kvm-arm: Cleanup stage2 pgd handling

Now that we don't have any fake page table levels for arm64,
cleanup the common code to get rid of the dead code.

Cc: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>

arch/arm/include/asm/kvm_mmu.h

@@ -150,25 +150,6 @@ static inline bool kvm_page_empty(void *ptr)
 #define hyp_pmd_table_empty(pmdp) kvm_page_empty(pmdp)
 #define hyp_pud_table_empty(pudp) false
 
-static inline void *kvm_get_hwpgd(struct kvm *kvm)
-{
-	return kvm->arch.pgd;
-}
-
-static inline unsigned int kvm_get_hwpgd_size(void)
-{
-	return PTRS_PER_S2_PGD * sizeof(pgd_t);
-}
-
-static inline pgd_t *kvm_setup_fake_pgd(pgd_t *hwpgd)
-{
-	return hwpgd;
-}
-
-static inline void kvm_free_fake_pgd(pgd_t *pgd)
-{
-}
-
 struct kvm;
 
 #define kvm_flush_dcache_to_poc(a,l)	__cpuc_flush_dcache_area((a), (l))

arch/arm/kvm/arm.c

@@ -448,7 +448,7 @@ static void update_vttbr(struct kvm *kvm)
 	kvm_next_vmid &= (1 << kvm_vmid_bits) - 1;
 
 	/* update vttbr to be used with the new vmid */
-	pgd_phys = virt_to_phys(kvm_get_hwpgd(kvm));
+	pgd_phys = virt_to_phys(kvm->arch.pgd);
 	BUG_ON(pgd_phys & ~VTTBR_BADDR_MASK);
 	vmid = ((u64)(kvm->arch.vmid) << VTTBR_VMID_SHIFT) & VTTBR_VMID_MASK(kvm_vmid_bits);
 	kvm->arch.vttbr = pgd_phys | vmid;

arch/arm/kvm/mmu.c

@@ -43,6 +43,7 @@ static unsigned long hyp_idmap_start;
 static unsigned long hyp_idmap_end;
 static phys_addr_t hyp_idmap_vector;
 
+#define S2_PGD_SIZE	(PTRS_PER_S2_PGD * sizeof(pgd_t))
 #define hyp_pgd_order get_order(PTRS_PER_PGD * sizeof(pgd_t))
 
 #define KVM_S2PTE_FLAG_IS_IOMAP		(1UL << 0)
@@ -736,20 +737,6 @@ int create_hyp_io_mappings(void *from, void *to, phys_addr_t phys_addr)
 				     __phys_to_pfn(phys_addr), PAGE_HYP_DEVICE);
 }
 
-/* Free the HW pgd, one page at a time */
-static void kvm_free_hwpgd(void *hwpgd)
-{
-	free_pages_exact(hwpgd, kvm_get_hwpgd_size());
-}
-
-/* Allocate the HW PGD, making sure that each page gets its own refcount */
-static void *kvm_alloc_hwpgd(void)
-{
-	unsigned int size = kvm_get_hwpgd_size();
-
-	return alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO);
-}
-
 /**
  * kvm_alloc_stage2_pgd - allocate level-1 table for stage-2 translation.
  * @kvm:	The KVM struct pointer for the VM.
@@ -764,29 +751,17 @@ static void *kvm_alloc_hwpgd(void)
 int kvm_alloc_stage2_pgd(struct kvm *kvm)
 {
 	pgd_t *pgd;
-	void *hwpgd;
 
 	if (kvm->arch.pgd != NULL) {
 		kvm_err("kvm_arch already initialized?\n");
 		return -EINVAL;
 	}
 
-	hwpgd = kvm_alloc_hwpgd();
+	/* Allocate the HW PGD, making sure that each page gets its own refcount */
-	if (!hwpgd)
+	pgd = alloc_pages_exact(S2_PGD_SIZE, GFP_KERNEL | __GFP_ZERO);
+	if (!pgd)
 		return -ENOMEM;
 
-	/*
-	 * When the kernel uses more levels of page tables than the
-	 * guest, we allocate a fake PGD and pre-populate it to point
-	 * to the next-level page table, which will be the real
-	 * initial page table pointed to by the VTTBR.
-	 */
-	pgd = kvm_setup_fake_pgd(hwpgd);
-	if (IS_ERR(pgd)) {
-		kvm_free_hwpgd(hwpgd);
-		return PTR_ERR(pgd);
-	}
-
 	kvm_clean_pgd(pgd);
 	kvm->arch.pgd = pgd;
 	return 0;
@@ -874,8 +849,8 @@ void kvm_free_stage2_pgd(struct kvm *kvm)
 		return;
 
 	unmap_stage2_range(kvm, 0, KVM_PHYS_SIZE);
-	kvm_free_hwpgd(kvm_get_hwpgd(kvm));
+	/* Free the HW pgd, one page at a time */
-	kvm_free_fake_pgd(kvm->arch.pgd);
+	free_pages_exact(kvm->arch.pgd, S2_PGD_SIZE);
 	kvm->arch.pgd = NULL;
 }
 

arch/arm64/include/asm/kvm_mmu.h

@@ -141,24 +141,6 @@ static inline bool kvm_s2pmd_readonly(pmd_t *pmd)
 	return (pmd_val(*pmd) & PMD_S2_RDWR) == PMD_S2_RDONLY;
 }
 
-static inline void *kvm_get_hwpgd(struct kvm *kvm)
-{
-	return kvm->arch.pgd;
-}
-
-static inline unsigned int kvm_get_hwpgd_size(void)
-{
-	return PTRS_PER_S2_PGD * sizeof(pgd_t);
-}
-
-static inline pgd_t *kvm_setup_fake_pgd(pgd_t *hwpgd)
-{
-	return hwpgd;
-}
-
-static inline void kvm_free_fake_pgd(pgd_t *pgd)
-{
-}
 static inline bool kvm_page_empty(void *ptr)
 {
 	struct page *ptr_page = virt_to_page(ptr);