Commit a1a1f1ff authored by Quentin Perret's avatar Quentin Perret Committed by Marc Zyngier
Browse files

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: default avatarFuad Tabba <tabba@google.com>
Reviewed-by: default avatarFuad Tabba <tabba@google.com>
Signed-off-by: default avatarQuentin Perret <qperret@google.com>
Link: https://lore.kernel.org/r/20241218194059.3670226-2-qperret@google.com


Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
parent 78d4f34e

arch/arm64/kvm/hyp/include/nvhe/mem_protect.h

+9 −7
Original line number Diff line number Diff line
@@ -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 {