Re: [PATCH 2/4] KVM/MIPS32: Wrap calls to gfn_to_pfn() with srcu_read_lock/unlock()

2013-05-21 Thread Gleb Natapov 
On Sun, May 19, 2013 at 10:36:32AM -0400, Sanjay Lal wrote:
 
 On May 19, 2013, at 8:52 AM, Gleb Natapov wrote:
 
  On Sat, May 18, 2013 at 06:54:24AM -0700, Sanjay Lal wrote:
  - As suggested by Gleb, wrap calls to gfn_to_pfn() with 
  srcu_read_lock/unlock().
   Memory slots should be acccessed from a SRCU read section.
  - kvm_mips_map_page() now returns an error code to it's callers, instead 
  of calling panic()
  if it cannot find a mapping for a particular gfn.
  
  Signed-off-by: Sanjay Lal sanj...@kymasys.com
  ---
  arch/mips/kvm/kvm_tlb.c | 36 +++-
  1 file changed, 27 insertions(+), 9 deletions(-)
  
  diff --git a/arch/mips/kvm/kvm_tlb.c b/arch/mips/kvm/kvm_tlb.c
  index 89511a9..ab2e9b0 100644
  --- a/arch/mips/kvm/kvm_tlb.c
  +++ b/arch/mips/kvm/kvm_tlb.c
  @@ -16,7 +16,10 @@
  #include linux/mm.h
  #include linux/delay.h
  #include linux/module.h
  +#include linux/bootmem.h
  You haven't answered it when I asked it on v2:
  Is this include still needed now when export of min_low_pfn is not
  longer here?
  
 
 Sorry about that, juggling too many patches, bootmem.h is no longer needed in 
 kvm_tlb.c.  Actually, I thought I had removed it before posting v3.
 
Should I expect new version, or can I just drop this include from the
patch and apply?

--
Gleb.
--
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 2/4] KVM/MIPS32: Wrap calls to gfn_to_pfn() with srcu_read_lock/unlock()

2013-05-21 Thread Sanjay Lal 

On May 21, 2013, at 1:00 AM, Gleb Natapov wrote:

 On Sun, May 19, 2013 at 10:36:32AM -0400, Sanjay Lal wrote:
 
 On May 19, 2013, at 8:52 AM, Gleb Natapov wrote:
 
 On Sat, May 18, 2013 at 06:54:24AM -0700, Sanjay Lal wrote:
 - As suggested by Gleb, wrap calls to gfn_to_pfn() with 
 srcu_read_lock/unlock().
 Memory slots should be acccessed from a SRCU read section.
 - kvm_mips_map_page() now returns an error code to it's callers, instead 
 of calling panic()
 if it cannot find a mapping for a particular gfn.
 
 Signed-off-by: Sanjay Lal sanj...@kymasys.com
 ---
 arch/mips/kvm/kvm_tlb.c | 36 +++-
 1 file changed, 27 insertions(+), 9 deletions(-)
 
 diff --git a/arch/mips/kvm/kvm_tlb.c b/arch/mips/kvm/kvm_tlb.c
 index 89511a9..ab2e9b0 100644
 --- a/arch/mips/kvm/kvm_tlb.c
 +++ b/arch/mips/kvm/kvm_tlb.c
 @@ -16,7 +16,10 @@
 #include linux/mm.h
 #include linux/delay.h
 #include linux/module.h
 +#include linux/bootmem.h
 You haven't answered it when I asked it on v2:
 Is this include still needed now when export of min_low_pfn is not
 longer here?
 
 
 Sorry about that, juggling too many patches, bootmem.h is no longer needed 
 in kvm_tlb.c.  Actually, I thought I had removed it before posting v3.
 
 Should I expect new version, or can I just drop this include from the
 patch and apply?
 
Please drop the include.

Regards
Sanjay


--
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 2/4] KVM/MIPS32: Wrap calls to gfn_to_pfn() with srcu_read_lock/unlock()

2013-05-19 Thread Gleb Natapov 
On Sat, May 18, 2013 at 06:54:24AM -0700, Sanjay Lal wrote:
 - As suggested by Gleb, wrap calls to gfn_to_pfn() with 
 srcu_read_lock/unlock().
   Memory slots should be acccessed from a SRCU read section.
 - kvm_mips_map_page() now returns an error code to it's callers, instead of 
 calling panic()
  if it cannot find a mapping for a particular gfn.
 
 Signed-off-by: Sanjay Lal sanj...@kymasys.com
 ---
  arch/mips/kvm/kvm_tlb.c | 36 +++-
  1 file changed, 27 insertions(+), 9 deletions(-)
 
 diff --git a/arch/mips/kvm/kvm_tlb.c b/arch/mips/kvm/kvm_tlb.c
 index 89511a9..ab2e9b0 100644
 --- a/arch/mips/kvm/kvm_tlb.c
 +++ b/arch/mips/kvm/kvm_tlb.c
 @@ -16,7 +16,10 @@
  #include linux/mm.h
  #include linux/delay.h
  #include linux/module.h
 +#include linux/bootmem.h
You haven't answered it when I asked it on v2:
Is this include still needed now when export of min_low_pfn is not
longer here?

  #include linux/kvm_host.h
 +#include linux/srcu.h
 +
  
  #include asm/cpu.h
  #include asm/bootinfo.h
 @@ -169,21 +172,27 @@ void kvm_mips_dump_shadow_tlbs(struct kvm_vcpu *vcpu)
   }
  }
  
 -static void kvm_mips_map_page(struct kvm *kvm, gfn_t gfn)
 +static int kvm_mips_map_page(struct kvm *kvm, gfn_t gfn)
  {
 + int srcu_idx, err = 0;
   pfn_t pfn;
  
   if (kvm-arch.guest_pmap[gfn] != KVM_INVALID_PAGE)
 - return;
 + return 0;
  
 +srcu_idx = srcu_read_lock(kvm-srcu);
   pfn = kvm_mips_gfn_to_pfn(kvm, gfn);
  
   if (kvm_mips_is_error_pfn(pfn)) {
 - panic(Couldn't get pfn for gfn %# PRIx64 !\n, gfn);
 + kvm_err(Couldn't get pfn for gfn %# PRIx64 !\n, gfn);
 + err = -EFAULT;
 + goto out;
   }
  
   kvm-arch.guest_pmap[gfn] = pfn;
 - return;
 +out:
 + srcu_read_unlock(kvm-srcu, srcu_idx);
 + return err;
  }
  
  /* Translate guest KSEG0 addresses to Host PA */
 @@ -207,7 +216,10 @@ unsigned long 
 kvm_mips_translate_guest_kseg0_to_hpa(struct kvm_vcpu *vcpu,
   gva);
   return KVM_INVALID_PAGE;
   }
 - kvm_mips_map_page(vcpu-kvm, gfn);
 +
 + if (kvm_mips_map_page(vcpu-kvm, gfn)  0)
 + return KVM_INVALID_ADDR;
 +
   return (kvm-arch.guest_pmap[gfn]  PAGE_SHIFT) + offset;
  }
  
 @@ -310,8 +322,11 @@ int kvm_mips_handle_kseg0_tlb_fault(unsigned long 
 badvaddr,
   even = !(gfn  0x1);
   vaddr = badvaddr  (PAGE_MASK  1);
  
 - kvm_mips_map_page(vcpu-kvm, gfn);
 - kvm_mips_map_page(vcpu-kvm, gfn ^ 0x1);
 + if (kvm_mips_map_page(vcpu-kvm, gfn)  0)
 + return -1;
 +
 + if (kvm_mips_map_page(vcpu-kvm, gfn ^ 0x1)  0)
 + return -1;
  
   if (even) {
   pfn0 = kvm-arch.guest_pmap[gfn];
 @@ -389,8 +404,11 @@ kvm_mips_handle_mapped_seg_tlb_fault(struct kvm_vcpu 
 *vcpu,
   pfn0 = 0;
   pfn1 = 0;
   } else {
 - kvm_mips_map_page(kvm, mips3_tlbpfn_to_paddr(tlb-tlb_lo0)  
 PAGE_SHIFT);
 - kvm_mips_map_page(kvm, mips3_tlbpfn_to_paddr(tlb-tlb_lo1)  
 PAGE_SHIFT);
 + if (kvm_mips_map_page(kvm, mips3_tlbpfn_to_paddr(tlb-tlb_lo0) 
  PAGE_SHIFT)  0)
 + return -1;
 +
 + if (kvm_mips_map_page(kvm, mips3_tlbpfn_to_paddr(tlb-tlb_lo1) 
  PAGE_SHIFT)  0)
 + return -1;
  
   pfn0 = kvm-arch.guest_pmap[mips3_tlbpfn_to_paddr(tlb-tlb_lo0) 
  PAGE_SHIFT];
   pfn1 = kvm-arch.guest_pmap[mips3_tlbpfn_to_paddr(tlb-tlb_lo1) 
  PAGE_SHIFT];
 -- 
 1.7.11.3

--
Gleb.
--
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 2/4] KVM/MIPS32: Wrap calls to gfn_to_pfn() with srcu_read_lock/unlock()

2013-05-19 Thread Sanjay Lal 

On May 19, 2013, at 8:52 AM, Gleb Natapov wrote:

 On Sat, May 18, 2013 at 06:54:24AM -0700, Sanjay Lal wrote:
 - As suggested by Gleb, wrap calls to gfn_to_pfn() with 
 srcu_read_lock/unlock().
  Memory slots should be acccessed from a SRCU read section.
 - kvm_mips_map_page() now returns an error code to it's callers, instead of 
 calling panic()
 if it cannot find a mapping for a particular gfn.
 
 Signed-off-by: Sanjay Lal sanj...@kymasys.com
 ---
 arch/mips/kvm/kvm_tlb.c | 36 +++-
 1 file changed, 27 insertions(+), 9 deletions(-)
 
 diff --git a/arch/mips/kvm/kvm_tlb.c b/arch/mips/kvm/kvm_tlb.c
 index 89511a9..ab2e9b0 100644
 --- a/arch/mips/kvm/kvm_tlb.c
 +++ b/arch/mips/kvm/kvm_tlb.c
 @@ -16,7 +16,10 @@
 #include linux/mm.h
 #include linux/delay.h
 #include linux/module.h
 +#include linux/bootmem.h
 You haven't answered it when I asked it on v2:
 Is this include still needed now when export of min_low_pfn is not
 longer here?
 

Sorry about that, juggling too many patches, bootmem.h is no longer needed in 
kvm_tlb.c.  Actually, I thought I had removed it before posting v3.

Regards
Sanjay


--
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

[PATCH 2/4] KVM/MIPS32: Wrap calls to gfn_to_pfn() with srcu_read_lock/unlock()

2013-05-18 Thread Sanjay Lal 
- As suggested by Gleb, wrap calls to gfn_to_pfn() with srcu_read_lock/unlock().
  Memory slots should be acccessed from a SRCU read section.
- kvm_mips_map_page() now returns an error code to it's callers, instead of 
calling panic()
 if it cannot find a mapping for a particular gfn.

Signed-off-by: Sanjay Lal sanj...@kymasys.com
---
 arch/mips/kvm/kvm_tlb.c | 36 +++-
 1 file changed, 27 insertions(+), 9 deletions(-)

diff --git a/arch/mips/kvm/kvm_tlb.c b/arch/mips/kvm/kvm_tlb.c
index 89511a9..ab2e9b0 100644
--- a/arch/mips/kvm/kvm_tlb.c
+++ b/arch/mips/kvm/kvm_tlb.c
@@ -16,7 +16,10 @@
 #include linux/mm.h
 #include linux/delay.h
 #include linux/module.h
+#include linux/bootmem.h
 #include linux/kvm_host.h
+#include linux/srcu.h
+
 
 #include asm/cpu.h
 #include asm/bootinfo.h
@@ -169,21 +172,27 @@ void kvm_mips_dump_shadow_tlbs(struct kvm_vcpu *vcpu)
}
 }
 
-static void kvm_mips_map_page(struct kvm *kvm, gfn_t gfn)
+static int kvm_mips_map_page(struct kvm *kvm, gfn_t gfn)
 {
+   int srcu_idx, err = 0;
pfn_t pfn;
 
if (kvm-arch.guest_pmap[gfn] != KVM_INVALID_PAGE)
-   return;
+   return 0;
 
+srcu_idx = srcu_read_lock(kvm-srcu);
pfn = kvm_mips_gfn_to_pfn(kvm, gfn);
 
if (kvm_mips_is_error_pfn(pfn)) {
-   panic(Couldn't get pfn for gfn %# PRIx64 !\n, gfn);
+   kvm_err(Couldn't get pfn for gfn %# PRIx64 !\n, gfn);
+   err = -EFAULT;
+   goto out;
}
 
kvm-arch.guest_pmap[gfn] = pfn;
-   return;
+out:
+   srcu_read_unlock(kvm-srcu, srcu_idx);
+   return err;
 }
 
 /* Translate guest KSEG0 addresses to Host PA */
@@ -207,7 +216,10 @@ unsigned long kvm_mips_translate_guest_kseg0_to_hpa(struct 
kvm_vcpu *vcpu,
gva);
return KVM_INVALID_PAGE;
}
-   kvm_mips_map_page(vcpu-kvm, gfn);
+
+   if (kvm_mips_map_page(vcpu-kvm, gfn)  0)
+   return KVM_INVALID_ADDR;
+
return (kvm-arch.guest_pmap[gfn]  PAGE_SHIFT) + offset;
 }
 
@@ -310,8 +322,11 @@ int kvm_mips_handle_kseg0_tlb_fault(unsigned long badvaddr,
even = !(gfn  0x1);
vaddr = badvaddr  (PAGE_MASK  1);
 
-   kvm_mips_map_page(vcpu-kvm, gfn);
-   kvm_mips_map_page(vcpu-kvm, gfn ^ 0x1);
+   if (kvm_mips_map_page(vcpu-kvm, gfn)  0)
+   return -1;
+
+   if (kvm_mips_map_page(vcpu-kvm, gfn ^ 0x1)  0)
+   return -1;
 
if (even) {
pfn0 = kvm-arch.guest_pmap[gfn];
@@ -389,8 +404,11 @@ kvm_mips_handle_mapped_seg_tlb_fault(struct kvm_vcpu *vcpu,
pfn0 = 0;
pfn1 = 0;
} else {
-   kvm_mips_map_page(kvm, mips3_tlbpfn_to_paddr(tlb-tlb_lo0)  
PAGE_SHIFT);
-   kvm_mips_map_page(kvm, mips3_tlbpfn_to_paddr(tlb-tlb_lo1)  
PAGE_SHIFT);
+   if (kvm_mips_map_page(kvm, mips3_tlbpfn_to_paddr(tlb-tlb_lo0) 
 PAGE_SHIFT)  0)
+   return -1;
+
+   if (kvm_mips_map_page(kvm, mips3_tlbpfn_to_paddr(tlb-tlb_lo1) 
 PAGE_SHIFT)  0)
+   return -1;
 
pfn0 = kvm-arch.guest_pmap[mips3_tlbpfn_to_paddr(tlb-tlb_lo0) 
 PAGE_SHIFT];
pfn1 = kvm-arch.guest_pmap[mips3_tlbpfn_to_paddr(tlb-tlb_lo1) 
 PAGE_SHIFT];
-- 
1.7.11.3

--
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