From 3d467f7b8c0a179a10aa4e9f17cd2d3c3b7e5403 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Wed, 15 Dec 2021 16:12:25 +0000 Subject: [PATCH] KVM: arm64: Extend pkvm_page_state enumeration to handle absent pages Explicitly name the combination of SW0 | SW1 as reserved in the pte and introduce a new PKVM_NOPAGE meta-state which, although not directly stored in the software bits of the pte, can be used to represent an entry for which there is no underlying page. This is distinct from an invalid pte, as stage-2 identity mappings for the host are created lazily and so an invalid pte there is the same as a valid mapping for the purposes of ownership information. This state will be used for permission checking during page transitions in later patches. Reviewed-by: Andrew Walbran Signed-off-by: Will Deacon Signed-off-by: Quentin Perret Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20211215161232.1480836-9-qperret@google.com --- arch/arm64/kvm/hyp/include/nvhe/mem_protect.h | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h index b58c910babafd..56445586c7551 100644 --- a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h +++ b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h @@ -24,6 +24,11 @@ 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, + + /* Meta-states which aren't encoded directly in the PTE's SW bits */ + PKVM_NOPAGE, }; #define PKVM_PAGE_STATE_PROT_MASK (KVM_PGTABLE_PROT_SW0 | KVM_PGTABLE_PROT_SW1)