Jork Loeser <Jork.Loeser@xxxxxxxxxxxxx> writes: >> -----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). > Oh, I didn't know that! I'll switch to doing a single pass. Unfortunately I have no Hyper-V setup with > 64 vCPUs so I can't really test if it works or not (I mean empty banks, *_EX hypercalls work). -- Vitaly _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
