diff --git a/arch/riscv/include/asm/kvm_gstage.h b/arch/riscv/include/asm/kvm_gstage.h index 595e2183173ebd..373748c6745ee6 100644 --- a/arch/riscv/include/asm/kvm_gstage.h +++ b/arch/riscv/include/asm/kvm_gstage.h @@ -53,6 +53,10 @@ int kvm_riscv_gstage_map_page(struct kvm_gstage *gstage, bool page_rdonly, bool page_exec, struct kvm_gstage_mapping *out_map); +int kvm_riscv_gstage_split_huge(struct kvm_gstage *gstage, + struct kvm_mmu_memory_cache *pcache, + gpa_t addr, u32 target_level, bool flush); + enum kvm_riscv_gstage_op { GSTAGE_OP_NOP = 0, /* Nothing */ GSTAGE_OP_CLEAR, /* Clear/Unmap */ diff --git a/arch/riscv/kvm/gstage.c b/arch/riscv/kvm/gstage.c index b67d60d722c2fb..27ea6bb81553d2 100644 --- a/arch/riscv/kvm/gstage.c +++ b/arch/riscv/kvm/gstage.c @@ -171,6 +171,9 @@ int kvm_riscv_gstage_map_page(struct kvm_gstage *gstage, { pgprot_t prot; int ret; + pte_t *ptep; + u32 ptep_level; + bool found_leaf; out_map->addr = gpa; out_map->level = 0; @@ -179,6 +182,12 @@ int kvm_riscv_gstage_map_page(struct kvm_gstage *gstage, if (ret) return ret; + found_leaf = kvm_riscv_gstage_get_leaf(gstage, gpa, &ptep, &ptep_level); + if (found_leaf && ptep_level > out_map->level) { + kvm_riscv_gstage_split_huge(gstage, pcache, gpa, + out_map->level, true); + } + /* * A RISC-V implementation can choose to either: * 1) Update 'A' and 'D' PTE bits in hardware @@ -209,6 +218,75 @@ int kvm_riscv_gstage_map_page(struct kvm_gstage *gstage, return kvm_riscv_gstage_set_pte(gstage, pcache, out_map); } +static inline unsigned long make_child_pte(unsigned long huge_pte, int index, + unsigned long child_page_size) +{ + unsigned long child_pte = huge_pte; + unsigned long child_pfn_offset; + + /* + * The child_pte already has the base address of the huge page being + * split. So we just have to OR in the offset to the page at the next + * lower level for the given index. + */ + child_pfn_offset = index * (child_page_size / PAGE_SIZE); + child_pte |= pte_val(pfn_pte(child_pfn_offset, __pgprot(0))); + + return child_pte; +} + +int kvm_riscv_gstage_split_huge(struct kvm_gstage *gstage, + struct kvm_mmu_memory_cache *pcache, + gpa_t addr, u32 target_level, bool flush) +{ + u32 current_level = kvm_riscv_gstage_pgd_levels - 1; + pte_t *next_ptep = (pte_t *)gstage->pgd; + pte_t *ptep; + unsigned long huge_pte, child_pte; + unsigned long child_page_size; + int i, ret; + + while(current_level > target_level) { + ptep = (pte_t *)&next_ptep[gstage_pte_index(addr, current_level)]; + + if (!pte_val(ptep_get(ptep))) + break; + + if (!gstage_pte_leaf(ptep)) { + next_ptep = (pte_t *)gstage_pte_page_vaddr(ptep_get(ptep)); + current_level--; + continue; + } + + huge_pte = pte_val(ptep_get(ptep)); + + ret = gstage_level_to_page_size(current_level - 1, &child_page_size); + if (ret) + return ret; + + if (!pcache) + return -ENOMEM; + next_ptep = kvm_mmu_memory_cache_alloc(pcache); + if (!next_ptep) + return -ENOMEM; + + set_pte(ptep, pfn_pte(PFN_DOWN(__pa(next_ptep)), + __pgprot(_PAGE_TABLE))); + + for (i = 0; i < PTRS_PER_PTE; i++) { + child_pte = make_child_pte(huge_pte, i, child_page_size); + set_pte((pte_t *)&next_ptep[i], __pte(child_pte)); + } + + if (flush) + gstage_tlb_flush(gstage, current_level, addr); + + current_level--; + } + + return 0; +} + void kvm_riscv_gstage_op_pte(struct kvm_gstage *gstage, gpa_t addr, pte_t *ptep, u32 ptep_level, enum kvm_riscv_gstage_op op) { @@ -304,10 +382,9 @@ void kvm_riscv_gstage_wp_range(struct kvm_gstage *gstage, gpa_t start, gpa_t end if (!found_leaf) goto next; - if (!(addr & (page_size - 1)) && ((end - addr) >= page_size)) - kvm_riscv_gstage_op_pte(gstage, addr, ptep, - ptep_level, GSTAGE_OP_WP); - + addr = ALIGN_DOWN(addr, page_size); + kvm_riscv_gstage_op_pte(gstage, addr, ptep, + ptep_level, GSTAGE_OP_WP); next: addr += page_size; }