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KVM: arm64: Change the layout of enum pkvm_page_state

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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>
This commit is contained in:
Quentin Perret
2024-12-18 19:40:42 +00:00
committed by Marc Zyngier
parent 78d4f34e21
commit a1a1f1ff1f
1 changed files with 9 additions and 7 deletions
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16
arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
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@@ -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 {