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

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * Copyright (C) 2020 Google LLC
   4  * Author: Quentin Perret <qperret@google.com>
   5  */
   6
   7 #ifndef __KVM_NVHE_MEM_PROTECT__
   8 #define __KVM_NVHE_MEM_PROTECT__
   9 #include <linux/kvm_host.h>
  10 #include <asm/kvm_hyp.h>
  11 #include <asm/kvm_mmu.h>
  12 #include <asm/kvm_pgtable.h>
  13 #include <asm/virt.h>
  14 #include <nvhe/spinlock.h>
  15
  16 /*
  17  * SW bits 0-1 are reserved to track the memory ownership state of each page:
  18  *   00: The page is owned exclusively by the page-table owner.
  19  *   01: The page is owned by the page-table owner, but is shared
  20  *       with another entity.
  21  *   10: The page is shared with, but not owned by the page-table owner.
  22  *   11: Reserved for future use (lending).
  23  */
  24 enum pkvm_page_state {
  25         PKVM_PAGE_OWNED                 = 0ULL,
  26         PKVM_PAGE_SHARED_OWNED          = KVM_PGTABLE_PROT_SW0,
  27         PKVM_PAGE_SHARED_BORROWED       = KVM_PGTABLE_PROT_SW1,
  28         __PKVM_PAGE_RESERVED            = KVM_PGTABLE_PROT_SW0 |
  29                                           KVM_PGTABLE_PROT_SW1,
  30
  31         /* Meta-states which aren't encoded directly in the PTE's SW bits */
  32         PKVM_NOPAGE,
  33 };
  34
  35 #define PKVM_PAGE_STATE_PROT_MASK       (KVM_PGTABLE_PROT_SW0 | KVM_PGTABLE_PROT_SW1)
  36 static inline enum kvm_pgtable_prot pkvm_mkstate(enum kvm_pgtable_prot prot,
  37                                                  enum pkvm_page_state state)
  38 {
  39         return (prot & ~PKVM_PAGE_STATE_PROT_MASK) | state;
  40 }
  41
  42 static inline enum pkvm_page_state pkvm_getstate(enum kvm_pgtable_prot prot)
  43 {
  44         return prot & PKVM_PAGE_STATE_PROT_MASK;
  45 }
  46
  47 struct host_mmu {
  48         struct kvm_arch arch;
  49         struct kvm_pgtable pgt;
  50         struct kvm_pgtable_mm_ops mm_ops;
  51         hyp_spinlock_t lock;
  52 };
  53 extern struct host_mmu host_mmu;
  54
  55 /* This corresponds to page-table locking order */
  56 enum pkvm_component_id {
  57         PKVM_ID_HOST,
  58         PKVM_ID_HYP,
  59 };
  60
  61 int __pkvm_prot_finalize(void);
  62 int __pkvm_host_share_hyp(u64 pfn);
  63 int __pkvm_host_unshare_hyp(u64 pfn);
  64 int __pkvm_host_donate_hyp(u64 pfn, u64 nr_pages);
  65 int __pkvm_hyp_donate_host(u64 pfn, u64 nr_pages);
  66
  67 bool addr_is_memory(phys_addr_t phys);
  68 int host_stage2_idmap_locked(phys_addr_t addr, u64 size, enum kvm_pgtable_prot prot);
  69 int host_stage2_set_owner_locked(phys_addr_t addr, u64 size, u8 owner_id);
  70 int kvm_host_prepare_stage2(void *pgt_pool_base);
  71 void handle_host_mem_abort(struct kvm_cpu_context *host_ctxt);
  72
  73 int hyp_pin_shared_mem(void *from, void *to);
  74 void hyp_unpin_shared_mem(void *from, void *to);
  75
  76 static __always_inline void __load_host_stage2(void)
  77 {
  78         if (static_branch_likely(&kvm_protected_mode_initialized))
  79                 __load_stage2(&host_mmu.arch.mmu, &host_mmu.arch);
  80         else
  81                 write_sysreg(0, vttbr_el2);
  82 }
  83 #endif /* __KVM_NVHE_MEM_PROTECT__ */