2010-06-08 12:08:37

by Xiao Guangrong

Subject: [PATCH 1/3] KVM: MMU: remove unnecessary remote tlb flush

This remote tlb flush is no necessary since we have synced while
sp is zapped

Signed-off-by: Xiao Guangrong <[email protected]>
---
arch/x86/kvm/mmu.c | 2 --
1 files changed, 0 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 6b2c644..959c248 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -3038,8 +3038,6 @@ restart:

kvm_mmu_commit_zap_page(kvm, &invalid_list);
spin_unlock(&kvm->mmu_lock);
-
- kvm_flush_remote_tlbs(kvm);
}

static int kvm_mmu_remove_some_alloc_mmu_pages(struct kvm *kvm,
--
1.6.1.2

2010-06-08 12:09:31

by Xiao Guangrong

Subject: [PATCH 2/3] KVM: MMU: using wrapper function to flush local tlb

Using kvm_mmu_flush_tlb() function instead of calling
kvm_x86_ops->tlb_flush(vcpu) directly

Signed-off-by: Xiao Guangrong <[email protected]>
---
arch/x86/kvm/mmu.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 959c248..7319098 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1982,7 +1982,7 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
reset_host_protection)) {
if (write_fault)
*ptwrite = 1;
- kvm_x86_ops->tlb_flush(vcpu);
+ kvm_mmu_flush_tlb(vcpu);
}

pgprintk("%s: setting spte %llx\n", __func__, *sptep);
--
1.6.1.2

2010-06-08 12:10:34

by Xiao Guangrong

Subject: [PATCH 3/3] KVM: MMU: delay local tlb flush

delay local tlb flush until enter guest moden, it can reduce vpid flush
frequency and reduce remote tlb flush IPI(if KVM_REQ_TLB_FLUSH bit is
already set, IPI is not sent)

Signed-off-by: Xiao Guangrong <[email protected]>
---
arch/x86/kvm/mmu.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 7319098..75ddaa1 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -2362,7 +2362,7 @@ static int nonpaging_init_context(struct kvm_vcpu *vcpu)
void kvm_mmu_flush_tlb(struct kvm_vcpu *vcpu)
{
++vcpu->stat.tlb_flush;
- kvm_x86_ops->tlb_flush(vcpu);
+ set_bit(KVM_REQ_TLB_FLUSH, &vcpu->requests);
}

static void paging_new_cr3(struct kvm_vcpu *vcpu)
--
1.6.1.2

2010-06-09 12:06:58

by Avi Kivity

Subject: Re: [PATCH 3/3] KVM: MMU: delay local tlb flush

On 06/08/2010 03:07 PM, Xiao Guangrong wrote:
> delay local tlb flush until enter guest moden, it can reduce vpid flush
> frequency and reduce remote tlb flush IPI(if KVM_REQ_TLB_FLUSH bit is
> already set, IPI is not sent)
>

Applied all, thanks.

--
error compiling committee.c: too many arguments to function