4 files changed, 103 insertions, 46 deletions

diff --git a/arch/powerpc/include/asm/kvm_book3s_64.h b/arch/powerpc/include/asm/kvm_book3s_64.h
index 2054e4726ba2..fa3dc79af702 100644
--- a/arch/powerpc/include/asm/kvm_book3s_64.h
+++ b/arch/powerpc/include/asm/kvm_book3s_64.h
@@ -35,6 +35,14 @@ static inline void svcpu_put(struct kvmppc_book3s_shadow_vcpu *svcpu)
 
 #define SPAPR_TCE_SHIFT         12
 
+#ifdef CONFIG_KVM_BOOK3S_64_HV
+/* For now use fixed-size 16MB page table */
+#define HPT_ORDER       24
+#define HPT_NPTEG       (1ul << (HPT_ORDER - 7))        /* 128B per pteg */
+#define HPT_NPTE        (HPT_NPTEG << 3)                /* 8 PTEs per PTEG */
+#define HPT_HASH_MASK   (HPT_NPTEG - 1)
+#endif
+
 static inline unsigned long compute_tlbie_rb(unsigned long v, unsigned long r,
                                              unsigned long pte_index)
 {
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index 66c75cddaec6..629df2ed22f7 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -166,9 +166,19 @@ struct kvmppc_rma_info {
         atomic_t         use_count;
 };
 
+/*
+ * The reverse mapping array has one entry for each HPTE,
+ * which stores the guest's view of the second word of the HPTE
+ * (including the guest physical address of the mapping).
+ */
+struct revmap_entry {
+        unsigned long guest_rpte;
+};
+
 struct kvm_arch {
 #ifdef CONFIG_KVM_BOOK3S_64_HV
         unsigned long hpt_virt;
+        struct revmap_entry *revmap;
         unsigned long ram_npages;
         unsigned long ram_psize;
         unsigned long ram_porder;
diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c
index bc3a2ea94217..80ece8de4070 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_hv.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c
@@ -23,6 +23,7 @@
 #include <linux/gfp.h>
 #include <linux/slab.h>
 #include <linux/hugetlb.h>
+#include <linux/vmalloc.h>
 
 #include <asm/tlbflush.h>
 #include <asm/kvm_ppc.h>
@@ -33,11 +34,6 @@
 #include <asm/ppc-opcode.h>
 #include <asm/cputable.h>
 
-/* For now use fixed-size 16MB page table */
-#define HPT_ORDER       24
-#define HPT_NPTEG       (1ul << (HPT_ORDER - 7))        /* 128B per pteg */
-#define HPT_HASH_MASK   (HPT_NPTEG - 1)
-
 /* Pages in the VRMA are 16MB pages */
 #define VRMA_PAGE_ORDER 24
 #define VRMA_VSID       0x1ffffffUL     /* 1TB VSID reserved for VRMA */
@@ -51,7 +47,9 @@ long kvmppc_alloc_hpt(struct kvm *kvm)
 {
         unsigned long hpt;
         unsigned long lpid;
+        struct revmap_entry *rev;
 
+        /* Allocate guest's hashed page table */
         hpt = __get_free_pages(GFP_KERNEL|__GFP_ZERO|__GFP_REPEAT|__GFP_NOWARN,
                                HPT_ORDER - PAGE_SHIFT);
         if (!hpt) {
@@ -60,12 +58,20 @@ long kvmppc_alloc_hpt(struct kvm *kvm)
         }
         kvm->arch.hpt_virt = hpt;
 
+        /* Allocate reverse map array */
+        rev = vmalloc(sizeof(struct revmap_entry) * HPT_NPTE);
+        if (!rev) {
+                pr_err("kvmppc_alloc_hpt: Couldn't alloc reverse map array\n");
+                goto out_freehpt;
+        }
+        kvm->arch.revmap = rev;
+
+        /* Allocate the guest's logical partition ID */
         do {
                 lpid = find_first_zero_bit(lpid_inuse, NR_LPIDS);
                 if (lpid >= NR_LPIDS) {
                         pr_err("kvm_alloc_hpt: No LPIDs free\n");
-                        free_pages(hpt, HPT_ORDER - PAGE_SHIFT);
-                        return -ENOMEM;
+                        goto out_freeboth;
                 }
         } while (test_and_set_bit(lpid, lpid_inuse));
 
@@ -74,11 +80,18 @@ long kvmppc_alloc_hpt(struct kvm *kvm)
 
         pr_info("KVM guest htab at %lx, LPID %lx\n", hpt, lpid);
         return 0;
+
+ out_freeboth:
+        vfree(rev);
+ out_freehpt:
+        free_pages(hpt, HPT_ORDER - PAGE_SHIFT);
+        return -ENOMEM;
 }
 
 void kvmppc_free_hpt(struct kvm *kvm)
 {
         clear_bit(kvm->arch.lpid, lpid_inuse);
+        vfree(kvm->arch.revmap);
         free_pages(kvm->arch.hpt_virt, HPT_ORDER - PAGE_SHIFT);
 }
 
@@ -89,14 +102,16 @@ void kvmppc_map_vrma(struct kvm *kvm, struct kvm_userspace_memory_region *mem)
         unsigned long pfn;
         unsigned long *hpte;
         unsigned long hash;
+        unsigned long porder = kvm->arch.ram_porder;
+        struct revmap_entry *rev;
         struct kvmppc_pginfo *pginfo = kvm->arch.ram_pginfo;
 
         if (!pginfo)
                 return;
 
         /* VRMA can't be > 1TB */
-        if (npages > 1ul << (40 - kvm->arch.ram_porder))
-                npages = 1ul << (40 - kvm->arch.ram_porder);
+        if (npages > 1ul << (40 - porder))
+                npages = 1ul << (40 - porder);
         /* Can't use more than 1 HPTE per HPTEG */
         if (npages > HPT_NPTEG)
                 npages = HPT_NPTEG;
@@ -113,15 +128,20 @@ void kvmppc_map_vrma(struct kvm *kvm, struct kvm_userspace_memory_region *mem)
                  * at most one HPTE per HPTEG, we just assume entry 7
                  * is available and use it.
                  */
-                hpte = (unsigned long *) (kvm->arch.hpt_virt + (hash << 7));
-                hpte += 7 * 2;
+                hash = (hash << 3) + 7;
+                hpte = (unsigned long *) (kvm->arch.hpt_virt + (hash << 4));
                 /* HPTE low word - RPN, protection, etc. */
                 hpte[1] = (pfn << PAGE_SHIFT) | HPTE_R_R | HPTE_R_C |
                         HPTE_R_M | PP_RWXX;
-                wmb();
+                smp_wmb();
                 hpte[0] = HPTE_V_1TB_SEG | (VRMA_VSID << (40 - 16)) |
                         (i << (VRMA_PAGE_ORDER - 16)) | HPTE_V_BOLTED |
                         HPTE_V_LARGE | HPTE_V_VALID;
+
+                /* Reverse map info */
+                rev = &kvm->arch.revmap[hash];
+                rev->guest_rpte = (i << porder) | HPTE_R_R | HPTE_R_C |
+                        HPTE_R_M | PP_RWXX;
         }
 }
 
diff --git a/arch/powerpc/kvm/book3s_hv_rm_mmu.c b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
index bacb0cfa3602..614849360a0a 100644
--- a/arch/powerpc/kvm/book3s_hv_rm_mmu.c
+++ b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
@@ -20,10 +20,19 @@
 #include <asm/synch.h>
 #include <asm/ppc-opcode.h>
 
-/* For now use fixed-size 16MB page table */
-#define HPT_ORDER       24
-#define HPT_NPTEG       (1ul << (HPT_ORDER - 7))        /* 128B per pteg */
-#define HPT_HASH_MASK   (HPT_NPTEG - 1)
+/* Translate address of a vmalloc'd thing to a linear map address */
+static void *real_vmalloc_addr(void *x)
+{
+        unsigned long addr = (unsigned long) x;
+        pte_t *p;
+
+        p = find_linux_pte(swapper_pg_dir, addr);
+        if (!p || !pte_present(*p))
+                return NULL;
+        /* assume we don't have huge pages in vmalloc space... */
+        addr = (pte_pfn(*p) << PAGE_SHIFT) | (addr & ~PAGE_MASK);
+        return __va(addr);
+}
 
 #define HPTE_V_HVLOCK   0x40UL
 
@@ -52,6 +61,8 @@ long kvmppc_h_enter(struct kvm_vcpu *vcpu, unsigned long flags,
         struct kvm *kvm = vcpu->kvm;
         unsigned long i, lpn, pa;
         unsigned long *hpte;
+        struct revmap_entry *rev;
+        unsigned long g_ptel = ptel;
 
         /* only handle 4k, 64k and 16M pages for now */
         porder = 12;
@@ -82,7 +93,7 @@ long kvmppc_h_enter(struct kvm_vcpu *vcpu, unsigned long flags,
         pteh &= ~0x60UL;
         ptel &= ~(HPTE_R_PP0 - kvm->arch.ram_psize);
         ptel |= pa;
-        if (pte_index >= (HPT_NPTEG << 3))
+        if (pte_index >= HPT_NPTE)
                 return H_PARAMETER;
         if (likely((flags & H_EXACT) == 0)) {
                 pte_index &= ~7UL;
@@ -95,18 +106,22 @@ long kvmppc_h_enter(struct kvm_vcpu *vcpu, unsigned long flags,
                                 break;
                         hpte += 2;
                 }
+                pte_index += i;
         } else {
-                i = 0;
                 hpte = (unsigned long *)(kvm->arch.hpt_virt + (pte_index << 4));
                 if (!lock_hpte(hpte, HPTE_V_HVLOCK | HPTE_V_VALID))
                         return H_PTEG_FULL;
         }
+
+        /* Save away the guest's idea of the second HPTE dword */
+        rev = real_vmalloc_addr(&kvm->arch.revmap[pte_index]);
+        if (rev)
+                rev->guest_rpte = g_ptel;
         hpte[1] = ptel;
         eieio();
         hpte[0] = pteh;
         asm volatile("ptesync" : : : "memory");
-        atomic_inc(&kvm->arch.ram_pginfo[lpn].refcnt);
-        vcpu->arch.gpr[4] = pte_index + i;
+        vcpu->arch.gpr[4] = pte_index;
         return H_SUCCESS;
 }
 
@@ -138,7 +153,7 @@ long kvmppc_h_remove(struct kvm_vcpu *vcpu, unsigned long flags,
         unsigned long *hpte;
         unsigned long v, r, rb;
 
-        if (pte_index >= (HPT_NPTEG << 3))
+        if (pte_index >= HPT_NPTE)
                 return H_PARAMETER;
         hpte = (unsigned long *)(kvm->arch.hpt_virt + (pte_index << 4));
         while (!lock_hpte(hpte, HPTE_V_HVLOCK))
@@ -193,7 +208,7 @@ long kvmppc_h_bulk_remove(struct kvm_vcpu *vcpu)
                 if (req == 3)
                         break;
                 if (req != 1 || flags == 3 ||
-                    pte_index >= (HPT_NPTEG << 3)) {
+                    pte_index >= HPT_NPTE) {
                         /* parameter error */
                         args[i * 2] = ((0xa0 | flags) << 56) + pte_index;
                         ret = H_PARAMETER;
@@ -256,9 +271,10 @@ long kvmppc_h_protect(struct kvm_vcpu *vcpu, unsigned long flags,
 {
         struct kvm *kvm = vcpu->kvm;
         unsigned long *hpte;
-        unsigned long v, r, rb;
+        struct revmap_entry *rev;
+        unsigned long v, r, rb, mask, bits;
 
-        if (pte_index >= (HPT_NPTEG << 3))
+        if (pte_index >= HPT_NPTE)
                 return H_PARAMETER;
         hpte = (unsigned long *)(kvm->arch.hpt_virt + (pte_index << 4));
         while (!lock_hpte(hpte, HPTE_V_HVLOCK))
@@ -271,11 +287,21 @@ long kvmppc_h_protect(struct kvm_vcpu *vcpu, unsigned long flags,
         if (atomic_read(&kvm->online_vcpus) == 1)
                 flags |= H_LOCAL;
         v = hpte[0];
-        r = hpte[1] & ~(HPTE_R_PP0 | HPTE_R_PP | HPTE_R_N |
-                        HPTE_R_KEY_HI | HPTE_R_KEY_LO);
-        r |= (flags << 55) & HPTE_R_PP0;
-        r |= (flags << 48) & HPTE_R_KEY_HI;
-        r |= flags & (HPTE_R_PP | HPTE_R_N | HPTE_R_KEY_LO);
+        bits = (flags << 55) & HPTE_R_PP0;
+        bits |= (flags << 48) & HPTE_R_KEY_HI;
+        bits |= flags & (HPTE_R_PP | HPTE_R_N | HPTE_R_KEY_LO);
+
+        /* Update guest view of 2nd HPTE dword */
+        mask = HPTE_R_PP0 | HPTE_R_PP | HPTE_R_N |
+                HPTE_R_KEY_HI | HPTE_R_KEY_LO;
+        rev = real_vmalloc_addr(&kvm->arch.revmap[pte_index]);
+        if (rev) {
+                r = (rev->guest_rpte & ~mask) | bits;
+                rev->guest_rpte = r;
+        }
+        r = (hpte[1] & ~mask) | bits;
+
+        /* Update HPTE */
         rb = compute_tlbie_rb(v, r, pte_index);
         hpte[0] = v & ~HPTE_V_VALID;
         if (!(flags & H_LOCAL)) {
@@ -298,38 +324,31 @@ long kvmppc_h_protect(struct kvm_vcpu *vcpu, unsigned long flags,
         return H_SUCCESS;
 }
 
-static unsigned long reverse_xlate(struct kvm *kvm, unsigned long realaddr)
-{
-        long int i;
-        unsigned long offset, rpn;
-
-        offset = realaddr & (kvm->arch.ram_psize - 1);
-        rpn = (realaddr - offset) >> PAGE_SHIFT;
-        for (i = 0; i < kvm->arch.ram_npages; ++i)
-                if (rpn == kvm->arch.ram_pginfo[i].pfn)
-                        return (i << PAGE_SHIFT) + offset;
-        return HPTE_R_RPN;      /* all 1s in the RPN field */
-}
-
 long kvmppc_h_read(struct kvm_vcpu *vcpu, unsigned long flags,
                    unsigned long pte_index)
 {
         struct kvm *kvm = vcpu->kvm;
         unsigned long *hpte, r;
         int i, n = 1;
+        struct revmap_entry *rev = NULL;
 
-        if (pte_index >= (HPT_NPTEG << 3))
+        if (pte_index >= HPT_NPTE)
                 return H_PARAMETER;
         if (flags & H_READ_4) {
                 pte_index &= ~3;
                 n = 4;
         }
+        if (flags & H_R_XLATE)
+                rev = real_vmalloc_addr(&kvm->arch.revmap[pte_index]);
         for (i = 0; i < n; ++i, ++pte_index) {
                 hpte = (unsigned long *)(kvm->arch.hpt_virt + (pte_index << 4));
                 r = hpte[1];
-                if ((flags & H_R_XLATE) && (hpte[0] & HPTE_V_VALID))
-                        r = reverse_xlate(kvm, r & HPTE_R_RPN) |
-                                (r & ~HPTE_R_RPN);
+                if (hpte[0] & HPTE_V_VALID) {
+                        if (rev)
+                                r = rev[i].guest_rpte;
+                        else
+                                r = hpte[1] | HPTE_R_RPN;
+                }
                 vcpu->arch.gpr[4 + i * 2] = hpte[0];
                 vcpu->arch.gpr[5 + i * 2] = r;
         }