Snap for 9470583 from d3a0a4237549fbdc7211871c0280e7858ff013fc to tm-qpr3-release
Change-Id: I3cf3372fd54e3c0e7b6a455f5b65454a39421c3c
diff --git a/devices/src/virtio/queue.rs b/devices/src/virtio/queue.rs
index a436f74..1e4d8bd 100644
--- a/devices/src/virtio/queue.rs
+++ b/devices/src/virtio/queue.rs
@@ -162,11 +162,8 @@
if self.len > 0 {
match self.get_mem_regions() {
Ok(regions) => {
- if regions.iter().any(|r| {
- self.mem
- .checked_offset(r.gpa, r.len as u64 - 1u64)
- .is_none()
- }) {
+ // Each region in `self.regions` must be a contiguous range in `self.mem`.
+ if !regions.iter().all(|r| self.mem.is_valid_range(r.gpa, r.len as u64)) {
return false;
}
}
diff --git a/vm_memory/src/guest_memory.rs b/vm_memory/src/guest_memory.rs
index 47c3ba4..7c5b4d4 100644
--- a/vm_memory/src/guest_memory.rs
+++ b/vm_memory/src/guest_memory.rs
@@ -315,7 +315,10 @@
.any(|region| region.start() < end && start < region.end())
}
- /// Returns the address plus the offset if it is in range.
+ /// Returns an address `addr + offset` if it's in range.
+ ///
+ /// This function doesn't care whether a region `[addr, addr + offset)` is in range or not. To
+ /// guarantee it's a valid range, use `is_valid_range()` instead.
pub fn checked_offset(&self, addr: GuestAddress, offset: u64) -> Option<GuestAddress> {
addr.checked_add(offset).and_then(|a| {
if self.address_in_range(a) {
@@ -326,6 +329,24 @@
})
}
+ /// Returns true if the given range `[start, start + length)` is a valid contiguous memory
+ /// range available to the guest and it's backed by a single underlying memory region.
+ pub fn is_valid_range(&self, start: GuestAddress, length: u64) -> bool {
+ if length == 0 {
+ return false;
+ }
+
+ let end = if let Some(end) = start.checked_add(length - 1) {
+ end
+ } else {
+ return false;
+ };
+
+ self.regions
+ .iter()
+ .any(|region| region.start() <= start && end < region.end())
+ }
+
/// Returns the size of the memory region in bytes.
pub fn num_regions(&self) -> u64 {
self.regions.len() as u64