KVM: arm/arm64: Introduce helpers to manipulate page table entries

Introduce helpers to abstract architectural handling of the conversion
of pfn to page table entries and marking a PMD page table entry as a
block entry.

The helpers are introduced in preparation for supporting PUD hugepages
at stage 2 - which are supported on arm64 but do not exist on arm.

Signed-off-by: Punit Agrawal <punit.agrawal@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

arch/arm/include/asm/kvm_mmu.h

@@ -82,6 +82,11 @@ void kvm_clear_hyp_idmap(void);
 #define kvm_mk_pud(pmdp)	__pud(__pa(pmdp) | PMD_TYPE_TABLE)
 #define kvm_mk_pgd(pudp)	({ BUILD_BUG(); 0; })
 
+#define kvm_pfn_pte(pfn, prot)	pfn_pte(pfn, prot)
+#define kvm_pfn_pmd(pfn, prot)	pfn_pmd(pfn, prot)
+
+#define kvm_pmd_mkhuge(pmd)	pmd_mkhuge(pmd)
+
 static inline pte_t kvm_s2pte_mkwrite(pte_t pte)
 {
 	pte_val(pte) |= L_PTE_S2_RDWR;

arch/arm64/include/asm/kvm_mmu.h

@@ -184,6 +184,11 @@ void kvm_clear_hyp_idmap(void);
 #define kvm_mk_pgd(pudp)					\
 	__pgd(__phys_to_pgd_val(__pa(pudp)) | PUD_TYPE_TABLE)
 
+#define kvm_pfn_pte(pfn, prot)		pfn_pte(pfn, prot)
+#define kvm_pfn_pmd(pfn, prot)		pfn_pmd(pfn, prot)
+
+#define kvm_pmd_mkhuge(pmd)		pmd_mkhuge(pmd)
+
 static inline pte_t kvm_s2pte_mkwrite(pte_t pte)
 {
 	pte_val(pte) |= PTE_S2_RDWR;

virt/kvm/arm/mmu.c

@@ -607,7 +607,7 @@ static void create_hyp_pte_mappings(pmd_t *pmd, unsigned long start,
 	addr = start;
 	do {
 		pte = pte_offset_kernel(pmd, addr);
-		kvm_set_pte(pte, pfn_pte(pfn, prot));
+		kvm_set_pte(pte, kvm_pfn_pte(pfn, prot));
 		get_page(virt_to_page(pte));
 		pfn++;
 	} while (addr += PAGE_SIZE, addr != end);
@@ -1202,7 +1202,7 @@ int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa,
 	pfn = __phys_to_pfn(pa);
 
 	for (addr = guest_ipa; addr < end; addr += PAGE_SIZE) {
-		pte_t pte = pfn_pte(pfn, PAGE_S2_DEVICE);
+		pte_t pte = kvm_pfn_pte(pfn, PAGE_S2_DEVICE);
 
 		if (writable)
 			pte = kvm_s2pte_mkwrite(pte);
@@ -1611,8 +1611,10 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
 		(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);
+		pmd_t new_pmd = kvm_pfn_pmd(pfn, mem_type);
+
+		new_pmd = kvm_pmd_mkhuge(new_pmd);
+
 		if (writable)
 			new_pmd = kvm_s2pmd_mkwrite(new_pmd);
 
@@ -1621,7 +1623,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
 
 		ret = stage2_set_pmd_huge(kvm, memcache, fault_ipa, &new_pmd);
 	} else {
-		pte_t new_pte = pfn_pte(pfn, mem_type);
+		pte_t new_pte = kvm_pfn_pte(pfn, mem_type);
 
 		if (writable) {
 			new_pte = kvm_s2pte_mkwrite(new_pte);
@@ -1878,7 +1880,7 @@ void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte)
 	 * just like a translation fault and clean the cache to the PoC.
 	 */
 	clean_dcache_guest_page(pfn, PAGE_SIZE);
-	stage2_pte = pfn_pte(pfn, PAGE_S2);
+	stage2_pte = kvm_pfn_pte(pfn, PAGE_S2);
 	handle_hva_to_gpa(kvm, hva, end, &kvm_set_spte_handler, &stage2_pte);
 }