Jork Loeser <[email protected]> writes: >> -----Original Message----- >> From: Vitaly Kuznetsov [mailto:[email protected]] >> Sent: Tuesday, May 30, 2017 04:34 >> To: [email protected]; [email protected] >> Cc: [email protected]; KY Srinivasan <[email protected]>; Haiyang >> Zhang <[email protected]>; Stephen Hemminger >> <[email protected]>; Thomas Gleixner <[email protected]>; Ingo >> Molnar <[email protected]>; H. Peter Anvin <[email protected]>; Steven >> Rostedt <[email protected]>; Jork Loeser <[email protected]>; >> Simon Xiao <[email protected]>; Andy Lutomirski <[email protected]>; Andy >> Shevchenko <[email protected]> >> 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 [email protected] http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
