Re: [Qemu-devel] [PULL v2 1/2] hw/block/pflash_cfi01: Add missing DeviceReset() handler

[Laszlo Ersek <lersek@redhat.com>]

On 07/23/19 11:35, Philippe Mathieu-Daudé wrote:
> To avoid incoherent states when the machine resets (see bug report
> below), add the device reset callback.
> 
> A "system reset" sets the device state machine in READ_ARRAY mode
> and, after some delay, set the SR.7 READY bit.
> 
> Since we do not model timings, we set the SR.7 bit directly.
> 
> Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1678713
> Reported-by: Laszlo Ersek <lersek@redhat.com>
> Reviewed-by: John Snow <jsnow@redhat.com>
> Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
> Reviewed-by: Laszlo Ersek <lersek@redhat.com>
> Tested-by: Laszlo Ersek <lersek@redhat.com>
> [Laszlo Ersek: Regression tested EDK2 OVMF IA32X64, ArmVirtQemu Aarch64
>  https://lists.gnu.org/archive/html/qemu-devel/2019-07/msg04373.html]

Nice, thanks! :)
Laszlo

> Message-Id: <20190718104837.13905-2-philmd@redhat.com>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
>  hw/block/pflash_cfi01.c | 19 +++++++++++++++++++
>  1 file changed, 19 insertions(+)
> 
> diff --git a/hw/block/pflash_cfi01.c b/hw/block/pflash_cfi01.c
> index 435be1e35c..a1ec1faae5 100644
> --- a/hw/block/pflash_cfi01.c
> +++ b/hw/block/pflash_cfi01.c
> @@ -865,6 +865,24 @@ static void pflash_cfi01_realize(DeviceState *dev, Error **errp)
>      pfl->cfi_table[0x3f] = 0x01; /* Number of protection fields */
>  }
>  
> +static void pflash_cfi01_system_reset(DeviceState *dev)
> +{
> +    PFlashCFI01 *pfl = PFLASH_CFI01(dev);
> +
> +    /*
> +     * The command 0x00 is not assigned by the CFI open standard,
> +     * but QEMU historically uses it for the READ_ARRAY command (0xff).
> +     */
> +    pfl->cmd = 0x00;
> +    pfl->wcycle = 0;
> +    memory_region_rom_device_set_romd(&pfl->mem, true);
> +    /*
> +     * The WSM ready timer occurs at most 150ns after system reset.
> +     * This model deliberately ignores this delay.
> +     */
> +    pfl->status = 0x80;
> +}
> +
>  static Property pflash_cfi01_properties[] = {
>      DEFINE_PROP_DRIVE("drive", PFlashCFI01, blk),
>      /* num-blocks is the number of blocks actually visible to the guest,
> @@ -909,6 +927,7 @@ static void pflash_cfi01_class_init(ObjectClass *klass, void *data)
>  {
>      DeviceClass *dc = DEVICE_CLASS(klass);
>  
> +    dc->reset = pflash_cfi01_system_reset;
>      dc->realize = pflash_cfi01_realize;
>      dc->props = pflash_cfi01_properties;
>      dc->vmsd = &vmstate_pflash;
>