fix(fdt): Support FDT setup for CPU caches with high number of sets

Change the type of `CacheEntry`'s `number_of_sets` field from `u16` to
`u32`, to allow correctly parsing CPU cache information from sysfs and
successfully setting up the FDT on hosts with CPU caches with a number
of sets that is higher than `u16::MAX`.

This also makes a couple of `u16`->`u32` conversions redundant, which
we therefore remove.

Signed-off-by: Christos Katsakioris <[email protected]>
Signed-off-by: Filippos Tofalos <[email protected]>

src/vmm/src/arch/aarch64/cache_info.rs

@@ -38,7 +38,7 @@ pub(crate) struct CacheEntry {
     // Type of cache: Unified, Data, Instruction.
     pub type_: CacheType,
     pub size_: Option<u32>,
-    pub number_of_sets: Option<u16>,
+    pub number_of_sets: Option<u32>,
     pub line_size: Option<u16>,
     // How many CPUS share this cache.
     pub cpus_per_unit: u16,
@@ -114,7 +114,7 @@ impl CacheEntry {
         }
 
         if let Ok(number_of_sets) = store.get_by_key(index, "number_of_sets") {
-            cache.number_of_sets = Some(number_of_sets.parse::<u16>().map_err(|err| {
+            cache.number_of_sets = Some(number_of_sets.parse::<u32>().map_err(|err| {
                 CacheInfoError::InvalidCacheAttr("number_of_sets".to_string(), err.to_string())
             })?);
         } else {

src/vmm/src/arch/aarch64/fdt.rs

@@ -147,7 +147,7 @@ fn create_cpu_nodes(fdt: &mut FdtWriter, vcpu_mpidr: &[u64]) -> Result<(), FdtEr
                 fdt.property_u32(cache.type_.of_cache_line_size(), u32::from(line_size))?;
             }
             if let Some(number_of_sets) = cache.number_of_sets {
-                fdt.property_u32(cache.type_.of_cache_sets(), u32::from(number_of_sets))?;
+                fdt.property_u32(cache.type_.of_cache_sets(), number_of_sets)?;
             }
         }
 
@@ -197,7 +197,7 @@ fn create_cpu_nodes(fdt: &mut FdtWriter, vcpu_mpidr: &[u64]) -> Result<(), FdtEr
                     fdt.property_u32(cache.type_.of_cache_line_size(), u32::from(line_size))?;
                 }
                 if let Some(number_of_sets) = cache.number_of_sets {
-                    fdt.property_u32(cache.type_.of_cache_sets(), u32::from(number_of_sets))?;
+                    fdt.property_u32(cache.type_.of_cache_sets(), number_of_sets)?;
                 }
                 if let Some(cache_type) = cache.type_.of_cache_type() {
                     fdt.property_null(cache_type)?;