Hi Pavel, On 06/23/2015 09:38 AM, Pavel Fedin wrote: > Hello! > >> What is done currently at qemu level for other archs - if I understand >> it correctly - is there is static GSI routing for standard IRQ. > > Yes, this is correct. GSI number = SPI number for ARM. Also something > similar for MIPS (haven't > study that). > >> For MSI >> irqfd setup they use spare gsi number not yet used for GSI routing < max >> route number. > > No. > On ARM with vGICv2m MSI data is effectively IRQ offset, with base being 32. > So, original convention > works without any change, they simply retrieve SPI number from MSI data and > set up irqfd to that > SPI. No allocation is done. Yes on ARM we use gsi direct mapping feature. I was talking about what is done without this "gsi direct mapping" feature. In that case the low GSI numbers are used by irqchip routing entries. So kvm_irqchip_get_virq returns a gsi beyond the irqchip routed gsi's.
Eric > Allocation is done only on x86, with routing. They just allocate GSI numbers > starting from zero and > route them to something (either irqchip or MSI). > > Kind regards, > Pavel Fedin > Expert Engineer > Samsung Electronics Research center Russia > > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
