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Andrew Walbran68a8c162022-03-07 15:38:42 +00001// Copyright 2022, The Android Open Source Project
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7// http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15//! pVM firmware.
16
17#![no_main]
18#![no_std]
19
Pierre-Clément Tosidb74cb12022-12-08 13:56:25 +000020extern crate alloc;
21
Jiyong Parkc5d2ef22023-04-11 01:23:46 +090022mod bootargs;
Pierre-Clément Tosi20b60962022-10-17 13:35:27 +010023mod config;
Pierre-Clément Tosi90cd4f12023-02-17 11:19:56 +000024mod crypto;
Pierre-Clément Tosi4f4f5eb2022-12-08 14:31:42 +000025mod dice;
Pierre-Clément Tosi5bbfca52022-10-21 12:14:35 +010026mod entry;
Andrew Walbrandfb73372022-04-21 10:52:27 +000027mod exceptions;
Pierre-Clément Tosia0934c12022-11-25 20:54:11 +000028mod fdt;
Pierre-Clément Tosi1cc5eb72023-02-02 11:09:18 +000029mod gpt;
Pierre-Clément Tosifc531152022-10-20 12:22:23 +010030mod heap;
Pierre-Clément Tosida4440a2022-08-22 18:06:32 +010031mod helpers;
Andrew Walbranba47d1d2022-12-14 15:21:44 +000032mod hvc;
Pierre-Clément Tosi1cc5eb72023-02-02 11:09:18 +000033mod instance;
Pierre-Clément Tosia0934c12022-11-25 20:54:11 +000034mod memory;
Pierre-Clément Tosia8a4a202022-11-03 14:16:46 +000035mod mmu;
Pierre-Clément Tosi90cd4f12023-02-17 11:19:56 +000036mod rand;
Andrew Walbran848decf2022-12-15 14:39:38 +000037mod virtio;
Andrew Walbran68a8c162022-03-07 15:38:42 +000038
Pierre-Clément Tosidb74cb12022-12-08 13:56:25 +000039use alloc::boxed::Box;
Alan Stokesd1ee63e2023-04-24 16:17:39 +010040use alloc::string::ToString;
Pierre-Clément Tosidb74cb12022-12-08 13:56:25 +000041
Pierre-Clément Tosi4ba79662023-02-13 11:22:41 +000042use crate::dice::PartialInputs;
43use crate::entry::RebootReason;
44use crate::fdt::modify_for_next_stage;
45use crate::helpers::flush;
46use crate::helpers::GUEST_PAGE_SIZE;
Pierre-Clément Tosi1cc5eb72023-02-02 11:09:18 +000047use crate::instance::get_or_generate_instance_salt;
Pierre-Clément Tosi4ba79662023-02-13 11:22:41 +000048use crate::memory::MemoryTracker;
49use crate::virtio::pci;
Alan Stokesd1ee63e2023-04-24 16:17:39 +010050use ciborium::{de::from_reader, value::Value};
Pierre-Clément Tosi1cc5eb72023-02-02 11:09:18 +000051use diced_open_dice::bcc_handover_main_flow;
52use diced_open_dice::bcc_handover_parse;
Pierre-Clément Tosi90cd4f12023-02-17 11:19:56 +000053use diced_open_dice::DiceArtifacts;
Andrew Walbran730375d2022-12-21 14:04:34 +000054use fdtpci::{PciError, PciInfo};
Andrew Walbran19690632022-12-07 16:41:30 +000055use libfdt::Fdt;
Pierre-Clément Tosi8edf72e2022-12-06 16:02:57 +000056use log::{debug, error, info, trace};
Pierre-Clément Tosi2d652982023-01-09 19:30:17 +000057use pvmfw_avb::verify_payload;
Jiyong Parkc5d2ef22023-04-11 01:23:46 +090058use pvmfw_avb::DebugLevel;
Alice Wang0aa30322023-01-31 11:00:10 +000059use pvmfw_embedded_key::PUBLIC_KEY;
Andrew Walbran68a8c162022-03-07 15:38:42 +000060
Pierre-Clément Tosi4f4f5eb2022-12-08 14:31:42 +000061const NEXT_BCC_SIZE: usize = GUEST_PAGE_SIZE;
62
Alan Stokesd1ee63e2023-04-24 16:17:39 +010063type CiboriumError = ciborium::de::Error<ciborium_io::EndOfFile>;
64
65/// Decodes the provided binary CBOR-encoded value and returns a
66/// ciborium::Value struct wrapped in Result.
67fn value_from_bytes(mut bytes: &[u8]) -> Result<Value, CiboriumError> {
68 let value = from_reader(&mut bytes)?;
69 // Ciborium tries to read one Value, but doesn't care if there is trailing data. We do.
70 if !bytes.is_empty() {
71 return Err(CiboriumError::Semantic(Some(0), "unexpected trailing data".to_string()));
72 }
73 Ok(value)
74}
75
Alice Wang28cbcf12022-12-01 07:58:28 +000076fn main(
Pierre-Clément Tosidb74cb12022-12-08 13:56:25 +000077 fdt: &mut Fdt,
Alice Wang28cbcf12022-12-01 07:58:28 +000078 signed_kernel: &[u8],
79 ramdisk: Option<&[u8]>,
Alice Wang843d8312023-02-15 09:47:06 +000080 current_bcc_handover: &[u8],
Jiyong Parkc23426b2023-04-10 17:32:27 +090081 debug_policy: Option<&mut [u8]>,
Andrew Walbran19690632022-12-07 16:41:30 +000082 memory: &mut MemoryTracker,
Alice Wang0a688d22022-12-02 09:48:41 +000083) -> Result<(), RebootReason> {
Pierre-Clément Tosi37105a62022-10-18 12:21:48 +010084 info!("pVM firmware");
Pierre-Clément Tosi8036b4f2023-02-17 10:31:31 +000085 debug!("FDT: {:?}", fdt.as_ptr());
Pierre-Clément Tosia0934c12022-11-25 20:54:11 +000086 debug!("Signed kernel: {:?} ({:#x} bytes)", signed_kernel.as_ptr(), signed_kernel.len());
Alice Wanga78279c2022-12-16 12:41:19 +000087 debug!("AVB public key: addr={:?}, size={:#x} ({1})", PUBLIC_KEY.as_ptr(), PUBLIC_KEY.len());
Pierre-Clément Tosia0934c12022-11-25 20:54:11 +000088 if let Some(rd) = ramdisk {
89 debug!("Ramdisk: {:?} ({:#x} bytes)", rd.as_ptr(), rd.len());
90 } else {
91 debug!("Ramdisk: None");
92 }
Alice Wang843d8312023-02-15 09:47:06 +000093 let bcc_handover = bcc_handover_parse(current_bcc_handover).map_err(|e| {
94 error!("Invalid BCC Handover: {e:?}");
95 RebootReason::InvalidBcc
96 })?;
97 trace!("BCC: {bcc_handover:x?}");
Andrew Walbran19690632022-12-07 16:41:30 +000098
Alan Stokesd1ee63e2023-04-24 16:17:39 +010099 // Minimal BCC verification - check the BCC exists & is valid CBOR.
100 // TODO(alanstokes): Do something more useful.
101 if let Some(bytes) = bcc_handover.bcc() {
102 let _ = value_from_bytes(bytes).map_err(|e| {
103 error!("Invalid BCC: {e:?}");
104 RebootReason::InvalidBcc
105 })?;
106 } else {
107 error!("Missing BCC");
108 return Err(RebootReason::InvalidBcc);
109 }
110
Andrew Walbran19690632022-12-07 16:41:30 +0000111 // Set up PCI bus for VirtIO devices.
Andrew Walbrand1d03182022-12-09 18:20:01 +0000112 let pci_info = PciInfo::from_fdt(fdt).map_err(handle_pci_error)?;
113 debug!("PCI: {:#x?}", pci_info);
Andrew Walbranb398fc82023-01-24 14:45:46 +0000114 let mut pci_root = pci::initialise(pci_info, memory)?;
Andrew Walbran19690632022-12-07 16:41:30 +0000115
Alice Wang1f0add02023-01-23 16:22:53 +0000116 let verified_boot_data = verify_payload(signed_kernel, ramdisk, PUBLIC_KEY).map_err(|e| {
Pierre-Clément Tosi2d652982023-01-09 19:30:17 +0000117 error!("Failed to verify the payload: {e}");
118 RebootReason::PayloadVerificationError
119 })?;
120
Pierre-Clément Tosidb74cb12022-12-08 13:56:25 +0000121 let next_bcc = heap::aligned_boxed_slice(NEXT_BCC_SIZE, GUEST_PAGE_SIZE).ok_or_else(|| {
122 error!("Failed to allocate the next-stage BCC");
123 RebootReason::InternalError
124 })?;
125 // By leaking the slice, its content will be left behind for the next stage.
126 let next_bcc = Box::leak(next_bcc);
Pierre-Clément Tosi4f4f5eb2022-12-08 14:31:42 +0000127
Pierre-Clément Tosif58f3a32023-02-02 16:24:23 +0000128 let dice_inputs = PartialInputs::new(&verified_boot_data).map_err(|e| {
129 error!("Failed to compute partial DICE inputs: {e:?}");
130 RebootReason::InternalError
131 })?;
Pierre-Clément Tosi90cd4f12023-02-17 11:19:56 +0000132 let cdi_seal = DiceArtifacts::cdi_seal(&bcc_handover);
133 let (new_instance, salt) = get_or_generate_instance_salt(&mut pci_root, &dice_inputs, cdi_seal)
134 .map_err(|e| {
Pierre-Clément Tosi1cc5eb72023-02-02 11:09:18 +0000135 error!("Failed to get instance.img salt: {e}");
136 RebootReason::InternalError
137 })?;
138 trace!("Got salt from instance.img: {salt:x?}");
139
Pierre-Clément Tosif58f3a32023-02-02 16:24:23 +0000140 let dice_inputs = dice_inputs.into_input_values(&salt).map_err(|e| {
141 error!("Failed to generate DICE inputs: {e:?}");
142 RebootReason::InternalError
143 })?;
Alice Wang843d8312023-02-15 09:47:06 +0000144 let _ = bcc_handover_main_flow(current_bcc_handover, &dice_inputs, next_bcc).map_err(|e| {
Pierre-Clément Tosif58f3a32023-02-02 16:24:23 +0000145 error!("Failed to derive next-stage DICE secrets: {e:?}");
146 RebootReason::SecretDerivationError
147 })?;
Pierre-Clément Tosidb74cb12022-12-08 13:56:25 +0000148 flush(next_bcc);
149
Pierre-Clément Tosib2d8aa72023-02-17 15:22:50 +0000150 let strict_boot = true;
Jiyong Parkc5d2ef22023-04-11 01:23:46 +0900151 let debuggable = verified_boot_data.debug_level != DebugLevel::None;
152 modify_for_next_stage(fdt, next_bcc, new_instance, strict_boot, debug_policy, debuggable)
153 .map_err(|e| {
154 error!("Failed to configure device tree: {e}");
155 RebootReason::InternalError
156 })?;
Pierre-Clément Tosidb74cb12022-12-08 13:56:25 +0000157
Alice Wang4379c832022-12-05 15:50:20 +0000158 info!("Starting payload...");
Alice Wang28cbcf12022-12-01 07:58:28 +0000159 Ok(())
Pierre-Clément Tosi263ffd52022-10-05 20:27:50 +0100160}
Andrew Walbrand1d03182022-12-09 18:20:01 +0000161
162/// Logs the given PCI error and returns the appropriate `RebootReason`.
163fn handle_pci_error(e: PciError) -> RebootReason {
164 error!("{}", e);
165 match e {
166 PciError::FdtErrorPci(_)
167 | PciError::FdtNoPci
168 | PciError::FdtErrorReg(_)
169 | PciError::FdtMissingReg
170 | PciError::FdtRegEmpty
171 | PciError::FdtRegMissingSize
172 | PciError::CamWrongSize(_)
173 | PciError::FdtErrorRanges(_)
174 | PciError::FdtMissingRanges
175 | PciError::RangeAddressMismatch { .. }
176 | PciError::NoSuitableRange => RebootReason::InvalidFdt,
Andrew Walbrand1d03182022-12-09 18:20:01 +0000177 }
178}