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| author | Alexandre Ghiti <alexghiti@rivosinc.com> | 2023-12-13 21:30:01 +0100 |
|---|---|---|
| committer | Palmer Dabbelt <palmer@rivosinc.com> | 2023-12-20 10:48:15 -0800 |
| commit | edf955647269422e387732870d04fc15933a25ea (patch) | |
| tree | a7474d4bdd56a5c3c2c9ad3040235a076f0ac970 /arch/riscv/kvm/mmu.c | |
| parent | d6508999d1882ddd0db8b3b4bd7967d83e9909fa (diff) | |
riscv: Use accessors to page table entries instead of direct dereference
As very well explained in commit 20a004e7b017 ("arm64: mm: Use
READ_ONCE/WRITE_ONCE when accessing page tables"), an architecture whose
page table walker can modify the PTE in parallel must use
READ_ONCE()/WRITE_ONCE() macro to avoid any compiler transformation.
So apply that to riscv which is such architecture.
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Acked-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20231213203001.179237-5-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Diffstat (limited to 'arch/riscv/kvm/mmu.c')
| -rw-r--r-- | arch/riscv/kvm/mmu.c | 22 |
1 files changed, 11 insertions, 11 deletions
diff --git a/arch/riscv/kvm/mmu.c b/arch/riscv/kvm/mmu.c index 068c74593871..a9e2fd7245e1 100644 --- a/arch/riscv/kvm/mmu.c +++ b/arch/riscv/kvm/mmu.c @@ -103,7 +103,7 @@ static bool gstage_get_leaf_entry(struct kvm *kvm, gpa_t addr, *ptep_level = current_level; ptep = (pte_t *)kvm->arch.pgd; ptep = &ptep[gstage_pte_index(addr, current_level)]; - while (ptep && pte_val(*ptep)) { + while (ptep && pte_val(ptep_get(ptep))) { if (gstage_pte_leaf(ptep)) { *ptep_level = current_level; *ptepp = ptep; @@ -113,7 +113,7 @@ static bool gstage_get_leaf_entry(struct kvm *kvm, gpa_t addr, if (current_level) { current_level--; *ptep_level = current_level; - ptep = (pte_t *)gstage_pte_page_vaddr(*ptep); + ptep = (pte_t *)gstage_pte_page_vaddr(ptep_get(ptep)); ptep = &ptep[gstage_pte_index(addr, current_level)]; } else { ptep = NULL; @@ -149,25 +149,25 @@ static int gstage_set_pte(struct kvm *kvm, u32 level, if (gstage_pte_leaf(ptep)) return -EEXIST; - if (!pte_val(*ptep)) { + if (!pte_val(ptep_get(ptep))) { if (!pcache) return -ENOMEM; next_ptep = kvm_mmu_memory_cache_alloc(pcache); if (!next_ptep) return -ENOMEM; - *ptep = pfn_pte(PFN_DOWN(__pa(next_ptep)), - __pgprot(_PAGE_TABLE)); + set_pte(ptep, pfn_pte(PFN_DOWN(__pa(next_ptep)), + __pgprot(_PAGE_TABLE))); } else { if (gstage_pte_leaf(ptep)) return -EEXIST; - next_ptep = (pte_t *)gstage_pte_page_vaddr(*ptep); + next_ptep = (pte_t *)gstage_pte_page_vaddr(ptep_get(ptep)); } current_level--; ptep = &next_ptep[gstage_pte_index(addr, current_level)]; } - *ptep = *new_pte; + set_pte(ptep, *new_pte); if (gstage_pte_leaf(ptep)) gstage_remote_tlb_flush(kvm, current_level, addr); @@ -239,11 +239,11 @@ static void gstage_op_pte(struct kvm *kvm, gpa_t addr, BUG_ON(addr & (page_size - 1)); - if (!pte_val(*ptep)) + if (!pte_val(ptep_get(ptep))) return; if (ptep_level && !gstage_pte_leaf(ptep)) { - next_ptep = (pte_t *)gstage_pte_page_vaddr(*ptep); + next_ptep = (pte_t *)gstage_pte_page_vaddr(ptep_get(ptep)); next_ptep_level = ptep_level - 1; ret = gstage_level_to_page_size(next_ptep_level, &next_page_size); @@ -261,7 +261,7 @@ static void gstage_op_pte(struct kvm *kvm, gpa_t addr, if (op == GSTAGE_OP_CLEAR) set_pte(ptep, __pte(0)); else if (op == GSTAGE_OP_WP) - set_pte(ptep, __pte(pte_val(*ptep) & ~_PAGE_WRITE)); + set_pte(ptep, __pte(pte_val(ptep_get(ptep)) & ~_PAGE_WRITE)); gstage_remote_tlb_flush(kvm, ptep_level, addr); } } @@ -603,7 +603,7 @@ bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) &ptep, &ptep_level)) return false; - return pte_young(*ptep); + return pte_young(ptep_get(ptep)); } int kvm_riscv_gstage_map(struct kvm_vcpu *vcpu, |