From: Fuad Tabba Simplify the non-cacheable attributes assignment by using a ternary operator. Additionally, hoist the MTE validation check (mte_allowed) out of kvm_s2_fault_map() and into kvm_s2_fault_compute_prot(). This allows us to fail faster and avoid acquiring the KVM MMU lock unnecessarily when the VMM introduces a disallowed VMA for an MTE-enabled guest. Signed-off-by: Fuad Tabba Signed-off-by: Marc Zyngier --- arch/arm64/kvm/mmu.c | 28 ++++++++++++---------------- 1 file changed, 12 insertions(+), 16 deletions(-) diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index 0c71e3a9af8b0..ee2a548999b1b 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -1870,18 +1870,21 @@ static int kvm_s2_fault_compute_prot(struct kvm_s2_fault *fault) if (fault->exec_fault) fault->prot |= KVM_PGTABLE_PROT_X; - if (fault->s2_force_noncacheable) { - if (fault->vm_flags & VM_ALLOW_ANY_UNCACHED) - fault->prot |= KVM_PGTABLE_PROT_NORMAL_NC; - else - fault->prot |= KVM_PGTABLE_PROT_DEVICE; - } else if (cpus_have_final_cap(ARM64_HAS_CACHE_DIC)) { + if (fault->s2_force_noncacheable) + fault->prot |= (fault->vm_flags & VM_ALLOW_ANY_UNCACHED) ? + KVM_PGTABLE_PROT_NORMAL_NC : KVM_PGTABLE_PROT_DEVICE; + else if (cpus_have_final_cap(ARM64_HAS_CACHE_DIC)) fault->prot |= KVM_PGTABLE_PROT_X; - } if (fault->nested) adjust_nested_exec_perms(kvm, fault->nested, &fault->prot); + if (!fault->fault_is_perm && !fault->s2_force_noncacheable && kvm_has_mte(kvm)) { + /* Check the VMM hasn't introduced a new disallowed VMA */ + if (!fault->mte_allowed) + return -EFAULT; + } + return 0; } @@ -1918,15 +1921,8 @@ static int kvm_s2_fault_map(struct kvm_s2_fault *fault, void *memcache) } } - if (!fault->fault_is_perm && !fault->s2_force_noncacheable && kvm_has_mte(kvm)) { - /* Check the VMM hasn't introduced a new disallowed VMA */ - if (fault->mte_allowed) { - sanitise_mte_tags(kvm, fault->pfn, fault->vma_pagesize); - } else { - ret = -EFAULT; - goto out_unlock; - } - } + if (!fault->fault_is_perm && !fault->s2_force_noncacheable && kvm_has_mte(kvm)) + sanitise_mte_tags(kvm, fault->pfn, fault->vma_pagesize); /* * Under the premise of getting a FSC_PERM fault, we just need to relax -- 2.47.3