[PATCH 21/46] KVM: MMU: remove global page optimization logic
From: Avi Kivity
Date: Wed May 20 2009 - 07:27:04 EST
From: Marcelo Tosatti <mtosatti@xxxxxxxxxx>
Complexity to fix it not worthwhile the gains, as discussed
in http://article.gmane.org/gmane.comp.emulators.kvm.devel/28649.
Signed-off-by: Marcelo Tosatti <mtosatti@xxxxxxxxxx>
Signed-off-by: Avi Kivity <avi@xxxxxxxxxx>
---
arch/x86/include/asm/kvm_host.h | 4 ---
arch/x86/kvm/mmu.c | 50 ++++----------------------------------
arch/x86/kvm/paging_tmpl.h | 6 +---
arch/x86/kvm/x86.c | 4 ---
4 files changed, 8 insertions(+), 56 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 3fc4623..0e3a7c6 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -213,7 +213,6 @@ struct kvm_mmu_page {
int multimapped; /* More than one parent_pte? */
int root_count; /* Currently serving as active root */
bool unsync;
- bool global;
unsigned int unsync_children;
union {
u64 *parent_pte; /* !multimapped */
@@ -395,7 +394,6 @@ struct kvm_arch{
*/
struct list_head active_mmu_pages;
struct list_head assigned_dev_head;
- struct list_head oos_global_pages;
struct iommu_domain *iommu_domain;
struct kvm_pic *vpic;
struct kvm_ioapic *vioapic;
@@ -425,7 +423,6 @@ struct kvm_vm_stat {
u32 mmu_recycled;
u32 mmu_cache_miss;
u32 mmu_unsync;
- u32 mmu_unsync_global;
u32 remote_tlb_flush;
u32 lpages;
};
@@ -640,7 +637,6 @@ void __kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu);
int kvm_mmu_load(struct kvm_vcpu *vcpu);
void kvm_mmu_unload(struct kvm_vcpu *vcpu);
void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu);
-void kvm_mmu_sync_global(struct kvm_vcpu *vcpu);
int kvm_emulate_hypercall(struct kvm_vcpu *vcpu);
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 409d08e..5b79afa 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1075,18 +1075,10 @@ static struct kvm_mmu_page *kvm_mmu_lookup_page(struct kvm *kvm, gfn_t gfn)
return NULL;
}
-static void kvm_unlink_unsync_global(struct kvm *kvm, struct kvm_mmu_page *sp)
-{
- list_del(&sp->oos_link);
- --kvm->stat.mmu_unsync_global;
-}
-
static void kvm_unlink_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp)
{
WARN_ON(!sp->unsync);
sp->unsync = 0;
- if (sp->global)
- kvm_unlink_unsync_global(kvm, sp);
--kvm->stat.mmu_unsync;
}
@@ -1249,7 +1241,6 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
pgprintk("%s: adding gfn %lx role %x\n", __func__, gfn, role.word);
sp->gfn = gfn;
sp->role = role;
- sp->global = 0;
hlist_add_head(&sp->hash_link, bucket);
if (!direct) {
if (rmap_write_protect(vcpu->kvm, gfn))
@@ -1647,11 +1638,7 @@ static int kvm_unsync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
++vcpu->kvm->stat.mmu_unsync;
sp->unsync = 1;
- if (sp->global) {
- list_add(&sp->oos_link, &vcpu->kvm->arch.oos_global_pages);
- ++vcpu->kvm->stat.mmu_unsync_global;
- } else
- kvm_mmu_mark_parents_unsync(vcpu, sp);
+ kvm_mmu_mark_parents_unsync(vcpu, sp);
mmu_convert_notrap(sp);
return 0;
@@ -1678,21 +1665,12 @@ static int mmu_need_write_protect(struct kvm_vcpu *vcpu, gfn_t gfn,
static int set_spte(struct kvm_vcpu *vcpu, u64 *shadow_pte,
unsigned pte_access, int user_fault,
int write_fault, int dirty, int largepage,
- int global, gfn_t gfn, pfn_t pfn, bool speculative,
+ gfn_t gfn, pfn_t pfn, bool speculative,
bool can_unsync)
{
u64 spte;
int ret = 0;
u64 mt_mask = shadow_mt_mask;
- struct kvm_mmu_page *sp = page_header(__pa(shadow_pte));
-
- if (!global && sp->global) {
- sp->global = 0;
- if (sp->unsync) {
- kvm_unlink_unsync_global(vcpu->kvm, sp);
- kvm_mmu_mark_parents_unsync(vcpu, sp);
- }
- }
/*
* We don't set the accessed bit, since we sometimes want to see
@@ -1766,8 +1744,8 @@ set_pte:
static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *shadow_pte,
unsigned pt_access, unsigned pte_access,
int user_fault, int write_fault, int dirty,
- int *ptwrite, int largepage, int global,
- gfn_t gfn, pfn_t pfn, bool speculative)
+ int *ptwrite, int largepage, gfn_t gfn,
+ pfn_t pfn, bool speculative)
{
int was_rmapped = 0;
int was_writeble = is_writeble_pte(*shadow_pte);
@@ -1796,7 +1774,7 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *shadow_pte,
was_rmapped = 1;
}
if (set_spte(vcpu, shadow_pte, pte_access, user_fault, write_fault,
- dirty, largepage, global, gfn, pfn, speculative, true)) {
+ dirty, largepage, gfn, pfn, speculative, true)) {
if (write_fault)
*ptwrite = 1;
kvm_x86_ops->tlb_flush(vcpu);
@@ -1844,7 +1822,7 @@ static int __direct_map(struct kvm_vcpu *vcpu, gpa_t v, int write,
|| (largepage && iterator.level == PT_DIRECTORY_LEVEL)) {
mmu_set_spte(vcpu, iterator.sptep, ACC_ALL, ACC_ALL,
0, write, 1, &pt_write,
- largepage, 0, gfn, pfn, false);
+ largepage, gfn, pfn, false);
++vcpu->stat.pf_fixed;
break;
}
@@ -2015,15 +1993,6 @@ static void mmu_sync_roots(struct kvm_vcpu *vcpu)
}
}
-static void mmu_sync_global(struct kvm_vcpu *vcpu)
-{
- struct kvm *kvm = vcpu->kvm;
- struct kvm_mmu_page *sp, *n;
-
- list_for_each_entry_safe(sp, n, &kvm->arch.oos_global_pages, oos_link)
- kvm_sync_page(vcpu, sp);
-}
-
void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu)
{
spin_lock(&vcpu->kvm->mmu_lock);
@@ -2031,13 +2000,6 @@ void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu)
spin_unlock(&vcpu->kvm->mmu_lock);
}
-void kvm_mmu_sync_global(struct kvm_vcpu *vcpu)
-{
- spin_lock(&vcpu->kvm->mmu_lock);
- mmu_sync_global(vcpu);
- spin_unlock(&vcpu->kvm->mmu_lock);
-}
-
static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, gva_t vaddr)
{
return vaddr;
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index 09782a9..258e459 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -268,8 +268,7 @@ static void FNAME(update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *page,
kvm_get_pfn(pfn);
mmu_set_spte(vcpu, spte, page->role.access, pte_access, 0, 0,
gpte & PT_DIRTY_MASK, NULL, largepage,
- gpte & PT_GLOBAL_MASK, gpte_to_gfn(gpte),
- pfn, true);
+ gpte_to_gfn(gpte), pfn, true);
}
/*
@@ -303,7 +302,6 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
user_fault, write_fault,
gw->ptes[gw->level-1] & PT_DIRTY_MASK,
ptwrite, largepage,
- gw->ptes[gw->level-1] & PT_GLOBAL_MASK,
gw->gfn, pfn, false);
break;
}
@@ -592,7 +590,7 @@ static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
nr_present++;
pte_access = sp->role.access & FNAME(gpte_access)(vcpu, gpte);
set_spte(vcpu, &sp->spt[i], pte_access, 0, 0,
- is_dirty_pte(gpte), 0, gpte & PT_GLOBAL_MASK, gfn,
+ is_dirty_pte(gpte), 0, gfn,
spte_to_pfn(sp->spt[i]), true, false);
}
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 95f1369..9b89d9b 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -108,7 +108,6 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {
{ "mmu_recycled", VM_STAT(mmu_recycled) },
{ "mmu_cache_miss", VM_STAT(mmu_cache_miss) },
{ "mmu_unsync", VM_STAT(mmu_unsync) },
- { "mmu_unsync_global", VM_STAT(mmu_unsync_global) },
{ "remote_tlb_flush", VM_STAT(remote_tlb_flush) },
{ "largepages", VM_STAT(lpages) },
{ NULL }
@@ -322,7 +321,6 @@ void kvm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
kvm_x86_ops->set_cr0(vcpu, cr0);
vcpu->arch.cr0 = cr0;
- kvm_mmu_sync_global(vcpu);
kvm_mmu_reset_context(vcpu);
return;
}
@@ -367,7 +365,6 @@ void kvm_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
kvm_x86_ops->set_cr4(vcpu, cr4);
vcpu->arch.cr4 = cr4;
vcpu->arch.mmu.base_role.cr4_pge = (cr4 & X86_CR4_PGE) && !tdp_enabled;
- kvm_mmu_sync_global(vcpu);
kvm_mmu_reset_context(vcpu);
}
EXPORT_SYMBOL_GPL(kvm_set_cr4);
@@ -4360,7 +4357,6 @@ struct kvm *kvm_arch_create_vm(void)
return ERR_PTR(-ENOMEM);
INIT_LIST_HEAD(&kvm->arch.active_mmu_pages);
- INIT_LIST_HEAD(&kvm->arch.oos_global_pages);
INIT_LIST_HEAD(&kvm->arch.assigned_dev_head);
/* Reserve bit 0 of irq_sources_bitmap for userspace irq source */
--
1.6.0.6
--
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