On Mon, Jan 25, 2021 at 07:03:32PM +0100, Klaus Jensen wrote: > On Jan 24 11:54, Minwoo Im wrote: > > We have nvme-subsys and nvme devices mapped together. To support > > multi-controller scheme to this setup, controller identifier(id) has to > > be managed. Earlier, cntlid(controller id) used to be always 0 because > > we didn't have any subsystem scheme that controller id matters. > > > > This patch introduced 'cntlid' attribute to the nvme controller > > instance(NvmeCtrl) and make it allocated by the nvme-subsys device > > mapped to the controller. If nvme-subsys is not given to the > > controller, then it will always be 0 as it was. > > > > Added 'ctrls' array in the nvme-subsys instance to manage attached > > controllers to the subsystem with a limit(32). This patch didn't take > > list for the controllers to make it seamless with nvme-ns device. > > > > Signed-off-by: Minwoo Im <minwoo.im....@gmail.com> > > --- > > hw/block/nvme-subsys.c | 21 +++++++++++++++++++++ > > hw/block/nvme-subsys.h | 4 ++++ > > hw/block/nvme.c | 29 +++++++++++++++++++++++++++++ > > hw/block/nvme.h | 1 + > > 4 files changed, 55 insertions(+) > > > > diff --git a/hw/block/nvme.c b/hw/block/nvme.c > > index b525fca14103..7138389be4bd 100644 > > --- a/hw/block/nvme.c > > +++ b/hw/block/nvme.c > > @@ -4481,6 +4484,10 @@ static void nvme_init_ctrl(NvmeCtrl *n, PCIDevice > > *pci_dev) > > id->psd[0].enlat = cpu_to_le32(0x10); > > id->psd[0].exlat = cpu_to_le32(0x4); > > > > + if (n->subsys) { > > + id->cmic |= NVME_CMIC_MULTI_CTRL; > > + } > > Since multiple controllers show up with a PCIe port of their own, do we > need to set bit 0 (NVME_CMIC_MULTI_PORT?) as well? Or am I > misunderstanding that bit?
AIUI, if you report this MULTI_PORT bit, then each PCI device in the subsystem needs to report a different "Port Number" in their PCIe Link Capabilities register. I don't think we can manipulate that value from the nvme "device", but I also don't know what a host should do with this information even if we could. So, I think it's safe to leave it at 0.