On Tue, Aug 28, 2018 at 6:22 PM Arnd Bergmann <arnd@xxxxxxxx> wrote: > > On Tue, Aug 28, 2018 at 2:48 PM Sunil Kovvuri <sunil.kovvuri@xxxxxxxxx> wrote: > > > > On Tue, Aug 28, 2018 at 5:33 PM Arnd Bergmann <arnd@xxxxxxxx> wrote: > > > > > > On Tue, Aug 28, 2018 at 12:57 PM <sunil.kovvuri@xxxxxxxxx> wrote: > > > > > > > > From: Aleksey Makarov <amakarov@xxxxxxxxxxx> > > > > > > > > This patch adds mailbox support infrastructure APIs. > > > > Each RVU device has a dedicated 64KB mailbox region > > > > shared with it's peer for communication. RVU AF has > > > > a separate mailbox region shared with each of RVU PFs > > > > and a RVU PF has a separate region shared with each of > > > > it's VF. > > > > > > > > These set of APIs are used by this driver (RVU AF) and > > > > other RVU PF/VF drivers eg netdev, crypto e.t.c. > > > > > > > > Signed-off-by: Aleksey Makarov <amakarov@xxxxxxxxxxx> > > > > Signed-off-by: Sunil Goutham <sgoutham@xxxxxxxxxxx> > > > > Signed-off-by: Lukasz Bartosik <lbartosik@xxxxxxxxxxx> > > > > > > Why does this driver not use the drivers/mailbox/ infrastructure? > > > > > This is a common administrative software driver which will be handling requests > > from kernel drivers and as well as drivers in userspace applications. > > We had to keep mailbox communication infrastructure same across all usages. > > Can you explain more about the usage of userspace applications > and what interface you plan to use into the kernel? Any PCI device here irrespective in what domain (kernel or userspace) they are in use common mailbox communication. Which is # Write a mailbox msg (format is agreed between all parties) into shared (between AF and other PF/VFs) memory region and trigger a interrupt to admin function. # Admin function processes the msg and puts reply in the same memory region and trigger IRQ to the requesting device. If the device has a driver instance in kernel then it uses IRQ and userspace applications does polling on the IRQ status bit. > > Do you things like AF_XDP and virtual machines, or something else? I meant drivers in DPDK which may or may not use AF_XDP. And yes if a PCI device is attached to a virtual machine then that also uses the same mailbox communication. Sunil. > > Arnd
