From: Punit Agrawal punit.agrawal@arm.com
mainline inclusion from mainline-v5.0-rc1 commit 6396b852e46e562f4742ed0a9042b537eb26b8aa category: feature feature: Support PUD hugepage at stage 2
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Stage 2 fault handler marks a page as executable if it is handling an execution fault or if it was a permission fault in which case the executable bit needs to be preserved.
The logic to decide if the page should be marked executable is duplicated for PMD and PTE entries. To avoid creating another copy when support for PUD hugepages is introduced refactor the code to share the checks needed to mark a page table entry as executable.
Signed-off-by: Punit Agrawal punit.agrawal@arm.com Reviewed-by: Suzuki K Poulose suzuki.poulose@arm.com Reviewed-by: Christoffer Dall christoffer.dall@arm.com Signed-off-by: Suzuki K Poulose suzuki.poulose@arm.com Signed-off-by: Marc Zyngier marc.zyngier@arm.com Signed-off-by: Zenghui Yu yuzenghui@huawei.com Reviewed-by: Hailiang Zhang zhang.zhanghailiang@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- virt/kvm/arm/mmu.c | 28 +++++++++++++++------------- 1 file changed, 15 insertions(+), 13 deletions(-)
diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c index 58dc9b4..7fa7982 100644 --- a/virt/kvm/arm/mmu.c +++ b/virt/kvm/arm/mmu.c @@ -1481,7 +1481,8 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, unsigned long fault_status) { int ret; - bool write_fault, exec_fault, writable, force_pte = false; + bool write_fault, writable, force_pte = false; + bool exec_fault, needs_exec; unsigned long mmu_seq; gfn_t gfn = fault_ipa >> PAGE_SHIFT; struct kvm *kvm = vcpu->kvm; @@ -1604,19 +1605,25 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, if (exec_fault) invalidate_icache_guest_page(pfn, vma_pagesize);
+ /* + * If we took an execution fault we have made the + * icache/dcache coherent above and should now let the s2 + * mapping be executable. + * + * Write faults (!exec_fault && FSC_PERM) are orthogonal to + * execute permissions, and we preserve whatever we have. + */ + needs_exec = exec_fault || + (fault_status == FSC_PERM && stage2_is_exec(kvm, fault_ipa)); + if (vma_pagesize == PMD_SIZE) { pmd_t new_pmd = pfn_pmd(pfn, mem_type); new_pmd = pmd_mkhuge(new_pmd); if (writable) new_pmd = kvm_s2pmd_mkwrite(new_pmd);
- if (exec_fault) { + if (needs_exec) new_pmd = kvm_s2pmd_mkexec(new_pmd); - } else if (fault_status == FSC_PERM) { - /* Preserve execute if XN was already cleared */ - if (stage2_is_exec(kvm, fault_ipa)) - new_pmd = kvm_s2pmd_mkexec(new_pmd); - }
ret = stage2_set_pmd_huge(kvm, memcache, fault_ipa, &new_pmd); } else { @@ -1627,13 +1634,8 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, mark_page_dirty(kvm, gfn); }
- if (exec_fault) { + if (needs_exec) new_pte = kvm_s2pte_mkexec(new_pte); - } else if (fault_status == FSC_PERM) { - /* Preserve execute if XN was already cleared */ - if (stage2_is_exec(kvm, fault_ipa)) - new_pte = kvm_s2pte_mkexec(new_pte); - }
ret = stage2_set_pte(kvm, memcache, fault_ipa, &new_pte, flags); }