Commit 2857ba69 authored by Yanan Wang's avatar Yanan Wang Committed by Zheng Zengkai
Browse files

KVM: arm64: Adjust partial code of hyp stage-1 map and guest stage-2 map 

mainline inclusion
from mainline-v5.12-rc1-dontuse
commit 8ed80051
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I4IZOS
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=8ed80051c8c3



----------------------------------------------------------------------

Procedures of hyp stage-1 map and guest stage-2 map are quite different,
but they are tied closely by function kvm_set_valid_leaf_pte().
So adjust the relative code for ease of code maintenance in the future.

Signed-off-by: default avatarWill Deacon <will@kernel.org>
Signed-off-by: default avatarYanan Wang <wangyanan55@huawei.com>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210114121350.123684-2-wangyanan55@huawei.com


Reviewed-by: default avatarZenghui Yu <yuzenghui@huawei.com>
Signed-off-by: default avatarZheng Zengkai <zhengzengkai@huawei.com>
parent 6de85909

arch/arm64/kvm/hyp/pgtable.c

+28 −27
Original line number Diff line number Diff line
@@ -170,10 +170,9 @@ static void kvm_set_table_pte(kvm_pte_t *ptep, kvm_pte_t *childp) 
	smp_store_release(ptep, pte);

}



static bool kvm_set_valid_leaf_pte(kvm_pte_t *ptep, u64 pa, kvm_pte_t attr,

				   u32 level)

static kvm_pte_t kvm_init_valid_leaf_pte(u64 pa, kvm_pte_t attr, u32 level)

{

	kvm_pte_t old = *ptep, pte = kvm_phys_to_pte(pa);

	kvm_pte_t pte = kvm_phys_to_pte(pa);

	u64 type = (level == KVM_PGTABLE_MAX_LEVELS - 1) ? KVM_PTE_TYPE_PAGE :

							   KVM_PTE_TYPE_BLOCK;
@@ -181,12 +180,7 @@ static bool kvm_set_valid_leaf_pte(kvm_pte_t *ptep, u64 pa, kvm_pte_t attr, 
	pte |= FIELD_PREP(KVM_PTE_TYPE, type);

	pte |= KVM_PTE_VALID;



	/* Tolerate KVM recreating the exact same mapping. */

	if (kvm_pte_valid(old))

		return old == pte;



	smp_store_release(ptep, pte);

	return true;

	return pte;

}



static int kvm_pgtable_visitor_cb(struct kvm_pgtable_walk_data *data, u64 addr,
@@ -342,12 +336,17 @@ static int hyp_map_set_prot_attr(enum kvm_pgtable_prot prot, 
static bool hyp_map_walker_try_leaf(u64 addr, u64 end, u32 level,

				    kvm_pte_t *ptep, struct hyp_map_data *data)

{

	kvm_pte_t new, old = *ptep;

	u64 granule = kvm_granule_size(level), phys = data->phys;



	if (!kvm_block_mapping_supported(addr, end, phys, level))

		return false;



	WARN_ON(!kvm_set_valid_leaf_pte(ptep, phys, data->attr, level));

	/* Tolerate KVM recreating the exact same mapping */

	new = kvm_init_valid_leaf_pte(phys, data->attr, level);

	if (old != new && !WARN_ON(kvm_pte_valid(old)))

		smp_store_release(ptep, new);



	data->phys += granule;

	return true;

}
@@ -466,27 +465,30 @@ static bool stage2_map_walker_try_leaf(u64 addr, u64 end, u32 level, 
				       kvm_pte_t *ptep,

				       struct stage2_map_data *data)

{

	kvm_pte_t new, old = *ptep;

	u64 granule = kvm_granule_size(level), phys = data->phys;

	struct page *page = virt_to_page(ptep);



	if (!kvm_block_mapping_supported(addr, end, phys, level))

		return false;



	/*

	 * If the PTE was already valid, drop the refcount on the table

	 * early, as it will be bumped-up again in stage2_map_walk_leaf().

	 * This ensures that the refcount stays constant across a valid to

	 * valid PTE update.

	 */

	if (kvm_pte_valid(*ptep))

		put_page(virt_to_page(ptep));



	if (kvm_set_valid_leaf_pte(ptep, phys, data->attr, level))

	new = kvm_init_valid_leaf_pte(phys, data->attr, level);

	if (kvm_pte_valid(old)) {

		/* Tolerate KVM recreating the exact same mapping */

		if (old == new)

			goto out;



	/* There's an existing valid leaf entry, so perform break-before-make */

		/*

		 * There's an existing different valid leaf entry, so perform

		 * break-before-make.

		 */

		kvm_set_invalid_pte(ptep);

		kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, data->mmu, addr, level);

	kvm_set_valid_leaf_pte(ptep, phys, data->attr, level);

		put_page(page);

	}



	smp_store_release(ptep, new);

	get_page(page);

out:

	data->phys += granule;

	return true;
@@ -528,7 +530,7 @@ static int stage2_map_walk_leaf(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, 
	}



	if (stage2_map_walker_try_leaf(addr, end, level, ptep, data))

		goto out_get_page;

		return 0;



	if (WARN_ON(level == KVM_PGTABLE_MAX_LEVELS - 1))

		return -EINVAL;
@@ -552,9 +554,8 @@ static int stage2_map_walk_leaf(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, 
	}



	kvm_set_table_pte(ptep, childp);



out_get_page:

	get_page(page);



	return 0;

}