* [patch 2/2] KVM: MMU: remove global page optimization logic
2009-04-05 17:54 [patch 0/2] disable unsync global page optimization Marcelo Tosatti
2009-04-05 17:54 ` [patch 1/2] KVM: MMU: disable " Marcelo Tosatti
@ 2009-04-05 17:54 ` Marcelo Tosatti
2009-04-09 16:16 ` [patch 0/2] disable unsync global page optimization Avi Kivity
2 siblings, 0 replies; 4+ messages in thread
From: Marcelo Tosatti @ 2009-04-05 17:54 UTC (permalink / raw)
To: kvm; +Cc: avi, Marcelo Tosatti
[-- Attachment #1: remove-global-logic --]
[-- Type: text/plain, Size: 7630 bytes --]
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@redhat.com>
Index: kvm/arch/x86/include/asm/kvm_host.h
===================================================================
--- kvm.orig/arch/x86/include/asm/kvm_host.h
+++ kvm/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 kv
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);
Index: kvm/arch/x86/kvm/mmu.c
===================================================================
--- kvm.orig/arch/x86/kvm/mmu.c
+++ kvm/arch/x86/kvm/mmu.c
@@ -1080,18 +1080,10 @@ static struct kvm_mmu_page *kvm_mmu_look
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;
}
@@ -1254,7 +1246,6 @@ static struct kvm_mmu_page *kvm_mmu_get_
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))
@@ -1652,11 +1643,7 @@ static int kvm_unsync_page(struct kvm_vc
++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;
@@ -1683,21 +1670,12 @@ static int mmu_need_write_protect(struct
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
@@ -1771,8 +1749,8 @@ 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);
@@ -1801,7 +1779,7 @@ static void mmu_set_spte(struct kvm_vcpu
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);
@@ -1849,7 +1827,7 @@ static int __direct_map(struct kvm_vcpu
|| (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;
}
@@ -2020,15 +1998,6 @@ static void mmu_sync_roots(struct kvm_vc
}
}
-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);
@@ -2036,13 +2005,6 @@ void kvm_mmu_sync_roots(struct kvm_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;
Index: kvm/arch/x86/kvm/paging_tmpl.h
===================================================================
--- kvm.orig/arch/x86/kvm/paging_tmpl.h
+++ kvm/arch/x86/kvm/paging_tmpl.h
@@ -268,8 +268,7 @@ static void FNAME(update_pte)(struct kvm
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
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_v
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);
}
Index: kvm/arch/x86/kvm/x86.c
===================================================================
--- kvm.orig/arch/x86/kvm/x86.c
+++ kvm/arch/x86/kvm/x86.c
@@ -108,7 +108,6 @@ struct kvm_stats_debugfs_item debugfs_en
{ "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 }
@@ -321,7 +320,6 @@ void kvm_set_cr0(struct kvm_vcpu *vcpu,
kvm_x86_ops->set_cr0(vcpu, cr0);
vcpu->arch.cr0 = cr0;
- kvm_mmu_sync_global(vcpu);
kvm_mmu_reset_context(vcpu);
return;
}
@@ -366,7 +364,6 @@ void kvm_set_cr4(struct kvm_vcpu *vcpu,
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);
@@ -4329,7 +4326,6 @@ 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 */
--
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