From 628f54cc6451d2706ba8a56763dbf93be02aaa80 Mon Sep 17 00:00:00 2001 From: Vitaly Kuznetsov Date: Wed, 2 Aug 2017 18:09:20 +0200 Subject: [PATCH] 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. Signed-off-by: Vitaly Kuznetsov Reviewed-by: Andy Shevchenko Reviewed-by: Stephen Hemminger Cc: Andy Lutomirski Cc: Haiyang Zhang Cc: Jork Loeser Cc: K. Y. Srinivasan Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Simon Xiao Cc: Steven Rostedt Cc: Thomas Gleixner Cc: devel@linuxdriverproject.org Link: http://lkml.kernel.org/r/20170802160921.21791-9-vkuznets@redhat.com Signed-off-by: Ingo Molnar --- arch/x86/hyperv/mmu.c | 133 ++++++++++++++++++++++++++++- arch/x86/include/uapi/asm/hyperv.h | 10 +++ 2 files changed, 140 insertions(+), 3 deletions(-) diff --git a/arch/x86/hyperv/mmu.c b/arch/x86/hyperv/mmu.c index 9419a20b1d75..51b44be03f50 100644 --- a/arch/x86/hyperv/mmu.c +++ b/arch/x86/hyperv/mmu.c @@ -18,11 +18,25 @@ struct hv_flush_pcpu { u64 gva_list[]; }; +/* HvFlushVirtualAddressSpaceEx, HvFlushVirtualAddressListEx hypercalls */ +struct hv_flush_pcpu_ex { + u64 address_space; + u64 flags; + struct { + u64 format; + u64 valid_bank_mask; + u64 bank_contents[]; + } hv_vp_set; + u64 gva_list[]; +}; + /* Each gva in gva_list encodes up to 4096 pages to flush */ #define HV_TLB_FLUSH_UNIT (4096 * PAGE_SIZE) static struct hv_flush_pcpu __percpu *pcpu_flush; +static struct hv_flush_pcpu_ex __percpu *pcpu_flush_ex; + /* * Fills in gva_list starting from offset. Returns the number of items added. */ @@ -53,6 +67,34 @@ static inline int fill_gva_list(u64 gva_list[], int offset, return gva_n - offset; } +/* Return the number of banks in the resulting vp_set */ +static inline int cpumask_to_vp_set(struct hv_flush_pcpu_ex *flush, + const struct cpumask *cpus) +{ + int cpu, vcpu, vcpu_bank, vcpu_offset, nr_bank = 1; + + /* + * Some banks may end up being empty but this is acceptable. + */ + for_each_cpu(cpu, cpus) { + vcpu = hv_cpu_number_to_vp_number(cpu); + vcpu_bank = vcpu / 64; + vcpu_offset = vcpu % 64; + + /* valid_bank_mask can represent up to 64 banks */ + if (vcpu_bank >= 64) + return 0; + + __set_bit(vcpu_offset, (unsigned long *) + &flush->hv_vp_set.bank_contents[vcpu_bank]); + if (vcpu_bank >= nr_bank) + nr_bank = vcpu_bank + 1; + } + flush->hv_vp_set.valid_bank_mask = GENMASK_ULL(nr_bank - 1, 0); + + return nr_bank; +} + static void hyperv_flush_tlb_others(const struct cpumask *cpus, const struct flush_tlb_info *info) { @@ -122,17 +164,102 @@ do_native: native_flush_tlb_others(cpus, info); } +static void hyperv_flush_tlb_others_ex(const struct cpumask *cpus, + const struct flush_tlb_info *info) +{ + int nr_bank = 0, max_gvas, gva_n; + struct hv_flush_pcpu_ex *flush; + u64 status = U64_MAX; + unsigned long flags; + + if (!pcpu_flush_ex || !hv_hypercall_pg) + goto do_native; + + if (cpumask_empty(cpus)) + return; + + local_irq_save(flags); + + flush = this_cpu_ptr(pcpu_flush_ex); + + if (info->mm) { + flush->address_space = virt_to_phys(info->mm->pgd); + flush->flags = 0; + } else { + flush->address_space = 0; + flush->flags = HV_FLUSH_ALL_VIRTUAL_ADDRESS_SPACES; + } + + flush->hv_vp_set.valid_bank_mask = 0; + + if (!cpumask_equal(cpus, cpu_present_mask)) { + flush->hv_vp_set.format = HV_GENERIC_SET_SPARCE_4K; + nr_bank = cpumask_to_vp_set(flush, cpus); + } + + if (!nr_bank) { + flush->hv_vp_set.format = HV_GENERIC_SET_ALL; + flush->flags |= HV_FLUSH_ALL_PROCESSORS; + } + + /* + * We can flush not more than max_gvas with one hypercall. Flush the + * whole address space if we were asked to do more. + */ + max_gvas = + (PAGE_SIZE - sizeof(*flush) - nr_bank * + sizeof(flush->hv_vp_set.bank_contents[0])) / + sizeof(flush->gva_list[0]); + + if (info->end == TLB_FLUSH_ALL) { + flush->flags |= HV_FLUSH_NON_GLOBAL_MAPPINGS_ONLY; + status = hv_do_rep_hypercall( + HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX, + 0, nr_bank + 2, flush, NULL); + } else if (info->end && + ((info->end - info->start)/HV_TLB_FLUSH_UNIT) > max_gvas) { + status = hv_do_rep_hypercall( + HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX, + 0, nr_bank + 2, flush, NULL); + } else { + gva_n = fill_gva_list(flush->gva_list, nr_bank, + info->start, info->end); + status = hv_do_rep_hypercall( + HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX, + gva_n, nr_bank + 2, flush, NULL); + } + + local_irq_restore(flags); + + if (!(status & HV_HYPERCALL_RESULT_MASK)) + return; +do_native: + native_flush_tlb_others(cpus, info); +} + void hyperv_setup_mmu_ops(void) { - if (ms_hyperv.hints & HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED) { + if (!(ms_hyperv.hints & HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED)) + return; + + setup_clear_cpu_cap(X86_FEATURE_PCID); + + if (!(ms_hyperv.hints & HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED)) { pr_info("Using hypercall for remote TLB flush\n"); pv_mmu_ops.flush_tlb_others = hyperv_flush_tlb_others; - setup_clear_cpu_cap(X86_FEATURE_PCID); + } else { + pr_info("Using ext hypercall for remote TLB flush\n"); + pv_mmu_ops.flush_tlb_others = hyperv_flush_tlb_others_ex; } } void hyper_alloc_mmu(void) { - if (ms_hyperv.hints & HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED) + if (!(ms_hyperv.hints & HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED)) + return; + + if (!(ms_hyperv.hints & HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED)) pcpu_flush = __alloc_percpu(PAGE_SIZE, PAGE_SIZE); + else + pcpu_flush_ex = __alloc_percpu(PAGE_SIZE, PAGE_SIZE); } diff --git a/arch/x86/include/uapi/asm/hyperv.h b/arch/x86/include/uapi/asm/hyperv.h index a6fdd3b82b4a..7032f4d8dff3 100644 --- a/arch/x86/include/uapi/asm/hyperv.h +++ b/arch/x86/include/uapi/asm/hyperv.h @@ -149,6 +149,9 @@ */ #define HV_X64_DEPRECATING_AEOI_RECOMMENDED (1 << 9) +/* Recommend using the newer ExProcessorMasks interface */ +#define HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED (1 << 11) + /* * HV_VP_SET available */ @@ -245,6 +248,8 @@ #define HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE 0x0002 #define HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST 0x0003 #define HVCALL_NOTIFY_LONG_SPIN_WAIT 0x0008 +#define HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX 0x0013 +#define HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX 0x0014 #define HVCALL_POST_MESSAGE 0x005c #define HVCALL_SIGNAL_EVENT 0x005d @@ -266,6 +271,11 @@ #define HV_FLUSH_NON_GLOBAL_MAPPINGS_ONLY BIT(2) #define HV_FLUSH_USE_EXTENDED_RANGE_FORMAT BIT(3) +enum HV_GENERIC_SET_FORMAT { + HV_GENERIC_SET_SPARCE_4K, + HV_GENERIC_SET_ALL, +}; + /* hypercall status code */ #define HV_STATUS_SUCCESS 0 #define HV_STATUS_INVALID_HYPERCALL_CODE 2 -- 2.20.1