Re: [Qemu-devel] [PATCH-for-4.1 v2] hw/ssi/xilinx_spips: Avoid AXI writes to the LQSPI linear memory

[P J P]

+-- On Fri, 5 Jul 2019, Philippe Mathieu-Daudé wrote --+
| +static bool lqspi_accepts(void *opaque, hwaddr addr,
| +                          unsigned size, bool is_write,
| +                          MemTxAttrs attrs)
| +{
| +    /*
| +     * From UG1085, Chapter 24 (Quad-SPI controllers):
| +     * - Writes are ignored
| +     * - AXI writes generate an external AXI slave error (SLVERR)
| +     */
| +    return !is_write;
| +}
| +
|  static uint64_t
|  lqspi_read(void *opaque, hwaddr addr, unsigned int size)
|  {
| @@ -1225,6 +1237,7 @@ static const MemoryRegionOps lqspi_ops = {
|      .read = lqspi_read,
|      .endianness = DEVICE_NATIVE_ENDIAN,
|      .valid = {
| +        .accepts = lqspi_accepts,
|          .min_access_size = 1,
|          .max_access_size = 4
|      }

Looks okay.

To confirm,
  When lqspi_accepts() returns false, guest will see an error/exception?


Reviewed-by: Prasad J Pandit <address@hidden>

Thank you.
--
Prasad J Pandit / Red Hat Product Security Team
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