From a1a1f1ff1f28d52deb39aa29b89663de2afefd67 Mon Sep 17 00:00:00 2001
From: Quentin Perret <qperret@google.com>
Date: Wed, 18 Dec 2024 19:40:42 +0000
Subject: [PATCH] KVM: arm64: Change the layout of enum pkvm_page_state
The 'concrete' (a.k.a non-meta) page states are currently encoded using
software bits in PTEs. For performance reasons, the abstract
pkvm_page_state enum uses the same bits to encode these states as that
makes conversions from and to PTEs easy.
In order to prepare the ground for moving the 'concrete' state storage
to the hyp vmemmap, re-arrange the enum to use bits 0 and 1 for this
purpose.
No functional changes intended.
Tested-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Quentin Perret <qperret@google.com>
Link: https://lore.kernel.org/r/20241218194059.3670226-2-qperret@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
arch/arm64/kvm/hyp/include/nvhe/mem_protect.h | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)
diff --git a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
index 0972faccc2af0..5462faf6bfeeb 100644
--- a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
+++ b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
@@ -24,25 +24,27 @@
*/
enum pkvm_page_state {
PKVM_PAGE_OWNED = 0ULL,
- PKVM_PAGE_SHARED_OWNED = KVM_PGTABLE_PROT_SW0,
- PKVM_PAGE_SHARED_BORROWED = KVM_PGTABLE_PROT_SW1,
- __PKVM_PAGE_RESERVED = KVM_PGTABLE_PROT_SW0 |
- KVM_PGTABLE_PROT_SW1,
+ PKVM_PAGE_SHARED_OWNED = BIT(0),
+ PKVM_PAGE_SHARED_BORROWED = BIT(1),
+ __PKVM_PAGE_RESERVED = BIT(0) | BIT(1),
/* Meta-states which aren't encoded directly in the PTE's SW bits */
- PKVM_NOPAGE,
+ PKVM_NOPAGE = BIT(2),
};
+#define PKVM_PAGE_META_STATES_MASK (~__PKVM_PAGE_RESERVED)
#define PKVM_PAGE_STATE_PROT_MASK (KVM_PGTABLE_PROT_SW0 | KVM_PGTABLE_PROT_SW1)
static inline enum kvm_pgtable_prot pkvm_mkstate(enum kvm_pgtable_prot prot,
enum pkvm_page_state state)
{
- return (prot & ~PKVM_PAGE_STATE_PROT_MASK) | state;
+ prot &= ~PKVM_PAGE_STATE_PROT_MASK;
+ prot |= FIELD_PREP(PKVM_PAGE_STATE_PROT_MASK, state);
+ return prot;
}
static inline enum pkvm_page_state pkvm_getstate(enum kvm_pgtable_prot prot)
{
- return prot & PKVM_PAGE_STATE_PROT_MASK;
+ return FIELD_GET(PKVM_PAGE_STATE_PROT_MASK, prot);
}
struct host_mmu {