Ensure that VirtIO buffers are aligned to PAGE_SIZE as required.
The existing code assumed that the hypervisor granule was greater than
virtio_driver::PAGE_SIZE, which is true in practice so far but not
guaranteed.
Removed redundant documentation from the Hal trait implementation, and
made the implementation safety comments more explicit.
Bug: 274732281
Bug: 237249346
Test: Build virt APEX
Change-Id: I776dcda7f5660b6f6e696c6834ac03f8e4023543
diff --git a/pvmfw/src/memory.rs b/pvmfw/src/memory.rs
index cfd6b0a..b0a9406 100644
--- a/pvmfw/src/memory.rs
+++ b/pvmfw/src/memory.rs
@@ -395,10 +395,8 @@
}
}
-/// Allocates a memory range of at least the given size that is shared with
-/// host. Returns a pointer to the buffer.
-///
-/// It will be aligned to the memory sharing granule size supported by the hypervisor.
+/// Allocates a memory range of at least the given size and alignment that is shared with the host.
+/// Returns a pointer to the buffer.
pub fn alloc_shared(layout: Layout) -> hyp::Result<NonNull<u8>> {
assert_ne!(layout.size(), 0);
let Some(buffer) = try_shared_alloc(layout) else {
@@ -424,11 +422,11 @@
/// Unshares and deallocates a memory range which was previously allocated by `alloc_shared`.
///
-/// The size passed in must be the size passed to the original `alloc_shared` call.
+/// The layout passed in must be the same layout passed to the original `alloc_shared` call.
///
/// # Safety
///
-/// The memory must have been allocated by `alloc_shared` with the same size, and not yet
+/// The memory must have been allocated by `alloc_shared` with the same layout, and not yet
/// deallocated.
pub unsafe fn dealloc_shared(vaddr: NonNull<u8>, layout: Layout) -> hyp::Result<()> {
SHARED_POOL.get().unwrap().lock().dealloc(vaddr, layout);