diff options
| -rw-r--r-- | arch/arm64/kvm/hyp/include/nvhe/memory.h | 29 |
1 files changed, 19 insertions, 10 deletions
diff --git a/arch/arm64/kvm/hyp/include/nvhe/memory.h b/arch/arm64/kvm/hyp/include/nvhe/memory.h index 34233d586060..178028172c0b 100644 --- a/arch/arm64/kvm/hyp/include/nvhe/memory.h +++ b/arch/arm64/kvm/hyp/include/nvhe/memory.h @@ -8,20 +8,29 @@ #include <linux/types.h> /* - * Bits 0-1 are reserved to track the memory ownership state of each page: - * 00: The page is owned exclusively by the page-table owner. - * 01: The page is owned by the page-table owner, but is shared - * with another entity. - * 10: The page is shared with, but not owned by the page-table owner. - * 11: Reserved for future use (lending). + * Bits 0-1 are used to encode the memory ownership state of each page from the + * point of view of a pKVM "component" (host, hyp, guest, ... see enum + * pkvm_component_id): + * 00: The page is owned and exclusively accessible by the component; + * 01: The page is owned and accessible by the component, but is also + * accessible by another component; + * 10: The page is accessible but not owned by the component; + * The storage of this state depends on the component: either in the + * hyp_vmemmap for the host state or in PTE software bits for the hypervisor + * and guests. */ enum pkvm_page_state { PKVM_PAGE_OWNED = 0ULL, 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_PAGE_RESERVED = BIT(0) | BIT(1), + + /* + * 'Meta-states' are not stored directly in PTE SW bits for hyp and + * guest states, but inferred from the context (e.g. invalid PTE + * entries). For the host, meta-states are stored directly in the + * struct hyp_page. + */ PKVM_NOPAGE = BIT(2), }; #define PKVM_PAGE_META_STATES_MASK (~__PKVM_PAGE_RESERVED) @@ -44,7 +53,7 @@ struct hyp_page { u16 refcount; u8 order; - /* Host (non-meta) state. Guarded by the host stage-2 lock. */ + /* Host state. Guarded by the host stage-2 lock. */ enum pkvm_page_state host_state : 8; u32 host_share_guest_count; |