On 8/31/24 1:54 AM, Steven Price wrote:
On 26/08/2024 11:03, Catalin Marinas wrote:
On Mon, Aug 19, 2024 at 02:19:10PM +0100, Steven Price wrote:
[...]
+
+void __init arm64_rsi_setup_memory(void)
+{
+ u64 i;
+ phys_addr_t start, end;
+
+ if (!is_realm_world())
+ return;
+
+ /*
+ * Iterate over the available memory ranges and convert the state to
+ * protected memory. We should take extra care to ensure that we DO NOT
+ * permit any "DESTROYED" pages to be converted to "RAM".
+ *
+ * BUG_ON is used because if the attempt to switch the memory to
+ * protected has failed here, then future accesses to the memory are
+ * simply going to be reflected as a SEA (Synchronous External Abort)
+ * which we can't handle. Bailing out early prevents the guest limping
+ * on and dying later.
+ */
+ for_each_mem_range(i, &start, &end) {
+ BUG_ON(rsi_set_memory_range_protected_safe(start, end));
+ }
Would it help debugging if we print the memory ranges as well rather
than just a BUG_ON()?
Yes that would probably be useful - I'll fix that.
One potential issue I'm seeing is WARN_ON() followed by BUG_ON(). They're a bit
duplicate. I would suggest to remove the WARN_ON() and print informative messages
in rsi_set_memory_range().
setup_arch
arm64_rsi_setup_memory // BUG_ON(error)
rsi_set_memory_range_protected_safe
rsi_set_memory_range // WARN_ON(error)
Thanks,
Gavin
