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Revert "KVM: Check the allocation of pv cpu mask" 

The commit 0f99022210 ("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 0f99022210.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
zero-sugar-mainline-defconfig
Vitaly Kuznetsov 2020-09-20 09:10:12 -04:00 committed by Paolo Bonzini
parent 37f66bbef0
commit 7d1f8691cc
1 changed files with 3 additions and 19 deletions
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22
arch/x86/kernel/kvm.c
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@ -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);