10 files changed, 200 insertions, 54 deletions

diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index 930126698a0f..310fe508d9cd 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -1930,6 +1930,42 @@ The "pte_enc" field provides a value that can OR'ed into the hash
 PTE's RPN field (ie, it needs to be shifted left by 12 to OR it
 into the hash PTE second double word).
 
+
+4.75 KVM_PPC_ALLOCATE_HTAB
+
+Capability: KVM_CAP_PPC_ALLOC_HTAB
+Architectures: powerpc
+Type: vm ioctl
+Parameters: Pointer to u32 containing hash table order (in/out)
+Returns: 0 on success, -1 on error
+
+This requests the host kernel to allocate an MMU hash table for a
+guest using the PAPR paravirtualization interface.  This only does
+anything if the kernel is configured to use the Book 3S HV style of
+virtualization.  Otherwise the capability doesn't exist and the ioctl
+returns an ENOTTY error.  The rest of this description assumes Book 3S
+HV.
+
+There must be no vcpus running when this ioctl is called; if there
+are, it will do nothing and return an EBUSY error.
+
+The parameter is a pointer to a 32-bit unsigned integer variable
+containing the order (log base 2) of the desired size of the hash
+table, which must be between 18 and 46.  On successful return from the
+ioctl, it will have been updated with the order of the hash table that
+was allocated.
+
+If no hash table has been allocated when any vcpu is asked to run
+(with the KVM_RUN ioctl), the host kernel will allocate a
+default-sized hash table (16 MB).
+
+If this ioctl is called when a hash table has already been allocated,
+the kernel will clear out the existing hash table (zero all HPTEs) and
+return the hash table order in the parameter.  (If the guest is using
+the virtualized real-mode area (VRMA) facility, the kernel will
+re-create the VMRA HPTEs on the next KVM_RUN of any vcpu.)
+
+
 5. The kvm_run structure
 ------------------------
 
diff --git a/arch/powerpc/include/asm/kvm_book3s_64.h b/arch/powerpc/include/asm/kvm_book3s_64.h
index b0c08b142770..0dd1d86d3e31 100644
--- a/arch/powerpc/include/asm/kvm_book3s_64.h
+++ b/arch/powerpc/include/asm/kvm_book3s_64.h
@@ -36,11 +36,8 @@ 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)
+#define KVM_DEFAULT_HPT_ORDER   24      /* 16MB HPT by default */
+extern int kvm_hpt_order;               /* order of preallocated HPTs */
 #endif
 
 #define VRMA_VSID       0x1ffffffUL     /* 1TB VSID reserved for VRMA */
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index d848cdc49715..dd783beb88b3 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -237,6 +237,10 @@ struct kvm_arch {
         unsigned long vrma_slb_v;
         int rma_setup_done;
         int using_mmu_notifiers;
+        u32 hpt_order;
+        atomic_t vcpus_running;
+        unsigned long hpt_npte;
+        unsigned long hpt_mask;
         spinlock_t slot_phys_lock;
         unsigned long *slot_phys[KVM_MEM_SLOTS_NUM];
         int slot_npages[KVM_MEM_SLOTS_NUM];
diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index f68c22fa2fce..0124937a23b9 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -119,7 +119,8 @@ extern void kvmppc_core_destroy_mmu(struct kvm_vcpu *vcpu);
 extern int kvmppc_kvm_pv(struct kvm_vcpu *vcpu);
 extern void kvmppc_map_magic(struct kvm_vcpu *vcpu);
 
-extern long kvmppc_alloc_hpt(struct kvm *kvm);
+extern long kvmppc_alloc_hpt(struct kvm *kvm, u32 *htab_orderp);
+extern long kvmppc_alloc_reset_hpt(struct kvm *kvm, u32 *htab_orderp);
 extern void kvmppc_free_hpt(struct kvm *kvm);
 extern long kvmppc_prepare_vrma(struct kvm *kvm,
                                 struct kvm_userspace_memory_region *mem);
diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c
index 80a577517584..d03eb6f7b058 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_hv.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c
@@ -37,56 +37,121 @@
 /* POWER7 has 10-bit LPIDs, PPC970 has 6-bit LPIDs */
 #define MAX_LPID_970    63
 
-long kvmppc_alloc_hpt(struct kvm *kvm)
+/* Power architecture requires HPT is at least 256kB */
+#define PPC_MIN_HPT_ORDER       18
+
+long kvmppc_alloc_hpt(struct kvm *kvm, u32 *htab_orderp)
 {
         unsigned long hpt;
-        long lpid;
         struct revmap_entry *rev;
         struct kvmppc_linear_info *li;
+        long order = kvm_hpt_order;
 
-        /* Allocate guest's hashed page table */
-        li = kvm_alloc_hpt();
-        if (li) {
-                /* using preallocated memory */
-                hpt = (ulong)li->base_virt;
-                kvm->arch.hpt_li = li;
-        } else {
-                /* using dynamic memory */
+        if (htab_orderp) {
+                order = *htab_orderp;
+                if (order < PPC_MIN_HPT_ORDER)
+                        order = PPC_MIN_HPT_ORDER;
+        }
+
+        /*
+         * If the user wants a different size from default,
+         * try first to allocate it from the kernel page allocator.
+         */
+        hpt = 0;
+        if (order != kvm_hpt_order) {
                 hpt = __get_free_pages(GFP_KERNEL|__GFP_ZERO|__GFP_REPEAT|
-                                       __GFP_NOWARN, HPT_ORDER - PAGE_SHIFT);
+                                       __GFP_NOWARN, order - PAGE_SHIFT);
+                if (!hpt)
+                        --order;
         }
 
+        /* Next try to allocate from the preallocated pool */
         if (!hpt) {
-                pr_err("kvm_alloc_hpt: Couldn't alloc HPT\n");
-                return -ENOMEM;
+                li = kvm_alloc_hpt();
+                if (li) {
+                        hpt = (ulong)li->base_virt;
+                        kvm->arch.hpt_li = li;
+                        order = kvm_hpt_order;
+                }
         }
+
+        /* Lastly try successively smaller sizes from the page allocator */
+        while (!hpt && order > PPC_MIN_HPT_ORDER) {
+                hpt = __get_free_pages(GFP_KERNEL|__GFP_ZERO|__GFP_REPEAT|
+                                       __GFP_NOWARN, order - PAGE_SHIFT);
+                if (!hpt)
+                        --order;
+        }
+
+        if (!hpt)
+                return -ENOMEM;
+
         kvm->arch.hpt_virt = hpt;
+        kvm->arch.hpt_order = order;
+        /* HPTEs are 2**4 bytes long */
+        kvm->arch.hpt_npte = 1ul << (order - 4);
+        /* 128 (2**7) bytes in each HPTEG */
+        kvm->arch.hpt_mask = (1ul << (order - 7)) - 1;
 
         /* Allocate reverse map array */
-        rev = vmalloc(sizeof(struct revmap_entry) * HPT_NPTE);
+        rev = vmalloc(sizeof(struct revmap_entry) * kvm->arch.hpt_npte);
         if (!rev) {
                 pr_err("kvmppc_alloc_hpt: Couldn't alloc reverse map array\n");
                 goto out_freehpt;
         }
         kvm->arch.revmap = rev;
+        kvm->arch.sdr1 = __pa(hpt) | (order - 18);
 
-        lpid = kvmppc_alloc_lpid();
-        if (lpid < 0)
-                goto out_freeboth;
+        pr_info("KVM guest htab at %lx (order %ld), LPID %x\n",
+                hpt, order, kvm->arch.lpid);
 
-        kvm->arch.sdr1 = __pa(hpt) | (HPT_ORDER - 18);
-        kvm->arch.lpid = lpid;
-
-        pr_info("KVM guest htab at %lx, LPID %lx\n", hpt, lpid);
+        if (htab_orderp)
+                *htab_orderp = order;
         return 0;
 
- out_freeboth:
-        vfree(rev);
  out_freehpt:
-        free_pages(hpt, HPT_ORDER - PAGE_SHIFT);
+        if (kvm->arch.hpt_li)
+                kvm_release_hpt(kvm->arch.hpt_li);
+        else
+                free_pages(hpt, order - PAGE_SHIFT);
         return -ENOMEM;
 }
 
+long kvmppc_alloc_reset_hpt(struct kvm *kvm, u32 *htab_orderp)
+{
+        long err = -EBUSY;
+        long order;
+
+        mutex_lock(&kvm->lock);
+        if (kvm->arch.rma_setup_done) {
+                kvm->arch.rma_setup_done = 0;
+                /* order rma_setup_done vs. vcpus_running */
+                smp_mb();
+                if (atomic_read(&kvm->arch.vcpus_running)) {
+                        kvm->arch.rma_setup_done = 1;
+                        goto out;
+                }
+        }
+        if (kvm->arch.hpt_virt) {
+                order = kvm->arch.hpt_order;
+                /* Set the entire HPT to 0, i.e. invalid HPTEs */
+                memset((void *)kvm->arch.hpt_virt, 0, 1ul << order);
+                /*
+                 * Set the whole last_vcpu array to an invalid vcpu number.
+                 * This ensures that each vcpu will flush its TLB on next entry.
+                 */
+                memset(kvm->arch.last_vcpu, 0xff, sizeof(kvm->arch.last_vcpu));
+                *htab_orderp = order;
+                err = 0;
+        } else {
+                err = kvmppc_alloc_hpt(kvm, htab_orderp);
+                order = *htab_orderp;
+        }
+ out:
+        mutex_unlock(&kvm->lock);
+        return err;
+}
+
 void kvmppc_free_hpt(struct kvm *kvm)
 {
         kvmppc_free_lpid(kvm->arch.lpid);
@@ -94,7 +159,8 @@ void kvmppc_free_hpt(struct kvm *kvm)
         if (kvm->arch.hpt_li)
                 kvm_release_hpt(kvm->arch.hpt_li);
         else
-                free_pages(kvm->arch.hpt_virt, HPT_ORDER - PAGE_SHIFT);
+                free_pages(kvm->arch.hpt_virt,
+                           kvm->arch.hpt_order - PAGE_SHIFT);
 }
 
 /* Bits in first HPTE dword for pagesize 4k, 64k or 16M */
@@ -119,6 +185,7 @@ void kvmppc_map_vrma(struct kvm_vcpu *vcpu, struct kvm_memory_slot *memslot,
         unsigned long psize;
         unsigned long hp0, hp1;
         long ret;
+        struct kvm *kvm = vcpu->kvm;
 
         psize = 1ul << porder;
         npages = memslot->npages >> (porder - PAGE_SHIFT);
@@ -127,8 +194,8 @@ void kvmppc_map_vrma(struct kvm_vcpu *vcpu, struct kvm_memory_slot *memslot,
         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;
+        if (npages > kvm->arch.hpt_mask + 1)
+                npages = kvm->arch.hpt_mask + 1;
 
         hp0 = HPTE_V_1TB_SEG | (VRMA_VSID << (40 - 16)) |
                 HPTE_V_BOLTED | hpte0_pgsize_encoding(psize);
@@ -138,7 +205,7 @@ void kvmppc_map_vrma(struct kvm_vcpu *vcpu, struct kvm_memory_slot *memslot,
         for (i = 0; i < npages; ++i) {
                 addr = i << porder;
                 /* can't use hpt_hash since va > 64 bits */
-                hash = (i ^ (VRMA_VSID ^ (VRMA_VSID << 25))) & HPT_HASH_MASK;
+                hash = (i ^ (VRMA_VSID ^ (VRMA_VSID << 25))) & kvm->arch.hpt_mask;
                 /*
                  * We assume that the hash table is empty and no
                  * vcpus are using it at this stage.  Since we create
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index c6af1d623839..d084e412b3c5 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -56,7 +56,7 @@
 /* #define EXIT_DEBUG_INT */
 
 static void kvmppc_end_cede(struct kvm_vcpu *vcpu);
-static int kvmppc_hv_setup_rma(struct kvm_vcpu *vcpu);
+static int kvmppc_hv_setup_htab_rma(struct kvm_vcpu *vcpu);
 
 void kvmppc_core_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 {
@@ -1068,11 +1068,15 @@ int kvmppc_vcpu_run(struct kvm_run *run, struct kvm_vcpu *vcpu)
                 return -EINTR;
         }
 
-        /* On the first time here, set up VRMA or RMA */
+        atomic_inc(&vcpu->kvm->arch.vcpus_running);
+        /* Order vcpus_running vs. rma_setup_done, see kvmppc_alloc_reset_hpt */
+        smp_mb();
+
+        /* On the first time here, set up HTAB and VRMA or RMA */
         if (!vcpu->kvm->arch.rma_setup_done) {
-                r = kvmppc_hv_setup_rma(vcpu);
+                r = kvmppc_hv_setup_htab_rma(vcpu);
                 if (r)
-                        return r;
+                        goto out;
         }
 
         flush_fp_to_thread(current);
@@ -1090,6 +1094,9 @@ int kvmppc_vcpu_run(struct kvm_run *run, struct kvm_vcpu *vcpu)
                         kvmppc_core_prepare_to_enter(vcpu);
                 }
         } while (r == RESUME_GUEST);
+
+ out:
+        atomic_dec(&vcpu->kvm->arch.vcpus_running);
         return r;
 }
 
@@ -1305,7 +1312,7 @@ void kvmppc_core_commit_memory_region(struct kvm *kvm,
 {
 }
 
-static int kvmppc_hv_setup_rma(struct kvm_vcpu *vcpu)
+static int kvmppc_hv_setup_htab_rma(struct kvm_vcpu *vcpu)
 {
         int err = 0;
         struct kvm *kvm = vcpu->kvm;
@@ -1324,6 +1331,15 @@ static int kvmppc_hv_setup_rma(struct kvm_vcpu *vcpu)
         if (kvm->arch.rma_setup_done)
                 goto out;       /* another vcpu beat us to it */
 
+        /* Allocate hashed page table (if not done already) and reset it */
+        if (!kvm->arch.hpt_virt) {
+                err = kvmppc_alloc_hpt(kvm, NULL);
+                if (err) {
+                        pr_err("KVM: Couldn't alloc HPT\n");
+                        goto out;
+                }
+        }
+
         /* Look up the memslot for guest physical address 0 */
         memslot = gfn_to_memslot(kvm, 0);
 
@@ -1435,13 +1451,14 @@ static int kvmppc_hv_setup_rma(struct kvm_vcpu *vcpu)
 
 int kvmppc_core_init_vm(struct kvm *kvm)
 {
-        long r;
-        unsigned long lpcr;
+        unsigned long lpcr, lpid;
 
-        /* Allocate hashed page table */
-        r = kvmppc_alloc_hpt(kvm);
-        if (r)
-                return r;
+        /* Allocate the guest's logical partition ID */
+
+        lpid = kvmppc_alloc_lpid();
+        if (lpid < 0)
+                return -ENOMEM;
+        kvm->arch.lpid = lpid;
 
         INIT_LIST_HEAD(&kvm->arch.spapr_tce_tables);
 
@@ -1451,7 +1468,6 @@ int kvmppc_core_init_vm(struct kvm *kvm)
 
         if (cpu_has_feature(CPU_FTR_ARCH_201)) {
                 /* PPC970; HID4 is effectively the LPCR */
-                unsigned long lpid = kvm->arch.lpid;
                 kvm->arch.host_lpid = 0;
                 kvm->arch.host_lpcr = lpcr = mfspr(SPRN_HID4);
                 lpcr &= ~((3 << HID4_LPID1_SH) | (0xful << HID4_LPID5_SH));
diff --git a/arch/powerpc/kvm/book3s_hv_builtin.c b/arch/powerpc/kvm/book3s_hv_builtin.c
index e1b60f56f2a1..fb4eac290fef 100644
--- a/arch/powerpc/kvm/book3s_hv_builtin.c
+++ b/arch/powerpc/kvm/book3s_hv_builtin.c
@@ -25,6 +25,9 @@ static void __init kvm_linear_init_one(ulong size, int count, int type);
 static struct kvmppc_linear_info *kvm_alloc_linear(int type);
 static void kvm_release_linear(struct kvmppc_linear_info *ri);
 
+int kvm_hpt_order = KVM_DEFAULT_HPT_ORDER;
+EXPORT_SYMBOL_GPL(kvm_hpt_order);
+
 /*************** RMA *************/
 
 /*
@@ -209,7 +212,7 @@ static void kvm_release_linear(struct kvmppc_linear_info *ri)
 void __init kvm_linear_init(void)
 {
         /* HPT */
-        kvm_linear_init_one(1 << HPT_ORDER, kvm_hpt_count, KVM_LINEAR_HPT);
+        kvm_linear_init_one(1 << kvm_hpt_order, kvm_hpt_count, KVM_LINEAR_HPT);
 
         /* RMA */
         /* Only do this on PPC970 in HV mode */
diff --git a/arch/powerpc/kvm/book3s_hv_rm_mmu.c b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
index cec4daddbf31..5c70d19494f9 100644
--- a/arch/powerpc/kvm/book3s_hv_rm_mmu.c
+++ b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
@@ -237,7 +237,7 @@ long kvmppc_h_enter(struct kvm_vcpu *vcpu, unsigned long flags,
 
         /* Find and lock the HPTEG slot to use */
  do_insert:
-        if (pte_index >= HPT_NPTE)
+        if (pte_index >= kvm->arch.hpt_npte)
                 return H_PARAMETER;
         if (likely((flags & H_EXACT) == 0)) {
                 pte_index &= ~7UL;
@@ -352,7 +352,7 @@ long kvmppc_h_remove(struct kvm_vcpu *vcpu, unsigned long flags,
         unsigned long v, r, rb;
         struct revmap_entry *rev;
 
-        if (pte_index >= HPT_NPTE)
+        if (pte_index >= kvm->arch.hpt_npte)
                 return H_PARAMETER;
         hpte = (unsigned long *)(kvm->arch.hpt_virt + (pte_index << 4));
         while (!try_lock_hpte(hpte, HPTE_V_HVLOCK))
@@ -419,7 +419,8 @@ long kvmppc_h_bulk_remove(struct kvm_vcpu *vcpu)
                                 i = 4;
                                 break;
                         }
-                        if (req != 1 || flags == 3 || pte_index >= HPT_NPTE) {
+                        if (req != 1 || flags == 3 ||
+                            pte_index >= kvm->arch.hpt_npte) {
                                 /* parameter error */
                                 args[j] = ((0xa0 | flags) << 56) + pte_index;
                                 ret = H_PARAMETER;
@@ -521,7 +522,7 @@ long kvmppc_h_protect(struct kvm_vcpu *vcpu, unsigned long flags,
         struct revmap_entry *rev;
         unsigned long v, r, rb, mask, bits;
 
-        if (pte_index >= HPT_NPTE)
+        if (pte_index >= kvm->arch.hpt_npte)
                 return H_PARAMETER;
 
         hpte = (unsigned long *)(kvm->arch.hpt_virt + (pte_index << 4));
@@ -583,7 +584,7 @@ long kvmppc_h_read(struct kvm_vcpu *vcpu, unsigned long flags,
         int i, n = 1;
         struct revmap_entry *rev = NULL;
 
-        if (pte_index >= HPT_NPTE)
+        if (pte_index >= kvm->arch.hpt_npte)
                 return H_PARAMETER;
         if (flags & H_READ_4) {
                 pte_index &= ~3;
@@ -678,7 +679,7 @@ long kvmppc_hv_find_lock_hpte(struct kvm *kvm, gva_t eaddr, unsigned long slb_v,
                 somask = (1UL << 28) - 1;
                 vsid = (slb_v & ~SLB_VSID_B) >> SLB_VSID_SHIFT;
         }
-        hash = (vsid ^ ((eaddr & somask) >> pshift)) & HPT_HASH_MASK;
+        hash = (vsid ^ ((eaddr & somask) >> pshift)) & kvm->arch.hpt_mask;
         avpn = slb_v & ~(somask >> 16); /* also includes B */
         avpn |= (eaddr & somask) >> 16;
 
@@ -723,7 +724,7 @@ long kvmppc_hv_find_lock_hpte(struct kvm *kvm, gva_t eaddr, unsigned long slb_v,
                 if (val & HPTE_V_SECONDARY)
                         break;
                 val |= HPTE_V_SECONDARY;
-                hash = hash ^ HPT_HASH_MASK;
+                hash = hash ^ kvm->arch.hpt_mask;
         }
         return -1;
 }
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 1493c8de947b..87f4dc886076 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -246,6 +246,7 @@ int kvm_dev_ioctl_check_extension(long ext)
 #endif
 #ifdef CONFIG_PPC_BOOK3S_64
         case KVM_CAP_SPAPR_TCE:
+        case KVM_CAP_PPC_ALLOC_HTAB:
                 r = 1;
                 break;
 #endif /* CONFIG_PPC_BOOK3S_64 */
@@ -802,6 +803,23 @@ long kvm_arch_vm_ioctl(struct file *filp,
                         r = -EFAULT;
                 break;
         }
+
+        case KVM_PPC_ALLOCATE_HTAB: {
+                struct kvm *kvm = filp->private_data;
+                u32 htab_order;
+
+                r = -EFAULT;
+                if (get_user(htab_order, (u32 __user *)argp))
+                        break;
+                r = kvmppc_alloc_reset_hpt(kvm, &htab_order);
+                if (r)
+                        break;
+                r = -EFAULT;
+                if (put_user(htab_order, (u32 __user *)argp))
+                        break;
+                r = 0;
+                break;
+        }
 #endif /* CONFIG_KVM_BOOK3S_64_HV */
 
 #ifdef CONFIG_PPC_BOOK3S_64
diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index 09f2b3aa2da7..2ce09aa7d3b3 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -617,6 +617,7 @@ struct kvm_ppc_smmu_info {
 #define KVM_CAP_SIGNAL_MSI 77
 #define KVM_CAP_PPC_GET_SMMU_INFO 78
 #define KVM_CAP_S390_COW 79
+#define KVM_CAP_PPC_ALLOC_HTAB 80
 
 #ifdef KVM_CAP_IRQ_ROUTING
 
@@ -828,6 +829,8 @@ struct kvm_s390_ucas_mapping {
 #define KVM_SIGNAL_MSI            _IOW(KVMIO,  0xa5, struct kvm_msi)
 /* Available with KVM_CAP_PPC_GET_SMMU_INFO */
 #define KVM_PPC_GET_SMMU_INFO     _IOR(KVMIO,  0xa6, struct kvm_ppc_smmu_info)
+/* Available with KVM_CAP_PPC_ALLOC_HTAB */
+#define KVM_PPC_ALLOCATE_HTAB     _IOWR(KVMIO, 0xa7, __u32)
 
 /*
  * ioctls for vcpu fds