book3s_32_mmu_host.c

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/*
 * Copyright (C) 2010 SUSE Linux Products GmbH. All rights reserved.
 *
 * Authors:
 *     Alexander Graf <[email protected]>
 *
 * 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-hash32.h>
#include <asm/machdep.h>
#include <asm/mmu_context.h>
#include <asm/hw_irq.h>

/* #define DEBUG_MMU */
/* #define DEBUG_SR */

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

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

#if PAGE_SHIFT != 12
#error Unknown page size
#endif

#ifdef CONFIG_SMP
#error XXX need to grab mmu_hash_lock
#endif

#ifdef CONFIG_PTE_64BIT
#error Only 32 bit pages are supported for now
#endif

static ulong htab;
static u32 htabmask;

void kvmppc_mmu_invalidate_pte(struct kvm_vcpu *vcpu, struct hpte_cache *pte)
{
    volatile u32 *pteg;

    /* Remove from host HTAB */
    pteg = (u32*)pte->slot;
    pteg[0] = 0;

    /* And make sure it's gone from the TLB too */
    asm volatile ("sync");
    asm volatile ("tlbie %0" : : "r" (pte->pte.eaddr) : "memory");
    asm volatile ("sync");
    asm volatile ("tlbsync");
}

/* 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.shared->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_sr("SR: 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_sr("SR: Searching 0x%llx -> 0x%llx\n",
                gvsid, map->host_vsid);
        return map;
    }

    dprintk_sr("SR: Searching 0x%llx -> not found\n", gvsid);
    return NULL;
}

static u32 *kvmppc_mmu_get_pteg(struct kvm_vcpu *vcpu, u32 vsid, u32 eaddr,
                bool primary)
{
    u32 page, hash;
    ulong pteg = htab;

    page = (eaddr & ~ESID_MASK) >> 12;

    hash = ((vsid ^ page) << 6);
    if (!primary)
        hash = ~hash;

    hash &= htabmask;

    pteg |= hash;

    dprintk_mmu("htab: %lx | hash: %x | htabmask: %x | pteg: %lx\n",
        htab, hash, htabmask, pteg);

    return (u32*)pteg;
}

extern char etext[];

int kvmppc_mmu_map_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *orig_pte)
{
    pfn_t hpaddr;
    u64 vpn;
    u64 vsid;
    struct kvmppc_sid_map *map;
    volatile u32 *pteg;
    u32 eaddr = orig_pte->eaddr;
    u32 pteg0, pteg1;
    register int rr = 0;
    bool primary = false;
    bool evict = false;
    struct hpte_cache *pte;
    int r = 0;

    /* Get host physical address for gpa */
    hpaddr = kvmppc_gfn_to_pfn(vcpu, orig_pte->raddr >> PAGE_SHIFT);
    if (is_error_pfn(hpaddr)) {
        printk(KERN_INFO "Couldn't get guest page for gfn %lx!\n",
                 orig_pte->eaddr);
        r = -EINVAL;
        goto out;
    }
    hpaddr <<= PAGE_SHIFT;

    /* 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) {
        kvmppc_mmu_map_segment(vcpu, eaddr);
        map = find_sid_vsid(vcpu, vsid);
    }
    BUG_ON(!map);

    vsid = map->host_vsid;
    vpn = (vsid << (SID_SHIFT - VPN_SHIFT)) |
        ((eaddr & ~ESID_MASK) >> VPN_SHIFT);
next_pteg:
    if (rr == 16) {
        primary = !primary;
        evict = true;
        rr = 0;
    }

    pteg = kvmppc_mmu_get_pteg(vcpu, vsid, eaddr, primary);

    /* not evicting yet */
    if (!evict && (pteg[rr] & PTE_V)) {
        rr += 2;
        goto next_pteg;
    }

    dprintk_mmu("KVM: old PTEG: %p (%d)\n", pteg, rr);
    dprintk_mmu("KVM:   %08x - %08x\n", pteg[0], pteg[1]);
    dprintk_mmu("KVM:   %08x - %08x\n", pteg[2], pteg[3]);
    dprintk_mmu("KVM:   %08x - %08x\n", pteg[4], pteg[5]);
    dprintk_mmu("KVM:   %08x - %08x\n", pteg[6], pteg[7]);
    dprintk_mmu("KVM:   %08x - %08x\n", pteg[8], pteg[9]);
    dprintk_mmu("KVM:   %08x - %08x\n", pteg[10], pteg[11]);
    dprintk_mmu("KVM:   %08x - %08x\n", pteg[12], pteg[13]);
    dprintk_mmu("KVM:   %08x - %08x\n", pteg[14], pteg[15]);

    pteg0 = ((eaddr & 0x0fffffff) >> 22) | (vsid << 7) | PTE_V |
        (primary ? 0 : PTE_SEC);
    pteg1 = hpaddr | PTE_M | PTE_R | PTE_C;

    if (orig_pte->may_write) {
        pteg1 |= PP_RWRW;
        mark_page_dirty(vcpu->kvm, orig_pte->raddr >> PAGE_SHIFT);
    } else {
        pteg1 |= PP_RWRX;
    }

    if (orig_pte->may_execute)
        kvmppc_mmu_flush_icache(hpaddr >> PAGE_SHIFT);

    local_irq_disable();

    if (pteg[rr]) {
        pteg[rr] = 0;
        asm volatile ("sync");
    }
    pteg[rr + 1] = pteg1;
    pteg[rr] = pteg0;
    asm volatile ("sync");

    local_irq_enable();

    dprintk_mmu("KVM: new PTEG: %p\n", pteg);
    dprintk_mmu("KVM:   %08x - %08x\n", pteg[0], pteg[1]);
    dprintk_mmu("KVM:   %08x - %08x\n", pteg[2], pteg[3]);
    dprintk_mmu("KVM:   %08x - %08x\n", pteg[4], pteg[5]);
    dprintk_mmu("KVM:   %08x - %08x\n", pteg[6], pteg[7]);
    dprintk_mmu("KVM:   %08x - %08x\n", pteg[8], pteg[9]);
    dprintk_mmu("KVM:   %08x - %08x\n", pteg[10], pteg[11]);
    dprintk_mmu("KVM:   %08x - %08x\n", pteg[12], pteg[13]);
    dprintk_mmu("KVM:   %08x - %08x\n", pteg[14], pteg[15]);


    /* Now tell our Shadow PTE code about the new page */

    pte = kvmppc_mmu_hpte_cache_next(vcpu);

    dprintk_mmu("KVM: %c%c Map 0x%llx: [%lx] 0x%llx (0x%llx) -> %lx\n",
            orig_pte->may_write ? 'w' : '-',
            orig_pte->may_execute ? 'x' : '-',
            orig_pte->eaddr, (ulong)pteg, vpn,
            orig_pte->vpage, hpaddr);

    pte->slot = (ulong)&pteg[rr];
    pte->host_vpn = vpn;
    pte->pte = *orig_pte;
    pte->pfn = hpaddr >> PAGE_SHIFT;

    kvmppc_mmu_hpte_cache_map(vcpu, pte);

out:
    return r;
}

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.shared->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 >= VSID_POOL_SIZE) {
        vcpu_book3s->vsid_next = 0;
        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_pool[vcpu_book3s->vsid_next];
    vcpu_book3s->vsid_next++;

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

    return map;
}

int kvmppc_mmu_map_segment(struct kvm_vcpu *vcpu, ulong eaddr)
{
    u32 esid = eaddr >> SID_SHIFT;
    u64 gvsid;
    u32 sr;
    struct kvmppc_sid_map *map;
    struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
    int r = 0;

    if (vcpu->arch.mmu.esid_to_vsid(vcpu, esid, &gvsid)) {
        /* Invalidate an entry */
        svcpu->sr[esid] = SR_INVALID;
        r = -ENOENT;
        goto out;
    }

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

    map->guest_esid = esid;
    sr = map->host_vsid | SR_KP;
    svcpu->sr[esid] = sr;

    dprintk_sr("MMU: mtsr %d, 0x%x\n", esid, sr);

out:
    svcpu_put(svcpu);
    return r;
}

void kvmppc_mmu_flush_segments(struct kvm_vcpu *vcpu)
{
    int i;
    struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);

    dprintk_sr("MMU: flushing all segments (%d)\n", ARRAY_SIZE(svcpu->sr));
    for (i = 0; i < ARRAY_SIZE(svcpu->sr); i++)
        svcpu->sr[i] = SR_INVALID;

    svcpu_put(svcpu);
}

void kvmppc_mmu_destroy(struct kvm_vcpu *vcpu)
{
    int i;

    kvmppc_mmu_hpte_destroy(vcpu);
    preempt_disable();
    for (i = 0; i < SID_CONTEXTS; i++)
        __destroy_context(to_book3s(vcpu)->context_id[i]);
    preempt_enable();
}

/* From mm/mmu_context_hash32.c */
#define CTX_TO_VSID(c, id)  ((((c) * (897 * 16)) + (id * 0x111)) & 0xffffff)

int kvmppc_mmu_init(struct kvm_vcpu *vcpu)
{
    struct kvmppc_vcpu_book3s *vcpu3s = to_book3s(vcpu);
    int err;
    ulong sdr1;
    int i;
    int j;

    for (i = 0; i < SID_CONTEXTS; i++) {
        err = __init_new_context();
        if (err < 0)
            goto init_fail;
        vcpu3s->context_id[i] = err;

        /* Remember context id for this combination */
        for (j = 0; j < 16; j++)
            vcpu3s->vsid_pool[(i * 16) + j] = CTX_TO_VSID(err, j);
    }

    vcpu3s->vsid_next = 0;

    /* Remember where the HTAB is */
    asm ( "mfsdr1 %0" : "=r"(sdr1) );
    htabmask = ((sdr1 & 0x1FF) << 16) | 0xFFC0;
    htab = (ulong)__va(sdr1 & 0xffff0000);

    kvmppc_mmu_hpte_init(vcpu);

    return 0;

init_fail:
    for (j = 0; j < i; j++) {
        if (!vcpu3s->context_id[j])
            continue;

        __destroy_context(to_book3s(vcpu)->context_id[j]);
    }

    return -1;
}