Re: [Qemu-devel] [PATCH] nvme: do not advertise support for unsupported arbitration mechanism

[Max Reitz]

On 06.06.19 11:25, Klaus Birkelund Jensen wrote:
> The device mistakenly reports that the Weighted Round Robin with Urgent
> Priority Class arbitration mechanism is supported.
> 
> It is not.

I believe you based on the fact that there is no “weight” or “priority”
anywhere in nvme.c, and that it does not evaluate the Arbitration
Mechanism Selected field.

> Signed-off-by: Klaus Birkelund Jensen <address@hidden>
> ---
>  hw/block/nvme.c | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/hw/block/nvme.c b/hw/block/nvme.c
> index 30e50f7a3853..415b4641d6b4 100644
> --- a/hw/block/nvme.c
> +++ b/hw/block/nvme.c
> @@ -1383,7 +1383,6 @@ static void nvme_realize(PCIDevice *pci_dev, Error 
> **errp)
>      n->bar.cap = 0;
>      NVME_CAP_SET_MQES(n->bar.cap, 0x7ff);
>      NVME_CAP_SET_CQR(n->bar.cap, 1);
> -    NVME_CAP_SET_AMS(n->bar.cap, 1);

I suppose the better way would be to pass 0, so it is more explicit, I
think.

(Just removing it looks like it may have just been forgotten.)

Max

>      NVME_CAP_SET_TO(n->bar.cap, 0xf);
>      NVME_CAP_SET_CSS(n->bar.cap, 1);
>      NVME_CAP_SET_MPSMAX(n->bar.cap, 4);
>

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