Commit db14091d authored by Vincent Donnefort's avatar Vincent Donnefort Committed by Marc Zyngier
Browse files

KVM: arm64: Stage-2 huge mappings for np-guests 



Now np-guests hypercalls with range are supported, we can let the
hypervisor to install block mappings whenever the Stage-1 allows it,
that is when backed by either Hugetlbfs or THPs. The size of those block
mappings is limited to PMD_SIZE.

Signed-off-by: default avatarVincent Donnefort <vdonnefort@google.com>
Link: https://lore.kernel.org/r/20250521124834.1070650-10-vdonnefort@google.com


Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
parent 3669ddd8

arch/arm64/kvm/hyp/nvhe/mem_protect.c

+14 −9
Original line number Diff line number Diff line
@@ -166,12 +166,6 @@ int kvm_host_prepare_stage2(void *pgt_pool_base) 
	return 0;

}



static bool guest_stage2_force_pte_cb(u64 addr, u64 end,

				      enum kvm_pgtable_prot prot)

{

	return true;

}



static void *guest_s2_zalloc_pages_exact(size_t size)

{

	void *addr = hyp_alloc_pages(&current_vm->pool, get_order(size));
@@ -278,8 +272,7 @@ int kvm_guest_prepare_stage2(struct pkvm_hyp_vm *vm, void *pgd) 
	};



	guest_lock_component(vm);

	ret = __kvm_pgtable_stage2_init(mmu->pgt, mmu, &vm->mm_ops, 0,

					guest_stage2_force_pte_cb);

	ret = __kvm_pgtable_stage2_init(mmu->pgt, mmu, &vm->mm_ops, 0, NULL);

	guest_unlock_component(vm);

	if (ret)

		return ret;
@@ -908,12 +901,24 @@ int __pkvm_host_unshare_ffa(u64 pfn, u64 nr_pages) 


static int __guest_check_transition_size(u64 phys, u64 ipa, u64 nr_pages, u64 *size)

{

	size_t block_size;



	if (nr_pages == 1) {

		*size = PAGE_SIZE;

		return 0;

	}



	/* We solely support second to last level huge mapping */

	block_size = kvm_granule_size(KVM_PGTABLE_LAST_LEVEL - 1);



	if (nr_pages != block_size >> PAGE_SHIFT)

		return -EINVAL;



	if (!IS_ALIGNED(phys | ipa, block_size))

		return -EINVAL;



	*size = block_size;

	return 0;

}



int __pkvm_host_share_guest(u64 pfn, u64 gfn, u64 nr_pages, struct pkvm_hyp_vcpu *vcpu,

arch/arm64/kvm/mmu.c

+5 −1
Original line number Diff line number Diff line
@@ -1304,6 +1304,10 @@ static bool fault_supports_stage2_huge_mapping(struct kvm_memory_slot *memslot, 
	if (map_size == PAGE_SIZE)

		return true;



	/* pKVM only supports PMD_SIZE huge-mappings */

	if (is_protected_kvm_enabled() && map_size != PMD_SIZE)

		return false;



	size = memslot->npages * PAGE_SIZE;



	gpa_start = memslot->base_gfn << PAGE_SHIFT;
@@ -1537,7 +1541,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, 
	 * logging_active is guaranteed to never be true for VM_PFNMAP

	 * memslots.

	 */

	if (logging_active || is_protected_kvm_enabled()) {

	if (logging_active) {

		force_pte = true;

		vma_shift = PAGE_SHIFT;

	} else {

arch/arm64/kvm/pkvm.c

+1 −1
Original line number Diff line number Diff line
@@ -351,7 +351,7 @@ int pkvm_pgtable_stage2_map(struct kvm_pgtable *pgt, u64 addr, u64 size, 
	u64 pfn = phys >> PAGE_SHIFT;

	int ret;



	if (size != PAGE_SIZE)

	if (size != PAGE_SIZE && size != PMD_SIZE)

		return -EINVAL;



	lockdep_assert_held_write(&kvm->mmu_lock);