Re: [PATCH v2 15/18] hw/block/nvme: reject invalid nsid values in active namespace id list

[Klaus Jensen]

On Jul  3 11:14, Philippe Mathieu-Daudé wrote:
> On 7/3/20 10:37 AM, Klaus Jensen wrote:
> > On Jul  3 10:20, Philippe Mathieu-Daudé wrote:
> >> On 7/3/20 8:34 AM, Klaus Jensen wrote:
> >>> From: Klaus Jensen <k.jensen@samsung.com>
> >>>
> >>> Reject the nsid broadcast value (0xffffffff) and 0xfffffffe in the
> >>> Active Namespace ID list.
> >>
> >> Can we have a definition instead of this 0xfffffffe magic value please?
> >>
> > 
> > Hmm, not really actually. It's not a magic value, its just because the
> > logic in Active Namespace ID list would require that it should report
> > any namespaces with ids *higher* than the one specified, so since
> > 0xffffffff (NVME_NSID_BROADCAST) is invalid, NVME_NSID_BROADCAST - 1
> > needs to be as well.
> 
> OK.
> 
> > 
> > What do you say I change it to `min_nsid >= NVME_NSID_BROADCAST - 1`?
> > The original condition just reads well if you are sitting with the spec
> > on the side.
> 
> IMO this is clearer:
> 
>   if (min_nsid + 1 >= NVME_NSID_BROADCAST) {
>       return NVME_INVALID_NSID | NVME_DNR;
>   }
> 

But since min_nsid is uint32_t that would not be wise ;)

I'll go with the - 1 and add a comment!

> Whichever form you prefer you can amend to the respin patch:
> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> 
> > 
> >>>
> >>> Signed-off-by: Klaus Jensen <k.jensen@samsung.com>
> >>> ---
> >>>  hw/block/nvme.c | 4 ++++
> >>>  1 file changed, 4 insertions(+)
> >>>
> >>> diff --git a/hw/block/nvme.c b/hw/block/nvme.c
> >>> index 65c2fa3ac1f4..0dac7a41ddae 100644
> >>> --- a/hw/block/nvme.c
> >>> +++ b/hw/block/nvme.c
> >>> @@ -956,6 +956,10 @@ static uint16_t nvme_identify_nslist(NvmeCtrl *n, 
> >>> NvmeIdentify *c)
> >>>  
> >>>      trace_pci_nvme_identify_nslist(min_nsid);
> >>>  
> >>> +    if (min_nsid == 0xfffffffe || min_nsid == NVME_NSID_BROADCAST) {
> >>> +        return NVME_INVALID_NSID | NVME_DNR;
> >>> +    }
> >>> +
> >>>      list = g_malloc0(data_len);
> >>>      for (i = 0; i < n->num_namespaces; i++) {
> >>>          if (i < min_nsid) {
> >>>
> >>
> > 
>