KVM: arm64: Use kvm_arch for stage 2 pgtable

In order to make use of the stage 2 pgtable code for the host stage 2,
use struct kvm_arch in lieu of struct kvm as the host will have the
former but not the latter.
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210319100146.1149909-20-qperret@google.com

arch/arm64/include/asm/kvm_pgtable.h

@@ -162,12 +162,13 @@ int kvm_pgtable_hyp_map(struct kvm_pgtable *pgt, u64 addr, u64 size, u64 phys,
 /**
  * kvm_pgtable_stage2_init() - Initialise a guest stage-2 page-table.
  * @pgt:	Uninitialised page-table structure to initialise.
- * @kvm:	KVM structure representing the guest virtual machine.
+ * @arch:	Arch-specific KVM structure representing the guest virtual
+ *		machine.
  * @mm_ops:	Memory management callbacks.
  *
  * Return: 0 on success, negative error code on failure.
  */
-int kvm_pgtable_stage2_init(struct kvm_pgtable *pgt, struct kvm *kvm,
+int kvm_pgtable_stage2_init(struct kvm_pgtable *pgt, struct kvm_arch *arch,
 			    struct kvm_pgtable_mm_ops *mm_ops);
 
 /**

arch/arm64/kvm/hyp/pgtable.c

@@ -880,11 +880,11 @@ int kvm_pgtable_stage2_flush(struct kvm_pgtable *pgt, u64 addr, u64 size)
 	return kvm_pgtable_walk(pgt, addr, size, &walker);
 }
 
-int kvm_pgtable_stage2_init(struct kvm_pgtable *pgt, struct kvm *kvm,
+int kvm_pgtable_stage2_init(struct kvm_pgtable *pgt, struct kvm_arch *arch,
 			    struct kvm_pgtable_mm_ops *mm_ops)
 {
 	size_t pgd_sz;
-	u64 vtcr = kvm->arch.vtcr;
+	u64 vtcr = arch->vtcr;
 	u32 ia_bits = VTCR_EL2_IPA(vtcr);
 	u32 sl0 = FIELD_GET(VTCR_EL2_SL0_MASK, vtcr);
 	u32 start_level = VTCR_EL2_TGRAN_SL0_BASE - sl0;
@@ -897,7 +897,7 @@ int kvm_pgtable_stage2_init(struct kvm_pgtable *pgt, struct kvm *kvm,
 	pgt->ia_bits		= ia_bits;
 	pgt->start_level	= start_level;
 	pgt->mm_ops		= mm_ops;
-	pgt->mmu		= &kvm->arch.mmu;
+	pgt->mmu		= &arch->mmu;
 
 	/* Ensure zeroed PGD pages are visible to the hardware walker */
 	dsb(ishst);

arch/arm64/kvm/mmu.c

@@ -457,7 +457,7 @@ int kvm_init_stage2_mmu(struct kvm *kvm, struct kvm_s2_mmu *mmu)
 	if (!pgt)
 		return -ENOMEM;
 
-	err = kvm_pgtable_stage2_init(pgt, kvm, &kvm_s2_mm_ops);
+	err = kvm_pgtable_stage2_init(pgt, &kvm->arch, &kvm_s2_mm_ops);
 	if (err)
 		goto out_free_pgtable;