Re: [PATCH 3/3] add support for change_pte mmu notifiers

2009-09-24 Thread Marcelo Tosatti 
On Wed, Sep 23, 2009 at 09:47:18PM +0300, Izik Eidus wrote:
 this is needed for kvm if it want ksm to directly map pages into its
 shadow page tables.
 
 Signed-off-by: Izik Eidus iei...@redhat.com
 ---
  arch/x86/include/asm/kvm_host.h |1 +
  arch/x86/kvm/mmu.c  |   62 +-
  virt/kvm/kvm_main.c |   14 +
  3 files changed, 68 insertions(+), 9 deletions(-)
 
 diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
 index 3be0004..d838922 100644
 --- a/arch/x86/include/asm/kvm_host.h
 +++ b/arch/x86/include/asm/kvm_host.h
 @@ -796,6 +796,7 @@ asmlinkage void kvm_handle_fault_on_reboot(void);
  #define KVM_ARCH_WANT_MMU_NOTIFIER
  int kvm_unmap_hva(struct kvm *kvm, unsigned long hva);
  int kvm_age_hva(struct kvm *kvm, unsigned long hva);
 +void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte);
  int cpuid_maxphyaddr(struct kvm_vcpu *vcpu);
  int kvm_cpu_has_interrupt(struct kvm_vcpu *vcpu);
  int kvm_arch_interrupt_allowed(struct kvm_vcpu *vcpu);
 diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
 index 5cd8b4e..ceec065 100644
 --- a/arch/x86/kvm/mmu.c
 +++ b/arch/x86/kvm/mmu.c
 @@ -748,7 +748,7 @@ static int rmap_write_protect(struct kvm *kvm, u64 gfn)
   return write_protected;
  }
  
 -static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp)
 +static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp, u64 data)
  {
   u64 *spte;
   int need_tlb_flush = 0;
 @@ -763,8 +763,45 @@ static int kvm_unmap_rmapp(struct kvm *kvm, unsigned 
 long *rmapp)
   return need_tlb_flush;
  }
  
 -static int kvm_handle_hva(struct kvm *kvm, unsigned long hva,
 -   int (*handler)(struct kvm *kvm, unsigned long *rmapp))
 +static int kvm_set_pte_rmapp(struct kvm *kvm, unsigned long *rmapp, u64 data)
 +{
 + int need_flush = 0;
 + u64 *spte, new_spte;
 + pte_t *ptep = (pte_t *)data;
 + pfn_t new_pfn;
 +
 + WARN_ON(pte_huge(*ptep));
 + new_pfn = pte_pfn(*ptep);
 + spte = rmap_next(kvm, rmapp, NULL);
 + while (spte) {
 + BUG_ON(!is_shadow_present_pte(*spte));
 + rmap_printk(kvm_set_pte_rmapp: spte %p %llx\n, spte, *spte);
 + need_flush = 1;
 + if (pte_write(*ptep)) {
 + rmap_remove(kvm, spte);
 + __set_spte(spte, shadow_trap_nonpresent_pte);
 + spte = rmap_next(kvm, rmapp, NULL);
 + } else {
 + new_spte = *spte ~ (PT64_BASE_ADDR_MASK);
 + new_spte |= new_pfn  PAGE_SHIFT;

new_spte |= (u64)new_pfn  PAGE_SHIFT;

Otherwise looks good to me.

 + new_spte = ~PT_WRITABLE_MASK;
 + new_spte = ~SPTE_HOST_WRITEABLE;
 + if (is_writeble_pte(*spte))
 + kvm_set_pfn_dirty(spte_to_pfn(*spte));
 + __set_spte(spte, new_spte);
 + spte = rmap_next(kvm, rmapp, spte);
 + }
 + }
 + if (need_flush)
 + kvm_flush_remote_tlbs(kvm);
 +
 + return 0;
 +}
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[PATCH 3/3] add support for change_pte mmu notifiers

2009-09-23 Thread Izik Eidus 
this is needed for kvm if it want ksm to directly map pages into its
shadow page tables.

Signed-off-by: Izik Eidus iei...@redhat.com
---
 arch/x86/include/asm/kvm_host.h |1 +
 arch/x86/kvm/mmu.c  |   64 +-
 virt/kvm/kvm_main.c |   14 
 3 files changed, 70 insertions(+), 9 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 3be0004..d838922 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -796,6 +796,7 @@ asmlinkage void kvm_handle_fault_on_reboot(void);
 #define KVM_ARCH_WANT_MMU_NOTIFIER
 int kvm_unmap_hva(struct kvm *kvm, unsigned long hva);
 int kvm_age_hva(struct kvm *kvm, unsigned long hva);
+void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte);
 int cpuid_maxphyaddr(struct kvm_vcpu *vcpu);
 int kvm_cpu_has_interrupt(struct kvm_vcpu *vcpu);
 int kvm_arch_interrupt_allowed(struct kvm_vcpu *vcpu);
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 5cd8b4e..0905ca2 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -748,7 +748,7 @@ static int rmap_write_protect(struct kvm *kvm, u64 gfn)
return write_protected;
 }
 
-static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp)
+static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp, u64 data)
 {
u64 *spte;
int need_tlb_flush = 0;
@@ -763,8 +763,47 @@ static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long 
*rmapp)
return need_tlb_flush;
 }
 
-static int kvm_handle_hva(struct kvm *kvm, unsigned long hva,
- int (*handler)(struct kvm *kvm, unsigned long *rmapp))
+static int kvm_set_pte_rmapp(struct kvm *kvm, unsigned long *rmapp, u64 data)
+{
+   int need_flush = 0;
+   u64 *spte, new_spte;
+   pte_t *ptep = (pte_t *)data;
+   pfn_t new_pfn;
+
+   WARN_ON(pte_huge(*ptep));
+   new_pfn = pte_pfn(*ptep);
+   spte = rmap_next(kvm, rmapp, NULL);
+   while (spte) {
+   BUG_ON(!is_shadow_present_pte(*spte));
+   rmap_printk(kvm_set_pte_rmapp: spte %p %llx\n, spte, *spte);
+   need_flush = 1;
+   if (pte_write(*ptep)) {
+   rmap_remove(kvm, spte);
+   __set_spte(spte, shadow_trap_nonpresent_pte);
+   spte = rmap_next(kvm, rmapp, NULL);
+   } else {
+   new_spte = *spte ~ (PT64_BASE_ADDR_MASK);
+   new_spte |= new_pfn  PAGE_SHIFT;
+
+   if (!pte_write(*ptep)) {
+   new_spte = ~PT_WRITABLE_MASK;
+   new_spte = ~SPTE_HOST_WRITEABLE;
+   if (is_writeble_pte(*spte))
+   kvm_set_pfn_dirty(spte_to_pfn(*spte));
+   }
+   __set_spte(spte, new_spte);
+   spte = rmap_next(kvm, rmapp, spte);
+   }
+   }
+   if (need_flush)
+   kvm_flush_remote_tlbs(kvm);
+
+   return 0;
+}
+
+static int kvm_handle_hva(struct kvm *kvm, unsigned long hva, u64 data,
+ int (*handler)(struct kvm *kvm, unsigned long *rmapp,
+u64 data))
 {
int i, j;
int retval = 0;
@@ -786,13 +825,15 @@ static int kvm_handle_hva(struct kvm *kvm, unsigned long 
hva,
if (hva = start  hva  end) {
gfn_t gfn_offset = (hva - start)  PAGE_SHIFT;
 
-   retval |= handler(kvm, memslot-rmap[gfn_offset]);
+   retval |= handler(kvm, memslot-rmap[gfn_offset],
+ data);
 
for (j = 0; j  KVM_NR_PAGE_SIZES - 1; ++j) {
int idx = gfn_offset;
idx /= KVM_PAGES_PER_HPAGE(PT_DIRECTORY_LEVEL + 
j);
retval |= handler(kvm,
-   memslot-lpage_info[j][idx].rmap_pde);
+   memslot-lpage_info[j][idx].rmap_pde,
+   data);
}
}
}
@@ -802,10 +843,15 @@ static int kvm_handle_hva(struct kvm *kvm, unsigned long 
hva,
 
 int kvm_unmap_hva(struct kvm *kvm, unsigned long hva)
 {
-   return kvm_handle_hva(kvm, hva, kvm_unmap_rmapp);
+   return kvm_handle_hva(kvm, hva, 0, kvm_unmap_rmapp);
+}
+
+void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte)
+{
+   kvm_handle_hva(kvm, hva, (u64)pte, kvm_set_pte_rmapp);
 }
 
-static int kvm_age_rmapp(struct kvm *kvm, unsigned long *rmapp)
+static int kvm_age_rmapp(struct kvm *kvm, unsigned long *rmapp, u64 data)
 {
u64 *spte;
int young = 0;
@@ -841,13 +887,13 @@ static void rmap_recycle(struct kvm_vcpu *vcpu, u64 
*spte, gfn_t gfn)

Re: [PATCH 3/3] add support for change_pte mmu notifiers

2009-09-23 Thread Izik Eidus 

Izik Eidus wrote:

this is needed for kvm if it want ksm to directly map pages into its
shadow page tables.

Signed-off-by: Izik Eidus iei...@redhat.com
---
 arch/x86/include/asm/kvm_host.h |1 +
 arch/x86/kvm/mmu.c  |   64 +-
 virt/kvm/kvm_main.c |   14 
 3 files changed, 70 insertions(+), 9 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 3be0004..d838922 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -796,6 +796,7 @@ asmlinkage void kvm_handle_fault_on_reboot(void);
 #define KVM_ARCH_WANT_MMU_NOTIFIER
 int kvm_unmap_hva(struct kvm *kvm, unsigned long hva);
 int kvm_age_hva(struct kvm *kvm, unsigned long hva);
+void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte);
 int cpuid_maxphyaddr(struct kvm_vcpu *vcpu);
 int kvm_cpu_has_interrupt(struct kvm_vcpu *vcpu);
 int kvm_arch_interrupt_allowed(struct kvm_vcpu *vcpu);
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 5cd8b4e..0905ca2 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -748,7 +748,7 @@ static int rmap_write_protect(struct kvm *kvm, u64 gfn)
return write_protected;
 }
 
-static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp)

+static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp, u64 data)
 {
u64 *spte;
int need_tlb_flush = 0;
@@ -763,8 +763,47 @@ static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long 
*rmapp)
return need_tlb_flush;
 }
 
-static int kvm_handle_hva(struct kvm *kvm, unsigned long hva,

- int (*handler)(struct kvm *kvm, unsigned long *rmapp))
+static int kvm_set_pte_rmapp(struct kvm *kvm, unsigned long *rmapp, u64 data)
+{
+   int need_flush = 0;
+   u64 *spte, new_spte;
+   pte_t *ptep = (pte_t *)data;
+   pfn_t new_pfn;
+
+   WARN_ON(pte_huge(*ptep));
+   new_pfn = pte_pfn(*ptep);
+   spte = rmap_next(kvm, rmapp, NULL);
+   while (spte) {
+   BUG_ON(!is_shadow_present_pte(*spte));
+   rmap_printk(kvm_set_pte_rmapp: spte %p %llx\n, spte, *spte);
+   need_flush = 1;
+   if (pte_write(*ptep)) {
+   rmap_remove(kvm, spte);
+   __set_spte(spte, shadow_trap_nonpresent_pte);
+   spte = rmap_next(kvm, rmapp, NULL);
+   } else {
+   new_spte = *spte ~ (PT64_BASE_ADDR_MASK);
+   new_spte |= new_pfn  PAGE_SHIFT;
+
+   if (!pte_write(*ptep)) {
  


Just noticed that this if is not needed (we got to get here if we had 
if (pte_write(*ptep)) { few lines before...)..

I will resend

+   new_spte = ~PT_WRITABLE_MASK;
+   new_spte = ~SPTE_HOST_WRITEABLE;
+   if (is_writeble_pte(*spte))
+   kvm_set_pfn_dirty(spte_to_pfn(*spte));
+   }
+   __set_spte(spte, new_spte);
+   spte = rmap_next(kvm, rmapp, spte);
+   }
+   }
+   if (need_flush)
+   kvm_flush_remote_tlbs(kvm);
+


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[PATCH 3/3] add support for change_pte mmu notifiers

2009-09-23 Thread Izik Eidus 
this is needed for kvm if it want ksm to directly map pages into its
shadow page tables.

Signed-off-by: Izik Eidus iei...@redhat.com
---
 arch/x86/include/asm/kvm_host.h |1 +
 arch/x86/kvm/mmu.c  |   62 +-
 virt/kvm/kvm_main.c |   14 +
 3 files changed, 68 insertions(+), 9 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 3be0004..d838922 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -796,6 +796,7 @@ asmlinkage void kvm_handle_fault_on_reboot(void);
 #define KVM_ARCH_WANT_MMU_NOTIFIER
 int kvm_unmap_hva(struct kvm *kvm, unsigned long hva);
 int kvm_age_hva(struct kvm *kvm, unsigned long hva);
+void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte);
 int cpuid_maxphyaddr(struct kvm_vcpu *vcpu);
 int kvm_cpu_has_interrupt(struct kvm_vcpu *vcpu);
 int kvm_arch_interrupt_allowed(struct kvm_vcpu *vcpu);
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 5cd8b4e..ceec065 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -748,7 +748,7 @@ static int rmap_write_protect(struct kvm *kvm, u64 gfn)
return write_protected;
 }
 
-static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp)
+static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp, u64 data)
 {
u64 *spte;
int need_tlb_flush = 0;
@@ -763,8 +763,45 @@ static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long 
*rmapp)
return need_tlb_flush;
 }
 
-static int kvm_handle_hva(struct kvm *kvm, unsigned long hva,
- int (*handler)(struct kvm *kvm, unsigned long *rmapp))
+static int kvm_set_pte_rmapp(struct kvm *kvm, unsigned long *rmapp, u64 data)
+{
+   int need_flush = 0;
+   u64 *spte, new_spte;
+   pte_t *ptep = (pte_t *)data;
+   pfn_t new_pfn;
+
+   WARN_ON(pte_huge(*ptep));
+   new_pfn = pte_pfn(*ptep);
+   spte = rmap_next(kvm, rmapp, NULL);
+   while (spte) {
+   BUG_ON(!is_shadow_present_pte(*spte));
+   rmap_printk(kvm_set_pte_rmapp: spte %p %llx\n, spte, *spte);
+   need_flush = 1;
+   if (pte_write(*ptep)) {
+   rmap_remove(kvm, spte);
+   __set_spte(spte, shadow_trap_nonpresent_pte);
+   spte = rmap_next(kvm, rmapp, NULL);
+   } else {
+   new_spte = *spte ~ (PT64_BASE_ADDR_MASK);
+   new_spte |= new_pfn  PAGE_SHIFT;
+
+   new_spte = ~PT_WRITABLE_MASK;
+   new_spte = ~SPTE_HOST_WRITEABLE;
+   if (is_writeble_pte(*spte))
+   kvm_set_pfn_dirty(spte_to_pfn(*spte));
+   __set_spte(spte, new_spte);
+   spte = rmap_next(kvm, rmapp, spte);
+   }
+   }
+   if (need_flush)
+   kvm_flush_remote_tlbs(kvm);
+
+   return 0;
+}
+
+static int kvm_handle_hva(struct kvm *kvm, unsigned long hva, u64 data,
+ int (*handler)(struct kvm *kvm, unsigned long *rmapp,
+u64 data))
 {
int i, j;
int retval = 0;
@@ -786,13 +823,15 @@ static int kvm_handle_hva(struct kvm *kvm, unsigned long 
hva,
if (hva = start  hva  end) {
gfn_t gfn_offset = (hva - start)  PAGE_SHIFT;
 
-   retval |= handler(kvm, memslot-rmap[gfn_offset]);
+   retval |= handler(kvm, memslot-rmap[gfn_offset],
+ data);
 
for (j = 0; j  KVM_NR_PAGE_SIZES - 1; ++j) {
int idx = gfn_offset;
idx /= KVM_PAGES_PER_HPAGE(PT_DIRECTORY_LEVEL + 
j);
retval |= handler(kvm,
-   memslot-lpage_info[j][idx].rmap_pde);
+   memslot-lpage_info[j][idx].rmap_pde,
+   data);
}
}
}
@@ -802,10 +841,15 @@ static int kvm_handle_hva(struct kvm *kvm, unsigned long 
hva,
 
 int kvm_unmap_hva(struct kvm *kvm, unsigned long hva)
 {
-   return kvm_handle_hva(kvm, hva, kvm_unmap_rmapp);
+   return kvm_handle_hva(kvm, hva, 0, kvm_unmap_rmapp);
+}
+
+void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte)
+{
+   kvm_handle_hva(kvm, hva, (u64)pte, kvm_set_pte_rmapp);
 }
 
-static int kvm_age_rmapp(struct kvm *kvm, unsigned long *rmapp)
+static int kvm_age_rmapp(struct kvm *kvm, unsigned long *rmapp, u64 data)
 {
u64 *spte;
int young = 0;
@@ -841,13 +885,13 @@ static void rmap_recycle(struct kvm_vcpu *vcpu, u64 
*spte, gfn_t gfn)
gfn = unalias_gfn(vcpu-kvm, gfn);
rmapp = gfn_to_rmap(vcpu-kvm, gfn, sp-role.level);
 
-

Re: [PATCH 3/3] add support for change_pte mmu notifiers

2009-09-12 Thread Marcelo Tosatti 
On Sat, Sep 12, 2009 at 09:41:10AM +0300, Izik Eidus wrote:
 Marcelo Tosatti wrote:
 On Thu, Sep 10, 2009 at 07:38:58PM +0300, Izik Eidus wrote:
   
 this is needed for kvm if it want ksm to directly map pages into its
 shadow page tables.

 Signed-off-by: Izik Eidus iei...@redhat.com
 ---
  arch/x86/include/asm/kvm_host.h |1 +
  arch/x86/kvm/mmu.c  |   70 
 ++
  virt/kvm/kvm_main.c |   14 
  3 files changed, 77 insertions(+), 8 deletions(-)

 diff --git a/arch/x86/include/asm/kvm_host.h 
 b/arch/x86/include/asm/kvm_host.h
 index 6046e6f..594d131 100644
 --- a/arch/x86/include/asm/kvm_host.h
 +++ b/arch/x86/include/asm/kvm_host.h
 @@ -797,6 +797,7 @@ asmlinkage void kvm_handle_fault_on_reboot(void);
  #define KVM_ARCH_WANT_MMU_NOTIFIER
  int kvm_unmap_hva(struct kvm *kvm, unsigned long hva);
  int kvm_age_hva(struct kvm *kvm, unsigned long hva);
 +void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte);
  int cpuid_maxphyaddr(struct kvm_vcpu *vcpu);
  int kvm_cpu_has_interrupt(struct kvm_vcpu *vcpu);
  int kvm_arch_interrupt_allowed(struct kvm_vcpu *vcpu);
 diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
 index a7151b8..3fd19f2 100644
 --- a/arch/x86/kvm/mmu.c
 +++ b/arch/x86/kvm/mmu.c
 @@ -282,6 +282,11 @@ static pfn_t spte_to_pfn(u64 pte)
 return (pte  PT64_BASE_ADDR_MASK)  PAGE_SHIFT;
  }
  +static pte_t ptep_val(pte_t *ptep)
 +{
 +   return *ptep;
 +}
 +
  static gfn_t pse36_gfn_delta(u32 gpte)
  {
 int shift = 32 - PT32_DIR_PSE36_SHIFT - PAGE_SHIFT;
 @@ -748,7 +753,8 @@ static int rmap_write_protect(struct kvm *kvm, u64 gfn)
 return write_protected;
  }
  -static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp)
 +static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp,
 +  unsigned long data)
  {
 u64 *spte;
 int need_tlb_flush = 0;
 @@ -763,8 +769,48 @@ static int kvm_unmap_rmapp(struct kvm *kvm, unsigned 
 long *rmapp)
 return need_tlb_flush;
  }
  +static int kvm_set_pte_rmapp(struct kvm *kvm, unsigned long *rmapp,
 +unsigned long data)
 +{
 +   int need_flush = 0;
 +   u64 *spte, new_spte;
 +   pte_t *ptep = (pte_t *)data;
 +   pfn_t new_pfn;
 +
 +   new_pfn = pte_pfn(ptep_val(ptep));
 +   spte = rmap_next(kvm, rmapp, NULL);
 +   while (spte) {
 +   BUG_ON(!is_shadow_present_pte(*spte));
 +   rmap_printk(kvm_set_pte_rmapp: spte %p %llx\n, spte, *spte);
 +   need_flush = 1;
 +   if (pte_write(ptep_val(ptep))) {
 +   rmap_remove(kvm, spte);
 +   __set_spte(spte, shadow_trap_nonpresent_pte);
 +   spte = rmap_next(kvm, rmapp, NULL);
 +   } else {
 +   new_spte = *spte ~ (PT64_BASE_ADDR_MASK);
 +   new_spte |= new_pfn  PAGE_SHIFT;
 +
 +   if (!pte_write(ptep_val(ptep))) {
 +   new_spte = ~PT_WRITABLE_MASK;
 +   new_spte = ~SPTE_HOST_WRITEABLE;
 +   if (is_writeble_pte(*spte))
 +   kvm_set_pfn_dirty(spte_to_pfn(*spte));
 +   }
 +   __set_spte(spte, new_spte);
 +   spte = rmap_next(kvm, rmapp, spte);
 +   }
 +   }
 +   if (need_flush)
 +   kvm_flush_remote_tlbs(kvm);
 +
 +   return 0;
 +}
 +
  static int kvm_handle_hva(struct kvm *kvm, unsigned long hva,
 - int (*handler)(struct kvm *kvm, unsigned long *rmapp))
 + unsigned long data,
 + int (*handler)(struct kvm *kvm, unsigned long *rmapp,
 +unsigned long data))
  {
 int i, j;
 int retval = 0;
 @@ -786,13 +832,15 @@ static int kvm_handle_hva(struct kvm *kvm, unsigned 
 long hva,
 if (hva = start  hva  end) {
 gfn_t gfn_offset = (hva - start)  PAGE_SHIFT;
  -  retval |= handler(kvm, memslot-rmap[gfn_offset]);
 +   retval |= handler(kvm, memslot-rmap[gfn_offset],
 + data);
 for (j = 0; j  KVM_NR_PAGE_SIZES - 1; ++j) {
 int idx = gfn_offset;
 idx /= KVM_PAGES_PER_HPAGE(PT_DIRECTORY_LEVEL + 
 j);
 retval |= handler(kvm,
 -   memslot-lpage_info[j][idx].rmap_pde);
 +   memslot-lpage_info[j][idx].rmap_pde,
 +   data);
 

 If change_pte is called to modify a largepage pte, and the shadow has
 that largepage mapped with 4k sptes, you'll set the wrong pfn. That is,
 the patch does not attempt to handle different page sizes properly.

 So either disable change_pte updates to non-4k host vmas (making it
 explictly it does not handle different pagesizes), or handle largepages
 properly,

Re: [PATCH 3/3] add support for change_pte mmu notifiers

2009-09-12 Thread Izik Eidus 

Marcelo Tosatti wrote:

On Sat, Sep 12, 2009 at 09:41:10AM +0300, Izik Eidus wrote:
  

Marcelo Tosatti wrote:


On Thu, Sep 10, 2009 at 07:38:58PM +0300, Izik Eidus wrote:
  
  

this is needed for kvm if it want ksm to directly map pages into its
shadow page tables.

Signed-off-by: Izik Eidus iei...@redhat.com
---
 arch/x86/include/asm/kvm_host.h |1 +
 arch/x86/kvm/mmu.c  |   70 ++
 virt/kvm/kvm_main.c |   14 
 3 files changed, 77 insertions(+), 8 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 6046e6f..594d131 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -797,6 +797,7 @@ asmlinkage void kvm_handle_fault_on_reboot(void);
 #define KVM_ARCH_WANT_MMU_NOTIFIER
 int kvm_unmap_hva(struct kvm *kvm, unsigned long hva);
 int kvm_age_hva(struct kvm *kvm, unsigned long hva);
+void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte);
 int cpuid_maxphyaddr(struct kvm_vcpu *vcpu);
 int kvm_cpu_has_interrupt(struct kvm_vcpu *vcpu);
 int kvm_arch_interrupt_allowed(struct kvm_vcpu *vcpu);
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index a7151b8..3fd19f2 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -282,6 +282,11 @@ static pfn_t spte_to_pfn(u64 pte)
return (pte  PT64_BASE_ADDR_MASK)  PAGE_SHIFT;
 }
 +static pte_t ptep_val(pte_t *ptep)
+{
+   return *ptep;
+}
+
 static gfn_t pse36_gfn_delta(u32 gpte)
 {
int shift = 32 - PT32_DIR_PSE36_SHIFT - PAGE_SHIFT;
@@ -748,7 +753,8 @@ static int rmap_write_protect(struct kvm *kvm, u64 gfn)
return write_protected;
 }
 -static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp)
+static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp,
+  unsigned long data)
 {
u64 *spte;
int need_tlb_flush = 0;
@@ -763,8 +769,48 @@ static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long 
*rmapp)
return need_tlb_flush;
 }
 +static int kvm_set_pte_rmapp(struct kvm *kvm, unsigned long *rmapp,
+unsigned long data)
+{
+   int need_flush = 0;
+   u64 *spte, new_spte;
+   pte_t *ptep = (pte_t *)data;
+   pfn_t new_pfn;
+
+   new_pfn = pte_pfn(ptep_val(ptep));
+   spte = rmap_next(kvm, rmapp, NULL);
+   while (spte) {
+   BUG_ON(!is_shadow_present_pte(*spte));
+   rmap_printk(kvm_set_pte_rmapp: spte %p %llx\n, spte, *spte);
+   need_flush = 1;
+   if (pte_write(ptep_val(ptep))) {
+   rmap_remove(kvm, spte);
+   __set_spte(spte, shadow_trap_nonpresent_pte);
+   spte = rmap_next(kvm, rmapp, NULL);
+   } else {
+   new_spte = *spte ~ (PT64_BASE_ADDR_MASK);
+   new_spte |= new_pfn  PAGE_SHIFT;
+
+   if (!pte_write(ptep_val(ptep))) {
+   new_spte = ~PT_WRITABLE_MASK;
+   new_spte = ~SPTE_HOST_WRITEABLE;
+   if (is_writeble_pte(*spte))
+   kvm_set_pfn_dirty(spte_to_pfn(*spte));
+   }
+   __set_spte(spte, new_spte);
+   spte = rmap_next(kvm, rmapp, spte);
+   }
+   }
+   if (need_flush)
+   kvm_flush_remote_tlbs(kvm);
+
+   return 0;
+}
+
 static int kvm_handle_hva(struct kvm *kvm, unsigned long hva,
- int (*handler)(struct kvm *kvm, unsigned long *rmapp))
+ unsigned long data,
+ int (*handler)(struct kvm *kvm, unsigned long *rmapp,
+unsigned long data))
 {
int i, j;
int retval = 0;
@@ -786,13 +832,15 @@ static int kvm_handle_hva(struct kvm *kvm, unsigned long 
hva,
if (hva = start  hva  end) {
gfn_t gfn_offset = (hva - start)  PAGE_SHIFT;
 -  retval |= handler(kvm, memslot-rmap[gfn_offset]);
+   retval |= handler(kvm, memslot-rmap[gfn_offset],
+ data);
for (j = 0; j  KVM_NR_PAGE_SIZES - 1; ++j) {
int idx = gfn_offset;
idx /= KVM_PAGES_PER_HPAGE(PT_DIRECTORY_LEVEL + 
j);
retval |= handler(kvm,
-   memslot-lpage_info[j][idx].rmap_pde);
+   memslot-lpage_info[j][idx].rmap_pde,
+   data);



If change_pte is called to modify a largepage pte, and the shadow has
that largepage mapped with 4k sptes, you'll set the wrong pfn. That is,
the patch does not attempt to handle different page sizes properly.

Re: [PATCH 3/3] add support for change_pte mmu notifiers

2009-09-12 Thread Marcelo Tosatti 
On Sat, Sep 12, 2009 at 08:04:31PM +0300, Izik Eidus wrote:
 If change_pte is called to modify a largepage pte, and the shadow has
 that largepage mapped with 4k sptes, you'll set the wrong pfn. That is,
 the patch does not attempt to handle different page sizes properly.

 So either disable change_pte updates to non-4k host vmas (making it
 explictly it does not handle different pagesizes), or handle largepages
 properly, although i don't see any use for change_pte or largepage
 mappings?
 
 change_pte doesn't get called on 4k pages...
 So adding commet to this function saying it is working just on 4k 
 pages  would be enough ?
 

 It would be better to fail/WARN on non-4k host ptes (can't it?), but if
 that is not possible i think a comment would be enough.

   
 Ok so you want is_large_pte() check on data right? (and WARN() there..)

pte_huge(pte), yeah.


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[PATCH 3/3] add support for change_pte mmu notifiers

2009-09-10 Thread Izik Eidus 
this is needed for kvm if it want ksm to directly map pages into its
shadow page tables.

Signed-off-by: Izik Eidus iei...@redhat.com
---
 arch/x86/include/asm/kvm_host.h |1 +
 arch/x86/kvm/mmu.c  |   70 ++
 virt/kvm/kvm_main.c |   14 
 3 files changed, 77 insertions(+), 8 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 6046e6f..594d131 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -797,6 +797,7 @@ asmlinkage void kvm_handle_fault_on_reboot(void);
 #define KVM_ARCH_WANT_MMU_NOTIFIER
 int kvm_unmap_hva(struct kvm *kvm, unsigned long hva);
 int kvm_age_hva(struct kvm *kvm, unsigned long hva);
+void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte);
 int cpuid_maxphyaddr(struct kvm_vcpu *vcpu);
 int kvm_cpu_has_interrupt(struct kvm_vcpu *vcpu);
 int kvm_arch_interrupt_allowed(struct kvm_vcpu *vcpu);
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index a7151b8..3fd19f2 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -282,6 +282,11 @@ static pfn_t spte_to_pfn(u64 pte)
return (pte  PT64_BASE_ADDR_MASK)  PAGE_SHIFT;
 }
 
+static pte_t ptep_val(pte_t *ptep)
+{
+   return *ptep;
+}
+
 static gfn_t pse36_gfn_delta(u32 gpte)
 {
int shift = 32 - PT32_DIR_PSE36_SHIFT - PAGE_SHIFT;
@@ -748,7 +753,8 @@ static int rmap_write_protect(struct kvm *kvm, u64 gfn)
return write_protected;
 }
 
-static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp)
+static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp,
+  unsigned long data)
 {
u64 *spte;
int need_tlb_flush = 0;
@@ -763,8 +769,48 @@ static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long 
*rmapp)
return need_tlb_flush;
 }
 
+static int kvm_set_pte_rmapp(struct kvm *kvm, unsigned long *rmapp,
+unsigned long data)
+{
+   int need_flush = 0;
+   u64 *spte, new_spte;
+   pte_t *ptep = (pte_t *)data;
+   pfn_t new_pfn;
+
+   new_pfn = pte_pfn(ptep_val(ptep));
+   spte = rmap_next(kvm, rmapp, NULL);
+   while (spte) {
+   BUG_ON(!is_shadow_present_pte(*spte));
+   rmap_printk(kvm_set_pte_rmapp: spte %p %llx\n, spte, *spte);
+   need_flush = 1;
+   if (pte_write(ptep_val(ptep))) {
+   rmap_remove(kvm, spte);
+   __set_spte(spte, shadow_trap_nonpresent_pte);
+   spte = rmap_next(kvm, rmapp, NULL);
+   } else {
+   new_spte = *spte ~ (PT64_BASE_ADDR_MASK);
+   new_spte |= new_pfn  PAGE_SHIFT;
+
+   if (!pte_write(ptep_val(ptep))) {
+   new_spte = ~PT_WRITABLE_MASK;
+   new_spte = ~SPTE_HOST_WRITEABLE;
+   if (is_writeble_pte(*spte))
+   kvm_set_pfn_dirty(spte_to_pfn(*spte));
+   }
+   __set_spte(spte, new_spte);
+   spte = rmap_next(kvm, rmapp, spte);
+   }
+   }
+   if (need_flush)
+   kvm_flush_remote_tlbs(kvm);
+
+   return 0;
+}
+
 static int kvm_handle_hva(struct kvm *kvm, unsigned long hva,
- int (*handler)(struct kvm *kvm, unsigned long *rmapp))
+ unsigned long data,
+ int (*handler)(struct kvm *kvm, unsigned long *rmapp,
+unsigned long data))
 {
int i, j;
int retval = 0;
@@ -786,13 +832,15 @@ static int kvm_handle_hva(struct kvm *kvm, unsigned long 
hva,
if (hva = start  hva  end) {
gfn_t gfn_offset = (hva - start)  PAGE_SHIFT;
 
-   retval |= handler(kvm, memslot-rmap[gfn_offset]);
+   retval |= handler(kvm, memslot-rmap[gfn_offset],
+ data);
 
for (j = 0; j  KVM_NR_PAGE_SIZES - 1; ++j) {
int idx = gfn_offset;
idx /= KVM_PAGES_PER_HPAGE(PT_DIRECTORY_LEVEL + 
j);
retval |= handler(kvm,
-   memslot-lpage_info[j][idx].rmap_pde);
+   memslot-lpage_info[j][idx].rmap_pde,
+   data);
}
}
}
@@ -802,10 +850,16 @@ static int kvm_handle_hva(struct kvm *kvm, unsigned long 
hva,
 
 int kvm_unmap_hva(struct kvm *kvm, unsigned long hva)
 {
-   return kvm_handle_hva(kvm, hva, kvm_unmap_rmapp);
+   return kvm_handle_hva(kvm, hva, 0, kvm_unmap_rmapp);
+}
+
+void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte)
+{
+