Revert "KVM: Check the allocation of pv cpu mask" (7d1f8691) · Commits · 戴 / test

The commit ("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 . Signed-off-by:

Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by:

Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kernel/kvm.c

+3 −19

Original line number	Diff line number	Diff line
		@@ -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);

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