diff --git a/rialto/src/error.rs b/rialto/src/error.rs
new file mode 100644
index 0000000..8f34676
--- /dev/null
+++ b/rialto/src/error.rs
@@ -0,0 +1,55 @@
+// Copyright 2022, 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.
+
+//! This module contains the error thrown by Rialto.
+
+use aarch64_paging::MapError;
+use core::{fmt, result};
+use hyp::mmio_guard::Error as MmioError;
+
+pub type Result<T> = result::Result<T, Error>;
+
+#[derive(Clone, Debug)]
+pub enum Error {
+    /// MMIO guard failed.
+    MmioGuard(MmioError),
+    /// Failed when attempting to map some range in the page table.
+    PageTableMapping(MapError),
+    /// Failed to initialize the logger.
+    LoggerInit,
+}
+
+impl fmt::Display for Error {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            Self::MmioGuard(e) => write!(f, "MMIO guard failed: {e}."),
+            Self::PageTableMapping(e) => {
+                write!(f, "Failed when attempting to map some range in the page table: {e}.")
+            }
+            Self::LoggerInit => write!(f, "Failed to initialize the logger."),
+        }
+    }
+}
+
+impl From<MmioError> for Error {
+    fn from(e: MmioError) -> Self {
+        Self::MmioGuard(e)
+    }
+}
+
+impl From<MapError> for Error {
+    fn from(e: MapError) -> Self {
+        Self::PageTableMapping(e)
+    }
+}
diff --git a/rialto/src/main.rs b/rialto/src/main.rs
index 59ee0b6..76f5495 100644
--- a/rialto/src/main.rs
+++ b/rialto/src/main.rs
@@ -17,18 +17,20 @@
 #![no_main]
 #![no_std]
 
+mod error;
 mod exceptions;
 
 extern crate alloc;
 
+use crate::error::{Error, Result};
 use aarch64_paging::{
     idmap::IdMap,
     paging::{Attributes, MemoryRegion},
-    MapError,
 };
 use buddy_system_allocator::LockedHeap;
-use log::{debug, info};
-use vmbase::main;
+use hyp::mmio_guard;
+use log::{debug, error, info};
+use vmbase::{main, power::reboot};
 
 const SZ_1K: usize = 1024;
 const SZ_64K: usize = 64 * SZ_1K;
@@ -81,7 +83,7 @@
     info!("Initialized heap.");
 }
 
-fn init_kernel_pgt(pgt: &mut IdMap) -> Result<(), MapError> {
+fn init_kernel_pgt(pgt: &mut IdMap) -> Result<()> {
     // The first 1 GiB of address space is used by crosvm for MMIO.
     let reg_dev = MemoryRegion::new(0, SZ_1G);
     // SAFETY: Taking addresses of kernel image sections to set up page table
@@ -106,15 +108,39 @@
     Ok(())
 }
 
-/// Entry point for Rialto.
-pub fn main(_a0: u64, _a1: u64, _a2: u64, _a3: u64) {
-    vmbase::logger::init(log::LevelFilter::Debug).unwrap();
+fn try_init_logger() -> Result<()> {
+    match mmio_guard::init() {
+        // pKVM blocks MMIO by default, we need to enable MMIO guard to support logging.
+        Ok(()) => mmio_guard::map(vmbase::console::BASE_ADDRESS)?,
+        // MMIO guard enroll is not supported in unprotected VM.
+        Err(mmio_guard::Error::EnrollFailed(smccc::Error::NotSupported)) => {}
+        Err(e) => return Err(e.into()),
+    };
+    vmbase::logger::init(log::LevelFilter::Debug).map_err(|_| Error::LoggerInit)
+}
 
+fn try_main() -> Result<()> {
     info!("Welcome to Rialto!");
     init_heap();
 
     let mut pgt = IdMap::new(PT_ASID, PT_ROOT_LEVEL);
-    init_kernel_pgt(&mut pgt).unwrap();
+    init_kernel_pgt(&mut pgt)?;
+    Ok(())
+}
+
+/// Entry point for Rialto.
+pub fn main(_a0: u64, _a1: u64, _a2: u64, _a3: u64) {
+    if try_init_logger().is_err() {
+        // Don't log anything if the logger initialization fails.
+        reboot();
+    }
+    match try_main() {
+        Ok(()) => info!("Rialto ends successfully."),
+        Err(e) => {
+            error!("Rialto failed with {e}");
+            reboot()
+        }
+    }
 }
 
 extern "C" {