mtrr.c

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   {
       phys_base = ((uint64_t*)m->var_ranges)[seg*2];
       phys_mask = ((uint64_t*)m->var_ranges)[seg*2 + 1];
       if ( phys_mask & (1 << MTRR_PHYSMASK_VALID_BIT) )
       {
           if ( ((uint64_t) pa & phys_mask) >> MTRR_PHYSMASK_SHIFT ==
                (phys_base & phys_mask) >> MTRR_PHYSMASK_SHIFT )
           {
               if ( unlikely(m->overlapped) )
               {
                    overlap_mtrr |= 1 << (phys_base & MTRR_PHYSBASE_TYPE_MASK);
                    overlap_mtrr_pos = phys_base & MTRR_PHYSBASE_TYPE_MASK;
               }
               else
               {
                   /* If no overlap, return the found one */
                   return (phys_base & MTRR_PHYSBASE_TYPE_MASK);
               }
           }
       }
   }

   /* Overlapped or not found. */
   if ( unlikely(overlap_mtrr == 0) )
       return m->def_type;

   if ( likely(!(overlap_mtrr & ~( ((uint8_t)1) << overlap_mtrr_pos ))) )
       /* Covers both one variable memory range matches and
        * two or more identical match.
        */
       return overlap_mtrr_pos;

   if ( overlap_mtrr & 0x1 )
       /* Two or more match, one is UC. */
       return MTRR_TYPE_UNCACHABLE;

   if ( !(overlap_mtrr & 0xaf) )
       /* Two or more match, WT and WB. */
       return MTRR_TYPE_WRTHROUGH;

   /* Behaviour is undefined, but return the last overlapped type. */
   return overlap_mtrr_pos;
}

/*
 * return the memory type from PAT.
 * NOTE: valid only when paging is enabled.
 *       Only 4K page PTE is supported now.
 */
static uint8_t page_pat_type(uint64_t pat_cr, uint32_t pte_flags)
{
    int32_t pat_entry;

    /* PCD/PWT -> bit 1/0 of PAT entry */
    pat_entry = ( pte_flags >> 3 ) & 0x3;
    /* PAT bits as bit 2 of PAT entry */
    if ( pte_flags & _PAGE_PAT )
        pat_entry |= 4;

    return (uint8_t)pat_cr_2_paf(pat_cr, pat_entry);
}

/*
 * Effective memory type for leaf page.
 */
static uint8_t effective_mm_type(struct mtrr_state *m,
                                 uint64_t pat,
                                 paddr_t gpa,
                                 uint32_t pte_flags)
{
    uint8_t mtrr_mtype, pat_value, effective;

    mtrr_mtype = get_mtrr_type(m, gpa);

    pat_value = page_pat_type(pat, pte_flags);

    effective = mm_type_tbl[mtrr_mtype][pat_value];

    return effective;
}

static void init_mtrr_epat_tbl(void)
{
    int32_t i, j;
    /* set default value to an invalid type, just for checking conflict */
    memset(&mtrr_epat_tbl, INVALID_MEM_TYPE, sizeof(mtrr_epat_tbl));

    for ( i = 0; i < MTRR_NUM_TYPES; i++ )
    {
        for ( j = 0; j < PAT_TYPE_NUMS; j++ )
        {
            int32_t tmp = mm_type_tbl[i][j];
            if ( (tmp >= 0) && (tmp < MEMORY_NUM_TYPES) )
                mtrr_epat_tbl[i][tmp] = j;
        }
    }
}

uint32_t get_pat_flags(struct vcpu *v,
                       uint32_t gl1e_flags,
                       paddr_t gpaddr,
                       paddr_t spaddr)
{
    uint8_t guest_eff_mm_type;
    uint8_t shadow_mtrr_type;
    uint8_t pat_entry_value;
    uint64_t pat = v->arch.hvm_vcpu.pat_cr;
    struct mtrr_state *g = &v->arch.hvm_vcpu.mtrr;

    /* 1. Get the effective memory type of guest physical address,
     * with the pair of guest MTRR and PAT
     */
    guest_eff_mm_type = effective_mm_type(g, pat, gpaddr, gl1e_flags);
    /* 2. Get the memory type of host physical address, with MTRR */
    shadow_mtrr_type = get_mtrr_type(&mtrr_state, spaddr);

    /* 3. Find the memory type in PAT, with host MTRR memory type
     * and guest effective memory type.
     */
    pat_entry_value = mtrr_epat_tbl[shadow_mtrr_type][guest_eff_mm_type];
    /* If conflit occurs(e.g host MTRR is UC, guest memory type is
     * WB),set UC as effective memory. Here, returning PAT_TYPE_UNCACHABLE will
     * always set effective memory as UC.
     */
    if ( pat_entry_value == INVALID_MEM_TYPE )
    {
        gdprintk(XENLOG_WARNING,
                 "Conflict occurs for a given guest l1e flags:%x "
                 "at %"PRIx64" (the effective mm type:%d), "
                 "because the host mtrr type is:%d\n",
                 gl1e_flags, (uint64_t)gpaddr, guest_eff_mm_type,
                 shadow_mtrr_type);
        pat_entry_value = PAT_TYPE_UNCACHABLE;
    }
    /* 4. Get the pte flags */
    return pat_type_2_pte_flags(pat_entry_value);
}

/* Helper funtions for seting mtrr/pat */
bool_t pat_msr_set(uint64_t *pat, uint64_t msr_content)
{
    uint8_t *value = (uint8_t*)&msr_content;
    int32_t i;

    if ( *pat != msr_content )
    {
        for ( i = 0; i < 8; i++ )
            if ( unlikely(!(value[i] == 0 || value[i] == 1 ||
                            value[i] == 4 || value[i] == 5 ||
                            value[i] == 6 || value[i] == 7)) )
                return 0;

        *pat = msr_content;
    }

    return 1;
}

bool_t mtrr_def_type_msr_set(struct mtrr_state *m, uint64_t msr_content)
{
    uint8_t def_type = msr_content & 0xff;
    uint8_t enabled = (msr_content >> 10) & 0x3;

    if ( unlikely(!(def_type == 0 || def_type == 1 || def_type == 4 ||
                    def_type == 5 || def_type == 6)) )
    {
         HVM_DBG_LOG(DBG_LEVEL_MSR, "invalid MTRR def type:%x\n", def_type);
         return 0;
    }

    if ( unlikely(msr_content && (msr_content & ~0xcffUL)) )
    {
         HVM_DBG_LOG(DBG_LEVEL_MSR, "invalid msr content:%"PRIx64"\n",
                     msr_content);
         return 0;
    }

    m->enabled = enabled;
    m->def_type = def_type;

    return 1;
}

bool_t mtrr_fix_range_msr_set(struct mtrr_state *m, uint32_t row,
                              uint64_t msr_content)
{
    uint64_t *fixed_range_base = (uint64_t *)m->fixed_ranges;

    if ( fixed_range_base[row] != msr_content )
    {
        uint8_t *range = (uint8_t*)&msr_content;
        int32_t i, type;

        for ( i = 0; i < 8; i++ )
        {
            type = range[i];
            if ( unlikely(!(type == 0 || type == 1 ||
                            type == 4 || type == 5 || type == 6)) )
                return 0;
        }

        fixed_range_base[row] = msr_content;
    }

    return 1;
}

bool_t mtrr_var_range_msr_set(struct mtrr_state *m, uint32_t msr,
                              uint64_t msr_content)
{
    uint32_t index;
    uint64_t msr_mask;
    uint64_t *var_range_base = (uint64_t*)m->var_ranges;

    index = msr - MSR_IA32_MTRR_PHYSBASE0;

    if ( var_range_base[index] != msr_content )
    {
        uint32_t type = msr_content & 0xff;

        msr_mask = (index & 1) ? phys_mask_msr_mask : phys_base_msr_mask;

        if ( unlikely(!(type == 0 || type == 1 ||
                        type == 4 || type == 5 || type == 6)) )
            return 0;

        if ( unlikely(msr_content && (msr_content & msr_mask)) )
        {
            HVM_DBG_LOG(DBG_LEVEL_MSR, "invalid msr content:%"PRIx64"\n",
                        msr_content);
            return 0;
        }

        var_range_base[index] = msr_content;
    }

    m->overlapped = is_var_mtrr_overlapped(m);

    return 1;
}

bool_t mtrr_pat_not_equal(struct vcpu *vd, struct vcpu *vs)
{
    struct mtrr_state *md = &vd->arch.hvm_vcpu.mtrr;
    struct mtrr_state *ms = &vs->arch.hvm_vcpu.mtrr;
    int32_t res;
    uint8_t num_var_ranges = (uint8_t)md->mtrr_cap;

    /* Test fixed ranges. */
    res = memcmp(md->fixed_ranges, ms->fixed_ranges,
            NUM_FIXED_RANGES*sizeof(mtrr_type));
    if ( res )
        return 1;

    /* Test var ranges. */
    res = memcmp(md->var_ranges, ms->var_ranges,
            num_var_ranges*sizeof(struct mtrr_var_range));
    if ( res )
        return 1;

    /* Test default type MSR. */
    if ( (md->def_type != ms->def_type)
            && (md->enabled != ms->enabled) )
        return 1;

    /* Test PAT. */
    if ( vd->arch.hvm_vcpu.pat_cr != vs->arch.hvm_vcpu.pat_cr )
        return 1;

    return 0;
}

void hvm_init_cacheattr_region_list(
    struct domain *d)
{
    INIT_LIST_HEAD(&d->arch.hvm_domain.pinned_cacheattr_ranges);
}

void hvm_destroy_cacheattr_region_list(
    struct domain *d)
{
    struct list_head *head = &d->arch.hvm_domain.pinned_cacheattr_ranges;
    struct hvm_mem_pinned_cacheattr_range *range;

    while ( !list_empty(head) )
    {
        range = list_entry(head->next,
                           struct hvm_mem_pinned_cacheattr_range,
                           list);
        list_del(&range->list);
        xfree(range);
    }
}

int32_t hvm_get_mem_pinned_cacheattr(
    struct domain *d,
    uint64_t guest_fn,
    uint32_t *type)
{
    struct hvm_mem_pinned_cacheattr_range *range;

    *type = 0;

    if ( !is_hvm_domain(d) )
        return 0;

    list_for_each_entry_rcu ( range,
                              &d->arch.hvm_domain.pinned_cacheattr_ranges,
                              list )
    {
        if ( (guest_fn >= range->start) && (guest_fn <= range->end) )
        {
            *type = range->type;
            return 1;
        }
    }

    return 0;
}

int32_t hvm_set_mem_pinned_cacheattr(
    struct domain *d,
    uint64_t gfn_start,
    uint64_t gfn_end,
    uint32_t  type)
{
    struct hvm_mem_pinned_cacheattr_range *range;

    if ( !((type == PAT_TYPE_UNCACHABLE) ||
           (type == PAT_TYPE_WRCOMB) ||
           (type == PAT_TYPE_WRTHROUGH) ||
           (type == PAT_TYPE_WRPROT) ||
           (type == PAT_TYPE_WRBACK) ||
           (type == PAT_TYPE_UC_MINUS)) ||
         !is_hvm_domain(d) )
        return -EINVAL;

    range = xmalloc(struct hvm_mem_pinned_cacheattr_range);
    if ( range == NULL )
        return -ENOMEM;

    memset(range, 0, sizeof(*range));

    range->start = gfn_start;
    range->end = gfn_end;
    range->type = type;

    list_add_rcu(&range->list, &d->arch.hvm_domain.pinned_cacheattr_ranges);

    return 0;
}

static int hvm_save_mtrr_msr(struct domain *d, hvm_domain_context_t *h)
{
    int i;
    struct vcpu *v;
    struct hvm_hw_mtrr hw_mtrr;
    struct mtrr_state *mtrr_state;
    /* save mtrr&pat */
    for_each_vcpu(d, v)
    {
        mtrr_state = &v->arch.hvm_vcpu.mtrr;

        hw_mtrr.msr_pat_cr = v->arch.hvm_vcpu.pat_cr;

        hw_mtrr.msr_mtrr_def_type = mtrr_state->def_type
                                | (mtrr_state->enabled << 10);
        hw_mtrr.msr_mtrr_cap = mtrr_state->mtrr_cap;

        for ( i = 0; i < MTRR_VCNT; i++ )
        {
            /* save physbase */
            hw_mtrr.msr_mtrr_var[i*2] =
                ((uint64_t*)mtrr_state->var_ranges)[i*2];
            /* save physmask */
            hw_mtrr.msr_mtrr_var[i*2+1] =
                ((uint64_t*)mtrr_state->var_ranges)[i*2+1];
        }

        for ( i = 0; i < NUM_FIXED_MSR; i++ )
            hw_mtrr.msr_mtrr_fixed[i] =
                ((uint64_t*)mtrr_state->fixed_ranges)[i];

        if ( hvm_save_entry(MTRR, v->vcpu_id, h, &hw_mtrr) != 0 )
            return 1;
    }
    return 0;
}

static int hvm_load_mtrr_msr(struct domain *d, hvm_domain_context_t *h)
{
    int vcpuid, i;
    struct vcpu *v;
    struct mtrr_state *mtrr_state;
    struct hvm_hw_mtrr hw_mtrr;

    vcpuid = hvm_load_instance(h);
    if ( vcpuid > MAX_VIRT_CPUS || (v = d->vcpu[vcpuid]) == NULL )
    {
        gdprintk(XENLOG_ERR, "HVM restore: domain has no vcpu %u\n", vcpuid);
        return -EINVAL;
    }

    if ( hvm_load_entry(MTRR, h, &hw_mtrr) != 0 )
        return -EINVAL;

    mtrr_state = &v->arch.hvm_vcpu.mtrr;

    pat_msr_set(&v->arch.hvm_vcpu.pat_cr, hw_mtrr.msr_pat_cr);

    mtrr_state->mtrr_cap = hw_mtrr.msr_mtrr_cap;

    for ( i = 0; i < NUM_FIXED_MSR; i++ )
        mtrr_fix_range_msr_set(mtrr_state, i, hw_mtrr.msr_mtrr_fixed[i]);

    for ( i = 0; i < MTRR_VCNT; i++ )
    {
        mtrr_var_range_msr_set(mtrr_state,
                MTRRphysBase_MSR(i), hw_mtrr.msr_mtrr_var[i*2]);
        mtrr_var_range_msr_set(mtrr_state,
                MTRRphysMask_MSR(i), hw_mtrr.msr_mtrr_var[i*2+1]);
    }

    mtrr_def_type_msr_set(mtrr_state, hw_mtrr.msr_mtrr_def_type);

    v->arch.hvm_vcpu.mtrr.is_initialized = 1;
    return 0;
}

HVM_REGISTER_SAVE_RESTORE(MTRR, hvm_save_mtrr_msr, hvm_load_mtrr_msr,
                          1, HVMSR_PER_VCPU);