Commit 76458291 authored by Sean Christopherson's avatar Sean Christopherson
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KVM: x86/mmu: Add KVM_RMAP_MANY to replace open coded '1' and '1ul' literals 

Replace all of the open coded '1' literals used to mark a PTE list as
having many/multiple entries with a proper define.  It's hard enough to
read the code with one magic bit, and a future patch to support "locking"
a single rmap will add another.

No functional change intended.

Link: https://lore.kernel.org/r/20240809194335.1726916-17-seanjc@google.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent 7aac9dc6

arch/x86/kvm/mmu/mmu.c

+16 −15
Original line number Diff line number Diff line
@@ -912,6 +912,7 @@ static struct kvm_memory_slot *gfn_to_memslot_dirty_bitmap(struct kvm_vcpu *vcpu 
 * in this rmap chain. Otherwise, (rmap_head->val & ~1) points to a struct

 * pte_list_desc containing more mappings.

 */

#define KVM_RMAP_MANY	BIT(0)



/*

 * Returns the number of pointers in the rmap chain, not counting the new one.
@@ -924,16 +925,16 @@ static int pte_list_add(struct kvm_mmu_memory_cache *cache, u64 *spte, 


	if (!rmap_head->val) {

		rmap_head->val = (unsigned long)spte;

	} else if (!(rmap_head->val & 1)) {

	} else if (!(rmap_head->val & KVM_RMAP_MANY)) {

		desc = kvm_mmu_memory_cache_alloc(cache);

		desc->sptes[0] = (u64 *)rmap_head->val;

		desc->sptes[1] = spte;

		desc->spte_count = 2;

		desc->tail_count = 0;

		rmap_head->val = (unsigned long)desc | 1;

		rmap_head->val = (unsigned long)desc | KVM_RMAP_MANY;

		++count;

	} else {

		desc = (struct pte_list_desc *)(rmap_head->val & ~1ul);

		desc = (struct pte_list_desc *)(rmap_head->val & ~KVM_RMAP_MANY);

		count = desc->tail_count + desc->spte_count;



		/*
@@ -942,10 +943,10 @@ static int pte_list_add(struct kvm_mmu_memory_cache *cache, u64 *spte, 
		 */

		if (desc->spte_count == PTE_LIST_EXT) {

			desc = kvm_mmu_memory_cache_alloc(cache);

			desc->more = (struct pte_list_desc *)(rmap_head->val & ~1ul);

			desc->more = (struct pte_list_desc *)(rmap_head->val & ~KVM_RMAP_MANY);

			desc->spte_count = 0;

			desc->tail_count = count;

			rmap_head->val = (unsigned long)desc | 1;

			rmap_head->val = (unsigned long)desc | KVM_RMAP_MANY;

		}

		desc->sptes[desc->spte_count++] = spte;

	}
@@ -956,7 +957,7 @@ static void pte_list_desc_remove_entry(struct kvm *kvm, 
				       struct kvm_rmap_head *rmap_head,

				       struct pte_list_desc *desc, int i)

{

	struct pte_list_desc *head_desc = (struct pte_list_desc *)(rmap_head->val & ~1ul);

	struct pte_list_desc *head_desc = (struct pte_list_desc *)(rmap_head->val & ~KVM_RMAP_MANY);

	int j = head_desc->spte_count - 1;



	/*
@@ -985,7 +986,7 @@ static void pte_list_desc_remove_entry(struct kvm *kvm, 
	if (!head_desc->more)

		rmap_head->val = 0;

	else

		rmap_head->val = (unsigned long)head_desc->more | 1;

		rmap_head->val = (unsigned long)head_desc->more | KVM_RMAP_MANY;

	mmu_free_pte_list_desc(head_desc);

}
@@ -998,13 +999,13 @@ static void pte_list_remove(struct kvm *kvm, u64 *spte, 
	if (KVM_BUG_ON_DATA_CORRUPTION(!rmap_head->val, kvm))

		return;



	if (!(rmap_head->val & 1)) {

	if (!(rmap_head->val & KVM_RMAP_MANY)) {

		if (KVM_BUG_ON_DATA_CORRUPTION((u64 *)rmap_head->val != spte, kvm))

			return;



		rmap_head->val = 0;

	} else {

		desc = (struct pte_list_desc *)(rmap_head->val & ~1ul);

		desc = (struct pte_list_desc *)(rmap_head->val & ~KVM_RMAP_MANY);

		while (desc) {

			for (i = 0; i < desc->spte_count; ++i) {

				if (desc->sptes[i] == spte) {
@@ -1037,12 +1038,12 @@ static bool kvm_zap_all_rmap_sptes(struct kvm *kvm, 
	if (!rmap_head->val)

		return false;



	if (!(rmap_head->val & 1)) {

	if (!(rmap_head->val & KVM_RMAP_MANY)) {

		mmu_spte_clear_track_bits(kvm, (u64 *)rmap_head->val);

		goto out;

	}



	desc = (struct pte_list_desc *)(rmap_head->val & ~1ul);

	desc = (struct pte_list_desc *)(rmap_head->val & ~KVM_RMAP_MANY);



	for (; desc; desc = next) {

		for (i = 0; i < desc->spte_count; i++)
@@ -1062,10 +1063,10 @@ unsigned int pte_list_count(struct kvm_rmap_head *rmap_head) 


	if (!rmap_head->val)

		return 0;

	else if (!(rmap_head->val & 1))

	else if (!(rmap_head->val & KVM_RMAP_MANY))

		return 1;



	desc = (struct pte_list_desc *)(rmap_head->val & ~1ul);

	desc = (struct pte_list_desc *)(rmap_head->val & ~KVM_RMAP_MANY);

	return desc->tail_count + desc->spte_count;

}
@@ -1127,13 +1128,13 @@ static u64 *rmap_get_first(struct kvm_rmap_head *rmap_head, 
	if (!rmap_head->val)

		return NULL;



	if (!(rmap_head->val & 1)) {

	if (!(rmap_head->val & KVM_RMAP_MANY)) {

		iter->desc = NULL;

		sptep = (u64 *)rmap_head->val;

		goto out;

	}



	iter->desc = (struct pte_list_desc *)(rmap_head->val & ~1ul);

	iter->desc = (struct pte_list_desc *)(rmap_head->val & ~KVM_RMAP_MANY);

	iter->pos = 0;

	sptep = iter->desc->sptes[iter->pos];

out: