Re: [PATCH v5 05/14] hw/block/nvme: Add support for Namespace Types

[Keith Busch]

On Thu, Oct 01, 2020 at 11:22:46AM +0000, Niklas Cassel wrote:
> On Mon, Sep 28, 2020 at 11:35:19AM +0900, Dmitry Fomichev wrote:
> > From: Niklas Cassel <niklas.cassel@wdc.com>
> > @@ -2222,6 +2328,30 @@ static void nvme_write_bar(NvmeCtrl *n, hwaddr 
> > offset, uint64_t data,
> >          break;
> >      case 0x14:  /* CC */
> >          trace_pci_nvme_mmio_cfg(data & 0xffffffff);
> > +
> > +        if (NVME_CC_CSS(data) != NVME_CC_CSS(n->bar.cc)) {
> > +            if (NVME_CC_EN(n->bar.cc)) {
> 
> I just saw this print when doing controller reset on a live system.
> 
> Added a debug print:
> nvme_write_bar WRITING: 0x0 previous: 0x464061
> 
> so the second if-statement has to be:
> 
>     if (NVME_CC_EN(n->bar.cc) && NVME_CC_EN(data)) {
> 
> Sorry for introducing the bug in the first place.

No worries.

I don't think the check should be here at all, really. The only check for valid
CSS should be in nvme_start_ctrl(), which I posted yesterday.
 
> > +                NVME_GUEST_ERR(pci_nvme_err_change_css_when_enabled,
> > +                               "changing selected command set when 
> > enabled");
> > +            } else {
> > +                switch (NVME_CC_CSS(data)) {
> > +                case CSS_NVM_ONLY:
> > +                    trace_pci_nvme_css_nvm_cset_selected_by_host(data &
> > +                                                                 
> > 0xffffffff);
> > +                    break;
> > +                case CSS_CSI:
> > +                    NVME_SET_CC_CSS(n->bar.cc, CSS_CSI);
> > +                    trace_pci_nvme_css_all_csets_sel_by_host(data & 
> > 0xffffffff);
> > +                    break;
> > +                case CSS_ADMIN_ONLY:
> > +                    break;
> > +                default:
> > +                    NVME_GUEST_ERR(pci_nvme_ub_unknown_css_value,
> > +                                   "unknown value in CC.CSS field");
> > +                }
> > +            }
> > +        }