From 1ae0a13def678876b9acfb5ac1e2cf7d5d45a60d Mon Sep 17 00:00:00 2001 From: "Dong, Eddie" Date: Mon, 7 Jan 2008 13:20:25 +0200 Subject: [PATCH] KVM: MMU: Simplify hash table indexing Signed-off-by: Yaozu (Eddie) Dong Signed-off-by: Avi Kivity --- arch/x86/kvm/mmu.c | 10 +++++----- include/asm-x86/kvm_host.h | 3 ++- 2 files changed, 7 insertions(+), 6 deletions(-) diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 28f9a44060cc..6f8392d4034e 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -559,7 +559,7 @@ static void kvm_mmu_free_page(struct kvm *kvm, struct kvm_mmu_page *sp) static unsigned kvm_page_table_hashfn(gfn_t gfn) { - return gfn; + return gfn & ((1 << KVM_MMU_HASH_SHIFT) - 1); } static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu, @@ -663,7 +663,7 @@ static struct kvm_mmu_page *kvm_mmu_lookup_page(struct kvm *kvm, gfn_t gfn) struct hlist_node *node; pgprintk("%s: looking for gfn %lx\n", __FUNCTION__, gfn); - index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES; + index = kvm_page_table_hashfn(gfn); bucket = &kvm->arch.mmu_page_hash[index]; hlist_for_each_entry(sp, node, bucket, hash_link) if (sp->gfn == gfn && !sp->role.metaphysical) { @@ -701,7 +701,7 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, } pgprintk("%s: looking gfn %lx role %x\n", __FUNCTION__, gfn, role.word); - index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES; + index = kvm_page_table_hashfn(gfn); bucket = &vcpu->kvm->arch.mmu_page_hash[index]; hlist_for_each_entry(sp, node, bucket, hash_link) if (sp->gfn == gfn && sp->role.word == role.word) { @@ -840,7 +840,7 @@ static int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn) pgprintk("%s: looking for gfn %lx\n", __FUNCTION__, gfn); r = 0; - index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES; + index = kvm_page_table_hashfn(gfn); bucket = &kvm->arch.mmu_page_hash[index]; hlist_for_each_entry_safe(sp, node, n, bucket, hash_link) if (sp->gfn == gfn && !sp->role.metaphysical) { @@ -1450,7 +1450,7 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, vcpu->arch.last_pt_write_count = 1; vcpu->arch.last_pte_updated = NULL; } - index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES; + index = kvm_page_table_hashfn(gfn); bucket = &vcpu->kvm->arch.mmu_page_hash[index]; hlist_for_each_entry_safe(sp, node, n, bucket, hash_link) { if (sp->gfn != gfn || sp->role.metaphysical) diff --git a/include/asm-x86/kvm_host.h b/include/asm-x86/kvm_host.h index 68ee390b2844..e076790ee794 100644 --- a/include/asm-x86/kvm_host.h +++ b/include/asm-x86/kvm_host.h @@ -58,7 +58,8 @@ #define KVM_PERMILLE_MMU_PAGES 20 #define KVM_MIN_ALLOC_MMU_PAGES 64 -#define KVM_NUM_MMU_PAGES 1024 +#define KVM_MMU_HASH_SHIFT 10 +#define KVM_NUM_MMU_PAGES (1 << KVM_MMU_HASH_SHIFT) #define KVM_MIN_FREE_MMU_PAGES 5 #define KVM_REFILL_PAGES 25 #define KVM_MAX_CPUID_ENTRIES 40