Commit 1e40356c authored by Michael S. Tsirkin's avatar Michael S. Tsirkin
Browse files

virtio fix cfg endian-ness for BE targets 



address_space_rw assumes data is in target format
and byte-swaps it if target is BE and device is LE.
Use fixed-endian LE APIs instead.

Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent ada434cd

hw/virtio/virtio-pci.c

+83 −8
Original line number Diff line number Diff line
@@ -443,6 +443,83 @@ static const MemoryRegionOps virtio_pci_config_ops = { 
    .endianness = DEVICE_LITTLE_ENDIAN,

};



/* Below are generic functions to do memcpy from/to an address space,

 * without byteswaps, with input validation.

 *

 * As regular address_space_* APIs all do some kind of byteswap at least for

 * some host/target combinations, we are forced to explicitly convert to a

 * known-endianness integer value.

 * It doesn't really matter which endian format to go through, so the code

 * below selects the endian that causes the least amount of work on the given

 * host.

 *

 * Note: host pointer must be aligned.

 */

static

void virtio_address_space_write(AddressSpace *as, hwaddr addr,

                                const uint8_t *buf, int len)

{

    uint32_t val;



    /* address_space_* APIs assume an aligned address.

     * As address is under guest control, handle illegal values.

     */

    addr &= ~(len - 1);



    /* Make sure caller aligned buf properly */

    assert(!(((uintptr_t)buf) & (len - 1)));



    switch (len) {

    case 1:

        val = pci_get_byte(buf);

        address_space_stb(as, addr, val, MEMTXATTRS_UNSPECIFIED, NULL);

        break;

    case 2:

        val = pci_get_word(buf);

        address_space_stw_le(as, addr, val, MEMTXATTRS_UNSPECIFIED, NULL);

        break;

    case 4:

        val = pci_get_long(buf);

        address_space_stl_le(as, addr, val, MEMTXATTRS_UNSPECIFIED, NULL);

        break;

    default:

        /* As length is under guest control, handle illegal values. */

        break;

    }

}



static void

virtio_address_space_read(AddressSpace *as, hwaddr addr, uint8_t *buf, int len)

{

    uint32_t val;



    /* address_space_* APIs assume an aligned address.

     * As address is under guest control, handle illegal values.

     */

    addr &= ~(len - 1);



    /* Make sure caller aligned buf properly */

    assert(!(((uintptr_t)buf) & (len - 1)));



    switch (len) {

    case 1:

        val = address_space_ldub(as, addr, MEMTXATTRS_UNSPECIFIED, NULL);

        pci_set_byte(buf, val);

        break;

    case 2:

        val = address_space_lduw_le(as, addr, MEMTXATTRS_UNSPECIFIED, NULL);

        pci_set_word(buf, val);

        break;

    case 4:

        val = address_space_ldl_le(as, addr, MEMTXATTRS_UNSPECIFIED, NULL);

        pci_set_long(buf, val);

        break;

    default:

        /* As length is under guest control, handle illegal values. */

        break;

    }

}



static void virtio_write_config(PCIDevice *pci_dev, uint32_t address,

                                uint32_t val, int len)

{
@@ -469,9 +546,8 @@ static void virtio_write_config(PCIDevice *pci_dev, uint32_t address, 
        off = le32_to_cpu(cfg->cap.offset);

        len = le32_to_cpu(cfg->cap.length);



        if ((len == 1 || len == 2 || len == 4)) {

            address_space_write(&proxy->modern_as, off,

                                MEMTXATTRS_UNSPECIFIED,

        if (len <= sizeof cfg->pci_cfg_data) {

            virtio_address_space_write(&proxy->modern_as, off,

                                       cfg->pci_cfg_data, len);

        }

    }
@@ -494,9 +570,8 @@ static uint32_t virtio_read_config(PCIDevice *pci_dev, 
        off = le32_to_cpu(cfg->cap.offset);

        len = le32_to_cpu(cfg->cap.length);



        if ((len == 1 || len == 2 || len == 4)) {

            address_space_read(&proxy->modern_as, off,

                                MEMTXATTRS_UNSPECIFIED,

        if (len <= sizeof cfg->pci_cfg_data) {

            virtio_address_space_read(&proxy->modern_as, off,

                                      cfg->pci_cfg_data, len);

        }

    }