From 7d1f8691ccffe88cec70a6e4044adf1b9bbd8a7c Mon Sep 17 00:00:00 2001 From: Vitaly Kuznetsov Date: Sun, 20 Sep 2020 09:10:12 -0400 Subject: [PATCH] Revert "KVM: Check the allocation of pv cpu mask" The commit 0f990222108d ("KVM: Check the allocation of pv cpu mask") we have in 5.9-rc5 has two issue: 1) Compilation fails for !CONFIG_SMP, see: https://bugzilla.kernel.org/show_bug.cgi?id=209285 2) This commit completely disables PV TLB flush, see https://lore.kernel.org/kvm/87y2lrnnyf.fsf@vitty.brq.redhat.com/ The allocation problem is likely a theoretical one, if we don't have memory that early in boot process we're likely doomed anyway. Let's solve it properly later. This reverts commit 0f990222108d214a0924d920e6095b58107d7b59. Signed-off-by: Vitaly Kuznetsov Signed-off-by: Paolo Bonzini --- arch/x86/kernel/kvm.c | 22 +++------------------- 1 file changed, 3 insertions(+), 19 deletions(-) diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c index 1b51b727b140..9663ba31347c 100644 --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -652,6 +652,7 @@ static void __init kvm_guest_init(void) } if (pv_tlb_flush_supported()) { + pv_ops.mmu.flush_tlb_others = kvm_flush_tlb_others; pv_ops.mmu.tlb_remove_table = tlb_remove_table; pr_info("KVM setup pv remote TLB flush\n"); } @@ -764,14 +765,6 @@ static __init int activate_jump_labels(void) } arch_initcall(activate_jump_labels); -static void kvm_free_pv_cpu_mask(void) -{ - unsigned int cpu; - - for_each_possible_cpu(cpu) - free_cpumask_var(per_cpu(__pv_cpu_mask, cpu)); -} - static __init int kvm_alloc_cpumask(void) { int cpu; @@ -790,20 +783,11 @@ static __init int kvm_alloc_cpumask(void) if (alloc) for_each_possible_cpu(cpu) { - if (!zalloc_cpumask_var_node( - per_cpu_ptr(&__pv_cpu_mask, cpu), - GFP_KERNEL, cpu_to_node(cpu))) { - goto zalloc_cpumask_fail; - } + zalloc_cpumask_var_node(per_cpu_ptr(&__pv_cpu_mask, cpu), + GFP_KERNEL, cpu_to_node(cpu)); } - apic->send_IPI_mask_allbutself = kvm_send_ipi_mask_allbutself; - pv_ops.mmu.flush_tlb_others = kvm_flush_tlb_others; return 0; - -zalloc_cpumask_fail: - kvm_free_pv_cpu_mask(); - return -ENOMEM; } arch_initcall(kvm_alloc_cpumask);