1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 #ifndef __KVM_HYP_MEMORY_H 3 #define __KVM_HYP_MEMORY_H 4 5 #include <asm/kvm_mmu.h> 6 #include <asm/page.h> 7 8 #include <linux/types.h> 9 10 /* 11 * Bits 0-1 are used to encode the memory ownership state of each page from the 12 * point of view of a pKVM "component" (host, hyp, guest, ... see enum 13 * pkvm_component_id): 14 * 00: The page is owned and exclusively accessible by the component; 15 * 01: The page is owned and accessible by the component, but is also 16 * accessible by another component; 17 * 10: The page is accessible but not owned by the component; 18 * The storage of this state depends on the component: either in the 19 * hyp_vmemmap for the host and hyp states or in PTE software bits for guests. 20 */ 21 enum pkvm_page_state { 22 PKVM_PAGE_OWNED = 0ULL, 23 PKVM_PAGE_SHARED_OWNED = BIT(0), 24 PKVM_PAGE_SHARED_BORROWED = BIT(1), 25 26 /* 27 * 'Meta-states' are not stored directly in PTE SW bits for guest 28 * states, but inferred from the context (e.g. invalid PTE entries). 29 * For the host and hyp, meta-states are stored directly in the 30 * struct hyp_page. 31 */ 32 PKVM_NOPAGE = BIT(0) | BIT(1), 33 }; 34 #define PKVM_PAGE_STATE_MASK (BIT(0) | BIT(1)) 35 36 #define PKVM_PAGE_STATE_PROT_MASK (KVM_PGTABLE_PROT_SW0 | KVM_PGTABLE_PROT_SW1) 37 static inline enum kvm_pgtable_prot pkvm_mkstate(enum kvm_pgtable_prot prot, 38 enum pkvm_page_state state) 39 { 40 prot &= ~PKVM_PAGE_STATE_PROT_MASK; 41 prot |= FIELD_PREP(PKVM_PAGE_STATE_PROT_MASK, state); 42 return prot; 43 } 44 45 static inline enum pkvm_page_state pkvm_getstate(enum kvm_pgtable_prot prot) 46 { 47 return FIELD_GET(PKVM_PAGE_STATE_PROT_MASK, prot); 48 } 49 50 struct hyp_page { 51 u16 refcount; 52 u8 order; 53 54 /* Host state. Guarded by the host stage-2 lock. */ 55 unsigned __host_state : 4; 56 57 /* 58 * Complement of the hyp state. Guarded by the hyp stage-1 lock. We use 59 * the complement so that the initial 0 in __hyp_state_comp (due to the 60 * entire vmemmap starting off zeroed) encodes PKVM_NOPAGE. 61 */ 62 unsigned __hyp_state_comp : 4; 63 64 u32 host_share_guest_count; 65 }; 66 67 extern u64 __hyp_vmemmap; 68 #define hyp_vmemmap ((struct hyp_page *)__hyp_vmemmap) 69 70 #define __hyp_va(phys) ((void *)((phys_addr_t)(phys) - hyp_physvirt_offset)) 71 72 static inline void *hyp_phys_to_virt(phys_addr_t phys) 73 { 74 return __hyp_va(phys); 75 } 76 77 static inline phys_addr_t hyp_virt_to_phys(void *addr) 78 { 79 return __hyp_pa(addr); 80 } 81 82 #define hyp_phys_to_pfn(phys) ((phys) >> PAGE_SHIFT) 83 #define hyp_pfn_to_phys(pfn) ((phys_addr_t)((pfn) << PAGE_SHIFT)) 84 85 static inline struct hyp_page *hyp_phys_to_page(phys_addr_t phys) 86 { 87 BUILD_BUG_ON(sizeof(struct hyp_page) != sizeof(u64)); 88 return &hyp_vmemmap[hyp_phys_to_pfn(phys)]; 89 } 90 91 #define hyp_virt_to_page(virt) hyp_phys_to_page(__hyp_pa(virt)) 92 #define hyp_virt_to_pfn(virt) hyp_phys_to_pfn(__hyp_pa(virt)) 93 94 #define hyp_page_to_pfn(page) ((struct hyp_page *)(page) - hyp_vmemmap) 95 #define hyp_page_to_phys(page) hyp_pfn_to_phys((hyp_page_to_pfn(page))) 96 #define hyp_page_to_virt(page) __hyp_va(hyp_page_to_phys(page)) 97 #define hyp_page_to_pool(page) (((struct hyp_page *)page)->pool) 98 99 static inline enum pkvm_page_state get_host_state(struct hyp_page *p) 100 { 101 return p->__host_state; 102 } 103 104 static inline void set_host_state(struct hyp_page *p, enum pkvm_page_state state) 105 { 106 p->__host_state = state; 107 } 108 109 static inline enum pkvm_page_state get_hyp_state(struct hyp_page *p) 110 { 111 return p->__hyp_state_comp ^ PKVM_PAGE_STATE_MASK; 112 } 113 114 static inline void set_hyp_state(struct hyp_page *p, enum pkvm_page_state state) 115 { 116 p->__hyp_state_comp = state ^ PKVM_PAGE_STATE_MASK; 117 } 118 119 /* 120 * Refcounting for 'struct hyp_page'. 121 * hyp_pool::lock must be held if atomic access to the refcount is required. 122 */ 123 static inline int hyp_page_count(void *addr) 124 { 125 struct hyp_page *p = hyp_virt_to_page(addr); 126 127 return p->refcount; 128 } 129 130 static inline void hyp_page_ref_inc(struct hyp_page *p) 131 { 132 BUG_ON(p->refcount == USHRT_MAX); 133 p->refcount++; 134 } 135 136 static inline void hyp_page_ref_dec(struct hyp_page *p) 137 { 138 BUG_ON(!p->refcount); 139 p->refcount--; 140 } 141 142 static inline int hyp_page_ref_dec_and_test(struct hyp_page *p) 143 { 144 hyp_page_ref_dec(p); 145 return (p->refcount == 0); 146 } 147 148 static inline void hyp_set_page_refcounted(struct hyp_page *p) 149 { 150 BUG_ON(p->refcount); 151 p->refcount = 1; 152 } 153 #endif /* __KVM_HYP_MEMORY_H */ 154