Re: [PATCH] KVM: MMU: Disassociate direct maps from guest levels

2010-03-23 Thread Avi Kivity 

On 03/17/2010 08:16 PM, Marcelo Tosatti wrote:

On Sun, Mar 14, 2010 at 10:22:52AM +0200, Avi Kivity wrote:
   

Direct maps are linear translations for a section of memory, used for
real mode or with large pages.  As such, they are independent of the guest
levels.

Teach the mmu about this by making page-role.glevels = 0 for direct maps.
This allows direct maps to be shared among real mode and the various paging
modes.

@@ -1328,6 +1328,8 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct 
kvm_vcpu *vcpu,
role = vcpu-arch.mmu.base_role;
role.level = level;
role.direct = direct;
+   if (role.direct)
+   role.glevels = 0;
role.access = access;
if (vcpu-arch.mmu.root_level= PT32_ROOT_LEVEL) {
quadrant = gaddr  (PAGE_SHIFT + (PT64_PT_BITS * level));
--
1.7.0.2
 

Isnt this what happens already, since for tdp base_role.glevels is not
initialized?
   


Correct.  I was thinking about the nested npt case, which will use 
role.glevels.  Joerg, please incorporate this into your nnpt patchset.


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

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Re: [PATCH] KVM: MMU: Disassociate direct maps from guest levels

2010-03-23 Thread Avi Kivity 

On 03/23/2010 12:51 PM, Avi Kivity wrote:

On 03/17/2010 08:16 PM, Marcelo Tosatti wrote:

On Sun, Mar 14, 2010 at 10:22:52AM +0200, Avi Kivity wrote:

Direct maps are linear translations for a section of memory, used for
real mode or with large pages.  As such, they are independent of the 
guest

levels.

Teach the mmu about this by making page-role.glevels = 0 for direct 
maps.
This allows direct maps to be shared among real mode and the various 
paging

modes.

@@ -1328,6 +1328,8 @@ static struct kvm_mmu_page 
*kvm_mmu_get_page(struct kvm_vcpu *vcpu,

  role = vcpu-arch.mmu.base_role;
  role.level = level;
  role.direct = direct;
+if (role.direct)
+role.glevels = 0;
  role.access = access;
  if (vcpu-arch.mmu.root_level= PT32_ROOT_LEVEL) {
  quadrant = gaddr  (PAGE_SHIFT + (PT64_PT_BITS * level));
--
1.7.0.2

Isnt this what happens already, since for tdp base_role.glevels is not
initialized?


Correct.  I was thinking about the nested npt case, which will use 
role.glevels.  Joerg, please incorporate this into your nnpt patchset.




Actually, incorrect.  This patch is also applicable to non-tdp (which is 
the same case as nnpt).  It will allow reusing real-mode direct maps and 
large page mappings from the various modes.  It won't make any 
performance difference, it's more a documentation aid that direct maps 
aren't dependent on the guest at all, except for permissions.


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error compiling committee.c: too many arguments to function

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Re: [PATCH] KVM: MMU: Disassociate direct maps from guest levels

2010-03-23 Thread Marcelo Tosatti 
On Tue, Mar 23, 2010 at 01:02:35PM +0200, Avi Kivity wrote:
 On 03/23/2010 12:51 PM, Avi Kivity wrote:
 On 03/17/2010 08:16 PM, Marcelo Tosatti wrote:
 On Sun, Mar 14, 2010 at 10:22:52AM +0200, Avi Kivity wrote:
 Direct maps are linear translations for a section of memory, used for
 real mode or with large pages.  As such, they are independent
 of the guest
 levels.
 
 Teach the mmu about this by making page-role.glevels = 0 for
 direct maps.
 This allows direct maps to be shared among real mode and the
 various paging
 modes.
 
 @@ -1328,6 +1328,8 @@ static struct kvm_mmu_page
 *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
   role = vcpu-arch.mmu.base_role;
   role.level = level;
   role.direct = direct;
 +if (role.direct)
 +role.glevels = 0;
   role.access = access;
   if (vcpu-arch.mmu.root_level= PT32_ROOT_LEVEL) {
   quadrant = gaddr  (PAGE_SHIFT + (PT64_PT_BITS * level));
 -- 
 1.7.0.2
 Isnt this what happens already, since for tdp base_role.glevels is not
 initialized?
 
 Correct.  I was thinking about the nested npt case, which will use
 role.glevels.  Joerg, please incorporate this into your nnpt
 patchset.
 
 
 Actually, incorrect.  This patch is also applicable to non-tdp
 (which is the same case as nnpt).  It will allow reusing real-mode
 direct maps and large page mappings from the various modes.  It
 won't make any performance difference, it's more a documentation aid
 that direct maps aren't dependent on the guest at all, except for
 permissions.

Sure, makes sense.

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Re: [PATCH] KVM: MMU: Disassociate direct maps from guest levels

2010-03-17 Thread Marcelo Tosatti 
On Sun, Mar 14, 2010 at 10:22:52AM +0200, Avi Kivity wrote:
 Direct maps are linear translations for a section of memory, used for
 real mode or with large pages.  As such, they are independent of the guest
 levels.
 
 Teach the mmu about this by making page-role.glevels = 0 for direct maps.
 This allows direct maps to be shared among real mode and the various paging
 modes.
 
 Signed-off-by: Avi Kivity a...@redhat.com
 ---
  arch/x86/kvm/mmu.c |2 ++
  1 files changed, 2 insertions(+), 0 deletions(-)
 
 diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
 index b137515..a984bc1 100644
 --- a/arch/x86/kvm/mmu.c
 +++ b/arch/x86/kvm/mmu.c
 @@ -1328,6 +1328,8 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct 
 kvm_vcpu *vcpu,
   role = vcpu-arch.mmu.base_role;
   role.level = level;
   role.direct = direct;
 + if (role.direct)
 + role.glevels = 0;
   role.access = access;
   if (vcpu-arch.mmu.root_level = PT32_ROOT_LEVEL) {
   quadrant = gaddr  (PAGE_SHIFT + (PT64_PT_BITS * level));
 -- 
 1.7.0.2

Isnt this what happens already, since for tdp base_role.glevels is not 
initialized?
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[PATCH] KVM: MMU: Disassociate direct maps from guest levels

2010-03-14 Thread Avi Kivity 
Direct maps are linear translations for a section of memory, used for
real mode or with large pages.  As such, they are independent of the guest
levels.

Teach the mmu about this by making page-role.glevels = 0 for direct maps.
This allows direct maps to be shared among real mode and the various paging
modes.

Signed-off-by: Avi Kivity a...@redhat.com
---
 arch/x86/kvm/mmu.c |2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index b137515..a984bc1 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1328,6 +1328,8 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct 
kvm_vcpu *vcpu,
role = vcpu-arch.mmu.base_role;
role.level = level;
role.direct = direct;
+   if (role.direct)
+   role.glevels = 0;
role.access = access;
if (vcpu-arch.mmu.root_level = PT32_ROOT_LEVEL) {
quadrant = gaddr  (PAGE_SHIFT + (PT64_PT_BITS * level));
-- 
1.7.0.2

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