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 /* 35 * 'Meta-states' which aren't encoded directly in the PTE's SW bits (or 36 * the hyp_vmemmap entry for the host) 37 */ 38 PKVM_POISON = BIT(2), 39 }; 40 #define PKVM_PAGE_STATE_VMEMMAP_MASK (BIT(0) | BIT(1)) 41 42 #define PKVM_PAGE_STATE_PROT_MASK (KVM_PGTABLE_PROT_SW0 | KVM_PGTABLE_PROT_SW1) 43 static inline enum kvm_pgtable_prot pkvm_mkstate(enum kvm_pgtable_prot prot, 44 enum pkvm_page_state state) 45 { 46 prot &= ~PKVM_PAGE_STATE_PROT_MASK; 47 prot |= FIELD_PREP(PKVM_PAGE_STATE_PROT_MASK, state); 48 return prot; 49 } 50 51 static inline enum pkvm_page_state pkvm_getstate(enum kvm_pgtable_prot prot) 52 { 53 return FIELD_GET(PKVM_PAGE_STATE_PROT_MASK, prot); 54 } 55 56 struct hyp_page { 57 u16 refcount; 58 u8 order; 59 60 /* Host state. Guarded by the host stage-2 lock. */ 61 unsigned __host_state : 4; 62 63 /* 64 * Complement of the hyp state. Guarded by the hyp stage-1 lock. We use 65 * the complement so that the initial 0 in __hyp_state_comp (due to the 66 * entire vmemmap starting off zeroed) encodes PKVM_NOPAGE. 67 */ 68 unsigned __hyp_state_comp : 4; 69 70 u32 host_share_guest_count; 71 }; 72 73 extern u64 __hyp_vmemmap; 74 #define hyp_vmemmap ((struct hyp_page *)__hyp_vmemmap) 75 76 #define __hyp_va(phys) ((void *)((phys_addr_t)(phys) - hyp_physvirt_offset)) 77 78 static inline void *hyp_phys_to_virt(phys_addr_t phys) 79 { 80 return __hyp_va(phys); 81 } 82 83 static inline phys_addr_t hyp_virt_to_phys(void *addr) 84 { 85 return __hyp_pa(addr); 86 } 87 88 #define hyp_phys_to_pfn(phys) ((phys) >> PAGE_SHIFT) 89 #define hyp_pfn_to_phys(pfn) ((phys_addr_t)((pfn) << PAGE_SHIFT)) 90 91 static inline struct hyp_page *hyp_phys_to_page(phys_addr_t phys) 92 { 93 BUILD_BUG_ON(sizeof(struct hyp_page) != sizeof(u64)); 94 return &hyp_vmemmap[hyp_phys_to_pfn(phys)]; 95 } 96 97 #define hyp_virt_to_page(virt) hyp_phys_to_page(__hyp_pa(virt)) 98 #define hyp_virt_to_pfn(virt) hyp_phys_to_pfn(__hyp_pa(virt)) 99 100 #define hyp_page_to_pfn(page) ((struct hyp_page *)(page) - hyp_vmemmap) 101 #define hyp_page_to_phys(page) hyp_pfn_to_phys((hyp_page_to_pfn(page))) 102 #define hyp_page_to_virt(page) __hyp_va(hyp_page_to_phys(page)) 103 #define hyp_page_to_pool(page) (((struct hyp_page *)page)->pool) 104 105 static inline enum pkvm_page_state get_host_state(struct hyp_page *p) 106 { 107 return p->__host_state; 108 } 109 110 static inline void set_host_state(struct hyp_page *p, enum pkvm_page_state state) 111 { 112 p->__host_state = state; 113 } 114 115 static inline enum pkvm_page_state get_hyp_state(struct hyp_page *p) 116 { 117 return p->__hyp_state_comp ^ PKVM_PAGE_STATE_VMEMMAP_MASK; 118 } 119 120 static inline void set_hyp_state(struct hyp_page *p, enum pkvm_page_state state) 121 { 122 p->__hyp_state_comp = state ^ PKVM_PAGE_STATE_VMEMMAP_MASK; 123 } 124 125 /* 126 * Refcounting for 'struct hyp_page'. 127 * hyp_pool::lock must be held if atomic access to the refcount is required. 128 */ 129 static inline int hyp_page_count(void *addr) 130 { 131 struct hyp_page *p = hyp_virt_to_page(addr); 132 133 return p->refcount; 134 } 135 136 static inline void hyp_page_ref_inc(struct hyp_page *p) 137 { 138 BUG_ON(p->refcount == USHRT_MAX); 139 p->refcount++; 140 } 141 142 static inline void hyp_page_ref_dec(struct hyp_page *p) 143 { 144 BUG_ON(!p->refcount); 145 p->refcount--; 146 } 147 148 static inline int hyp_page_ref_dec_and_test(struct hyp_page *p) 149 { 150 hyp_page_ref_dec(p); 151 return (p->refcount == 0); 152 } 153 154 static inline void hyp_set_page_refcounted(struct hyp_page *p) 155 { 156 BUG_ON(p->refcount); 157 p->refcount = 1; 158 } 159 #endif /* __KVM_HYP_MEMORY_H */ 160