virtio-devices: iommu: Search full range for GVA conversion

Remove an erroneous optimisation that used the page size mask to reduce
the range to iterate through on the set of mappings. This doesn't work
as the virtio-iommu ranges are larger than a single page. This may have
worked in the past when the mappings were limited to a single page.

Signed-off-by: Rob Bradford <rbradford@rivosinc.com>

virtio-devices/src/iommu.rs

@@ -4,7 +4,6 @@
 
 use std::collections::BTreeMap;
 use std::mem::size_of;
-use std::ops::Bound::Included;
 use std::os::unix::io::AsRawFd;
 use std::sync::atomic::{AtomicBool, Ordering};
 use std::sync::{Arc, Barrier, Mutex, RwLock};
@@ -811,15 +810,7 @@ impl DmaRemapping for IommuMapping {
                     return Ok(addr);
                 }
 
-                let range_start = if VIRTIO_IOMMU_PAGE_SIZE_MASK > addr {
-                    0
-                } else {
-                    addr - VIRTIO_IOMMU_PAGE_SIZE_MASK
-                };
-                for (&key, &value) in domain
-                    .mappings
-                    .range((Included(&range_start), Included(&addr)))
-                {
+                for (&key, &value) in domain.mappings.iter() {
                     if addr >= key && addr < key + value.size {
                         let new_addr = addr - key + value.gpa;
                         debug!("Into GPA addr 0x{:x}", new_addr);