diff --git a/compos/common/compos_client.rs b/compos/common/compos_client.rs
index b03addf..77a1204 100644
--- a/compos/common/compos_client.rs
+++ b/compos/common/compos_client.rs
@@ -24,7 +24,10 @@
 use android_system_virtualizationservice::aidl::android::system::virtualizationservice::{
     CpuTopology::CpuTopology,
     IVirtualizationService::IVirtualizationService,
-    VirtualMachineAppConfig::{DebugLevel::DebugLevel, Payload::Payload, VirtualMachineAppConfig},
+    VirtualMachineAppConfig::{
+        CustomConfig::CustomConfig, DebugLevel::DebugLevel, Payload::Payload,
+        VirtualMachineAppConfig,
+    },
     VirtualMachineConfig::VirtualMachineConfig,
 };
 use anyhow::{anyhow, bail, Context, Result};
@@ -128,9 +131,10 @@
             protectedVm: protected_vm,
             memoryMib: parameters.memory_mib.unwrap_or(0), // 0 means use the default
             cpuTopology: cpu_topology,
-            taskProfiles: parameters.task_profiles.clone(),
-            gdbPort: 0, // Don't start gdb-server
-            customKernelImage: None,
+            customConfig: Some(CustomConfig {
+                taskProfiles: parameters.task_profiles.clone(),
+                ..Default::default()
+            }),
         });
 
         // Let logs go to logcat.
diff --git a/javalib/src/android/system/virtualmachine/VirtualMachineConfig.java b/javalib/src/android/system/virtualmachine/VirtualMachineConfig.java
index 93e65db..5f24f5b 100644
--- a/javalib/src/android/system/virtualmachine/VirtualMachineConfig.java
+++ b/javalib/src/android/system/virtualmachine/VirtualMachineConfig.java
@@ -61,7 +61,6 @@
 @SystemApi
 public final class VirtualMachineConfig {
     private static final String TAG = "VirtualMachineConfig";
-    private static final String[] EMPTY_STRING_ARRAY = {};
 
     // These define the schema of the config file persisted on disk.
     private static final int VERSION = 6;
@@ -482,8 +481,6 @@
                 vsConfig.cpuTopology = android.system.virtualizationservice.CpuTopology.ONE_CPU;
                 break;
         }
-        // Don't allow apps to set task profiles ... at least for now.
-        vsConfig.taskProfiles = EMPTY_STRING_ARRAY;
         return vsConfig;
     }
 
diff --git a/libs/hyp/src/hypervisor/geniezone.rs b/libs/hyp/src/hypervisor/geniezone.rs
index 73daff7..0741978 100644
--- a/libs/hyp/src/hypervisor/geniezone.rs
+++ b/libs/hyp/src/hypervisor/geniezone.rs
@@ -1,159 +1,159 @@
-// Copyright 2023, The Android Open Source Project
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-//! Wrappers around calls to the GenieZone hypervisor.
-
-use super::common::{Hypervisor, HypervisorCap, MMIO_GUARD_GRANULE_SIZE};
-use crate::error::{Error, Result};
-use crate::util::page_address;
-use core::fmt::{self, Display, Formatter};
-use smccc::{
-    error::{positive_or_error_64, success_or_error_64},
-    hvc64,
-};
-use uuid::{uuid, Uuid};
-
-pub(super) struct GeniezoneHypervisor;
-
-const ARM_SMCCC_GZVM_FUNC_HYP_MEMINFO: u32 = 0xc6000002;
-const ARM_SMCCC_GZVM_FUNC_MEM_SHARE: u32 = 0xc6000003;
-const ARM_SMCCC_GZVM_FUNC_MEM_UNSHARE: u32 = 0xc6000004;
-
-const VENDOR_HYP_GZVM_MMIO_GUARD_INFO_FUNC_ID: u32 = 0xc6000005;
-const VENDOR_HYP_GZVM_MMIO_GUARD_ENROLL_FUNC_ID: u32 = 0xc6000006;
-const VENDOR_HYP_GZVM_MMIO_GUARD_MAP_FUNC_ID: u32 = 0xc6000007;
-const VENDOR_HYP_GZVM_MMIO_GUARD_UNMAP_FUNC_ID: u32 = 0xc6000008;
-
-impl GeniezoneHypervisor {
-    // We generate this uuid by ourselves to identify GenieZone hypervisor
-    // and share the same identification along with guest VMs.
-    // The previous uuid was removed due to duplication elsewhere.
-    pub const UUID: Uuid = uuid!("7e134ed0-3b82-488d-8cee-69c19211dbe7");
-    const CAPABILITIES: HypervisorCap = HypervisorCap::DYNAMIC_MEM_SHARE;
-}
-
-/// Error from a GenieZone HVC call.
-#[derive(Copy, Clone, Debug, Eq, PartialEq)]
-pub enum GeniezoneError {
-    /// The call is not supported by the implementation.
-    NotSupported,
-    /// The call is not required to implement.
-    NotRequired,
-    /// One of the call parameters has a invalid value.
-    InvalidParameter,
-    /// There was an unexpected return value.
-    Unknown(i64),
-}
-
-impl From<i64> for GeniezoneError {
-    fn from(value: i64) -> Self {
-        match value {
-            -1 => GeniezoneError::NotSupported,
-            -2 => GeniezoneError::NotRequired,
-            -3 => GeniezoneError::InvalidParameter,
-            _ => GeniezoneError::Unknown(value),
-        }
-    }
-}
-
-impl From<i32> for GeniezoneError {
-    fn from(value: i32) -> Self {
-        i64::from(value).into()
-    }
-}
-
-impl Display for GeniezoneError {
-    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
-        match self {
-            Self::NotSupported => write!(f, "GenieZone call not supported"),
-            Self::NotRequired => write!(f, "GenieZone call not required"),
-            Self::InvalidParameter => write!(f, "GenieZone call received invalid value"),
-            Self::Unknown(e) => write!(f, "Unknown return value from GenieZone {} ({0:#x})", e),
-        }
-    }
-}
-
-impl Hypervisor for GeniezoneHypervisor {
-    fn mmio_guard_init(&self) -> Result<()> {
-        mmio_guard_enroll()?;
-        let mmio_granule = mmio_guard_granule()?;
-        if mmio_granule != MMIO_GUARD_GRANULE_SIZE {
-            return Err(Error::UnsupportedMmioGuardGranule(mmio_granule));
-        }
-        Ok(())
-    }
-
-    fn mmio_guard_map(&self, addr: usize) -> Result<()> {
-        let mut args = [0u64; 17];
-        args[0] = page_address(addr);
-
-        checked_hvc64_expect_zero(VENDOR_HYP_GZVM_MMIO_GUARD_MAP_FUNC_ID, args)
-    }
-
-    fn mmio_guard_unmap(&self, addr: usize) -> Result<()> {
-        let mut args = [0u64; 17];
-        args[0] = page_address(addr);
-
-        checked_hvc64_expect_zero(VENDOR_HYP_GZVM_MMIO_GUARD_UNMAP_FUNC_ID, args)
-    }
-
-    fn mem_share(&self, base_ipa: u64) -> Result<()> {
-        let mut args = [0u64; 17];
-        args[0] = base_ipa;
-
-        checked_hvc64_expect_zero(ARM_SMCCC_GZVM_FUNC_MEM_SHARE, args)
-    }
-
-    fn mem_unshare(&self, base_ipa: u64) -> Result<()> {
-        let mut args = [0u64; 17];
-        args[0] = base_ipa;
-
-        checked_hvc64_expect_zero(ARM_SMCCC_GZVM_FUNC_MEM_UNSHARE, args)
-    }
-
-    fn memory_protection_granule(&self) -> Result<usize> {
-        let args = [0u64; 17];
-        let granule = checked_hvc64(ARM_SMCCC_GZVM_FUNC_HYP_MEMINFO, args)?;
-        Ok(granule.try_into().unwrap())
-    }
-
-    fn has_cap(&self, cap: HypervisorCap) -> bool {
-        Self::CAPABILITIES.contains(cap)
-    }
-}
-
-fn mmio_guard_granule() -> Result<usize> {
-    let args = [0u64; 17];
-
-    let granule = checked_hvc64(VENDOR_HYP_GZVM_MMIO_GUARD_INFO_FUNC_ID, args)?;
-    Ok(granule.try_into().unwrap())
-}
-
-fn mmio_guard_enroll() -> Result<()> {
-    let args = [0u64; 17];
-    match success_or_error_64(hvc64(VENDOR_HYP_GZVM_MMIO_GUARD_ENROLL_FUNC_ID, args)[0]) {
-        Ok(_) => Ok(()),
-        Err(GeniezoneError::NotSupported) => Err(Error::MmioGuardNotsupported),
-        Err(GeniezoneError::NotRequired) => Err(Error::MmioGuardNotsupported),
-        Err(e) => Err(Error::GeniezoneError(e, VENDOR_HYP_GZVM_MMIO_GUARD_ENROLL_FUNC_ID)),
-    }
-}
-
-fn checked_hvc64_expect_zero(function: u32, args: [u64; 17]) -> Result<()> {
-    success_or_error_64(hvc64(function, args)[0]).map_err(|e| Error::GeniezoneError(e, function))
-}
-
-fn checked_hvc64(function: u32, args: [u64; 17]) -> Result<u64> {
-    positive_or_error_64(hvc64(function, args)[0]).map_err(|e| Error::GeniezoneError(e, function))
-}
+// Copyright 2023, The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//! Wrappers around calls to the GenieZone hypervisor.
+
+use super::common::{Hypervisor, HypervisorCap, MMIO_GUARD_GRANULE_SIZE};
+use crate::error::{Error, Result};
+use crate::util::page_address;
+use core::fmt::{self, Display, Formatter};
+use smccc::{
+    error::{positive_or_error_64, success_or_error_64},
+    hvc64,
+};
+use uuid::{uuid, Uuid};
+
+pub(super) struct GeniezoneHypervisor;
+
+const ARM_SMCCC_GZVM_FUNC_HYP_MEMINFO: u32 = 0xc6000002;
+const ARM_SMCCC_GZVM_FUNC_MEM_SHARE: u32 = 0xc6000003;
+const ARM_SMCCC_GZVM_FUNC_MEM_UNSHARE: u32 = 0xc6000004;
+
+const VENDOR_HYP_GZVM_MMIO_GUARD_INFO_FUNC_ID: u32 = 0xc6000005;
+const VENDOR_HYP_GZVM_MMIO_GUARD_ENROLL_FUNC_ID: u32 = 0xc6000006;
+const VENDOR_HYP_GZVM_MMIO_GUARD_MAP_FUNC_ID: u32 = 0xc6000007;
+const VENDOR_HYP_GZVM_MMIO_GUARD_UNMAP_FUNC_ID: u32 = 0xc6000008;
+
+impl GeniezoneHypervisor {
+    // We generate this uuid by ourselves to identify GenieZone hypervisor
+    // and share the same identification along with guest VMs.
+    // The previous uuid was removed due to duplication elsewhere.
+    pub const UUID: Uuid = uuid!("7e134ed0-3b82-488d-8cee-69c19211dbe7");
+    const CAPABILITIES: HypervisorCap = HypervisorCap::DYNAMIC_MEM_SHARE;
+}
+
+/// Error from a GenieZone HVC call.
+#[derive(Copy, Clone, Debug, Eq, PartialEq)]
+pub enum GeniezoneError {
+    /// The call is not supported by the implementation.
+    NotSupported,
+    /// The call is not required to implement.
+    NotRequired,
+    /// One of the call parameters has a invalid value.
+    InvalidParameter,
+    /// There was an unexpected return value.
+    Unknown(i64),
+}
+
+impl From<i64> for GeniezoneError {
+    fn from(value: i64) -> Self {
+        match value {
+            -1 => GeniezoneError::NotSupported,
+            -2 => GeniezoneError::NotRequired,
+            -3 => GeniezoneError::InvalidParameter,
+            _ => GeniezoneError::Unknown(value),
+        }
+    }
+}
+
+impl From<i32> for GeniezoneError {
+    fn from(value: i32) -> Self {
+        i64::from(value).into()
+    }
+}
+
+impl Display for GeniezoneError {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        match self {
+            Self::NotSupported => write!(f, "GenieZone call not supported"),
+            Self::NotRequired => write!(f, "GenieZone call not required"),
+            Self::InvalidParameter => write!(f, "GenieZone call received invalid value"),
+            Self::Unknown(e) => write!(f, "Unknown return value from GenieZone {} ({0:#x})", e),
+        }
+    }
+}
+
+impl Hypervisor for GeniezoneHypervisor {
+    fn mmio_guard_init(&self) -> Result<()> {
+        mmio_guard_enroll()?;
+        let mmio_granule = mmio_guard_granule()?;
+        if mmio_granule != MMIO_GUARD_GRANULE_SIZE {
+            return Err(Error::UnsupportedMmioGuardGranule(mmio_granule));
+        }
+        Ok(())
+    }
+
+    fn mmio_guard_map(&self, addr: usize) -> Result<()> {
+        let mut args = [0u64; 17];
+        args[0] = page_address(addr);
+
+        checked_hvc64_expect_zero(VENDOR_HYP_GZVM_MMIO_GUARD_MAP_FUNC_ID, args)
+    }
+
+    fn mmio_guard_unmap(&self, addr: usize) -> Result<()> {
+        let mut args = [0u64; 17];
+        args[0] = page_address(addr);
+
+        checked_hvc64_expect_zero(VENDOR_HYP_GZVM_MMIO_GUARD_UNMAP_FUNC_ID, args)
+    }
+
+    fn mem_share(&self, base_ipa: u64) -> Result<()> {
+        let mut args = [0u64; 17];
+        args[0] = base_ipa;
+
+        checked_hvc64_expect_zero(ARM_SMCCC_GZVM_FUNC_MEM_SHARE, args)
+    }
+
+    fn mem_unshare(&self, base_ipa: u64) -> Result<()> {
+        let mut args = [0u64; 17];
+        args[0] = base_ipa;
+
+        checked_hvc64_expect_zero(ARM_SMCCC_GZVM_FUNC_MEM_UNSHARE, args)
+    }
+
+    fn memory_protection_granule(&self) -> Result<usize> {
+        let args = [0u64; 17];
+        let granule = checked_hvc64(ARM_SMCCC_GZVM_FUNC_HYP_MEMINFO, args)?;
+        Ok(granule.try_into().unwrap())
+    }
+
+    fn has_cap(&self, cap: HypervisorCap) -> bool {
+        Self::CAPABILITIES.contains(cap)
+    }
+}
+
+fn mmio_guard_granule() -> Result<usize> {
+    let args = [0u64; 17];
+
+    let granule = checked_hvc64(VENDOR_HYP_GZVM_MMIO_GUARD_INFO_FUNC_ID, args)?;
+    Ok(granule.try_into().unwrap())
+}
+
+fn mmio_guard_enroll() -> Result<()> {
+    let args = [0u64; 17];
+    match success_or_error_64(hvc64(VENDOR_HYP_GZVM_MMIO_GUARD_ENROLL_FUNC_ID, args)[0]) {
+        Ok(_) => Ok(()),
+        Err(GeniezoneError::NotSupported) => Err(Error::MmioGuardNotsupported),
+        Err(GeniezoneError::NotRequired) => Err(Error::MmioGuardNotsupported),
+        Err(e) => Err(Error::GeniezoneError(e, VENDOR_HYP_GZVM_MMIO_GUARD_ENROLL_FUNC_ID)),
+    }
+}
+
+fn checked_hvc64_expect_zero(function: u32, args: [u64; 17]) -> Result<()> {
+    success_or_error_64(hvc64(function, args)[0]).map_err(|e| Error::GeniezoneError(e, function))
+}
+
+fn checked_hvc64(function: u32, args: [u64; 17]) -> Result<u64> {
+    positive_or_error_64(hvc64(function, args)[0]).map_err(|e| Error::GeniezoneError(e, function))
+}
diff --git a/libs/ignorabletest/Android.bp b/libs/ignorabletest/Android.bp
index 10aef8e..4ae89af 100644
--- a/libs/ignorabletest/Android.bp
+++ b/libs/ignorabletest/Android.bp
@@ -9,6 +9,8 @@
     rustlibs: [
         "liblibtest_mimic",
         "liblinkme",
+        "liblog_rust",
+        "liblogger",
     ],
     proc_macros: ["libpaste"],
     apex_available: [
diff --git a/libs/ignorabletest/src/runner.rs b/libs/ignorabletest/src/runner.rs
index 4ec3d79..fdac406 100644
--- a/libs/ignorabletest/src/runner.rs
+++ b/libs/ignorabletest/src/runner.rs
@@ -3,6 +3,7 @@
 use core::ops::{Deref, FnOnce};
 use libtest_mimic::{Arguments, Failed, Trial};
 use linkme::distributed_slice;
+use log::Level;
 use std::env;
 
 /// Command-line arguments to ignore, because they are not supported by libtest-mimic.
@@ -15,6 +16,7 @@
 
 /// Runs all tests.
 pub fn main() {
+    logger::init(logger::Config::default().with_min_level(Level::Debug));
     let args = Arguments::from_iter(env::args().filter(|arg| !IGNORED_ARGS.contains(&arg.deref())));
     let tests = IGNORABLETEST_TESTS.iter().map(|test| test()).collect();
     libtest_mimic::run(&args, tests).exit();
diff --git a/pvmfw/avb/Android.bp b/pvmfw/avb/Android.bp
index 5353a21..49c4717 100644
--- a/pvmfw/avb/Android.bp
+++ b/pvmfw/avb/Android.bp
@@ -2,8 +2,8 @@
     default_applicable_licenses: ["Android-Apache-2.0"],
 }
 
-rust_defaults {
-    name: "libpvmfw_avb_nostd_defaults",
+rust_library_rlib {
+    name: "libpvmfw_avb_nostd",
     crate_name: "pvmfw_avb",
     srcs: ["src/lib.rs"],
     prefer_rlib: true,
@@ -16,11 +16,6 @@
     whole_static_libs: [
         "libavb_baremetal",
     ],
-}
-
-rust_library_rlib {
-    name: "libpvmfw_avb_nostd",
-    defaults: ["libpvmfw_avb_nostd_defaults"],
     no_stdlibs: true,
     stdlibs: [
         "libcore.rust_sysroot",
diff --git a/pvmfw/src/entry.rs b/pvmfw/src/entry.rs
index 0d2dfda..78383d2 100644
--- a/pvmfw/src/entry.rs
+++ b/pvmfw/src/entry.rs
@@ -15,11 +15,11 @@
 //! Low-level entry and exit points of pvmfw.
 
 use crate::config;
+use crate::configure_global_allocator_size;
 use crate::crypto;
 use crate::fdt;
 use crate::heap;
 use crate::memory;
-use crate::rand;
 use core::arch::asm;
 use core::mem::{drop, size_of};
 use core::num::NonZeroUsize;
@@ -36,8 +36,9 @@
     console,
     layout::{self, crosvm},
     logger, main,
-    memory::{min_dcache_line_size, MemoryTracker, MEMORY, SIZE_4KB},
+    memory::{min_dcache_line_size, MemoryTracker, MEMORY, SIZE_128KB, SIZE_4KB},
     power::reboot,
+    rand,
 };
 use zeroize::Zeroize;
 
@@ -62,6 +63,7 @@
 }
 
 main!(start);
+configure_global_allocator_size!(SIZE_128KB);
 
 /// Entry point for pVM firmware.
 pub fn start(fdt_address: u64, payload_start: u64, payload_size: u64, _arg3: u64) {
diff --git a/pvmfw/src/heap.rs b/pvmfw/src/heap.rs
index 151049e..a28a02c 100644
--- a/pvmfw/src/heap.rs
+++ b/pvmfw/src/heap.rs
@@ -27,14 +27,30 @@
 
 use buddy_system_allocator::LockedHeap;
 
-/// 128 KiB
-const HEAP_SIZE: usize = 0x20000;
-static mut HEAP: [u8; HEAP_SIZE] = [0; HEAP_SIZE];
+/// Configures the size of the global allocator.
+#[macro_export]
+macro_rules! configure_global_allocator_size {
+    ($len:expr) => {
+        static mut __HEAP_ARRAY: [u8; $len] = [0; $len];
+        #[export_name = "HEAP"]
+        // SAFETY - HEAP will only be accessed once as mut, from init().
+        static mut __HEAP: &'static mut [u8] = unsafe { &mut __HEAP_ARRAY };
+    };
+}
+
+extern "Rust" {
+    /// Slice used by the global allocator, configured using configure_global_allocator_size!().
+    static mut HEAP: &'static mut [u8];
+}
 
 #[global_allocator]
 static HEAP_ALLOCATOR: LockedHeap<32> = LockedHeap::<32>::new();
 
-/// SAFETY: Must be called no more than once.
+/// Initialize the global allocator.
+///
+/// # Safety
+///
+/// Must be called no more than once.
 pub unsafe fn init() {
     // SAFETY: Nothing else accesses this memory, and we hand it over to the heap to manage and
     // never touch it again. The heap is locked, so there cannot be any races.
diff --git a/pvmfw/src/instance.rs b/pvmfw/src/instance.rs
index 56468b2..1035559 100644
--- a/pvmfw/src/instance.rs
+++ b/pvmfw/src/instance.rs
@@ -21,7 +21,6 @@
 use crate::gpt;
 use crate::gpt::Partition;
 use crate::gpt::Partitions;
-use crate::rand;
 use core::fmt;
 use core::mem::size_of;
 use diced_open_dice::DiceMode;
@@ -30,6 +29,7 @@
 use log::trace;
 use uuid::Uuid;
 use virtio_drivers::transport::{pci::bus::PciRoot, DeviceType, Transport};
+use vmbase::rand;
 use vmbase::util::ceiling_div;
 use vmbase::virtio::pci::{PciTransportIterator, VirtIOBlk};
 use zerocopy::AsBytes;
diff --git a/pvmfw/src/main.rs b/pvmfw/src/main.rs
index 1b2b769..032d87e 100644
--- a/pvmfw/src/main.rs
+++ b/pvmfw/src/main.rs
@@ -30,10 +30,8 @@
 mod gpt;
 mod heap;
 mod helpers;
-mod hvc;
 mod instance;
 mod memory;
-mod rand;
 
 use crate::bcc::Bcc;
 use crate::dice::PartialInputs;
diff --git a/virtualizationmanager/src/aidl.rs b/virtualizationmanager/src/aidl.rs
index 9cd70e6..968d2d2 100644
--- a/virtualizationmanager/src/aidl.rs
+++ b/virtualizationmanager/src/aidl.rs
@@ -317,15 +317,13 @@
             VirtualMachineConfig::RawConfig(_) => true,
             VirtualMachineConfig::AppConfig(config) => {
                 // Some features are reserved for platform apps only, even when using
-                // VirtualMachineAppConfig:
+                // VirtualMachineAppConfig. Almost all of these features are grouped in the
+                // CustomConfig struct:
                 // - controlling CPUs;
-                // - specifying a config file in the APK;
+                // - specifying a config file in the APK; (this one is not part of CustomConfig)
                 // - gdbPort is set, meaning that crosvm will start a gdb server;
                 // - using anything other than the default kernel.
-                !config.taskProfiles.is_empty()
-                    || matches!(config.payload, Payload::ConfigPath(_))
-                    || config.gdbPort > 0
-                    || config.customKernelImage.as_ref().is_some()
+                config.customConfig.is_some() || matches!(config.payload, Payload::ConfigPath(_))
             }
         };
         if is_custom {
@@ -606,8 +604,12 @@
     let vm_config_file = File::open(vm_config_path)?;
     let mut vm_config = VmConfig::load(&vm_config_file)?.to_parcelable()?;
 
-    if let Some(file) = config.customKernelImage.as_ref() {
-        vm_config.kernel = Some(ParcelFileDescriptor::new(clone_file(file)?))
+    if let Some(custom_config) = &config.customConfig {
+        if let Some(file) = custom_config.customKernelImage.as_ref() {
+            vm_config.kernel = Some(ParcelFileDescriptor::new(clone_file(file)?))
+        }
+        vm_config.taskProfiles = custom_config.taskProfiles.clone();
+        vm_config.gdbPort = custom_config.gdbPort;
     }
 
     if config.memoryMib > 0 {
@@ -617,8 +619,6 @@
     vm_config.name = config.name.clone();
     vm_config.protectedVm = config.protectedVm;
     vm_config.cpuTopology = config.cpuTopology;
-    vm_config.taskProfiles = config.taskProfiles.clone();
-    vm_config.gdbPort = config.gdbPort;
 
     // Microdroid takes additional init ramdisk & (optionally) storage image
     add_microdroid_system_images(config, instance_file, storage_image, &mut vm_config)?;
@@ -1053,7 +1053,9 @@
 fn extract_gdb_port(config: &VirtualMachineConfig) -> Option<NonZeroU16> {
     match config {
         VirtualMachineConfig::RawConfig(config) => NonZeroU16::new(config.gdbPort as u16),
-        VirtualMachineConfig::AppConfig(config) => NonZeroU16::new(config.gdbPort as u16),
+        VirtualMachineConfig::AppConfig(config) => {
+            NonZeroU16::new(config.customConfig.as_ref().map(|c| c.gdbPort).unwrap_or(0) as u16)
+        }
     }
 }
 
diff --git a/virtualizationservice/aidl/android/system/virtualizationservice/VirtualMachineAppConfig.aidl b/virtualizationservice/aidl/android/system/virtualizationservice/VirtualMachineAppConfig.aidl
index 5e05bb9..6a0bf7c 100644
--- a/virtualizationservice/aidl/android/system/virtualizationservice/VirtualMachineAppConfig.aidl
+++ b/virtualizationservice/aidl/android/system/virtualizationservice/VirtualMachineAppConfig.aidl
@@ -45,6 +45,8 @@
     union Payload {
         /**
          * Path to a JSON file in an APK containing the configuration.
+         *
+         * <p>Setting this field requires android.permission.USE_CUSTOM_VIRTUAL_MACHINE
          */
         @utf8InCpp String configPath;
 
@@ -70,16 +72,6 @@
     /** Debug level of the VM */
     DebugLevel debugLevel = DebugLevel.NONE;
 
-    /**
-     * Port at which crosvm will start a gdb server to debug guest kernel.
-     * If set to zero, then gdb server won't be started.
-     *
-     * Note: Specifying a value here requires android.permission.USE_CUSTOM_VIRTUAL_MACHINE.
-     *
-     * TODO(b/286225150): move to a separate struct
-     */
-    int gdbPort = 0;
-
     /** Whether the VM should be a protected VM. */
     boolean protectedVm;
 
@@ -93,20 +85,28 @@
     CpuTopology cpuTopology = CpuTopology.ONE_CPU;
 
     /**
-     * List of task profile names to apply for the VM
-     *
-     * Note: Specifying a value here requires android.permission.USE_CUSTOM_VIRTUAL_MACHINE.
-     *
-     * TODO(b/286225150): move to a separate struct
+     * Encapsulates parameters that require android.permission.USE_CUSTOM_VIRTUAL_MACHINE.
      */
-    String[] taskProfiles;
+    parcelable CustomConfig {
+        /**
+         * If specified, boot Microdroid VM with the given kernel.
+         *
+         */
+        @nullable ParcelFileDescriptor customKernelImage;
 
-    /**
-     * If specified, boot Microdroid VM with the given kernel.
-     *
-     * Note: Specifying a value here requires android.permission.USE_CUSTOM_VIRTUAL_MACHINE.
-     *
-     * TODO(b/286225150): move to a separate struct
-     */
-    @nullable ParcelFileDescriptor customKernelImage;
+        /**
+         * Port at which crosvm will start a gdb server to debug guest kernel.
+         * If set to zero, then gdb server won't be started.
+         *
+         */
+        int gdbPort = 0;
+
+        /**
+         * List of task profile names to apply for the VM
+         */
+        String[] taskProfiles;
+    }
+
+    /** Configuration parameters guarded by android.permission.USE_CUSTOM_VIRTUAL_MACHINE */
+    @nullable CustomConfig customConfig;
 }
diff --git a/vm/src/run.rs b/vm/src/run.rs
index 54c1de4..663fa25 100644
--- a/vm/src/run.rs
+++ b/vm/src/run.rs
@@ -19,7 +19,10 @@
     CpuTopology::CpuTopology,
     IVirtualizationService::IVirtualizationService,
     PartitionType::PartitionType,
-    VirtualMachineAppConfig::{DebugLevel::DebugLevel, Payload::Payload, VirtualMachineAppConfig},
+    VirtualMachineAppConfig::{
+        CustomConfig::CustomConfig, DebugLevel::DebugLevel, Payload::Payload,
+        VirtualMachineAppConfig,
+    },
     VirtualMachineConfig::VirtualMachineConfig,
     VirtualMachinePayloadConfig::VirtualMachinePayloadConfig,
     VirtualMachineState::VirtualMachineState,
@@ -136,6 +139,12 @@
 
     let payload_config_str = format!("{:?}!{:?}", apk, payload);
 
+    let custom_config = CustomConfig {
+        customKernelImage: kernel,
+        gdbPort: gdb.map(u16::from).unwrap_or(0) as i32, // 0 means no gdb
+        taskProfiles: task_profiles,
+    };
+
     let config = VirtualMachineConfig::AppConfig(VirtualMachineAppConfig {
         name: name.unwrap_or_else(|| String::from("VmRunApp")),
         apk: apk_fd.into(),
@@ -148,9 +157,7 @@
         protectedVm: protected,
         memoryMib: mem.unwrap_or(0) as i32, // 0 means use the VM default
         cpuTopology: cpu_topology,
-        taskProfiles: task_profiles,
-        gdbPort: gdb.map(u16::from).unwrap_or(0) as i32, // 0 means no gdb
-        customKernelImage: kernel,
+        customConfig: Some(custom_config),
     });
     run(service, &config, &payload_config_str, console_path, log_path)
 }
diff --git a/pvmfw/src/hvc.rs b/vmbase/src/hvc.rs
similarity index 95%
rename from pvmfw/src/hvc.rs
rename to vmbase/src/hvc.rs
index e03c9d3..9a5e716 100644
--- a/pvmfw/src/hvc.rs
+++ b/vmbase/src/hvc.rs
@@ -21,7 +21,6 @@
     hvc64,
 };
 
-// TODO(b/272226230): Move all the trng functions to trng module
 const ARM_SMCCC_TRNG_VERSION: u32 = 0x8400_0050;
 #[allow(dead_code)]
 const ARM_SMCCC_TRNG_FEATURES: u32 = 0x8400_0051;
diff --git a/pvmfw/src/hvc/trng.rs b/vmbase/src/hvc/trng.rs
similarity index 100%
rename from pvmfw/src/hvc/trng.rs
rename to vmbase/src/hvc/trng.rs
diff --git a/vmbase/src/lib.rs b/vmbase/src/lib.rs
index 54f3384..7fc7b20 100644
--- a/vmbase/src/lib.rs
+++ b/vmbase/src/lib.rs
@@ -23,11 +23,13 @@
 pub mod console;
 mod entry;
 pub mod fdt;
+mod hvc;
 pub mod layout;
 mod linker;
 pub mod logger;
 pub mod memory;
 pub mod power;
+pub mod rand;
 pub mod uart;
 pub mod util;
 pub mod virtio;
diff --git a/vmbase/src/memory/mod.rs b/vmbase/src/memory/mod.rs
index 9f14691..6bc600d 100644
--- a/vmbase/src/memory/mod.rs
+++ b/vmbase/src/memory/mod.rs
@@ -25,5 +25,5 @@
 pub use shared::{alloc_shared, dealloc_shared, MemoryRange, MemoryTracker, MEMORY};
 pub use util::{
     flush, flushed_zeroize, min_dcache_line_size, page_4kb_of, phys_to_virt, virt_to_phys,
-    PAGE_SIZE, SIZE_2MB, SIZE_4KB, SIZE_4MB,
+    PAGE_SIZE, SIZE_128KB, SIZE_2MB, SIZE_4KB, SIZE_4MB,
 };
diff --git a/vmbase/src/memory/util.rs b/vmbase/src/memory/util.rs
index 04d42cd..48007f3 100644
--- a/vmbase/src/memory/util.rs
+++ b/vmbase/src/memory/util.rs
@@ -22,6 +22,8 @@
 
 /// The size of a 4KB memory in bytes.
 pub const SIZE_4KB: usize = 4 << 10;
+/// The size of a 128KB memory in bytes.
+pub const SIZE_128KB: usize = 128 << 10;
 /// The size of a 2MB memory in bytes.
 pub const SIZE_2MB: usize = 2 << 20;
 /// The size of a 4MB memory in bytes.
diff --git a/pvmfw/src/rand.rs b/vmbase/src/rand.rs
similarity index 94%
rename from pvmfw/src/rand.rs
rename to vmbase/src/rand.rs
index b45538a..00567b8 100644
--- a/pvmfw/src/rand.rs
+++ b/vmbase/src/rand.rs
@@ -12,10 +12,13 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+//! Functions and drivers for obtaining true entropy.
+
 use crate::hvc;
 use core::fmt;
 use core::mem::size_of;
 
+/// Error type for rand operations.
 pub enum Error {
     /// Error during SMCCC TRNG call.
     Trng(hvc::trng::Error),
@@ -29,6 +32,7 @@
     }
 }
 
+/// Result type for rand operations.
 pub type Result<T> = core::result::Result<T, Error>;
 
 impl fmt::Display for Error {
@@ -96,6 +100,7 @@
     }
 }
 
+/// Generate an array of fixed-size initialized with true-random bytes.
 pub fn random_array<const N: usize>() -> Result<[u8; N]> {
     let mut arr = [0; N];
     fill_with_entropy(&mut arr)?;