdx")]
         let tdx_enabled = self.config.lock().unwrap().is_tdx_enabled();
 
+        #[cfg(target_arch = "aarch64")]
+        let vgic = self
+            .device_manager
+            .lock()
+            .unwrap()
+            .get_interrupt_controller()
+            .unwrap()
+            .lock()
+            .unwrap()
+            .get_vgic()
+            .unwrap();
+
+        #[cfg(target_arch = "aarch64")]
+        let redist_addr = vgic.lock().unwrap().device_properties();
+
         // Configure the vcpus that have been created
         let vcpus = self.cpu_manager.lock().unwrap().vcpus();
         for vcpu in vcpus {
@@ -2211,7 +2226,13 @@ impl Vm {
             self.cpu_manager
                 .lock()
                 .unwrap()
-                .configure_vcpu(vcpu, boot_setup)
+                .configure_vcpu(vcpu.clone(), boot_setup)
+                .map_err(Error::CpuManager)?;
+
+            #[cfg(target_arch = "aarch64")]
+            vcpu.lock()
+                .unwrap()
+                .set_gic_redistributor_addr(redist_addr[2], redist_addr[3])
                 .map_err(Error::CpuManager)?;
         }