6 files changed, 81 insertions, 12 deletions

diff --git a/arch/powerpc/include/asm/kvm_book3s.h b/arch/powerpc/include/asm/kvm_book3s.h
index b5b196166455..00cf8b07e502 100644
--- a/arch/powerpc/include/asm/kvm_book3s.h
+++ b/arch/powerpc/include/asm/kvm_book3s.h
@@ -130,6 +130,7 @@ extern void kvmppc_set_bat(struct kvm_vcpu *vcpu, struct kvmppc_bat *bat,
                            bool upper, u32 val);
 extern void kvmppc_giveup_ext(struct kvm_vcpu *vcpu, ulong msr);
 extern int kvmppc_emulate_paired_single(struct kvm_run *run, struct kvm_vcpu *vcpu);
+extern pfn_t kvmppc_gfn_to_pfn(struct kvm_vcpu *vcpu, gfn_t gfn);
 
 extern u32 kvmppc_trampoline_lowmem;
 extern u32 kvmppc_trampoline_enter;
diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index 0ed5376df82c..eee97b5a7400 100644
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -419,6 +419,25 @@ void kvmppc_set_pvr(struct kvm_vcpu *vcpu, u32 pvr)
         }
 }
 
+pfn_t kvmppc_gfn_to_pfn(struct kvm_vcpu *vcpu, gfn_t gfn)
+{
+        ulong mp_pa = vcpu->arch.magic_page_pa;
+
+        /* Magic page override */
+        if (unlikely(mp_pa) &&
+            unlikely(((gfn << PAGE_SHIFT) & KVM_PAM) ==
+                     ((mp_pa & PAGE_MASK) & KVM_PAM))) {
+                ulong shared_page = ((ulong)vcpu->arch.shared) & PAGE_MASK;
+                pfn_t pfn;
+
+                pfn = (pfn_t)virt_to_phys((void*)shared_page) >> PAGE_SHIFT;
+                get_page(pfn_to_page(pfn));
+                return pfn;
+        }
+
+        return gfn_to_pfn(vcpu->kvm, gfn);
+}
+
 /* Book3s_32 CPUs always have 32 bytes cache line size, which Linux assumes. To
  * make Book3s_32 Linux work on Book3s_64, we have to make sure we trap dcbz to
  * emulate 32 bytes dcbz length.
@@ -554,6 +573,13 @@ mmio:
 
 static int kvmppc_visible_gfn(struct kvm_vcpu *vcpu, gfn_t gfn)
 {
+        ulong mp_pa = vcpu->arch.magic_page_pa;
+
+        if (unlikely(mp_pa) &&
+            unlikely((mp_pa & KVM_PAM) >> PAGE_SHIFT == gfn)) {
+                return 1;
+        }
+
         return kvm_is_visible_gfn(vcpu->kvm, gfn);
 }
 
@@ -1257,6 +1283,7 @@ struct kvm_vcpu *kvmppc_core_vcpu_create(struct kvm *kvm, unsigned int id)
         struct kvmppc_vcpu_book3s *vcpu_book3s;
         struct kvm_vcpu *vcpu;
         int err = -ENOMEM;
+        unsigned long p;
 
         vcpu_book3s = vmalloc(sizeof(struct kvmppc_vcpu_book3s));
         if (!vcpu_book3s)
@@ -1274,8 +1301,10 @@ struct kvm_vcpu *kvmppc_core_vcpu_create(struct kvm *kvm, unsigned int id)
         if (err)
                 goto free_shadow_vcpu;
 
-        vcpu->arch.shared = (void*)__get_free_page(GFP_KERNEL|__GFP_ZERO);
-        if (!vcpu->arch.shared)
+        p = __get_free_page(GFP_KERNEL|__GFP_ZERO);
+        /* the real shared page fills the last 4k of our page */
+        vcpu->arch.shared = (void*)(p + PAGE_SIZE - 4096);
+        if (!p)
                 goto uninit_vcpu;
 
         vcpu->arch.host_retip = kvm_return_point;
@@ -1322,7 +1351,7 @@ void kvmppc_core_vcpu_free(struct kvm_vcpu *vcpu)
 {
         struct kvmppc_vcpu_book3s *vcpu_book3s = to_book3s(vcpu);
 
-        free_page((unsigned long)vcpu->arch.shared);
+        free_page((unsigned long)vcpu->arch.shared & PAGE_MASK);
         kvm_vcpu_uninit(vcpu);
         kfree(vcpu_book3s->shadow_vcpu);
         vfree(vcpu_book3s);
diff --git a/arch/powerpc/kvm/book3s_32_mmu.c b/arch/powerpc/kvm/book3s_32_mmu.c
index 449bce5f021a..a7d121adc842 100644
--- a/arch/powerpc/kvm/book3s_32_mmu.c
+++ b/arch/powerpc/kvm/book3s_32_mmu.c
@@ -281,8 +281,24 @@ static int kvmppc_mmu_book3s_32_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
                                       struct kvmppc_pte *pte, bool data)
 {
         int r;
+        ulong mp_ea = vcpu->arch.magic_page_ea;
 
         pte->eaddr = eaddr;
+
+        /* Magic page override */
+        if (unlikely(mp_ea) &&
+            unlikely((eaddr & ~0xfffULL) == (mp_ea & ~0xfffULL)) &&
+            !(vcpu->arch.shared->msr & MSR_PR)) {
+                pte->vpage = kvmppc_mmu_book3s_32_ea_to_vp(vcpu, eaddr, data);
+                pte->raddr = vcpu->arch.magic_page_pa | (pte->raddr & 0xfff);
+                pte->raddr &= KVM_PAM;
+                pte->may_execute = true;
+                pte->may_read = true;
+                pte->may_write = true;
+
+                return 0;
+        }
+
         r = kvmppc_mmu_book3s_32_xlate_bat(vcpu, eaddr, pte, data);
         if (r < 0)
                r = kvmppc_mmu_book3s_32_xlate_pte(vcpu, eaddr, pte, data, true);
diff --git a/arch/powerpc/kvm/book3s_32_mmu_host.c b/arch/powerpc/kvm/book3s_32_mmu_host.c
index 67b8c38d932f..05e8c9eb0e16 100644
--- a/arch/powerpc/kvm/book3s_32_mmu_host.c
+++ b/arch/powerpc/kvm/book3s_32_mmu_host.c
@@ -147,7 +147,7 @@ int kvmppc_mmu_map_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *orig_pte)
         struct hpte_cache *pte;
 
         /* Get host physical address for gpa */
-        hpaddr = gfn_to_pfn(vcpu->kvm, orig_pte->raddr >> PAGE_SHIFT);
+        hpaddr = kvmppc_gfn_to_pfn(vcpu, orig_pte->raddr >> PAGE_SHIFT);
         if (kvm_is_error_hva(hpaddr)) {
                 printk(KERN_INFO "Couldn't get guest page for gfn %lx!\n",
                                  orig_pte->eaddr);
diff --git a/arch/powerpc/kvm/book3s_64_mmu.c b/arch/powerpc/kvm/book3s_64_mmu.c
index 58aa8409dae0..d7889ef3211e 100644
--- a/arch/powerpc/kvm/book3s_64_mmu.c
+++ b/arch/powerpc/kvm/book3s_64_mmu.c
@@ -163,6 +163,22 @@ static int kvmppc_mmu_book3s_64_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
         bool found = false;
         bool perm_err = false;
         int second = 0;
+        ulong mp_ea = vcpu->arch.magic_page_ea;
+
+        /* Magic page override */
+        if (unlikely(mp_ea) &&
+            unlikely((eaddr & ~0xfffULL) == (mp_ea & ~0xfffULL)) &&
+            !(vcpu->arch.shared->msr & MSR_PR)) {
+                gpte->eaddr = eaddr;
+                gpte->vpage = kvmppc_mmu_book3s_64_ea_to_vp(vcpu, eaddr, data);
+                gpte->raddr = vcpu->arch.magic_page_pa | (gpte->raddr & 0xfff);
+                gpte->raddr &= KVM_PAM;
+                gpte->may_execute = true;
+                gpte->may_read = true;
+                gpte->may_write = true;
+
+                return 0;
+        }
 
         slbe = kvmppc_mmu_book3s_64_find_slbe(vcpu_book3s, eaddr);
         if (!slbe)
@@ -445,6 +461,7 @@ static int kvmppc_mmu_book3s_64_esid_to_vsid(struct kvm_vcpu *vcpu, ulong esid,
         ulong ea = esid << SID_SHIFT;
         struct kvmppc_slb *slb;
         u64 gvsid = esid;
+        ulong mp_ea = vcpu->arch.magic_page_ea;
 
         if (vcpu->arch.shared->msr & (MSR_DR|MSR_IR)) {
                 slb = kvmppc_mmu_book3s_64_find_slbe(to_book3s(vcpu), ea);
@@ -464,7 +481,7 @@ static int kvmppc_mmu_book3s_64_esid_to_vsid(struct kvm_vcpu *vcpu, ulong esid,
                 break;
         case MSR_DR|MSR_IR:
                 if (!slb)
-                        return -ENOENT;
+                        goto no_slb;
 
                 *vsid = gvsid;
                 break;
@@ -477,6 +494,17 @@ static int kvmppc_mmu_book3s_64_esid_to_vsid(struct kvm_vcpu *vcpu, ulong esid,
                 *vsid |= VSID_PR;
 
         return 0;
+
+no_slb:
+        /* Catch magic page case */
+        if (unlikely(mp_ea) &&
+            unlikely(esid == (mp_ea >> SID_SHIFT)) &&
+            !(vcpu->arch.shared->msr & MSR_PR)) {
+                *vsid = VSID_REAL | esid;
+                return 0;
+        }
+
+        return -EINVAL;
 }
 
 static bool kvmppc_mmu_book3s_64_is_dcbz32(struct kvm_vcpu *vcpu)
diff --git a/arch/powerpc/kvm/book3s_64_mmu_host.c b/arch/powerpc/kvm/book3s_64_mmu_host.c
index 71c1f9027abb..6cdd19a82bda 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_host.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_host.c
@@ -101,18 +101,13 @@ int kvmppc_mmu_map_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *orig_pte)
         struct kvmppc_sid_map *map;
 
         /* Get host physical address for gpa */
-        hpaddr = gfn_to_pfn(vcpu->kvm, orig_pte->raddr >> PAGE_SHIFT);
+        hpaddr = kvmppc_gfn_to_pfn(vcpu, orig_pte->raddr >> PAGE_SHIFT);
         if (kvm_is_error_hva(hpaddr)) {
                 printk(KERN_INFO "Couldn't get guest page for gfn %lx!\n", orig_pte->eaddr);
                 return -EINVAL;
         }
         hpaddr <<= PAGE_SHIFT;
-#if PAGE_SHIFT == 12
-#elif PAGE_SHIFT == 16
-        hpaddr |= orig_pte->raddr & 0xf000;
-#else
-#error Unknown page size
-#endif
+        hpaddr |= orig_pte->raddr & (~0xfffULL & ~PAGE_MASK);
 
         /* and write the mapping ea -> hpa into the pt */
         vcpu->arch.mmu.esid_to_vsid(vcpu, orig_pte->eaddr >> SID_SHIFT, &vsid);