[PATCH v2 17/30] KVM: arm64: Replace fault_is_perm with a helper

[Marc Zyngier]

Carrying a boolean to indicate that a given fault is a permission fault
is slightly odd, as this is a property of the fault itself, and we'd
better avoid duplicating state.

For this purpose, introduce a kvm_s2_fault_is_perm() predicate that
can take a fault descriptor as a parameter. fault_is_perm is therefore
dropped from kvm_s2_fault.

Tested-by: Fuad Tabba <tabba at google.com>
Reviewed-by: Fuad Tabba <tabba at google.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose at arm.com>
Reviewed-by: Joey Gouly <joey.gouly at arm.com>
Signed-off-by: Marc Zyngier <maz at kernel.org>
---
 arch/arm64/kvm/mmu.c | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 09e32f08028e4..1e0d93d6d265a 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -1711,8 +1711,6 @@ static short kvm_s2_resolve_vma_size(const struct kvm_s2_fault_desc *s2fd,
 }
 
 struct kvm_s2_fault {
-	bool fault_is_perm;
-
 	bool write_fault;
 	bool exec_fault;
 	bool writable;
@@ -1732,6 +1730,11 @@ struct kvm_s2_fault {
 	vm_flags_t vm_flags;
 };
 
+static bool kvm_s2_fault_is_perm(const struct kvm_s2_fault_desc *s2fd)
+{
+	return kvm_vcpu_trap_is_permission_fault(s2fd->vcpu);
+}
+
 static int kvm_s2_fault_get_vma_info(const struct kvm_s2_fault_desc *s2fd,
 				     struct kvm_s2_fault *fault)
 {
@@ -1888,7 +1891,7 @@ static int kvm_s2_fault_compute_prot(const struct kvm_s2_fault_desc *s2fd,
 	if (s2fd->nested)
 		adjust_nested_exec_perms(kvm, s2fd->nested, &fault->prot);
 
-	if (!fault->fault_is_perm && !fault->s2_force_noncacheable && kvm_has_mte(kvm)) {
+	if (!kvm_s2_fault_is_perm(s2fd) && !fault->s2_force_noncacheable && kvm_has_mte(kvm)) {
 		/* Check the VMM hasn't introduced a new disallowed VMA */
 		if (!fault->mte_allowed)
 			return -EFAULT;
@@ -1905,6 +1908,7 @@ static phys_addr_t get_ipa(const struct kvm_s2_fault *fault)
 static int kvm_s2_fault_map(const struct kvm_s2_fault_desc *s2fd,
 			    struct kvm_s2_fault *fault, void *memcache)
 {
+	bool fault_is_perm = kvm_s2_fault_is_perm(s2fd);
 	struct kvm *kvm = s2fd->vcpu->kvm;
 	struct kvm_pgtable *pgt;
 	int ret;
@@ -1922,7 +1926,7 @@ static int kvm_s2_fault_map(const struct kvm_s2_fault_desc *s2fd,
 	 */
 	if (fault->vma_pagesize == PAGE_SIZE &&
 	    !(fault->force_pte || fault->s2_force_noncacheable)) {
-		if (fault->fault_is_perm && fault->fault_granule > PAGE_SIZE) {
+		if (fault_is_perm && fault->fault_granule > PAGE_SIZE) {
 			fault->vma_pagesize = fault->fault_granule;
 		} else {
 			fault->vma_pagesize = transparent_hugepage_adjust(kvm, s2fd->memslot,
@@ -1936,7 +1940,7 @@ static int kvm_s2_fault_map(const struct kvm_s2_fault_desc *s2fd,
 		}
 	}
 
-	if (!fault->fault_is_perm && !fault->s2_force_noncacheable && kvm_has_mte(kvm))
+	if (!fault_is_perm && !fault->s2_force_noncacheable && kvm_has_mte(kvm))
 		sanitise_mte_tags(kvm, fault->pfn, fault->vma_pagesize);
 
 	/*
@@ -1944,7 +1948,7 @@ static int kvm_s2_fault_map(const struct kvm_s2_fault_desc *s2fd,
 	 * permissions only if fault->vma_pagesize equals fault->fault_granule. Otherwise,
 	 * kvm_pgtable_stage2_map() should be called to change block size.
 	 */
-	if (fault->fault_is_perm && fault->vma_pagesize == fault->fault_granule) {
+	if (fault_is_perm && fault->vma_pagesize == fault->fault_granule) {
 		/*
 		 * Drop the SW bits in favour of those stored in the
 		 * PTE, which will be preserved.
@@ -1977,7 +1981,6 @@ static int user_mem_abort(const struct kvm_s2_fault_desc *s2fd)
 	bool write_fault = kvm_is_write_fault(s2fd->vcpu);
 	bool logging_active = memslot_is_logging(s2fd->memslot);
 	struct kvm_s2_fault fault = {
-		.fault_is_perm = perm_fault,
 		.logging_active = logging_active,
 		.force_pte = logging_active,
 		.prot = KVM_PGTABLE_PROT_R,
-- 
2.47.3