Commit 3669ddd8 authored by Quentin Perret's avatar Quentin Perret Committed by Marc Zyngier
Browse files

KVM: arm64: Add a range to pkvm_mappings 



In preparation for supporting stage-2 huge mappings for np-guest, add a
nr_pages member for pkvm_mappings to allow EL1 to track the size of the
stage-2 mapping.

Signed-off-by: default avatarQuentin Perret <qperret@google.com>
Signed-off-by: default avatarVincent Donnefort <vdonnefort@google.com>
Link: https://lore.kernel.org/r/20250521124834.1070650-9-vdonnefort@google.com


Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
parent b38c9775

arch/arm64/include/asm/kvm_pkvm.h

+1 −0
Original line number Diff line number Diff line
@@ -173,6 +173,7 @@ struct pkvm_mapping { 
	struct rb_node node;

	u64 gfn;

	u64 pfn;

	u64 nr_pages;

	u64 __subtree_last;	/* Internal member for interval tree */

};

arch/arm64/kvm/pkvm.c

+28 −9
Original line number Diff line number Diff line
@@ -283,7 +283,7 @@ static u64 __pkvm_mapping_start(struct pkvm_mapping *m) 


static u64 __pkvm_mapping_end(struct pkvm_mapping *m)

{

	return (m->gfn + 1) * PAGE_SIZE - 1;

	return (m->gfn + m->nr_pages) * PAGE_SIZE - 1;

}



INTERVAL_TREE_DEFINE(struct pkvm_mapping, node, u64, __subtree_last,
@@ -324,7 +324,8 @@ static int __pkvm_pgtable_stage2_unmap(struct kvm_pgtable *pgt, u64 start, u64 e 
		return 0;



	for_each_mapping_in_range_safe(pgt, start, end, mapping) {

		ret = kvm_call_hyp_nvhe(__pkvm_host_unshare_guest, handle, mapping->gfn, 1);

		ret = kvm_call_hyp_nvhe(__pkvm_host_unshare_guest, handle, mapping->gfn,

					mapping->nr_pages);

		if (WARN_ON(ret))

			return ret;

		pkvm_mapping_remove(mapping, &pgt->pkvm_mappings);
@@ -354,16 +355,32 @@ int pkvm_pgtable_stage2_map(struct kvm_pgtable *pgt, u64 addr, u64 size, 
		return -EINVAL;



	lockdep_assert_held_write(&kvm->mmu_lock);

	ret = kvm_call_hyp_nvhe(__pkvm_host_share_guest, pfn, gfn, 1, prot);

	if (ret) {

		/* Is the gfn already mapped due to a racing vCPU? */

		if (ret == -EPERM)



	/*

	 * Calling stage2_map() on top of existing mappings is either happening because of a race

	 * with another vCPU, or because we're changing between page and block mappings. As per

	 * user_mem_abort(), same-size permission faults are handled in the relax_perms() path.

	 */

	mapping = pkvm_mapping_iter_first(&pgt->pkvm_mappings, addr, addr + size - 1);

	if (mapping) {

		if (size == (mapping->nr_pages * PAGE_SIZE))

			return -EAGAIN;



		/* Remove _any_ pkvm_mapping overlapping with the range, bigger or smaller. */

		ret = __pkvm_pgtable_stage2_unmap(pgt, addr, addr + size);

		if (ret)

			return ret;

		mapping = NULL;

	}



	ret = kvm_call_hyp_nvhe(__pkvm_host_share_guest, pfn, gfn, size / PAGE_SIZE, prot);

	if (WARN_ON(ret))

		return ret;



	swap(mapping, cache->mapping);

	mapping->gfn = gfn;

	mapping->pfn = pfn;

	mapping->nr_pages = size / PAGE_SIZE;

	pkvm_mapping_insert(mapping, &pgt->pkvm_mappings);



	return ret;
@@ -385,7 +402,8 @@ int pkvm_pgtable_stage2_wrprotect(struct kvm_pgtable *pgt, u64 addr, u64 size) 


	lockdep_assert_held(&kvm->mmu_lock);

	for_each_mapping_in_range_safe(pgt, addr, addr + size, mapping) {

		ret = kvm_call_hyp_nvhe(__pkvm_host_wrprotect_guest, handle, mapping->gfn, 1);

		ret = kvm_call_hyp_nvhe(__pkvm_host_wrprotect_guest, handle, mapping->gfn,

					mapping->nr_pages);

		if (WARN_ON(ret))

			break;

	}
@@ -400,7 +418,8 @@ int pkvm_pgtable_stage2_flush(struct kvm_pgtable *pgt, u64 addr, u64 size) 


	lockdep_assert_held(&kvm->mmu_lock);

	for_each_mapping_in_range_safe(pgt, addr, addr + size, mapping)

		__clean_dcache_guest_page(pfn_to_kaddr(mapping->pfn), PAGE_SIZE);

		__clean_dcache_guest_page(pfn_to_kaddr(mapping->pfn),

					  PAGE_SIZE * mapping->nr_pages);



	return 0;

}
@@ -415,7 +434,7 @@ bool pkvm_pgtable_stage2_test_clear_young(struct kvm_pgtable *pgt, u64 addr, u64 
	lockdep_assert_held(&kvm->mmu_lock);

	for_each_mapping_in_range_safe(pgt, addr, addr + size, mapping)

		young |= kvm_call_hyp_nvhe(__pkvm_host_test_clear_young_guest, handle, mapping->gfn,

					   1, mkold);

					   mapping->nr_pages, mkold);



	return young;

}