[PATCH] powerpc-kvm: fixing page alignment for TCE

[Alexey Kardashevskiy]

From: Paul Mackerras pau...@samba.org

TODO: ask Paul to make a proper message.

This is the fix for a host kernel compiled with a page size
other than 4K (TCE page size). In the case of a 64K page size,
the host used to lose address bits in hpte_rpn().
The patch fixes it.

Signed-off-by: Alexey Kardashevskiy a...@ozlabs.ru
---
 arch/powerpc/kvm/book3s_64_mmu_hv.c |9 -
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c 
b/arch/powerpc/kvm/book3s_64_mmu_hv.c
index 80a5775..a41f11b 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_hv.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c
@@ -503,7 +503,7 @@ int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct 
kvm_vcpu *vcpu,
struct kvm *kvm = vcpu-kvm;
unsigned long *hptep, hpte[3], r;
unsigned long mmu_seq, psize, pte_size;
-   unsigned long gfn, hva, pfn;
+   unsigned long gpa, gfn, hva, pfn;
struct kvm_memory_slot *memslot;
unsigned long *rmap;
struct revmap_entry *rev;
@@ -541,15 +541,14 @@ int kvmppc_book3s_hv_page_fault(struct kvm_run *run, 
struct kvm_vcpu *vcpu,
 
/* Translate the logical address and get the page */
psize = hpte_page_size(hpte[0], r);
-   gfn = hpte_rpn(r, psize);
+   gpa = (r  HPTE_R_RPN  ~(psize - 1)) | (ea  (psize - 1));
+   gfn = gpa  PAGE_SHIFT;
memslot = gfn_to_memslot(kvm, gfn);
 
/* No memslot means it's an emulated MMIO region */
-   if (!memslot || (memslot-flags  KVM_MEMSLOT_INVALID)) {
-   unsigned long gpa = (gfn  PAGE_SHIFT) | (ea  (psize - 1));
+   if (!memslot || (memslot-flags  KVM_MEMSLOT_INVALID))
return kvmppc_hv_emulate_mmio(run, vcpu, gpa, ea,
  dsisr  DSISR_ISSTORE);
-   }
 
if (!kvm-arch.using_mmu_notifiers)
return -EFAULT; /* should never get here */
-- 
1.7.10.4

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Re: [PATCH 6/6] powerpc/booke64: restore VDSO information on critical exception

[Benjamin Herrenschmidt]

On Mon, 2012-08-06 at 16:27 +0300, Mihai Caraman wrote:
 Critical exception handler on 64-bit booke uses user-visible SPRG3 as scratch.
 Restore VDSO information in SPRG3 on exception prolog.

Breaks the build on !BOOKE because of :

 diff --git a/arch/powerpc/kernel/vdso.c b/arch/powerpc/kernel/vdso.c
 index b67db22..a0b0d08 100644
 --- a/arch/powerpc/kernel/vdso.c
 +++ b/arch/powerpc/kernel/vdso.c
 @@ -725,6 +725,8 @@ int __cpuinit vdso_getcpu_init(void)
   mtspr(SPRN_SPRG3, val);
  #ifdef CONFIG_KVM_BOOK3S_HANDLER
   get_paca()-kvm_hstate.sprg3 = val;
 +#elif CONFIG_PPC_BOOK3E


You can't #elif a CONFIG option.

 + get_paca()-sprg3 = val;
  #endif
  
   put_cpu();

Now, my suggestion is to actually move the bloody thing out of
kvm_hstate on server as well, just make it a common sprg3 field
accross the board.

I'm dropping this one patch (the other ones seem fine so far and will
land in next soon unless I find another problem).

Cheers,
Ben.


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