Example #1
0
static void
p2m_remove_page(struct p2m_domain *p2m, unsigned long gfn, unsigned long mfn,
                unsigned int page_order)
{
    unsigned long i;
    mfn_t mfn_return;
    p2m_type_t t;
    p2m_access_t a;

    if ( !paging_mode_translate(p2m->domain) )
    {
        if ( need_iommu(p2m->domain) )
            for ( i = 0; i < (1 << page_order); i++ )
                iommu_unmap_page(p2m->domain, mfn + i);
        return;
    }

    ASSERT(gfn_locked_by_me(p2m, gfn));
    P2M_DEBUG("removing gfn=%#lx mfn=%#lx\n", gfn, mfn);

    if ( mfn_valid(_mfn(mfn)) )
    {
        for ( i = 0; i < (1UL << page_order); i++ )
        {
            mfn_return = p2m->get_entry(p2m, gfn + i, &t, &a, 0, NULL);
            if ( !p2m_is_grant(t) && !p2m_is_shared(t) )
                set_gpfn_from_mfn(mfn+i, INVALID_M2P_ENTRY);
            ASSERT( !p2m_is_valid(t) || mfn + i == mfn_x(mfn_return) );
        }
    }
    set_p2m_entry(p2m, gfn, _mfn(INVALID_MFN), page_order, p2m_invalid, p2m->default_access);
}
Example #2
0
static mfn_t
p2m_gfn_to_mfn(struct p2m_domain *p2m, unsigned long gfn, 
               p2m_type_t *t, p2m_access_t *a, p2m_query_t q,
               unsigned int *page_order)
{
    mfn_t mfn;
    paddr_t addr = ((paddr_t)gfn) << PAGE_SHIFT;
    l2_pgentry_t *l2e;
    l1_pgentry_t *l1e;
    unsigned long l1e_flags;
    p2m_type_t l1t;

    ASSERT(paging_mode_translate(p2m->domain));

    /* XXX This is for compatibility with the old model, where anything not 
     * XXX marked as RAM was considered to be emulated MMIO space.
     * XXX Once we start explicitly registering MMIO regions in the p2m 
     * XXX we will return p2m_invalid for unmapped gfns */
    *t = p2m_mmio_dm;
    /* Not implemented except with EPT */
    *a = p2m_access_rwx; 

    if ( gfn > p2m->max_mapped_pfn )
        /* This pfn is higher than the highest the p2m map currently holds */
        return _mfn(INVALID_MFN);

    /* Use the fast path with the linear mapping if we can */
    if ( p2m == p2m_get_hostp2m(current->domain) )
        return p2m_gfn_to_mfn_current(p2m, gfn, t, a, q, page_order);

    mfn = pagetable_get_mfn(p2m_get_pagetable(p2m));

#if CONFIG_PAGING_LEVELS >= 4
    {
        l4_pgentry_t *l4e = map_domain_page(mfn_x(mfn));
        l4e += l4_table_offset(addr);
        if ( (l4e_get_flags(*l4e) & _PAGE_PRESENT) == 0 )
        {
            unmap_domain_page(l4e);
            return _mfn(INVALID_MFN);
        }
        mfn = _mfn(l4e_get_pfn(*l4e));
        unmap_domain_page(l4e);
    }
#endif
    {
        l3_pgentry_t *l3e = map_domain_page(mfn_x(mfn));
#if CONFIG_PAGING_LEVELS == 3
        /* On PAE hosts the p2m has eight l3 entries, not four (see
         * shadow_set_p2m_entry()) so we can't use l3_table_offset.
         * Instead, just count the number of l3es from zero.  It's safe
         * to do this because we already checked that the gfn is within
         * the bounds of the p2m. */
        l3e += (addr >> L3_PAGETABLE_SHIFT);
#else
        l3e += l3_table_offset(addr);
#endif
pod_retry_l3:
        if ( (l3e_get_flags(*l3e) & _PAGE_PRESENT) == 0 )
        {
            if ( p2m_flags_to_type(l3e_get_flags(*l3e)) == p2m_populate_on_demand )
            {
                if ( q & P2M_ALLOC )
                {
                    if ( !p2m_pod_demand_populate(p2m, gfn, PAGE_ORDER_1G, q) )
                        goto pod_retry_l3;
                    gdprintk(XENLOG_ERR, "%s: Allocate 1GB failed!\n", __func__);
                }
                else
                    *t = p2m_populate_on_demand;
            }
            unmap_domain_page(l3e);
            return _mfn(INVALID_MFN);
        }
        else if ( (l3e_get_flags(*l3e) & _PAGE_PSE) )
        {
            mfn = _mfn(l3e_get_pfn(*l3e) +
                       l2_table_offset(addr) * L1_PAGETABLE_ENTRIES +
                       l1_table_offset(addr));
            *t = p2m_flags_to_type(l3e_get_flags(*l3e));
            unmap_domain_page(l3e);

            ASSERT(mfn_valid(mfn) || !p2m_is_ram(*t));
            if ( page_order )
                *page_order = PAGE_ORDER_1G;
            return (p2m_is_valid(*t)) ? mfn : _mfn(INVALID_MFN);
        }

        mfn = _mfn(l3e_get_pfn(*l3e));
        unmap_domain_page(l3e);
    }

    l2e = map_domain_page(mfn_x(mfn));
    l2e += l2_table_offset(addr);

pod_retry_l2:
    if ( (l2e_get_flags(*l2e) & _PAGE_PRESENT) == 0 )
    {
        /* PoD: Try to populate a 2-meg chunk */
        if ( p2m_flags_to_type(l2e_get_flags(*l2e)) == p2m_populate_on_demand )
        {
            if ( q & P2M_ALLOC ) {
                if ( !p2m_pod_demand_populate(p2m, gfn, PAGE_ORDER_2M, q) )
                    goto pod_retry_l2;
            } else
                *t = p2m_populate_on_demand;
        }
    
        unmap_domain_page(l2e);
        return _mfn(INVALID_MFN);
    }
    else if ( (l2e_get_flags(*l2e) & _PAGE_PSE) )
    {
        mfn = _mfn(l2e_get_pfn(*l2e) + l1_table_offset(addr));
        *t = p2m_flags_to_type(l2e_get_flags(*l2e));
        unmap_domain_page(l2e);
        
        ASSERT(mfn_valid(mfn) || !p2m_is_ram(*t));
        if ( page_order )
            *page_order = PAGE_ORDER_2M;
        return (p2m_is_valid(*t)) ? mfn : _mfn(INVALID_MFN);
    }

    mfn = _mfn(l2e_get_pfn(*l2e));
    unmap_domain_page(l2e);

    l1e = map_domain_page(mfn_x(mfn));
    l1e += l1_table_offset(addr);
pod_retry_l1:
    l1e_flags = l1e_get_flags(*l1e);
    l1t = p2m_flags_to_type(l1e_flags);
    if ( ((l1e_flags & _PAGE_PRESENT) == 0) && (!p2m_is_paging(l1t)) )
    {
        /* PoD: Try to populate */
        if ( l1t == p2m_populate_on_demand )
        {
            if ( q & P2M_ALLOC ) {
                if ( !p2m_pod_demand_populate(p2m, gfn, PAGE_ORDER_4K, q) )
                    goto pod_retry_l1;
            } else
                *t = p2m_populate_on_demand;
        }
    
        unmap_domain_page(l1e);
        return _mfn(INVALID_MFN);
    }
    mfn = _mfn(l1e_get_pfn(*l1e));
    *t = l1t;
    unmap_domain_page(l1e);

    ASSERT(mfn_valid(mfn) || !p2m_is_ram(*t) || p2m_is_paging(*t));
    if ( page_order )
        *page_order = PAGE_ORDER_4K;
    return (p2m_is_valid(*t) || p2m_is_grant(*t)) ? mfn : _mfn(INVALID_MFN);
}
Example #3
0
/* Read the current domain's p2m table (through the linear mapping). */
static mfn_t p2m_gfn_to_mfn_current(struct p2m_domain *p2m, 
                                    unsigned long gfn, p2m_type_t *t, 
                                    p2m_access_t *a, p2m_query_t q,
                                    unsigned int *page_order)
{
    mfn_t mfn = _mfn(INVALID_MFN);
    p2m_type_t p2mt = p2m_mmio_dm;
    paddr_t addr = ((paddr_t)gfn) << PAGE_SHIFT;
    /* XXX This is for compatibility with the old model, where anything not 
     * XXX marked as RAM was considered to be emulated MMIO space.
     * XXX Once we start explicitly registering MMIO regions in the p2m 
     * XXX we will return p2m_invalid for unmapped gfns */

    l1_pgentry_t l1e = l1e_empty(), *p2m_entry;
    l2_pgentry_t l2e = l2e_empty();
    int ret;
#if CONFIG_PAGING_LEVELS >= 4
    l3_pgentry_t l3e = l3e_empty();
#endif

    ASSERT(gfn < (RO_MPT_VIRT_END - RO_MPT_VIRT_START) 
           / sizeof(l1_pgentry_t));

#if CONFIG_PAGING_LEVELS >= 4
    /*
     * Read & process L3
     */
    p2m_entry = (l1_pgentry_t *)
        &__linear_l2_table[l2_linear_offset(RO_MPT_VIRT_START)
                           + l3_linear_offset(addr)];
pod_retry_l3:
    ret = __copy_from_user(&l3e, p2m_entry, sizeof(l3e));

    if ( ret != 0 || !(l3e_get_flags(l3e) & _PAGE_PRESENT) )
    {
        if ( (l3e_get_flags(l3e) & _PAGE_PSE) &&
             (p2m_flags_to_type(l3e_get_flags(l3e)) == p2m_populate_on_demand) )
        {
            /* The read has succeeded, so we know that mapping exists */
            if ( q & P2M_ALLOC )
            {
                if ( !p2m_pod_demand_populate(p2m, gfn, PAGE_ORDER_1G, q) )
                    goto pod_retry_l3;
                p2mt = p2m_invalid;
                gdprintk(XENLOG_ERR, "%s: Allocate 1GB failed!\n", __func__);
                goto out;
            }
            else
            {
                p2mt = p2m_populate_on_demand;
                goto out;
            }
        }
        goto pod_retry_l2;
    }

    if ( l3e_get_flags(l3e) & _PAGE_PSE )
    {
        p2mt = p2m_flags_to_type(l3e_get_flags(l3e));
        ASSERT(l3e_get_pfn(l3e) != INVALID_MFN || !p2m_is_ram(p2mt));
        if (p2m_is_valid(p2mt) )
            mfn = _mfn(l3e_get_pfn(l3e) + 
                       l2_table_offset(addr) * L1_PAGETABLE_ENTRIES + 
                       l1_table_offset(addr));
        else
            p2mt = p2m_mmio_dm;
            
        if ( page_order )
            *page_order = PAGE_ORDER_1G;
        goto out;
    }
#endif
    /*
     * Read & process L2
     */
    p2m_entry = &__linear_l1_table[l1_linear_offset(RO_MPT_VIRT_START)
                                   + l2_linear_offset(addr)];

pod_retry_l2:
    ret = __copy_from_user(&l2e,
                           p2m_entry,
                           sizeof(l2e));
    if ( ret != 0
         || !(l2e_get_flags(l2e) & _PAGE_PRESENT) )
    {
        if( (l2e_get_flags(l2e) & _PAGE_PSE)
            && ( p2m_flags_to_type(l2e_get_flags(l2e))
                 == p2m_populate_on_demand ) )
        {
            /* The read has succeeded, so we know that the mapping
             * exits at this point.  */
            if ( q & P2M_ALLOC )
            {
                if ( !p2m_pod_demand_populate(p2m, gfn, 
                                                PAGE_ORDER_2M, q) )
                    goto pod_retry_l2;

                /* Allocate failed. */
                p2mt = p2m_invalid;
                printk("%s: Allocate failed!\n", __func__);
                goto out;
            }
            else
            {
                p2mt = p2m_populate_on_demand;
                goto out;
            }
        }

        goto pod_retry_l1;
    }
        
    if (l2e_get_flags(l2e) & _PAGE_PSE)
    {
        p2mt = p2m_flags_to_type(l2e_get_flags(l2e));
        ASSERT(l2e_get_pfn(l2e) != INVALID_MFN || !p2m_is_ram(p2mt));

        if ( p2m_is_valid(p2mt) )
            mfn = _mfn(l2e_get_pfn(l2e) + l1_table_offset(addr));
        else
            p2mt = p2m_mmio_dm;

        if ( page_order )
            *page_order = PAGE_ORDER_2M;
        goto out;
    }

    /*
     * Read and process L1
     */

    /* Need to __copy_from_user because the p2m is sparse and this
     * part might not exist */
pod_retry_l1:
    p2m_entry = &phys_to_machine_mapping[gfn];

    ret = __copy_from_user(&l1e,
                           p2m_entry,
                           sizeof(l1e));
            
    if ( ret == 0 ) {
        unsigned long l1e_mfn = l1e_get_pfn(l1e);
        p2mt = p2m_flags_to_type(l1e_get_flags(l1e));
        ASSERT( mfn_valid(_mfn(l1e_mfn)) || !p2m_is_ram(p2mt) ||
                p2m_is_paging(p2mt) );

        if ( p2mt == p2m_populate_on_demand )
        {
            /* The read has succeeded, so we know that the mapping
             * exits at this point.  */
            if ( q & P2M_ALLOC )
            {
                if ( !p2m_pod_demand_populate(p2m, gfn, 
                                                PAGE_ORDER_4K, q) )
                    goto pod_retry_l1;

                /* Allocate failed. */
                p2mt = p2m_invalid;
                goto out;
            }
            else
            {
                p2mt = p2m_populate_on_demand;
                goto out;
            }
        }

        if ( p2m_is_valid(p2mt) || p2m_is_grant(p2mt) )
            mfn = _mfn(l1e_mfn);
        else 
            /* XXX see above */
            p2mt = p2m_mmio_dm;
    }
    
    if ( page_order )
        *page_order = PAGE_ORDER_4K;
out:
    *t = p2mt;
    return mfn;
}
Example #4
0
static mfn_t
p2m_pt_get_entry(struct p2m_domain *p2m, unsigned long gfn,
                 p2m_type_t *t, p2m_access_t *a, p2m_query_t q,
                 unsigned int *page_order)
{
    mfn_t mfn;
    paddr_t addr = ((paddr_t)gfn) << PAGE_SHIFT;
    l2_pgentry_t *l2e;
    l1_pgentry_t *l1e;
    unsigned long l1e_flags;
    p2m_type_t l1t;

    ASSERT(paging_mode_translate(p2m->domain));

    /* XXX This is for compatibility with the old model, where anything not 
     * XXX marked as RAM was considered to be emulated MMIO space.
     * XXX Once we start explicitly registering MMIO regions in the p2m 
     * XXX we will return p2m_invalid for unmapped gfns */
    *t = p2m_mmio_dm;
    /* Not implemented except with EPT */
    *a = p2m_access_rwx; 

    if ( gfn > p2m->max_mapped_pfn )
        /* This pfn is higher than the highest the p2m map currently holds */
        return _mfn(INVALID_MFN);

    mfn = pagetable_get_mfn(p2m_get_pagetable(p2m));

    {
        l4_pgentry_t *l4e = map_domain_page(mfn_x(mfn));
        l4e += l4_table_offset(addr);
        if ( (l4e_get_flags(*l4e) & _PAGE_PRESENT) == 0 )
        {
            unmap_domain_page(l4e);
            return _mfn(INVALID_MFN);
        }
        mfn = _mfn(l4e_get_pfn(*l4e));
        unmap_domain_page(l4e);
    }
    {
        l3_pgentry_t *l3e = map_domain_page(mfn_x(mfn));
        l3e += l3_table_offset(addr);
pod_retry_l3:
        if ( (l3e_get_flags(*l3e) & _PAGE_PRESENT) == 0 )
        {
            if ( p2m_flags_to_type(l3e_get_flags(*l3e)) == p2m_populate_on_demand )
            {
                if ( q & P2M_ALLOC )
                {
                    if ( !p2m_pod_demand_populate(p2m, gfn, PAGE_ORDER_1G, q) )
                        goto pod_retry_l3;
                    gdprintk(XENLOG_ERR, "%s: Allocate 1GB failed!\n", __func__);
                }
                else
                    *t = p2m_populate_on_demand;
            }
            unmap_domain_page(l3e);
            return _mfn(INVALID_MFN);
        }
        else if ( (l3e_get_flags(*l3e) & _PAGE_PSE) )
        {
            mfn = _mfn(l3e_get_pfn(*l3e) +
                       l2_table_offset(addr) * L1_PAGETABLE_ENTRIES +
                       l1_table_offset(addr));
            *t = p2m_flags_to_type(l3e_get_flags(*l3e));
            unmap_domain_page(l3e);

            ASSERT(mfn_valid(mfn) || !p2m_is_ram(*t));
            if ( page_order )
                *page_order = PAGE_ORDER_1G;
            return (p2m_is_valid(*t)) ? mfn : _mfn(INVALID_MFN);
        }

        mfn = _mfn(l3e_get_pfn(*l3e));
        unmap_domain_page(l3e);
    }

    l2e = map_domain_page(mfn_x(mfn));
    l2e += l2_table_offset(addr);

pod_retry_l2:
    if ( (l2e_get_flags(*l2e) & _PAGE_PRESENT) == 0 )
    {
        /* PoD: Try to populate a 2-meg chunk */
        if ( p2m_flags_to_type(l2e_get_flags(*l2e)) == p2m_populate_on_demand )
        {
            if ( q & P2M_ALLOC ) {
                if ( !p2m_pod_demand_populate(p2m, gfn, PAGE_ORDER_2M, q) )
                    goto pod_retry_l2;
            } else
                *t = p2m_populate_on_demand;
        }
    
        unmap_domain_page(l2e);
        return _mfn(INVALID_MFN);
    }
    else if ( (l2e_get_flags(*l2e) & _PAGE_PSE) )
    {
        mfn = _mfn(l2e_get_pfn(*l2e) + l1_table_offset(addr));
        *t = p2m_flags_to_type(l2e_get_flags(*l2e));
        unmap_domain_page(l2e);
        
        ASSERT(mfn_valid(mfn) || !p2m_is_ram(*t));
        if ( page_order )
            *page_order = PAGE_ORDER_2M;
        return (p2m_is_valid(*t)) ? mfn : _mfn(INVALID_MFN);
    }

    mfn = _mfn(l2e_get_pfn(*l2e));
    unmap_domain_page(l2e);

    l1e = map_domain_page(mfn_x(mfn));
    l1e += l1_table_offset(addr);
pod_retry_l1:
    l1e_flags = l1e_get_flags(*l1e);
    l1t = p2m_flags_to_type(l1e_flags);
    if ( ((l1e_flags & _PAGE_PRESENT) == 0) && (!p2m_is_paging(l1t)) )
    {
        /* PoD: Try to populate */
        if ( l1t == p2m_populate_on_demand )
        {
            if ( q & P2M_ALLOC ) {
                if ( !p2m_pod_demand_populate(p2m, gfn, PAGE_ORDER_4K, q) )
                    goto pod_retry_l1;
            } else
                *t = p2m_populate_on_demand;
        }
    
        unmap_domain_page(l1e);
        return _mfn(INVALID_MFN);
    }
    mfn = _mfn(l1e_get_pfn(*l1e));
    *t = l1t;
    unmap_domain_page(l1e);

    ASSERT(mfn_valid(mfn) || !p2m_is_ram(*t) || p2m_is_paging(*t));
    if ( page_order )
        *page_order = PAGE_ORDER_4K;
    return (p2m_is_valid(*t) || p2m_is_grant(*t)) ? mfn : _mfn(INVALID_MFN);
}