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openhcl: report bootloader log via device tree when configured #719

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openhcl: report bootloader log via device tree when configured #719

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18 changes: 18 additions & 0 deletions openhcl/bootloader_fdt_parser/src/lib.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -173,6 +173,8 @@ pub struct ParsedBootDtInfo {
/// VTL2 range for private pool memory.
#[inspect(iter_by_index)]
pub private_pool_ranges: Vec<MemoryRangeWithNode>,
/// The text boot log reported by the bootloader.
pub boot_log: String,
}

fn err_to_owned(e: fdt::parser::Error<'_>) -> anyhow::Error {
Expand Down Expand Up @@ -211,6 +213,7 @@ struct OpenhclInfo {
memory_allocation_mode: MemoryAllocationMode,
isolation: IsolationType,
private_pool_ranges: Vec<MemoryRangeWithNode>,
boot_log: String,
}

fn parse_memory_openhcl(node: &Node<'_>) -> anyhow::Result<AddressRange> {
Expand Down Expand Up @@ -347,6 +350,12 @@ fn parse_openhcl(node: &Node<'_>) -> anyhow::Result<OpenhclInfo> {
memory.sort_by_key(|r| r.range().start());
accepted_memory.sort_by_key(|r| r.start());

let boot_log = try_find_property(node, "boot-log")
.context("missing boot-log")?
.read_str()
.map_err(err_to_owned)?
.to_string();

// Report config ranges in a separate vec as well, for convenience.
let config_ranges = memory
.iter()
Expand Down Expand Up @@ -420,6 +429,7 @@ fn parse_openhcl(node: &Node<'_>) -> anyhow::Result<OpenhclInfo> {
memory_allocation_mode,
isolation,
private_pool_ranges,
boot_log,
})
}

Expand Down Expand Up @@ -514,6 +524,7 @@ impl ParsedBootDtInfo {
let mut isolation = IsolationType::None;
let mut vtl2_reserved_range = MemoryRange::EMPTY;
let mut private_pool_ranges = Vec::new();
let mut boot_log = String::new();

let parser = Parser::new(raw)
.map_err(err_to_owned)
Expand Down Expand Up @@ -548,6 +559,7 @@ impl ParsedBootDtInfo {
memory_allocation_mode: n_memory_allocation_mode,
isolation: n_isolation,
private_pool_ranges: n_private_pool_ranges,
boot_log: n_boot_log,
} = parse_openhcl(&child)?;
vtl0_mmio = n_vtl0_mmio;
config_ranges = n_config_ranges;
Expand All @@ -558,6 +570,7 @@ impl ParsedBootDtInfo {
isolation = n_isolation;
vtl2_reserved_range = n_vtl2_reserved_range;
private_pool_ranges = n_private_pool_ranges;
boot_log = n_boot_log;
}

_ if child.name.starts_with("memory@") => {
Expand Down Expand Up @@ -591,6 +604,7 @@ impl ParsedBootDtInfo {
isolation,
vtl2_reserved_range,
private_pool_ranges,
boot_log,
})
}
}
Expand Down Expand Up @@ -795,6 +809,9 @@ mod tests {
openhcl_builder = openhcl_builder.add_u64(p_vtl0_alias_map, data)?;
}

let p_boot_log = openhcl_builder.add_string("boot-log")?;
openhcl_builder = openhcl_builder.add_str(p_boot_log, &info.boot_log)?;

openhcl_builder = openhcl_builder
.start_node("vmbus-vtl0")?
.add_u32(p_address_cells, 2)?
Expand Down Expand Up @@ -962,6 +979,7 @@ mod tests {
range: MemoryRange::new(0x60000..0x70000),
vnode: 0,
}],
boot_log: "hello world".to_string(),
};

let dt = build_dt(&orig_info).unwrap();
Expand Down
21 changes: 21 additions & 0 deletions openhcl/openhcl_boot/src/boot_logger.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -12,6 +12,7 @@
use crate::arch::tdx::TdxIoAccess;
use crate::host_params::shim_params::IsolationType;
use crate::single_threaded::SingleThreaded;
use arrayvec::ArrayString;
use core::cell::RefCell;
use core::fmt;
use core::fmt::Write;
Expand Down Expand Up @@ -46,12 +47,16 @@ impl Logger {
}
}

const MAX_LOG_SIZE: usize = 4096 * 4;

pub struct BootLogger {
logger: SingleThreaded<RefCell<Logger>>,
memory_log: SingleThreaded<RefCell<ArrayString<MAX_LOG_SIZE>>>,
}

pub static BOOT_LOGGER: BootLogger = BootLogger {
logger: SingleThreaded(RefCell::new(Logger::None)),
memory_log: SingleThreaded(RefCell::new(ArrayString::new_const())),
};

/// Initialize the boot logger. This replaces any previous init calls.
Expand All @@ -74,10 +79,26 @@ pub fn boot_logger_init(isolation_type: IsolationType, logger_type: LoggerType)

impl Write for &BootLogger {
fn write_str(&mut self, s: &str) -> fmt::Result {
if let Ok(mut memory_log) = self.memory_log.try_borrow_mut() {
// TODO: Use a circular buffer instead of just ignoring logs after
// the buffer is full. This requires some other kind of
// non-allocating circular buffer, as arrayvec doesn't have any such
// data structures.
let _ = memory_log.write_str(s);
}

self.logger.borrow_mut().write_str(s)
}
}

impl BootLogger {
/// Get the current log buffer. This holds a borrow on the memory buffer, so
/// until this is dropped no new messages will be added.
pub fn log_buffer(&self) -> core::cell::Ref<'_, ArrayString<MAX_LOG_SIZE>> {
self.memory_log.borrow()
}
}

/// Log a message. These messages are always emitted regardless of debug or
/// release, if a corresponding logger was configured.
///
Expand Down
42 changes: 36 additions & 6 deletions openhcl/openhcl_boot/src/cmdline.rs
View file
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Original file line number Diff line number Diff line change
Expand Up @@ -13,6 +13,9 @@ use underhill_confidentiality::OPENHCL_CONFIDENTIAL_DEBUG_ENV_VAR_NAME;
const BOOT_LOG: &str = "OPENHCL_BOOT_LOG=";
const SERIAL_LOGGER: &str = "com3";

/// Enable boot log to be reported to usermode via the device tree.
const REPORT_BOOT_LOG: &str = "OPENHCL_REPORT_BOOT_LOG=1";

/// Enable the private VTL2 GPA pool for page allocations. This is only enabled
/// via the command line, because in order to support the VTL2 GPA pool
/// generically, the boot shim must read serialized data from the previous
Expand All @@ -30,6 +33,7 @@ pub struct BootCommandLineOptions {
pub logger: Option<LoggerType>,
pub confidential_debug: bool,
pub enable_vtl2_gpa_pool: Option<u64>,
pub report_boot_log: bool,
}

/// Parse arguments from a command line.
Expand All @@ -38,6 +42,7 @@ pub fn parse_boot_command_line(cmdline: &str) -> BootCommandLineOptions {
logger: None,
confidential_debug: false,
enable_vtl2_gpa_pool: None,
report_boot_log: false,
};

for arg in cmdline.split_whitespace() {
Expand Down Expand Up @@ -66,6 +71,8 @@ pub fn parse_boot_command_line(cmdline: &str) -> BootCommandLineOptions {
Some(num)
}
});
} else if arg.starts_with(REPORT_BOOT_LOG) {
result.report_boot_log = true;
}
}

Expand All @@ -83,7 +90,8 @@ mod tests {
BootCommandLineOptions {
logger: Some(LoggerType::Serial),
confidential_debug: false,
enable_vtl2_gpa_pool: None
enable_vtl2_gpa_pool: None,
report_boot_log: false,
}
);

Expand All @@ -92,7 +100,8 @@ mod tests {
BootCommandLineOptions {
logger: None,
confidential_debug: false,
enable_vtl2_gpa_pool: None
enable_vtl2_gpa_pool: None,
report_boot_log: false,
}
);

Expand All @@ -101,7 +110,8 @@ mod tests {
BootCommandLineOptions {
logger: None,
confidential_debug: false,
enable_vtl2_gpa_pool: None
enable_vtl2_gpa_pool: None,
report_boot_log: false,
}
);

Expand All @@ -110,7 +120,8 @@ mod tests {
BootCommandLineOptions {
logger: None,
confidential_debug: false,
enable_vtl2_gpa_pool: None
enable_vtl2_gpa_pool: None,
report_boot_log: false,
}
);

Expand All @@ -119,7 +130,8 @@ mod tests {
BootCommandLineOptions {
logger: None,
confidential_debug: false,
enable_vtl2_gpa_pool: None
enable_vtl2_gpa_pool: None,
report_boot_log: false,
}
);

Expand All @@ -129,7 +141,8 @@ mod tests {
BootCommandLineOptions {
logger: Some(LoggerType::Serial),
confidential_debug: true,
enable_vtl2_gpa_pool: None
enable_vtl2_gpa_pool: None,
report_boot_log: false,
}
);
}
Expand All @@ -142,6 +155,7 @@ mod tests {
logger: None,
confidential_debug: false,
enable_vtl2_gpa_pool: Some(1),
report_boot_log: false,
}
);
assert_eq!(
Expand All @@ -150,6 +164,7 @@ mod tests {
logger: None,
confidential_debug: false,
enable_vtl2_gpa_pool: None,
report_boot_log: false,
}
);
assert_eq!(
Expand All @@ -158,6 +173,7 @@ mod tests {
logger: None,
confidential_debug: false,
enable_vtl2_gpa_pool: None,
report_boot_log: false,
}
);
assert_eq!(
Expand All @@ -166,6 +182,20 @@ mod tests {
logger: None,
confidential_debug: false,
enable_vtl2_gpa_pool: Some(1024),
report_boot_log: false,
}
);
}

#[test]
fn test_report_boot_log() {
assert_eq!(
parse_boot_command_line("OPENHCL_REPORT_BOOT_LOG=1"),
BootCommandLineOptions {
logger: None,
confidential_debug: false,
enable_vtl2_gpa_pool: None,
report_boot_log: true,
}
);
}
Expand Down
15 changes: 15 additions & 0 deletions openhcl/openhcl_boot/src/dt.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -158,6 +158,7 @@ pub fn write_dt(
cmdline: &ArrayString<COMMAND_LINE_SIZE>,
sidecar: Option<&SidecarConfig<'_>>,
boot_times: Option<BootTimes>,
report_boot_log: bool,
) -> Result<(), DtError> {
// First, the reservation map is built. That keyes off of the x86 E820 memory map.
// The `/memreserve/` is used to tell the kernel that the reserved memory is RAM
Expand Down Expand Up @@ -461,6 +462,20 @@ pub fn write_dt(
};
openhcl_builder = openhcl_builder.add_str(p_isolation_type, isolation_type)?;

// If requested, capture the current memory log and report it to usermode.
//
// NOTE: This log is not all-inclusive, as any logs after this point are not
// saved to the device tree.
let p_boot_log = openhcl_builder.add_string("boot-log")?;
if report_boot_log {
openhcl_builder = openhcl_builder.add_str(
p_boot_log,
crate::boot_logger::BOOT_LOGGER.log_buffer().as_str(),
)?;
} else {
openhcl_builder = openhcl_builder.add_str(p_boot_log, "")?;
}

// Indicate what kind of memory allocation mode was done by the bootloader
// to usermode.
let p_memory_allocation_mode = openhcl_builder.add_string("memory-allocation-mode")?;
Expand Down
7 changes: 7 additions & 0 deletions openhcl/openhcl_boot/src/main.rs
View file
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Original file line number Diff line number Diff line change
Expand Up @@ -581,6 +581,7 @@ fn shim_main(shim_params_raw_offset: isize) -> ! {
boot_logger_init(p.isolation_type, typ);
log!("openhcl_boot: early debugging enabled");
}
let mut report_boot_log = static_options.report_boot_log;

let can_trust_host =
p.isolation_type == IsolationType::None || static_options.confidential_debug;
Expand Down Expand Up @@ -626,6 +627,8 @@ fn shim_main(shim_params_raw_offset: isize) -> ! {
// if it wasn't otherwise requested.
boot_logger_init(p.isolation_type, LoggerType::Serial);
}

report_boot_log |= dynamic_options.report_boot_log;
}

log!("openhcl_boot: entered shim_main");
Expand Down Expand Up @@ -748,6 +751,7 @@ fn shim_main(shim_params_raw_offset: isize) -> ! {
&cmdline,
sidecar.as_ref(),
boot_times,
report_boot_log,
)
.unwrap();

Expand Down Expand Up @@ -939,6 +943,7 @@ mod test {
&ArrayString::from("test").unwrap_or_default(),
None,
None,
false,
)
.unwrap();
}
Expand Down Expand Up @@ -1012,6 +1017,7 @@ mod test {
&ArrayString::from("test").unwrap_or_default(),
None,
None,
false,
)
.unwrap();

Expand Down Expand Up @@ -1040,6 +1046,7 @@ mod test {
&ArrayString::from("test").unwrap_or_default(),
None,
None,
false,
)
.unwrap();

Expand Down
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