vmbase: Enter clients with dynamic PTs live

The layout and linker sections of clients are controlled by a linker
script provided by vmbase so the library should know how to replicate
the client-specific static PTs to generate the dynamic PTs. Therefore,
teach vmbase to use the information it gets from the linker to replicate
the client static PTs, with client-agnostic code, and switch to the
dynamic PTs before entering its clients.

Bug: 377276983
Test: m {pvmfw,rialto,vmbase_example_{bios,kernel}}_bin
Test: atest rialto_test vmbase_example.integration_test
Change-Id: I90fa0e62e6e4cb8474f3294633cee775b1191c71
diff --git a/guest/pvmfw/src/entry.rs b/guest/pvmfw/src/entry.rs
index 1da0513..2f0b391 100644
--- a/guest/pvmfw/src/entry.rs
+++ b/guest/pvmfw/src/entry.rs
@@ -28,9 +28,8 @@
     arch::aarch64::min_dcache_line_size,
     configure_heap, console_writeln, layout, limit_stack_size, main,
     memory::{
-        deactivate_dynamic_page_tables, map_image_footer, switch_to_dynamic_page_tables,
-        unshare_all_memory, unshare_all_mmio_except_uart, unshare_uart, MemoryTrackerError,
-        SIZE_128KB, SIZE_4KB,
+        deactivate_dynamic_page_tables, map_image_footer, unshare_all_memory,
+        unshare_all_mmio_except_uart, unshare_uart, MemoryTrackerError, SIZE_128KB, SIZE_4KB,
     },
     power::reboot,
 };
@@ -109,13 +108,6 @@
 
     log::set_max_level(LevelFilter::Info);
 
-    let page_table = memory::init_page_table().map_err(|e| {
-        error!("Failed to set up the dynamic page tables: {e}");
-        RebootReason::InternalError
-    })?;
-    // Up to this point, we were using the built-in static (from .rodata) page tables.
-    switch_to_dynamic_page_tables(page_table);
-
     let appended_data = get_appended_data_slice().map_err(|e| {
         error!("Failed to map the appended data: {e}");
         RebootReason::InternalError
diff --git a/guest/pvmfw/src/memory.rs b/guest/pvmfw/src/memory.rs
index a0d2b14..35bfd3a 100644
--- a/guest/pvmfw/src/memory.rs
+++ b/guest/pvmfw/src/memory.rs
@@ -16,36 +16,17 @@
 
 use crate::entry::RebootReason;
 use crate::fdt;
-use aarch64_paging::MapError;
 use core::num::NonZeroUsize;
-use core::result;
 use core::slice;
 use log::debug;
 use log::error;
 use log::info;
 use log::warn;
 use vmbase::{
-    layout::{self, crosvm},
-    memory::{init_shared_pool, map_data, map_rodata, resize_available_memory, PageTable},
+    layout::crosvm,
+    memory::{init_shared_pool, map_data, map_rodata, resize_available_memory},
 };
 
-pub fn init_page_table() -> result::Result<PageTable, MapError> {
-    let mut page_table = PageTable::default();
-
-    // Stack and scratch ranges are explicitly zeroed and flushed before jumping to payload,
-    // so dirty state management can be omitted.
-    page_table.map_data(&layout::data_bss_range().into())?;
-    page_table.map_data(&layout::eh_stack_range().into())?;
-    page_table.map_data(&layout::stack_range().into())?;
-    page_table.map_code(&layout::text_range().into())?;
-    page_table.map_rodata(&layout::rodata_range().into())?;
-    if let Err(e) = page_table.map_device(&layout::console_uart_page().into()) {
-        error!("Failed to remap the UART as a dynamic page table entry: {e}");
-        return Err(e);
-    }
-    Ok(page_table)
-}
-
 pub(crate) struct MemorySlices<'a> {
     pub fdt: &'a mut libfdt::Fdt,
     pub kernel: &'a [u8],