[PATCH] kvm mmu: optimizations when tdp is in use

2010-05-27 Thread Gui Jianfeng 
In case of using tdp, checking write protected page isn't needed and
quadrant also no need to be calculated.

Signed-off-by: Gui Jianfeng guijianf...@cn.fujitsu.com
---
 arch/x86/kvm/mmu.c |7 +--
 1 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 0bb9f17..ce4bbd3 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -495,10 +495,13 @@ static int mapping_level(struct kvm_vcpu *vcpu, gfn_t 
large_gfn)
max_level = kvm_x86_ops-get_lpage_level()  host_level ?
kvm_x86_ops-get_lpage_level() : host_level;
 
+   if (tdp_enabled)
+   goto done;
+
for (level = PT_DIRECTORY_LEVEL; level = max_level; ++level)
if (has_wrprotected_page(vcpu-kvm, large_gfn, level))
break;
-
+done:
return level - 1;
 }
 
@@ -1346,7 +1349,7 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct 
kvm_vcpu *vcpu,
if (role.direct)
role.cr4_pae = 0;
role.access = access;
-   if (vcpu-arch.mmu.root_level = PT32_ROOT_LEVEL) {
+   if (!tdp_enabled  vcpu-arch.mmu.root_level = PT32_ROOT_LEVEL) {
quadrant = gaddr  (PAGE_SHIFT + (PT64_PT_BITS * level));
quadrant = (1  ((PT32_PT_BITS - PT64_PT_BITS) * level)) - 1;
role.quadrant = quadrant;
-- 
1.6.5.2
--
To unsubscribe from this list: send the line unsubscribe kvm in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH] kvm mmu: optimizations when tdp is in use

2010-05-27 Thread Avi Kivity 

On 05/27/2010 11:06 AM, Gui Jianfeng wrote:

In case of using tdp, checking write protected page isn't needed and
quadrant also no need to be calculated.

Signed-off-by: Gui Jianfengguijianf...@cn.fujitsu.com
---
  arch/x86/kvm/mmu.c |7 +--
  1 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 0bb9f17..ce4bbd3 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -495,10 +495,13 @@ static int mapping_level(struct kvm_vcpu *vcpu, gfn_t 
large_gfn)
max_level = kvm_x86_ops-get_lpage_level()  host_level ?
kvm_x86_ops-get_lpage_level() : host_level;

+   if (tdp_enabled)
+   goto done;
+
for (level = PT_DIRECTORY_LEVEL; level= max_level; ++level)
if (has_wrprotected_page(vcpu-kvm, large_gfn, level))
break;
-
+done:
return level - 1;
  }

   


We also use -write_count to prevent mapping the end of a 
non-large-page-aligned memslot with a large spte.


Undocumented in mmu.txt, I'll post a patch.

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

--
To unsubscribe from this list: send the line unsubscribe kvm in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH] kvm mmu: optimizations when tdp is in use

2010-05-27 Thread Marcelo Tosatti 
On Thu, May 27, 2010 at 04:06:34PM +0800, Gui Jianfeng wrote:
 In case of using tdp, checking write protected page isn't needed and
 quadrant also no need to be calculated.
 
 Signed-off-by: Gui Jianfeng guijianf...@cn.fujitsu.com
 ---
  arch/x86/kvm/mmu.c |7 +--
  1 files changed, 5 insertions(+), 2 deletions(-)
 
 diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
 index 0bb9f17..ce4bbd3 100644
 --- a/arch/x86/kvm/mmu.c
 +++ b/arch/x86/kvm/mmu.c
 @@ -495,10 +495,13 @@ static int mapping_level(struct kvm_vcpu *vcpu, gfn_t 
 large_gfn)
   max_level = kvm_x86_ops-get_lpage_level()  host_level ?
   kvm_x86_ops-get_lpage_level() : host_level;
  
 + if (tdp_enabled)
 + goto done;
 +

This is wrong. write_count is initialized for alignment purposes, not 
only write protected pages. See __kvm_set_memory_region in
virt/kvm/kvm_main.c.

   for (level = PT_DIRECTORY_LEVEL; level = max_level; ++level)
   if (has_wrprotected_page(vcpu-kvm, large_gfn, level))
   break;
 -
 +done:
   return level - 1;
  }
  
 @@ -1346,7 +1349,7 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct 
 kvm_vcpu *vcpu,
   if (role.direct)
   role.cr4_pae = 0;
   role.access = access;
 - if (vcpu-arch.mmu.root_level = PT32_ROOT_LEVEL) {
 + if (!tdp_enabled  vcpu-arch.mmu.root_level = PT32_ROOT_LEVEL) {
   quadrant = gaddr  (PAGE_SHIFT + (PT64_PT_BITS * level));
   quadrant = (1  ((PT32_PT_BITS - PT64_PT_BITS) * level)) - 1;
   role.quadrant = quadrant;
 -- 
 1.6.5.2
 --
 To unsubscribe from this list: send the line unsubscribe kvm in
 the body of a message to majord...@vger.kernel.org
 More majordomo info at  http://vger.kernel.org/majordomo-info.html
--
To unsubscribe from this list: send the line unsubscribe kvm in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH] kvm mmu: optimizations when tdp is in use

2010-05-27 Thread Gui Jianfeng 
Marcelo Tosatti wrote:
 On Thu, May 27, 2010 at 04:06:34PM +0800, Gui Jianfeng wrote:
 In case of using tdp, checking write protected page isn't needed and
 quadrant also no need to be calculated.

 Signed-off-by: Gui Jianfeng guijianf...@cn.fujitsu.com
 ---
  arch/x86/kvm/mmu.c |7 +--
  1 files changed, 5 insertions(+), 2 deletions(-)

 diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
 index 0bb9f17..ce4bbd3 100644
 --- a/arch/x86/kvm/mmu.c
 +++ b/arch/x86/kvm/mmu.c
 @@ -495,10 +495,13 @@ static int mapping_level(struct kvm_vcpu *vcpu, gfn_t 
 large_gfn)
  max_level = kvm_x86_ops-get_lpage_level()  host_level ?
  kvm_x86_ops-get_lpage_level() : host_level;
  
 +if (tdp_enabled)
 +goto done;
 +
 
 This is wrong. write_count is initialized for alignment purposes, not 
 only write protected pages. See __kvm_set_memory_region in
 virt/kvm/kvm_main.c.

thanks, avi also pointed this out.

Gui

 
  for (level = PT_DIRECTORY_LEVEL; level = max_level; ++level)
  if (has_wrprotected_page(vcpu-kvm, large_gfn, level))
  break;
 -
 +done:
  return level - 1;
  }
  
 @@ -1346,7 +1349,7 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct 
 kvm_vcpu *vcpu,
  if (role.direct)
  role.cr4_pae = 0;
  role.access = access;
 -if (vcpu-arch.mmu.root_level = PT32_ROOT_LEVEL) {
 +if (!tdp_enabled  vcpu-arch.mmu.root_level = PT32_ROOT_LEVEL) {
  quadrant = gaddr  (PAGE_SHIFT + (PT64_PT_BITS * level));
  quadrant = (1  ((PT32_PT_BITS - PT64_PT_BITS) * level)) - 1;
  role.quadrant = quadrant;
 -- 
 1.6.5.2
 --
 To unsubscribe from this list: send the line unsubscribe kvm in
 the body of a message to majord...@vger.kernel.org
 More majordomo info at  http://vger.kernel.org/majordomo-info.html
 
 

-- 
Regards
Gui Jianfeng
--
To unsubscribe from this list: send the line unsubscribe kvm in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html