> -----Original Message----- > From: Vitaly Kuznetsov [mailto:vkuznets@xxxxxxxxxx] > Sent: Tuesday, May 30, 2017 04:34 > To: x86@xxxxxxxxxx; devel@xxxxxxxxxxxxxxxxxxxxxx > Cc: linux-kernel@xxxxxxxxxxxxxxx; KY Srinivasan <kys@xxxxxxxxxxxxx>; Haiyang > Zhang <haiyangz@xxxxxxxxxxxxx>; Stephen Hemminger > <sthemmin@xxxxxxxxxxxxx>; Thomas Gleixner <tglx@xxxxxxxxxxxxx>; Ingo > Molnar <mingo@xxxxxxxxxx>; H. Peter Anvin <hpa@xxxxxxxxx>; Steven > Rostedt <rostedt@xxxxxxxxxxx>; Jork Loeser <Jork.Loeser@xxxxxxxxxxxxx>; > Simon Xiao <sixiao@xxxxxxxxxxxxx>; Andy Lutomirski <luto@xxxxxxxxxx>; Andy > Shevchenko <andy.shevchenko@xxxxxxxxx> > Subject: [PATCH v5 09/10] x86/hyper-v: support extended CPU ranges for TLB > flush hypercalls > > Hyper-V hosts may support more than 64 vCPUs, we need to use > HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX/LIST_EX hypercalls in this case. > +static inline int cpumask_to_vp_set(struct hv_flush_pcpu_ex *flush, > + const struct cpumask *cpus) > +{ > + int cpu, vcpu, vcpu_bank, vcpu_offset, cur_bank, nr_bank = 0; > + bool has_cpus; > + > + /* > + * We can't be sure that translated vCPU numbers will always be > + * in ascending order, so iterate over all possible banks and > + * check all vCPUs in it instead. > + */ > + for (cur_bank = 0; cur_bank < ms_hyperv.max_vp_index/64; > cur_bank++) { > + has_cpus = false; > + for_each_cpu(cpu, cpus) { > + vcpu = hv_cpu_number_to_vp_number(cpu); > + vcpu_bank = vcpu / 64; > + vcpu_offset = vcpu % 64; > + > + if (vcpu_bank != cur_bank) > + continue; > + __set_bit(vcpu_offset, (unsigned long *) > + &flush->hv_vp_set.bank_contents[nr_bank]); > + if (!has_cpus) { > + __set_bit(vcpu_bank, (unsigned long *) > + &flush->hv_vp_set.valid_bank_mask); > + has_cpus = true; > + } > + } > + if (has_cpus) > + nr_bank++; > + } > + > + return nr_bank; > +} Note that the HV_VP_SET may contain empty banks. As such, consider enabling all (5) bits in the valid_bank_mask, and a single for_each(cpu, cpus) pass - setting the bits as per hv_cpu_number_to_vp_number(cpu). Regards, Jork _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
