diff options
| -rw-r--r-- | arch/x86/kvm/mmu/mmu.c | 35 |
1 files changed, 22 insertions, 13 deletions
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 69ad8189d7eb..f1eb2fdfa473 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -138,11 +138,21 @@ module_param(dbg, bool, 0644); #include <trace/events/kvm.h> /* make pte_list_desc fit well in cache lines */ -#define PTE_LIST_EXT 15 +#define PTE_LIST_EXT 14 +/* + * Slight optimization of cacheline layout, by putting `more' and `spte_count' + * at the start; then accessing it will only use one single cacheline for + * either full (entries==PTE_LIST_EXT) case or entries<=6. + */ struct pte_list_desc { - u64 *sptes[PTE_LIST_EXT]; struct pte_list_desc *more; + /* + * Stores number of entries stored in the pte_list_desc. No need to be + * u64 but just for easier alignment. When PTE_LIST_EXT, means full. + */ + u64 spte_count; + u64 *sptes[PTE_LIST_EXT]; }; struct kvm_shadow_walk_iterator { @@ -901,7 +911,7 @@ static int pte_list_add(struct kvm_vcpu *vcpu, u64 *spte, struct kvm_rmap_head *rmap_head) { struct pte_list_desc *desc; - int i, count = 0; + int count = 0; if (!rmap_head->val) { rmap_printk("%p %llx 0->1\n", spte, *spte); @@ -911,24 +921,24 @@ static int pte_list_add(struct kvm_vcpu *vcpu, u64 *spte, desc = mmu_alloc_pte_list_desc(vcpu); desc->sptes[0] = (u64 *)rmap_head->val; desc->sptes[1] = spte; + desc->spte_count = 2; rmap_head->val = (unsigned long)desc | 1; ++count; } else { rmap_printk("%p %llx many->many\n", spte, *spte); desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); - while (desc->sptes[PTE_LIST_EXT-1]) { + while (desc->spte_count == PTE_LIST_EXT) { count += PTE_LIST_EXT; - if (!desc->more) { desc->more = mmu_alloc_pte_list_desc(vcpu); desc = desc->more; + desc->spte_count = 0; break; } desc = desc->more; } - for (i = 0; desc->sptes[i]; ++i) - ++count; - desc->sptes[i] = spte; + count += desc->spte_count; + desc->sptes[desc->spte_count++] = spte; } return count; } @@ -938,13 +948,12 @@ pte_list_desc_remove_entry(struct kvm_rmap_head *rmap_head, struct pte_list_desc *desc, int i, struct pte_list_desc *prev_desc) { - int j; + int j = desc->spte_count - 1; - for (j = PTE_LIST_EXT - 1; !desc->sptes[j] && j > i; --j) - ; desc->sptes[i] = desc->sptes[j]; desc->sptes[j] = NULL; - if (j != 0) + desc->spte_count--; + if (desc->spte_count) return; if (!prev_desc && !desc->more) rmap_head->val = 0; @@ -977,7 +986,7 @@ static void __pte_list_remove(u64 *spte, struct kvm_rmap_head *rmap_head) desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); prev_desc = NULL; while (desc) { - for (i = 0; i < PTE_LIST_EXT && desc->sptes[i]; ++i) { + for (i = 0; i < desc->spte_count; ++i) { if (desc->sptes[i] == spte) { pte_list_desc_remove_entry(rmap_head, desc, i, prev_desc); |