Jork Loeser <jork.loe...@microsoft.com> writes: >> -----Original Message----- >> From: Vitaly Kuznetsov [mailto:vkuzn...@redhat.com] >> Sent: Tuesday, May 30, 2017 04:34 >> To: x...@kernel.org; de...@linuxdriverproject.org >> Cc: linux-ker...@vger.kernel.org; KY Srinivasan <k...@microsoft.com>; Haiyang >> Zhang <haiya...@microsoft.com>; Stephen Hemminger >> <sthem...@microsoft.com>; Thomas Gleixner <t...@linutronix.de>; Ingo >> Molnar <mi...@redhat.com>; H. Peter Anvin <h...@zytor.com>; Steven >> Rostedt <rost...@goodmis.org>; Jork Loeser <jork.loe...@microsoft.com>; >> Simon Xiao <six...@microsoft.com>; Andy Lutomirski <l...@kernel.org>; Andy >> Shevchenko <andy.shevche...@gmail.com> >> 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 de...@linuxdriverproject.org http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
