arch/powerpc/kvm/book3s_64_mmu_host.c - maze/linux - Git at Google

 /*
  * Copyright (C) 2009 SUSE Linux Products GmbH. All rights reserved.
  *
  * Authors:
  *     Alexander Graf <agraf@suse.de>
  *     Kevin Wolf <mail@kevin-wolf.de>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License, version 2, as
  * published by the Free Software Foundation.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  */

 #include <linux/kvm_host.h>

 #include <asm/kvm_ppc.h>
 #include <asm/kvm_book3s.h>
 #include <asm/mmu-hash64.h>
 #include <asm/machdep.h>
 #include <asm/mmu_context.h>
 #include <asm/hw_irq.h>

 #define PTE_SIZE 12
 #define VSID_ALL 0

 /* #define DEBUG_MMU */
 /* #define DEBUG_SLB */

 #ifdef DEBUG_MMU
 #define dprintk_mmu(a, ...) printk(KERN_INFO a, __VA_ARGS__)
 #else
 #define dprintk_mmu(a, ...) do { } while(0)
 #endif

 #ifdef DEBUG_SLB
 #define dprintk_slb(a, ...) printk(KERN_INFO a, __VA_ARGS__)
 #else
 #define dprintk_slb(a, ...) do { } while(0)
 #endif

 static void invalidate_pte(struct hpte_cache *pte)
 {
 	dprintk_mmu("KVM: Flushing SPT: 0x%lx (0x%llx) -> 0x%llx\n",
 		    pte->pte.eaddr, pte->pte.vpage, pte->host_va);

 	ppc_md.hpte_invalidate(pte->slot, pte->host_va,
 			       MMU_PAGE_4K, MMU_SEGSIZE_256M,
 			       false);
 	pte->host_va = 0;

 	if (pte->pte.may_write)
 		kvm_release_pfn_dirty(pte->pfn);
 	else
 		kvm_release_pfn_clean(pte->pfn);
 }

 void kvmppc_mmu_pte_flush(struct kvm_vcpu *vcpu, ulong guest_ea, ulong ea_mask)
 {
 	int i;

 	dprintk_mmu("KVM: Flushing %d Shadow PTEs: 0x%lx & 0x%lx\n",
 		    vcpu->arch.hpte_cache_offset, guest_ea, ea_mask);
 	BUG_ON(vcpu->arch.hpte_cache_offset > HPTEG_CACHE_NUM);

 	guest_ea &= ea_mask;
 	for (i = 0; i < vcpu->arch.hpte_cache_offset; i++) {
 		struct hpte_cache *pte;

 		pte = &vcpu->arch.hpte_cache[i];
 		if (!pte->host_va)
 			continue;

 		if ((pte->pte.eaddr & ea_mask) == guest_ea) {
 			invalidate_pte(pte);
 		}
 	}

 	/* Doing a complete flush -> start from scratch */
 	if (!ea_mask)
 		vcpu->arch.hpte_cache_offset = 0;
 }

 void kvmppc_mmu_pte_vflush(struct kvm_vcpu *vcpu, u64 guest_vp, u64 vp_mask)
 {
 	int i;

 	dprintk_mmu("KVM: Flushing %d Shadow vPTEs: 0x%llx & 0x%llx\n",
 		    vcpu->arch.hpte_cache_offset, guest_vp, vp_mask);
 	BUG_ON(vcpu->arch.hpte_cache_offset > HPTEG_CACHE_NUM);

 	guest_vp &= vp_mask;
 	for (i = 0; i < vcpu->arch.hpte_cache_offset; i++) {
 		struct hpte_cache *pte;

 		pte = &vcpu->arch.hpte_cache[i];
 		if (!pte->host_va)
 			continue;

 		if ((pte->pte.vpage & vp_mask) == guest_vp) {
 			invalidate_pte(pte);
 		}
 	}
 }

 void kvmppc_mmu_pte_pflush(struct kvm_vcpu *vcpu, ulong pa_start, ulong pa_end)
 {
 	int i;

 	dprintk_mmu("KVM: Flushing %d Shadow pPTEs: 0x%lx & 0x%lx\n",
 		    vcpu->arch.hpte_cache_offset, pa_start, pa_end);
 	BUG_ON(vcpu->arch.hpte_cache_offset > HPTEG_CACHE_NUM);

 	for (i = 0; i < vcpu->arch.hpte_cache_offset; i++) {
 		struct hpte_cache *pte;

 		pte = &vcpu->arch.hpte_cache[i];
 		if (!pte->host_va)
 			continue;

 		if ((pte->pte.raddr >= pa_start) &&
 		    (pte->pte.raddr < pa_end)) {
 			invalidate_pte(pte);
 		}
 	}
 }

 struct kvmppc_pte *kvmppc_mmu_find_pte(struct kvm_vcpu *vcpu, u64 ea, bool data)
 {
 	int i;
 	u64 guest_vp;

 	guest_vp = vcpu->arch.mmu.ea_to_vp(vcpu, ea, false);
 	for (i=0; i<vcpu->arch.hpte_cache_offset; i++) {
 		struct hpte_cache *pte;

 		pte = &vcpu->arch.hpte_cache[i];
 		if (!pte->host_va)
 			continue;

 		if (pte->pte.vpage == guest_vp)
 			return &pte->pte;
 	}

 	return NULL;
 }

 static int kvmppc_mmu_hpte_cache_next(struct kvm_vcpu *vcpu)
 {
 	if (vcpu->arch.hpte_cache_offset == HPTEG_CACHE_NUM)
 		kvmppc_mmu_pte_flush(vcpu, 0, 0);

 	return vcpu->arch.hpte_cache_offset++;
 }

 /* We keep 512 gvsid->hvsid entries, mapping the guest ones to the array using
  * a hash, so we don't waste cycles on looping */
 static u16 kvmppc_sid_hash(struct kvm_vcpu *vcpu, u64 gvsid)
 {
 	return (u16)(((gvsid >> (SID_MAP_BITS * 7)) & SID_MAP_MASK) ^
 		     ((gvsid >> (SID_MAP_BITS * 6)) & SID_MAP_MASK) ^
 		     ((gvsid >> (SID_MAP_BITS * 5)) & SID_MAP_MASK) ^
 		     ((gvsid >> (SID_MAP_BITS * 4)) & SID_MAP_MASK) ^
 		     ((gvsid >> (SID_MAP_BITS * 3)) & SID_MAP_MASK) ^
 		     ((gvsid >> (SID_MAP_BITS * 2)) & SID_MAP_MASK) ^
 		     ((gvsid >> (SID_MAP_BITS * 1)) & SID_MAP_MASK) ^
 		     ((gvsid >> (SID_MAP_BITS * 0)) & SID_MAP_MASK));
 }


 static struct kvmppc_sid_map *find_sid_vsid(struct kvm_vcpu *vcpu, u64 gvsid)
 {
 	struct kvmppc_sid_map *map;
 	u16 sid_map_mask;

 	if (vcpu->arch.msr & MSR_PR)
 		gvsid |= VSID_PR;

 	sid_map_mask = kvmppc_sid_hash(vcpu, gvsid);
 	map = &to_book3s(vcpu)->sid_map[sid_map_mask];
 	if (map->guest_vsid == gvsid) {
 		dprintk_slb("SLB: Searching: 0x%llx -> 0x%llx\n",
 			    gvsid, map->host_vsid);
 		return map;
 	}

 	map = &to_book3s(vcpu)->sid_map[SID_MAP_MASK - sid_map_mask];
 	if (map->guest_vsid == gvsid) {
 		dprintk_slb("SLB: Searching 0x%llx -> 0x%llx\n",
 			    gvsid, map->host_vsid);
 		return map;
 	}

 	dprintk_slb("SLB: Searching %d/%d: 0x%llx -> not found\n",
 		    sid_map_mask, SID_MAP_MASK - sid_map_mask, gvsid);
 	return NULL;
 }

 int kvmppc_mmu_map_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *orig_pte)
 {
 	pfn_t hpaddr;
 	ulong hash, hpteg, va;
 	u64 vsid;
 	int ret;
 	int rflags = 0x192;
 	int vflags = 0;
 	int attempt = 0;
 	struct kvmppc_sid_map *map;

 	/* Get host physical address for gpa */
 	hpaddr = gfn_to_pfn(vcpu->kvm, 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

 	/* and write the mapping ea -> hpa into the pt */
 	vcpu->arch.mmu.esid_to_vsid(vcpu, orig_pte->eaddr >> SID_SHIFT, &vsid);
 	map = find_sid_vsid(vcpu, vsid);
 	if (!map) {
 		ret = kvmppc_mmu_map_segment(vcpu, orig_pte->eaddr);
 		WARN_ON(ret < 0);
 		map = find_sid_vsid(vcpu, vsid);
 	}
 	if (!map) {
 		printk(KERN_ERR "KVM: Segment map for 0x%llx (0x%lx) failed\n",
 				vsid, orig_pte->eaddr);
 		WARN_ON(true);
 		return -EINVAL;
 	}

 	vsid = map->host_vsid;
 	va = hpt_va(orig_pte->eaddr, vsid, MMU_SEGSIZE_256M);

 	if (!orig_pte->may_write)
 		rflags |= HPTE_R_PP;
 	else
 		mark_page_dirty(vcpu->kvm, orig_pte->raddr >> PAGE_SHIFT);

 	if (!orig_pte->may_execute)
 		rflags |= HPTE_R_N;

 	hash = hpt_hash(va, PTE_SIZE, MMU_SEGSIZE_256M);

 map_again:
 	hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);

 	/* In case we tried normal mapping already, let's nuke old entries */
 	if (attempt > 1)
 		if (ppc_md.hpte_remove(hpteg) < 0)
 			return -1;

 	ret = ppc_md.hpte_insert(hpteg, va, hpaddr, rflags, vflags, MMU_PAGE_4K, MMU_SEGSIZE_256M);

 	if (ret < 0) {
 		/* If we couldn't map a primary PTE, try a secondary */
 		hash = ~hash;
 		vflags ^= HPTE_V_SECONDARY;
 		attempt++;
 		goto map_again;
 	} else {
 		int hpte_id = kvmppc_mmu_hpte_cache_next(vcpu);
 		struct hpte_cache *pte = &vcpu->arch.hpte_cache[hpte_id];

 		dprintk_mmu("KVM: %c%c Map 0x%lx: [%lx] 0x%lx (0x%llx) -> %lx\n",
 			    ((rflags & HPTE_R_PP) == 3) ? '-' : 'w',
 			    (rflags & HPTE_R_N) ? '-' : 'x',
 			    orig_pte->eaddr, hpteg, va, orig_pte->vpage, hpaddr);

 		/* The ppc_md code may give us a secondary entry even though we
 		   asked for a primary. Fix up. */
 		if ((ret & _PTEIDX_SECONDARY) && !(vflags & HPTE_V_SECONDARY)) {
 			hash = ~hash;
 			hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
 		}

 		pte->slot = hpteg + (ret & 7);
 		pte->host_va = va;
 		pte->pte = *orig_pte;
 		pte->pfn = hpaddr >> PAGE_SHIFT;
 	}

 	return 0;
 }

 static struct kvmppc_sid_map *create_sid_map(struct kvm_vcpu *vcpu, u64 gvsid)
 {
 	struct kvmppc_sid_map *map;
 	struct kvmppc_vcpu_book3s *vcpu_book3s = to_book3s(vcpu);
 	u16 sid_map_mask;
 	static int backwards_map = 0;

 	if (vcpu->arch.msr & MSR_PR)
 		gvsid |= VSID_PR;

 	/* We might get collisions that trap in preceding order, so let's
 	   map them differently */

 	sid_map_mask = kvmppc_sid_hash(vcpu, gvsid);
 	if (backwards_map)
 		sid_map_mask = SID_MAP_MASK - sid_map_mask;

 	map = &to_book3s(vcpu)->sid_map[sid_map_mask];

 	/* Make sure we're taking the other map next time */
 	backwards_map = !backwards_map;

 	/* Uh-oh ... out of mappings. Let's flush! */
 	if (vcpu_book3s->vsid_next == vcpu_book3s->vsid_max) {
 		vcpu_book3s->vsid_next = vcpu_book3s->vsid_first;
 		memset(vcpu_book3s->sid_map, 0,
 		       sizeof(struct kvmppc_sid_map) * SID_MAP_NUM);
 		kvmppc_mmu_pte_flush(vcpu, 0, 0);
 		kvmppc_mmu_flush_segments(vcpu);
 	}
 	map->host_vsid = vcpu_book3s->vsid_next++;

 	map->guest_vsid = gvsid;
 	map->valid = true;

 	dprintk_slb("SLB: New mapping at %d: 0x%llx -> 0x%llx\n",
 		    sid_map_mask, gvsid, map->host_vsid);

 	return map;
 }

 static int kvmppc_mmu_next_segment(struct kvm_vcpu *vcpu, ulong esid)
 {
 	int i;
 	int max_slb_size = 64;
 	int found_inval = -1;
 	int r;

 	if (!to_svcpu(vcpu)->slb_max)
 		to_svcpu(vcpu)->slb_max = 1;

 	/* Are we overwriting? */
 	for (i = 1; i < to_svcpu(vcpu)->slb_max; i++) {
 		if (!(to_svcpu(vcpu)->slb[i].esid & SLB_ESID_V))
 			found_inval = i;
 		else if ((to_svcpu(vcpu)->slb[i].esid & ESID_MASK) == esid)
 			return i;
 	}

 	/* Found a spare entry that was invalidated before */
 	if (found_inval > 0)
 		return found_inval;

 	/* No spare invalid entry, so create one */

 	if (mmu_slb_size < 64)
 		max_slb_size = mmu_slb_size;

 	/* Overflowing -> purge */
 	if ((to_svcpu(vcpu)->slb_max) == max_slb_size)
 		kvmppc_mmu_flush_segments(vcpu);

 	r = to_svcpu(vcpu)->slb_max;
 	to_svcpu(vcpu)->slb_max++;

 	return r;
 }

 int kvmppc_mmu_map_segment(struct kvm_vcpu *vcpu, ulong eaddr)
 {
 	u64 esid = eaddr >> SID_SHIFT;
 	u64 slb_esid = (eaddr & ESID_MASK) | SLB_ESID_V;
 	u64 slb_vsid = SLB_VSID_USER;
 	u64 gvsid;
 	int slb_index;
 	struct kvmppc_sid_map *map;

 	slb_index = kvmppc_mmu_next_segment(vcpu, eaddr & ESID_MASK);

 	if (vcpu->arch.mmu.esid_to_vsid(vcpu, esid, &gvsid)) {
 		/* Invalidate an entry */
 		to_svcpu(vcpu)->slb[slb_index].esid = 0;
 		return -ENOENT;
 	}

 	map = find_sid_vsid(vcpu, gvsid);
 	if (!map)
 		map = create_sid_map(vcpu, gvsid);

 	map->guest_esid = esid;

 	slb_vsid |= (map->host_vsid << 12);
 	slb_vsid &= ~SLB_VSID_KP;
 	slb_esid |= slb_index;

 	to_svcpu(vcpu)->slb[slb_index].esid = slb_esid;
 	to_svcpu(vcpu)->slb[slb_index].vsid = slb_vsid;

 	dprintk_slb("slbmte %#llx, %#llx\n", slb_vsid, slb_esid);

 	return 0;
 }

 void kvmppc_mmu_flush_segments(struct kvm_vcpu *vcpu)
 {
 	to_svcpu(vcpu)->slb_max = 1;
 	to_svcpu(vcpu)->slb[0].esid = 0;
 }

 void kvmppc_mmu_destroy(struct kvm_vcpu *vcpu)
 {
 	kvmppc_mmu_pte_flush(vcpu, 0, 0);
 	__destroy_context(to_book3s(vcpu)->context_id);
 }

 int kvmppc_mmu_init(struct kvm_vcpu *vcpu)
 {
 	struct kvmppc_vcpu_book3s *vcpu3s = to_book3s(vcpu);
 	int err;

 	err = __init_new_context();
 	if (err < 0)
 		return -1;
 	vcpu3s->context_id = err;

 	vcpu3s->vsid_max = ((vcpu3s->context_id + 1) << USER_ESID_BITS) - 1;
 	vcpu3s->vsid_first = vcpu3s->context_id << USER_ESID_BITS;
 	vcpu3s->vsid_next = vcpu3s->vsid_first;

 	return 0;
 }
	/*
	* Copyright (C) 2009 SUSE Linux Products GmbH. All rights reserved.
	*
	* Authors:
	* Alexander Graf <agraf@suse.de>
	* Kevin Wolf <mail@kevin-wolf.de>
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License, version 2, as
	* published by the Free Software Foundation.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
	*/

	#include <linux/kvm_host.h>

	#include <asm/kvm_ppc.h>
	#include <asm/kvm_book3s.h>
	#include <asm/mmu-hash64.h>
	#include <asm/machdep.h>
	#include <asm/mmu_context.h>
	#include <asm/hw_irq.h>

	#define PTE_SIZE 12
	#define VSID_ALL 0

	/* #define DEBUG_MMU */
	/* #define DEBUG_SLB */

	#ifdef DEBUG_MMU
	#define dprintk_mmu(a, ...) printk(KERN_INFO a, __VA_ARGS__)
	#else
	#define dprintk_mmu(a, ...) do { } while(0)
	#endif

	#ifdef DEBUG_SLB
	#define dprintk_slb(a, ...) printk(KERN_INFO a, __VA_ARGS__)
	#else
	#define dprintk_slb(a, ...) do { } while(0)
	#endif

	static void invalidate_pte(struct hpte_cache *pte)
	{
	dprintk_mmu("KVM: Flushing SPT: 0x%lx (0x%llx) -> 0x%llx\n",
	pte->pte.eaddr, pte->pte.vpage, pte->host_va);

	ppc_md.hpte_invalidate(pte->slot, pte->host_va,
	MMU_PAGE_4K, MMU_SEGSIZE_256M,
	false);
	pte->host_va = 0;

	if (pte->pte.may_write)
	kvm_release_pfn_dirty(pte->pfn);
	else
	kvm_release_pfn_clean(pte->pfn);
	}

	void kvmppc_mmu_pte_flush(struct kvm_vcpu *vcpu, ulong guest_ea, ulong ea_mask)
	{
	int i;

	dprintk_mmu("KVM: Flushing %d Shadow PTEs: 0x%lx & 0x%lx\n",
	vcpu->arch.hpte_cache_offset, guest_ea, ea_mask);
	BUG_ON(vcpu->arch.hpte_cache_offset > HPTEG_CACHE_NUM);

	guest_ea &= ea_mask;
	for (i = 0; i < vcpu->arch.hpte_cache_offset; i++) {
	struct hpte_cache *pte;

	pte = &vcpu->arch.hpte_cache[i];
	if (!pte->host_va)
	continue;

	if ((pte->pte.eaddr & ea_mask) == guest_ea) {
	invalidate_pte(pte);
	}
	}

	/* Doing a complete flush -> start from scratch */
	if (!ea_mask)
	vcpu->arch.hpte_cache_offset = 0;
	}

	void kvmppc_mmu_pte_vflush(struct kvm_vcpu *vcpu, u64 guest_vp, u64 vp_mask)
	{
	int i;

	dprintk_mmu("KVM: Flushing %d Shadow vPTEs: 0x%llx & 0x%llx\n",
	vcpu->arch.hpte_cache_offset, guest_vp, vp_mask);
	BUG_ON(vcpu->arch.hpte_cache_offset > HPTEG_CACHE_NUM);

	guest_vp &= vp_mask;
	for (i = 0; i < vcpu->arch.hpte_cache_offset; i++) {
	struct hpte_cache *pte;

	pte = &vcpu->arch.hpte_cache[i];
	if (!pte->host_va)
	continue;

	if ((pte->pte.vpage & vp_mask) == guest_vp) {
	invalidate_pte(pte);
	}
	}
	}

	void kvmppc_mmu_pte_pflush(struct kvm_vcpu *vcpu, ulong pa_start, ulong pa_end)
	{
	int i;

	dprintk_mmu("KVM: Flushing %d Shadow pPTEs: 0x%lx & 0x%lx\n",
	vcpu->arch.hpte_cache_offset, pa_start, pa_end);
	BUG_ON(vcpu->arch.hpte_cache_offset > HPTEG_CACHE_NUM);

	for (i = 0; i < vcpu->arch.hpte_cache_offset; i++) {
	struct hpte_cache *pte;

	pte = &vcpu->arch.hpte_cache[i];
	if (!pte->host_va)
	continue;

	if ((pte->pte.raddr >= pa_start) &&
	(pte->pte.raddr < pa_end)) {
	invalidate_pte(pte);
	}
	}
	}

	struct kvmppc_pte kvmppc_mmu_find_pte(struct kvm_vcpu vcpu, u64 ea, bool data)
	{
	int i;
	u64 guest_vp;

	guest_vp = vcpu->arch.mmu.ea_to_vp(vcpu, ea, false);
	for (i=0; i<vcpu->arch.hpte_cache_offset; i++) {
	struct hpte_cache *pte;

	pte = &vcpu->arch.hpte_cache[i];
	if (!pte->host_va)
	continue;

	if (pte->pte.vpage == guest_vp)
	return &pte->pte;
	}

	return NULL;
	}

	static int kvmppc_mmu_hpte_cache_next(struct kvm_vcpu *vcpu)
	{
	if (vcpu->arch.hpte_cache_offset == HPTEG_CACHE_NUM)
	kvmppc_mmu_pte_flush(vcpu, 0, 0);

	return vcpu->arch.hpte_cache_offset++;
	}

	/* We keep 512 gvsid->hvsid entries, mapping the guest ones to the array using
	* a hash, so we don't waste cycles on looping */
	static u16 kvmppc_sid_hash(struct kvm_vcpu *vcpu, u64 gvsid)
	{
	return (u16)(((gvsid >> (SID_MAP_BITS * 7)) & SID_MAP_MASK) ^
	((gvsid >> (SID_MAP_BITS * 6)) & SID_MAP_MASK) ^
	((gvsid >> (SID_MAP_BITS * 5)) & SID_MAP_MASK) ^
	((gvsid >> (SID_MAP_BITS * 4)) & SID_MAP_MASK) ^
	((gvsid >> (SID_MAP_BITS * 3)) & SID_MAP_MASK) ^
	((gvsid >> (SID_MAP_BITS * 2)) & SID_MAP_MASK) ^
	((gvsid >> (SID_MAP_BITS * 1)) & SID_MAP_MASK) ^
	((gvsid >> (SID_MAP_BITS * 0)) & SID_MAP_MASK));
	}


	static struct kvmppc_sid_map find_sid_vsid(struct kvm_vcpu vcpu, u64 gvsid)
	{
	struct kvmppc_sid_map *map;
	u16 sid_map_mask;

	if (vcpu->arch.msr & MSR_PR)
	gvsid \|= VSID_PR;

	sid_map_mask = kvmppc_sid_hash(vcpu, gvsid);
	map = &to_book3s(vcpu)->sid_map[sid_map_mask];
	if (map->guest_vsid == gvsid) {
	dprintk_slb("SLB: Searching: 0x%llx -> 0x%llx\n",
	gvsid, map->host_vsid);
	return map;
	}

	map = &to_book3s(vcpu)->sid_map[SID_MAP_MASK - sid_map_mask];
	if (map->guest_vsid == gvsid) {
	dprintk_slb("SLB: Searching 0x%llx -> 0x%llx\n",
	gvsid, map->host_vsid);
	return map;
	}

	dprintk_slb("SLB: Searching %d/%d: 0x%llx -> not found\n",
	sid_map_mask, SID_MAP_MASK - sid_map_mask, gvsid);
	return NULL;
	}

	int kvmppc_mmu_map_page(struct kvm_vcpu vcpu, struct kvmppc_pte orig_pte)
	{
	pfn_t hpaddr;
	ulong hash, hpteg, va;
	u64 vsid;
	int ret;
	int rflags = 0x192;
	int vflags = 0;
	int attempt = 0;
	struct kvmppc_sid_map *map;

	/* Get host physical address for gpa */
	hpaddr = gfn_to_pfn(vcpu->kvm, 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

	/* and write the mapping ea -> hpa into the pt */
	vcpu->arch.mmu.esid_to_vsid(vcpu, orig_pte->eaddr >> SID_SHIFT, &vsid);
	map = find_sid_vsid(vcpu, vsid);
	if (!map) {
	ret = kvmppc_mmu_map_segment(vcpu, orig_pte->eaddr);
	WARN_ON(ret < 0);
	map = find_sid_vsid(vcpu, vsid);
	}
	if (!map) {
	printk(KERN_ERR "KVM: Segment map for 0x%llx (0x%lx) failed\n",
	vsid, orig_pte->eaddr);
	WARN_ON(true);
	return -EINVAL;
	}

	vsid = map->host_vsid;
	va = hpt_va(orig_pte->eaddr, vsid, MMU_SEGSIZE_256M);

	if (!orig_pte->may_write)
	rflags \|= HPTE_R_PP;
	else
	mark_page_dirty(vcpu->kvm, orig_pte->raddr >> PAGE_SHIFT);

	if (!orig_pte->may_execute)
	rflags \|= HPTE_R_N;

	hash = hpt_hash(va, PTE_SIZE, MMU_SEGSIZE_256M);

	map_again:
	hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);

	/* In case we tried normal mapping already, let's nuke old entries */
	if (attempt > 1)
	if (ppc_md.hpte_remove(hpteg) < 0)
	return -1;

	ret = ppc_md.hpte_insert(hpteg, va, hpaddr, rflags, vflags, MMU_PAGE_4K, MMU_SEGSIZE_256M);

	if (ret < 0) {
	/* If we couldn't map a primary PTE, try a secondary */
	hash = ~hash;
	vflags ^= HPTE_V_SECONDARY;
	attempt++;
	goto map_again;
	} else {
	int hpte_id = kvmppc_mmu_hpte_cache_next(vcpu);
	struct hpte_cache *pte = &vcpu->arch.hpte_cache[hpte_id];

	dprintk_mmu("KVM: %c%c Map 0x%lx: [%lx] 0x%lx (0x%llx) -> %lx\n",
	((rflags & HPTE_R_PP) == 3) ? '-' : 'w',
	(rflags & HPTE_R_N) ? '-' : 'x',
	orig_pte->eaddr, hpteg, va, orig_pte->vpage, hpaddr);

	/* The ppc_md code may give us a secondary entry even though we
	asked for a primary. Fix up. */
	if ((ret & _PTEIDX_SECONDARY) && !(vflags & HPTE_V_SECONDARY)) {
	hash = ~hash;
	hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
	}

	pte->slot = hpteg + (ret & 7);
	pte->host_va = va;
	pte->pte = *orig_pte;
	pte->pfn = hpaddr >> PAGE_SHIFT;
	}

	return 0;
	}

	static struct kvmppc_sid_map create_sid_map(struct kvm_vcpu vcpu, u64 gvsid)
	{
	struct kvmppc_sid_map *map;
	struct kvmppc_vcpu_book3s *vcpu_book3s = to_book3s(vcpu);
	u16 sid_map_mask;
	static int backwards_map = 0;

	if (vcpu->arch.msr & MSR_PR)
	gvsid \|= VSID_PR;

	/* We might get collisions that trap in preceding order, so let's
	map them differently */

	sid_map_mask = kvmppc_sid_hash(vcpu, gvsid);
	if (backwards_map)
	sid_map_mask = SID_MAP_MASK - sid_map_mask;

	map = &to_book3s(vcpu)->sid_map[sid_map_mask];

	/* Make sure we're taking the other map next time */
	backwards_map = !backwards_map;

	/* Uh-oh ... out of mappings. Let's flush! */
	if (vcpu_book3s->vsid_next == vcpu_book3s->vsid_max) {
	vcpu_book3s->vsid_next = vcpu_book3s->vsid_first;
	memset(vcpu_book3s->sid_map, 0,
	sizeof(struct kvmppc_sid_map) * SID_MAP_NUM);
	kvmppc_mmu_pte_flush(vcpu, 0, 0);
	kvmppc_mmu_flush_segments(vcpu);
	}
	map->host_vsid = vcpu_book3s->vsid_next++;

	map->guest_vsid = gvsid;
	map->valid = true;

	dprintk_slb("SLB: New mapping at %d: 0x%llx -> 0x%llx\n",
	sid_map_mask, gvsid, map->host_vsid);

	return map;
	}

	static int kvmppc_mmu_next_segment(struct kvm_vcpu *vcpu, ulong esid)
	{
	int i;
	int max_slb_size = 64;
	int found_inval = -1;
	int r;

	if (!to_svcpu(vcpu)->slb_max)
	to_svcpu(vcpu)->slb_max = 1;

	/* Are we overwriting? */
	for (i = 1; i < to_svcpu(vcpu)->slb_max; i++) {
	if (!(to_svcpu(vcpu)->slb[i].esid & SLB_ESID_V))
	found_inval = i;
	else if ((to_svcpu(vcpu)->slb[i].esid & ESID_MASK) == esid)
	return i;
	}

	/* Found a spare entry that was invalidated before */
	if (found_inval > 0)
	return found_inval;

	/* No spare invalid entry, so create one */

	if (mmu_slb_size < 64)
	max_slb_size = mmu_slb_size;

	/* Overflowing -> purge */
	if ((to_svcpu(vcpu)->slb_max) == max_slb_size)
	kvmppc_mmu_flush_segments(vcpu);

	r = to_svcpu(vcpu)->slb_max;
	to_svcpu(vcpu)->slb_max++;

	return r;
	}

	int kvmppc_mmu_map_segment(struct kvm_vcpu *vcpu, ulong eaddr)
	{
	u64 esid = eaddr >> SID_SHIFT;
	u64 slb_esid = (eaddr & ESID_MASK) \| SLB_ESID_V;
	u64 slb_vsid = SLB_VSID_USER;
	u64 gvsid;
	int slb_index;
	struct kvmppc_sid_map *map;

	slb_index = kvmppc_mmu_next_segment(vcpu, eaddr & ESID_MASK);

	if (vcpu->arch.mmu.esid_to_vsid(vcpu, esid, &gvsid)) {
	/* Invalidate an entry */
	to_svcpu(vcpu)->slb[slb_index].esid = 0;
	return -ENOENT;
	}

	map = find_sid_vsid(vcpu, gvsid);
	if (!map)
	map = create_sid_map(vcpu, gvsid);

	map->guest_esid = esid;

	slb_vsid \|= (map->host_vsid << 12);
	slb_vsid &= ~SLB_VSID_KP;
	slb_esid \|= slb_index;

	to_svcpu(vcpu)->slb[slb_index].esid = slb_esid;
	to_svcpu(vcpu)->slb[slb_index].vsid = slb_vsid;

	dprintk_slb("slbmte %#llx, %#llx\n", slb_vsid, slb_esid);

	return 0;
	}

	void kvmppc_mmu_flush_segments(struct kvm_vcpu *vcpu)
	{
	to_svcpu(vcpu)->slb_max = 1;
	to_svcpu(vcpu)->slb[0].esid = 0;
	}

	void kvmppc_mmu_destroy(struct kvm_vcpu *vcpu)
	{
	kvmppc_mmu_pte_flush(vcpu, 0, 0);
	__destroy_context(to_book3s(vcpu)->context_id);
	}

	int kvmppc_mmu_init(struct kvm_vcpu *vcpu)
	{
	struct kvmppc_vcpu_book3s *vcpu3s = to_book3s(vcpu);
	int err;

	err = __init_new_context();
	if (err < 0)
	return -1;
	vcpu3s->context_id = err;

	vcpu3s->vsid_max = ((vcpu3s->context_id + 1) << USER_ESID_BITS) - 1;
	vcpu3s->vsid_first = vcpu3s->context_id << USER_ESID_BITS;
	vcpu3s->vsid_next = vcpu3s->vsid_first;

	return 0;
	}