Hi Bertrand, On Wed, Apr 10, 2024 at 6:30 PM Bertrand Marquis <bertrand.marq...@arm.com> wrote: > > Hi Jens, > > > On 10 Apr 2024, at 17:45, Jens Wiklander <jens.wiklan...@linaro.org> wrote: > > > > On Tue, Apr 9, 2024 at 5:36 PM Jens Wiklander <jens.wiklan...@linaro.org> > > wrote: > >> > >> Add support for FF-A notifications, currently limited to an SP (Secure > >> Partition) sending an asynchronous notification to a guest. > >> > >> Guests and Xen itself are made aware of pending notifications with an > >> interrupt. The interrupt handler retrieves the notifications using the > >> FF-A ABI and deliver them to their destinations. > >> > >> Signed-off-by: Jens Wiklander <jens.wiklan...@linaro.org> > >> --- [snip] > >> + case FFA_FEATURE_NOTIF_PEND_INTR: > >> + if ( ctx->notif.enabled ) > >> + ffa_set_regs_success(regs, FFA_NOTIF_PEND_INTR_ID, 0); > >> + else > >> + ffa_set_regs_error(regs, FFA_RET_NOT_SUPPORTED); > >> + break; > >> + case FFA_FEATURE_SCHEDULE_RECV_INTR: > >> + if ( ctx->notif.enabled ) > >> + ffa_set_regs_success(regs, FFA_NOTIF_PEND_INTR_ID, 0); > >> + else > >> + ffa_set_regs_error(regs, FFA_RET_NOT_SUPPORTED); > >> + break; > > > > With the recently posted kernel patch > > https://lore.kernel.org/all/20240410-ffa_npi_support-v1-3-1a5223391...@arm.com/ > > we need to decide which feature interrupt to return since the kernel > > will only install a handle for the first it finds. Right now I propose > > to to not report FFA_FEATURE_SCHEDULE_RECV_INTR. When the time comes > > to use a secondary scheduler we'll need to report the SRI instead. > > > We just had a meeting with Sudeep to discuss that matter and he agreed that > he would register the interrupt handler for all the interrupts available so > that > we can keep a model where we will generate SRIs only to a secondary scheduler > and NPI for notification interrupts (so that the VM does not do a INFO_GET > when > not required). > > We will have to report both as any VM could act as secondary scheduler for SPs > in theory (we might need at some point a parameter for that) but for now those > should only be generated to Dom0 if there are pending notifications for SPs.
OK, thanks. I'll keep both then. Cheers, Jens
