On 12/13/24 1:55 AM, Steven Price wrote:
The RMM owns the stage 2 page tables for a realm, and KVM must request
that the RMM creates/destroys entries as necessary. The physical pages
to store the page tables are delegated to the realm as required, and can
be undelegated when no longer used.
Creating new RTTs is the easy part, tearing down is a little more
tricky. The result of realm_rtt_destroy() can be used to effectively
walk the tree and destroy the entries (undelegating pages that were
given to the realm).
Signed-off-by: Steven Price <steven.price@xxxxxxx>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
---
Changes since v5:
* Rename some RME_xxx defines to do with page sizes as RMM_xxx - they are
a property of the RMM specification not the RME architecture.
Changes since v2:
* Moved {alloc,free}_delegated_page() and ensure_spare_page() to a
later patch when they are actually used.
* Some simplifications now rmi_xxx() functions allow NULL as an output
parameter.
* Improved comments and code layout.
---
arch/arm64/include/asm/kvm_rme.h | 19 ++++++
arch/arm64/kvm/mmu.c | 6 +-
arch/arm64/kvm/rme.c | 112 +++++++++++++++++++++++++++++++
3 files changed, 134 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_rme.h b/arch/arm64/include/asm/kvm_rme.h
index 209cd99f03dd..32bdedf1d866 100644
--- a/arch/arm64/include/asm/kvm_rme.h
+++ b/arch/arm64/include/asm/kvm_rme.h
@@ -71,5 +71,24 @@ u32 kvm_realm_ipa_limit(void);
int kvm_realm_enable_cap(struct kvm *kvm, struct kvm_enable_cap *cap);
int kvm_init_realm_vm(struct kvm *kvm);
void kvm_destroy_realm(struct kvm *kvm);
+void kvm_realm_destroy_rtts(struct kvm *kvm, u32 ia_bits);
+
+#define RMM_RTT_BLOCK_LEVEL 2
+#define RMM_RTT_MAX_LEVEL 3
+
+#define RMM_PAGE_SHIFT 12
+#define RMM_PAGE_SIZE BIT(RMM_PAGE_SHIFT)
+/* See ARM64_HW_PGTABLE_LEVEL_SHIFT() */
+#define RMM_RTT_LEVEL_SHIFT(l) \
+ ((RMM_PAGE_SHIFT - 3) * (4 - (l)) + 3)
+#define RMM_L2_BLOCK_SIZE BIT(RMM_RTT_LEVEL_SHIFT(2))
+
+static inline unsigned long rme_rtt_level_mapsize(int level)
+{
+ if (WARN_ON(level > RMM_RTT_MAX_LEVEL))
+ return RMM_PAGE_SIZE;
+
+ return (1UL << RMM_RTT_LEVEL_SHIFT(level));
+}
#endif
All those definitions can be moved to rme.c since they're only used in rme.c
Thanks,
Gavin
