> Subject: Re: [EXTERNAL] Re: [PATCH] virtio: vdpa: vDPA driver for Marvell
> OCTEON DPU devices
>
> On Fri, Mar 29, 2024 at 01:02:28PM +0000, Srujana Challa wrote:
> >> Subject: [EXTERNAL] Re: [PATCH] virtio: vdpa: vDPA driver for Marvell
> >> OCTEON DPU devices
> >>
> >> Prioritize security for external emails: Confirm sender and content
> >> safety before clicking links or opening attachments
> >>
> >> ---------------------------------------------------------------------
> >> - On Wed, Mar 27, 2024 at 04:51:36PM +0530, Srujana Challa wrote:
> >> >This commit introduces a new vDPA driver specifically designed for
> >> >managing the virtio control plane over the vDPA bus for OCTEON DPU
> >> >devices. The driver consists of two layers:
> >> >
> >> >1. Octep HW Layer (Octeon Endpoint): Responsible for handling
> >> >hardware operations and configurations related to the DPU device.
> >> >
> >> >2. Octep Main Layer: Compliant with the vDPA bus framework, this
> >> >layer implements device operations for the vDPA bus. It handles
> >> >device probing, bus attachment, vring operations, and other relevant
> tasks.
> >> >
> >> >Signed-off-by: Srujana Challa <schalla@xxxxxxxxxxx>
> >> >Signed-off-by: Vamsi Attunuru <vattunuru@xxxxxxxxxxx>
> >> >Signed-off-by: Shijith Thotton <sthotton@xxxxxxxxxxx>
> >> >Signed-off-by: Nithin Dabilpuram <ndabilpuram@xxxxxxxxxxx>
> >> >---
> >> > MAINTAINERS | 5 +
> >> > drivers/vdpa/Kconfig | 9 +
> >> > drivers/vdpa/Makefile | 1 +
> >> > drivers/vdpa/octeon_ep/Makefile | 4 +
> >> > drivers/vdpa/octeon_ep/octep_vdpa.h | 93 +++
> >> > drivers/vdpa/octeon_ep/octep_vdpa_hw.c | 457 ++++++++++++
> >> > drivers/vdpa/octeon_ep/octep_vdpa_main.c | 903
> >> +++++++++++++++++++++++
> >> > 7 files changed, 1472 insertions(+) create mode 100644
> >> > drivers/vdpa/octeon_ep/Makefile create mode
> >> 100644
> >> >drivers/vdpa/octeon_ep/octep_vdpa.h
> >> > create mode 100644 drivers/vdpa/octeon_ep/octep_vdpa_hw.c
> >> > create mode 100644 drivers/vdpa/octeon_ep/octep_vdpa_main.c
>
> [...]
>
> >> >diff --git a/drivers/vdpa/Kconfig b/drivers/vdpa/Kconfig index
> >> >656c1cb541de..775149fad476 100644
> >> >--- a/drivers/vdpa/Kconfig
> >> >+++ b/drivers/vdpa/Kconfig
> >> >@@ -126,4 +126,13 @@ config PDS_VDPA
> >> > With this driver, the VirtIO dataplane can be
> >> > offloaded to an AMD/Pensando DSC device.
> >> >
> >> >+config OCTEONEP_VDPA
> >> >+ tristate "vDPA driver for Octeon DPU devices"
> >> >+ depends on m
> >>
> >> Just for curiosity, why restrict it to module-only?
> >
> >There is an etherent driver for the same class of devices. So, we made
> >this vDPA driver as module.
>
> Sorry, I didn`t get it.
>
> What would be the problem if we don`t put `depends on m` here?
Our device's firmware needs to boot up on the card before loading
the vdpa driver.
>
> >
> >>
> >> >+ depends on PCI_MSI
> >> >+ help
> >> >+ vDPA driver for Marvell's Octeon DPU devices.
> >> >+ With this driver, the VirtIO dataplane can be
> >> >+ offloaded to a Octeon DPU device.
> >> >+
> >> > endif # VDPA
>
> [...]
>
> >> >+
> >> >+void octep_notify_queue(struct octep_hw *oct_hw, u16 qid) {
> >> >+ iowrite16(qid, oct_hw->vqs[qid].notify_addr); }
> >> >+
> >> >+void octep_read_dev_config(struct octep_hw *oct_hw, u64 offset,
> >> >+void *dst, int length) {
> >> >+ u8 old_gen, new_gen, *p;
> >> >+ int i;
> >> >+
> >> >+ WARN_ON(offset + length > oct_hw->config_size);
> >> ^
> >> Should we return early in this case?
> >Yes, I will move this to caller of this function.
>
> Otherwise you can do this here:
>
> if (WARN_ON(offset + length > oct_hw->config_size))
> return;
>
> Thanks,
> Stefano
