From 6ed1485f65f0eb17aa7b649d5abe0b011b92f718 Mon Sep 17 00:00:00 2001
From: Paul Mackerras <paulus@samba.org>
Date: Sat, 22 Jun 2013 17:14:48 +1000
Subject: [PATCH] KVM: PPC: Book3S PR: Don't keep scanning HPTEG after we find
a match
The loop in kvmppc_mmu_book3s_64_xlate() that looks up a translation
in the guest hashed page table (HPT) keeps going if it finds an
HPTE that matches but doesn't allow access. This is incorrect; it
is different from what the hardware does, and there should never be
more than one matching HPTE anyway. This fixes it to stop when any
matching HPTE is found.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
---
arch/powerpc/kvm/book3s_64_mmu.c | 14 ++------------
1 file changed, 2 insertions(+), 12 deletions(-)
diff --git a/arch/powerpc/kvm/book3s_64_mmu.c b/arch/powerpc/kvm/book3s_64_mmu.c
index b871721c0050..2e93bb50a71c 100644
--- a/arch/powerpc/kvm/book3s_64_mmu.c
+++ b/arch/powerpc/kvm/book3s_64_mmu.c
@@ -167,7 +167,6 @@ static int kvmppc_mmu_book3s_64_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
int i;
u8 key = 0;
bool found = false;
- bool perm_err = false;
int second = 0;
ulong mp_ea = vcpu->arch.magic_page_ea;
@@ -248,11 +247,6 @@ static int kvmppc_mmu_book3s_64_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
break;
}
- if (!gpte->may_read) {
- perm_err = true;
- continue;
- }
-
dprintk("KVM MMU: Translated 0x%lx [0x%llx] -> 0x%llx "
"-> 0x%lx\n",
eaddr, avpn, gpte->vpage, gpte->raddr);
@@ -281,6 +275,8 @@ static int kvmppc_mmu_book3s_64_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
if (pteg[i+1] != oldr)
copy_to_user((void __user *)ptegp, pteg, sizeof(pteg));
+ if (!gpte->may_read)
+ return -EPERM;
return 0;
} else {
dprintk("KVM MMU: No PTE found (ea=0x%lx sdr1=0x%llx "
@@ -296,13 +292,7 @@ static int kvmppc_mmu_book3s_64_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
}
}
-
no_page_found:
-
-
- if (perm_err)
- return -EPERM;
-
return -ENOENT;
no_seg_found: