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From: Xiao Guangrong on 6 May 2010 05:40
Let invlpg not depends on kvm_mmu_pte_write path, later patch will need
this feature

Signed-off-by: Xiao Guangrong <xiaoguangrong(a)cn.fujitsu.com>
---
arch/x86/kvm/mmu.c | 22 +++++++++++++---------
arch/x86/kvm/paging_tmpl.h | 44 +++++++++++++++++++++++++++++++-------------
2 files changed, 44 insertions(+), 22 deletions(-)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 8ab1a49..5e32751 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -2318,6 +2318,10 @@ static bool is_rsvd_bits_set(struct kvm_vcpu *vcpu, u64 gpte, int level)
return (gpte & vcpu->arch.mmu.rsvd_bits_mask[bit7][level-1]) != 0;
}

+static void mmu_guess_page_from_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
+ u64 gpte);
+static void mmu_release_page_from_pte_write(struct kvm_vcpu *vcpu);
+
#define PTTYPE 64
#include "paging_tmpl.h"
#undef PTTYPE
@@ -2631,6 +2635,14 @@ static void mmu_guess_page_from_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
vcpu->arch.update_pte.pfn = pfn;
}

+static void mmu_release_page_from_pte_write(struct kvm_vcpu *vcpu)
+{
+ if (!is_error_pfn(vcpu->arch.update_pte.pfn)) {
+ kvm_release_pfn_clean(vcpu->arch.update_pte.pfn);
+ vcpu->arch.update_pte.pfn = bad_pfn;
+ }
+}
+
static void kvm_mmu_access_page(struct kvm_vcpu *vcpu, gfn_t gfn)
{
u64 *spte = vcpu->arch.last_pte_updated;
@@ -2663,12 +2675,9 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
int flooded = 0;
int npte;
int r;
- int invlpg_counter;

pgprintk("%s: gpa %llx bytes %d\n", __func__, gpa, bytes);

- invlpg_counter = atomic_read(&vcpu->kvm->arch.invlpg_counter);
-
/*
* Assume that the pte write on a page table of the same type
* as the current vcpu paging mode. This is nearly always true
@@ -2701,8 +2710,6 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,

mmu_guess_page_from_pte_write(vcpu, gpa, gentry);
spin_lock(&vcpu->kvm->mmu_lock);
- if (atomic_read(&vcpu->kvm->arch.invlpg_counter) != invlpg_counter)
- gentry = 0;
kvm_mmu_access_page(vcpu, gfn);
kvm_mmu_free_some_pages(vcpu);
++vcpu->kvm->stat.mmu_pte_write;
@@ -2779,10 +2786,7 @@ restart:
}
kvm_mmu_audit(vcpu, "post pte write");
spin_unlock(&vcpu->kvm->mmu_lock);
- if (!is_error_pfn(vcpu->arch.update_pte.pfn)) {
- kvm_release_pfn_clean(vcpu->arch.update_pte.pfn);
- vcpu->arch.update_pte.pfn = bad_pfn;
- }
+ mmu_release_page_from_pte_write(vcpu);
}

int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva)
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index 89d66ca..93ee2d9 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -462,11 +462,11 @@ out_unlock:

static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva)
{
+ struct kvm_mmu_page *sp = NULL;
struct kvm_shadow_walk_iterator iterator;
- gpa_t pte_gpa = -1;
- int level;
- u64 *sptep;
- int need_flush = 0;
+ gfn_t gfn = -1;
+ u64 *sptep = NULL, gentry;
+ int invlpg_counter, level, offset = 0, need_flush = 0;

spin_lock(&vcpu->kvm->mmu_lock);

@@ -475,15 +475,14 @@ static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva)
sptep = iterator.sptep;

if (is_last_spte(*sptep, level)) {
- struct kvm_mmu_page *sp = page_header(__pa(sptep));
- int offset, shift;
+ int shift;

+ sp = page_header(__pa(sptep));
shift = PAGE_SHIFT -
(PT_LEVEL_BITS - PT64_LEVEL_BITS) * level;
+ gfn = sp->gfn;
offset = sp->role.quadrant << shift;
-
- pte_gpa = (sp->gfn << PAGE_SHIFT) + offset;
- pte_gpa += (sptep - sp->spt) * sizeof(pt_element_t);
+ offset += (sptep - sp->spt) * sizeof(pt_element_t);

if (is_shadow_present_pte(*sptep)) {
rmap_remove(vcpu->kvm, sptep);
@@ -492,6 +491,7 @@ static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva)
need_flush = 1;
}
__set_spte(sptep, shadow_trap_nonpresent_pte);
+ sp->active_count++;
break;
}

@@ -502,16 +502,34 @@ static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva)
if (need_flush)
kvm_flush_remote_tlbs(vcpu->kvm);

- atomic_inc(&vcpu->kvm->arch.invlpg_counter);
-
+ invlpg_counter = atomic_add_return(1, &vcpu->kvm->arch.invlpg_counter);
spin_unlock(&vcpu->kvm->mmu_lock);

- if (pte_gpa == -1)
+ if (gfn == -1)
return;

if (mmu_topup_memory_caches(vcpu))
return;
- kvm_mmu_pte_write(vcpu, pte_gpa, NULL, sizeof(pt_element_t), 0);
+ if (kvm_read_guest_page(vcpu->kvm, gfn, &gentry, offset,
+ sizeof(pt_element_t)))
+ return;
+
+ mmu_guess_page_from_pte_write(vcpu, gfn_to_gpa(gfn) + offset, gentry);
+ spin_lock(&vcpu->kvm->mmu_lock);
+ sp->active_count--;
+ if (sp->role.invalid) {
+ if (!sp->active_count)
+ kvm_mmu_free_page(vcpu->kvm, sp);
+ goto unlock_exit;
+ }
+ if (atomic_read(&vcpu->kvm->arch.invlpg_counter) == invlpg_counter &&
+ sp->role.level == PT_PAGE_TABLE_LEVEL) {
+ ++vcpu->kvm->stat.mmu_pte_updated;
+ FNAME(update_pte)(vcpu, sp, sptep, &gentry);
+ }
+unlock_exit:
+ spin_unlock(&vcpu->kvm->mmu_lock);
+ mmu_release_page_from_pte_write(vcpu);
}

static gpa_t FNAME(gva_to_gpa)(struct kvm_vcpu *vcpu, gva_t vaddr, u32 access,
--
1.6.1.2





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Prev: [PATCH] Staging: comedi: Fixed printk call lengths and log levels
Next: [PATCH v4 9/9] KVM MMU: optimize sync/update unsync-page