The mmu_seq verification can be removed since we get the pfn in the
protection of mmu_lock
Signed-off-by: Xiao Guangrong <[email protected]>
---
arch/x86/include/asm/kvm_host.h | 2 +-
arch/x86/kvm/mmu.c | 16 +++++-----------
arch/x86/kvm/paging_tmpl.h | 4 +---
3 files changed, 7 insertions(+), 15 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 35f81b1..ea9fea3 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -258,7 +258,7 @@ struct kvm_mmu {
struct kvm_mmu_page *sp);
void (*invlpg)(struct kvm_vcpu *vcpu, gva_t gva);
void (*update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
- u64 *spte, const void *pte, unsigned long mmu_seq);
+ u64 *spte, const void *pte);
hpa_t root_hpa;
int root_level;
int shadow_root_level;
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 22fae75..2841805 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1206,7 +1206,7 @@ static void nonpaging_invlpg(struct kvm_vcpu *vcpu, gva_t gva)
static void nonpaging_update_pte(struct kvm_vcpu *vcpu,
struct kvm_mmu_page *sp, u64 *spte,
- const void *pte, unsigned long mmu_seq)
+ const void *pte)
{
WARN_ON(1);
}
@@ -3163,9 +3163,8 @@ static void mmu_pte_write_zap_pte(struct kvm_vcpu *vcpu,
}
static void mmu_pte_write_new_pte(struct kvm_vcpu *vcpu,
- struct kvm_mmu_page *sp,
- u64 *spte,
- const void *new, unsigned long mmu_seq)
+ struct kvm_mmu_page *sp, u64 *spte,
+ const void *new)
{
if (sp->role.level != PT_PAGE_TABLE_LEVEL) {
++vcpu->kvm->stat.mmu_pde_zapped;
@@ -3173,7 +3172,7 @@ static void mmu_pte_write_new_pte(struct kvm_vcpu *vcpu,
}
++vcpu->kvm->stat.mmu_pte_updated;
- vcpu->arch.mmu.update_pte(vcpu, sp, spte, new, mmu_seq);
+ vcpu->arch.mmu.update_pte(vcpu, sp, spte, new);
}
static bool need_remote_flush(u64 old, u64 new)
@@ -3229,7 +3228,6 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
struct kvm_mmu_page *sp;
struct hlist_node *node;
LIST_HEAD(invalid_list);
- unsigned long mmu_seq;
u64 entry, gentry, *spte;
unsigned pte_size, page_offset, misaligned, quadrant, offset;
int level, npte, invlpg_counter, r, flooded = 0;
@@ -3271,9 +3269,6 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
break;
}
- mmu_seq = vcpu->kvm->mmu_notifier_seq;
- smp_rmb();
-
spin_lock(&vcpu->kvm->mmu_lock);
if (atomic_read(&vcpu->kvm->arch.invlpg_counter) != invlpg_counter)
gentry = 0;
@@ -3345,8 +3340,7 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
if (gentry &&
!((sp->role.word ^ vcpu->arch.mmu.base_role.word)
& mask.word))
- mmu_pte_write_new_pte(vcpu, sp, spte, &gentry,
- mmu_seq);
+ mmu_pte_write_new_pte(vcpu, sp, spte, &gentry);
if (!remote_flush && need_remote_flush(entry, *spte))
remote_flush = true;
++spte;
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index c639779..74f8567 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -325,7 +325,7 @@ no_present:
}
static void FNAME(update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
- u64 *spte, const void *pte, unsigned long mmu_seq)
+ u64 *spte, const void *pte)
{
pt_element_t gpte;
unsigned pte_access;
@@ -342,8 +342,6 @@ static void FNAME(update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
kvm_release_pfn_clean(pfn);
return;
}
- if (mmu_notifier_retry(vcpu, mmu_seq))
- return;
/*
* we call mmu_set_spte() with host_writable = true because that
--
1.7.4
Simplely return from kvm_mmu_pte_write path if no shadow page is
write-protected, than we can avoid to walk all shadow pages and hold
mmu-lock
Signed-off-by: Xiao Guangrong <[email protected]>
---
arch/x86/kvm/mmu.c | 8 ++++++++
1 files changed, 8 insertions(+), 0 deletions(-)
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 2841805..ccac6c4 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -3219,6 +3219,11 @@ static void kvm_mmu_access_page(struct kvm_vcpu *vcpu, gfn_t gfn)
set_bit(PT_ACCESSED_SHIFT, (unsigned long *)spte);
}
+static bool need_track_pte_changed(struct kvm_vcpu *vcpu)
+{
+ return !tdp_enabled || mmu_is_nested(vcpu);
+}
+
void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
const u8 *new, int bytes,
bool guest_initiated)
@@ -3233,6 +3238,9 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
int level, npte, invlpg_counter, r, flooded = 0;
bool remote_flush, local_flush, zap_page;
+ if (!need_track_pte_changed(vcpu))
+ return;
+
zap_page = remote_flush = local_flush = false;
offset = offset_in_page(gpa);
--
1.7.4
On 03/28/2011 04:30 AM, Xiao Guangrong wrote:
> Simplely return from kvm_mmu_pte_write path if no shadow page is
> write-protected, than we can avoid to walk all shadow pages and hold
> mmu-lock
>
> Signed-off-by: Xiao Guangrong<[email protected]>
> ---
> arch/x86/kvm/mmu.c | 8 ++++++++
> 1 files changed, 8 insertions(+), 0 deletions(-)
>
> diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
> index 2841805..ccac6c4 100644
> --- a/arch/x86/kvm/mmu.c
> +++ b/arch/x86/kvm/mmu.c
> @@ -3219,6 +3219,11 @@ static void kvm_mmu_access_page(struct kvm_vcpu *vcpu, gfn_t gfn)
> set_bit(PT_ACCESSED_SHIFT, (unsigned long *)spte);
> }
>
> +static bool need_track_pte_changed(struct kvm_vcpu *vcpu)
> +{
> + return !tdp_enabled || mmu_is_nested(vcpu);
> +}
> +
What happens if this vcpu is nested but another vcpu is not?
Or if we have some indirect pages, but currently we're in non-nested mode?
Suggest instead to keep track of the number of indirect pages across the
guest. If it's zero, we can exit early.
> void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
> const u8 *new, int bytes,
> bool guest_initiated)
> @@ -3233,6 +3238,9 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
> int level, npte, invlpg_counter, r, flooded = 0;
> bool remote_flush, local_flush, zap_page;
>
> + if (!need_track_pte_changed(vcpu))
> + return;
> +
> zap_page = remote_flush = local_flush = false;
> offset = offset_in_page(gpa);
>
--
error compiling committee.c: too many arguments to function
On 03/28/2011 04:29 AM, Xiao Guangrong wrote:
> The mmu_seq verification can be removed since we get the pfn in the
> protection of mmu_lock
Applied, thanks.
--
error compiling committee.c: too many arguments to function