vmbase_example: Run most tests using dynamic PTs
Instead of enabling the dynamic page tables for a short duration and
switching back to idmap.S, enable them early and keep them (almost)
until main() returns.
Map the DT before it is accessed by the tests. As a result, the
assertion that the DT must be at a hard-coded location can be lifted and
we can remove the mapping from idmap.S. Note that the PT test was
previously using .map_rodata() for the DT but, given modify_fdt(), we
must actually use .map_data().
For the PCI BAR, avoid a BBM violation but detecting if the region is
already mapped. To do so, implement RangeExt for MemoryRegion.
Test: atest vmbase_example.integration_test
Change-Id: I1abbf1566c579282742f5a0936e0934e69c38797
diff --git a/guest/vmbase_example/idmap.S b/guest/vmbase_example/idmap.S
index 268de5f..2e62085 100644
--- a/guest/vmbase_example/idmap.S
+++ b/guest/vmbase_example/idmap.S
@@ -45,7 +45,7 @@
0: /* level 2 */
#if defined(VMBASE_EXAMPLE_IS_BIOS)
- .quad .L_BLOCK_MEM | 0x80000000 // DT provided by VMM
+ .quad 0 // 2 MiB not mapped (DT)
.quad .L_BLOCK_MEM_XIP | 0x80200000 // 2 MiB of DRAM containing image
.quad .L_BLOCK_MEM | 0x80400000 // 2 MiB of writable DRAM
.fill 509, 8, 0x0
diff --git a/guest/vmbase_example/src/main.rs b/guest/vmbase_example/src/main.rs
index 02c9429..7a3f427 100644
--- a/guest/vmbase_example/src/main.rs
+++ b/guest/vmbase_example/src/main.rs
@@ -36,12 +36,10 @@
use log::{debug, error, info, trace, warn, LevelFilter};
use vmbase::{
bionic, configure_heap, generate_image_header,
- layout::{
- crosvm::{FDT_MAX_SIZE, MEM_START},
- rodata_range, scratch_range, text_range,
- },
+ layout::{crosvm::FDT_MAX_SIZE, rodata_range, scratch_range, text_range},
linker, logger, main,
memory::{PageTable, SIZE_64KB},
+ util::RangeExt as _,
};
static INITIALISED_DATA: [u32; 4] = [1, 2, 3, 4];
@@ -80,13 +78,15 @@
check_data();
check_stack_guard();
+ let mut page_table = PageTable::default();
+ init_page_table(&mut page_table).unwrap();
+
info!("Checking FDT...");
let fdt_addr = usize::try_from(arg0).unwrap();
- // We are about to access the region so check that it matches our page tables in idmap.S.
- assert_eq!(fdt_addr, MEM_START);
// SAFETY: The DTB range is valid, writable memory, and we don't construct any aliases to it.
let fdt = unsafe { core::slice::from_raw_parts_mut(fdt_addr as *mut u8, FDT_MAX_SIZE) };
let fdt_region = (VirtualAddress(fdt_addr)..VirtualAddress(fdt_addr + fdt.len())).into();
+ page_table.map_data(&fdt_region).unwrap();
let fdt = Fdt::from_mut_slice(fdt).unwrap();
info!("FDT passed verification.");
check_fdt(fdt);
@@ -98,11 +98,13 @@
check_alloc();
- let mut page_table = PageTable::default();
- page_table.map_rodata(&fdt_region).unwrap();
- page_table.map_device(&get_bar_region(&pci_info)).unwrap();
- init_page_table(&mut page_table).unwrap();
- mem::drop(page_table); // Release PageTable and switch back to idmap.S
+ let bar_region = get_bar_region(&pci_info);
+ if bar_region.is_within(&DEVICE_REGION) {
+ // Avoid a MapError::BreakBeforeMakeViolation.
+ info!("BAR region is within already mapped device region: skipping page table ops.");
+ } else {
+ page_table.map_device(&bar_region).unwrap();
+ }
check_data();
check_dice();
@@ -112,6 +114,10 @@
check_pci(&mut pci_root);
emit_suppressed_log();
+
+ info!("De-activating IdMap...");
+ mem::drop(page_table); // Release PageTable and switch back to idmap.S
+ info!("De-activated.");
}
fn check_stack_guard() {
diff --git a/libs/libvmbase/src/util.rs b/libs/libvmbase/src/util.rs
index 8c230a1..e52ac8e 100644
--- a/libs/libvmbase/src/util.rs
+++ b/libs/libvmbase/src/util.rs
@@ -14,6 +14,7 @@
//! Utility functions.
+use aarch64_paging::paging::MemoryRegion;
use core::ops::Range;
/// Flatten [[T; N]] into &[T]
@@ -91,3 +92,13 @@
self.start < other.end && other.start < self.end
}
}
+
+impl RangeExt for MemoryRegion {
+ fn is_within(&self, other: &Self) -> bool {
+ self.start() >= other.start() && self.end() <= other.end()
+ }
+
+ fn overlaps(&self, other: &Self) -> bool {
+ self.start() < other.end() && other.start() < self.end()
+ }
+}