This is a note to let you know that I've just added the patch titled
KVM: arm64: Work out supported block level at compile time
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
kvm-arm64-work-out-supported-block-level-at-compile-time.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 3b5c082bbfa20d9a57924edd655bbe63fe98ab06 Mon Sep 17 00:00:00 2001
From: Oliver Upton <oliver.upton@xxxxxxxxx>
Date: Fri, 7 Oct 2022 23:41:50 +0000
Subject: KVM: arm64: Work out supported block level at compile time
From: Oliver Upton <oliver.upton@xxxxxxxxx>
commit 3b5c082bbfa20d9a57924edd655bbe63fe98ab06 upstream.
Work out the minimum page table level where KVM supports block mappings
at compile time. While at it, rewrite the comment around supported block
mappings to directly describe what KVM supports instead of phrasing in
terms of what it does not.
Signed-off-by: Oliver Upton <oliver.upton@xxxxxxxxx>
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20221007234151.461779-2-oliver.upton@xxxxxxxxx
Signed-off-by: Krister Johansen <kjlx@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/arm64/include/asm/kvm_pgtable.h | 18 +++++++++++++-----
1 file changed, 13 insertions(+), 5 deletions(-)
--- a/arch/arm64/include/asm/kvm_pgtable.h
+++ b/arch/arm64/include/asm/kvm_pgtable.h
@@ -13,6 +13,18 @@
#define KVM_PGTABLE_MAX_LEVELS 4U
+/*
+ * The largest supported block sizes for KVM (no 52-bit PA support):
+ * - 4K (level 1): 1GB
+ * - 16K (level 2): 32MB
+ * - 64K (level 2): 512MB
+ */
+#ifdef CONFIG_ARM64_4K_PAGES
+#define KVM_PGTABLE_MIN_BLOCK_LEVEL 1U
+#else
+#define KVM_PGTABLE_MIN_BLOCK_LEVEL 2U
+#endif
+
static inline u64 kvm_get_parange(u64 mmfr0)
{
u64 parange = cpuid_feature_extract_unsigned_field(mmfr0,
@@ -58,11 +70,7 @@ static inline u64 kvm_granule_size(u32 l
static inline bool kvm_level_supports_block_mapping(u32 level)
{
- /*
- * Reject invalid block mappings and don't bother with 4TB mappings for
- * 52-bit PAs.
- */
- return !(level == 0 || (PAGE_SIZE != SZ_4K && level == 1));
+ return level >= KVM_PGTABLE_MIN_BLOCK_LEVEL;
}
/**
Patches currently in stable-queue which might be from oliver.upton@xxxxxxxxx are
queue-5.15/kvm-arm64-work-out-supported-block-level-at-compile-time.patch
queue-5.15/kvm-arm64-limit-stage2_apply_range-batch-size-to-largest-block.patch
