Re: [PATCH v14 26/44] arm64: RMI: Allow populating initial contents
From: Suzuki K Poulose
Date: Mon Jun 08 2026 - 05:46:46 EST
On 08/06/2026 10:36, Steven Price wrote:
On 28/05/2026 06:30, Gavin Shan wrote:
Hi Steve,
On 5/13/26 11:17 PM, Steven Price wrote:
The VMM needs to populate the realm with some data before starting (e.g.
a kernel and initrd). This is measured by the RMM and used as part of
the attestation later on.
Signed-off-by: Steven Price <steven.price@xxxxxxx>
...
diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c
index a89873a5eb77..209087bcf399 100644
--- a/arch/arm64/kvm/rmi.c
+++ b/arch/arm64/kvm/rmi.c
@@ -486,6 +486,75 @@ void kvm_realm_unmap_range(struct kvm *kvm,
unsigned long start,
realm_unmap_private_range(kvm, start, end, may_block);
}
+static int realm_data_map_init(struct kvm *kvm, unsigned long ipa,
+ kvm_pfn_t dst_pfn, kvm_pfn_t src_pfn,
+ unsigned long flags)
+{
+ struct realm *realm = &kvm->arch.realm;
+ phys_addr_t rd = virt_to_phys(realm->rd);
+ phys_addr_t dst_phys, src_phys;
+ int ret;
+
+ dst_phys = __pfn_to_phys(dst_pfn);
+ src_phys = __pfn_to_phys(src_pfn);
+
+ if (rmi_delegate_page(dst_phys))
+ return -ENXIO;
+
+ ret = rmi_rtt_data_map_init(rd, dst_phys, ipa, src_phys, flags);
+ if (RMI_RETURN_STATUS(ret) == RMI_ERROR_RTT) {
+ /* Create missing RTTs and retry */
+ int level = RMI_RETURN_INDEX(ret);
+
+ KVM_BUG_ON(level == KVM_PGTABLE_LAST_LEVEL, kvm);
KVM_BUG_ON(level >= KVM_PGTABLE_LAST_LEVEL, kvm);
Ack.
Thinking more about this, I guess a buggy VMM can trigger this
by populating twice ? (level == KVM_PGTABLE_LAST_LEVEL). So, we should
return the error back, than warning here and suppressing the error ?
Suzuki