[PATCH v2 14/26] KVM: x86/mmu: Decouple rmap_add() and link_shadow_page() from kvm_vcpu

David Matlack
2022-03-11T00:26:00Z

Allow adding new entries to the rmap and linking shadow pages without a
struct kvm_vcpu pointer by moving the implementation of rmap_add() and
link_shadow_page() into inner helper functions.

No functional change intended.

Reviewed-by: Ben Gardon <bgardon@google.com>
Signed-off-by: David Matlack <dmatlack@google.com>
---
arch/x86/kvm/mmu/mmu.c | 43 +++++++++++++++++++++++++++---------------
1 file changed, 28 insertions(+), 15 deletions(-)

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index d7ad71be6c52..c57070ed157d 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -725,9 +725,9 @@ static void mmu_free_memory_caches(struct kvm_vcpu *vcpu)
kvm_mmu_free_memory_cache(&vcpu->arch.mmu_page_header_cache);
}

-static struct pte_list_desc *mmu_alloc_pte_list_desc(struct kvm_vcpu *vcpu)
+static struct pte_list_desc *mmu_alloc_pte_list_desc(struct kvm_mmu_memory_cache *cache)
{
- return kvm_mmu_memory_cache_alloc(&vcpu->arch.mmu_pte_list_desc_cache);
+ return kvm_mmu_memory_cache_alloc(cache);
}

static void mmu_free_pte_list_desc(struct pte_list_desc *pte_list_desc)
@@ -874,7 +874,7 @@ gfn_to_memslot_dirty_bitmap(struct kvm_vcpu *vcpu, gfn_t gfn,
/*
* Returns the number of pointers in the rmap chain, not counting the new one.
*/
-static int pte_list_add(struct kvm_vcpu *vcpu, u64 *spte,
+static int pte_list_add(struct kvm_mmu_memory_cache *cache, u64 *spte,
struct kvm_rmap_head *rmap_head)
{
struct pte_list_desc *desc;
@@ -885,7 +885,7 @@ static int pte_list_add(struct kvm_vcpu *vcpu, u64 *spte,
rmap_head->val = (unsigned long)spte;
} else if (!(rmap_head->val & 1)) {
rmap_printk("%p %llx 1->many\n", spte, *spte);
- desc = mmu_alloc_pte_list_desc(vcpu);
+ desc = mmu_alloc_pte_list_desc(cache);
desc->sptes[0] = (u64 *)rmap_head->val;
desc->sptes[1] = spte;
desc->spte_count = 2;
@@ -897,7 +897,7 @@ static int pte_list_add(struct kvm_vcpu *vcpu, u64 *spte,
while (desc->spte_count == PTE_LIST_EXT) {
count += PTE_LIST_EXT;
if (!desc->more) {
- desc->more = mmu_alloc_pte_list_desc(vcpu);
+ desc->more = mmu_alloc_pte_list_desc(cache);
desc = desc->more;
desc->spte_count = 0;
break;
@@ -1596,8 +1596,10 @@ static bool kvm_test_age_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head,

#define RMAP_RECYCLE_THRESHOLD 1000

-static void rmap_add(struct kvm_vcpu *vcpu, const struct kvm_memory_slot *slot,
- u64 *spte, gfn_t gfn)
+static void __rmap_add(struct kvm *kvm,
+ struct kvm_mmu_memory_cache *cache,
+ const struct kvm_memory_slot *slot,
+ u64 *spte, gfn_t gfn)
{
struct kvm_mmu_page *sp;
struct kvm_rmap_head *rmap_head;
@@ -1606,15 +1608,21 @@ static void rmap_add(struct kvm_vcpu *vcpu, const struct kvm_memory_slot *slot,
sp = sptep_to_sp(spte);
kvm_mmu_page_set_gfn(sp, spte - sp->spt, gfn);
rmap_head = gfn_to_rmap(gfn, sp->role.level, slot);
- rmap_count = pte_list_add(vcpu, spte, rmap_head);
+ rmap_count = pte_list_add(cache, spte, rmap_head);

if (rmap_count > RMAP_RECYCLE_THRESHOLD) {
- kvm_unmap_rmapp(vcpu->kvm, rmap_head, NULL, gfn, sp->role.level, __pte(0));
+ kvm_unmap_rmapp(kvm, rmap_head, NULL, gfn, sp->role.level, __pte(0));
kvm_flush_remote_tlbs_with_address(
- vcpu->kvm, sp->gfn, KVM_PAGES_PER_HPAGE(sp->role.level));
+ kvm, sp->gfn, KVM_PAGES_PER_HPAGE(sp->role.level));
}
}

+static void rmap_add(struct kvm_vcpu *vcpu, const struct kvm_memory_slot *slot,
+ u64 *spte, gfn_t gfn)
+{
+ __rmap_add(vcpu->kvm, &vcpu->arch.mmu_pte_list_desc_cache, slot, spte, gfn);
+}
+
bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
{
bool young = false;
@@ -1682,13 +1690,13 @@ static unsigned kvm_page_table_hashfn(gfn_t gfn)
return hash_64(gfn, KVM_MMU_HASH_SHIFT);
}

-static void mmu_page_add_parent_pte(struct kvm_vcpu *vcpu,
+static void mmu_page_add_parent_pte(struct kvm_mmu_memory_cache *cache,
struct kvm_mmu_page *sp, u64 *parent_pte)
{
if (!parent_pte)
return;

- pte_list_add(vcpu, parent_pte, &sp->parent_ptes);
+ pte_list_add(cache, parent_pte, &sp->parent_ptes);
}

static void mmu_page_remove_parent_pte(struct kvm_mmu_page *sp,
@@ -2307,8 +2315,8 @@ static void shadow_walk_next(struct kvm_shadow_walk_iterator *iterator)
__shadow_walk_next(iterator, *iterator->sptep);
}

-static void link_shadow_page(struct kvm_vcpu *vcpu, u64 *sptep,
- struct kvm_mmu_page *sp)
+static void __link_shadow_page(struct kvm_mmu_memory_cache *cache, u64 *sptep,
+ struct kvm_mmu_page *sp)
{
u64 spte;

@@ -2318,12 +2326,17 @@ static void link_shadow_page(struct kvm_vcpu *vcpu, u64 *sptep,

mmu_spte_set(sptep, spte);

- mmu_page_add_parent_pte(vcpu, sp, sptep);
+ mmu_page_add_parent_pte(cache, sp, sptep);

if (sp->unsync_children || sp->unsync)
mark_unsync(sptep);
}

+static void link_shadow_page(struct kvm_vcpu *vcpu, u64 *sptep, struct kvm_mmu_page *sp)
+{
+ __link_shadow_page(&vcpu->arch.mmu_pte_list_desc_cache, sptep, sp);
+}
+
static void validate_direct_spte(struct kvm_vcpu *vcpu, u64 *sptep,
unsigned direct_access)
{
--
2.35.1.723.g4982287a31-goog