On 23/07/2018 08:10, Wanpeng Li wrote: >>> On 20/07/2018 18:28, Wanpeng Li wrote: >>>> +a0: ipi_bitmap low 64 bits >>>> +a1: ipi_bitmap high 64 bits >>>> +a2: the lowest APIC ID in bitmap >>>> +a3: APIC ICR >>>> + >>>> +The hypercall lets a guest send multicast IPIs at most can handle >>>> +128 vCPUs per hypercall on 64-bit machines and 64 vCPUs per hypercall >>>> +on 32-bit machines. >>>> + >>>> +Returns 0 if successfully delivery the IPIs and 1 if discarded. >>> This description does not mention what happens in 32-bit mode. > Sorry, I think I mentioned "64 vCPUs per hypercall on 32-bit machines" above. Yes, but the description of a0 and a1 is not accurate. Something like a0: lower part of the bitmap of destination APIC IDs a1: higher part of the bitmap of destination APIC IDs .... The hypercall lets a guest send multicast IPIs, with at most 128 128 destinations per hypercall in 64-bit mode and 64 vCPUs per hypercall in 32-bit mode. The destinations are represented by a bitmap contained in the first two arguments (a0 and a1). Bit 0 of a0 corresponds to the APIC ID in the third argument (a2), bit 1 corresponds to the APIC ID a2+1, and so on. Thanks, Paolo
