[PATCH 5.8 034/118] KVM: Check the allocation of pv cpu mask

Greg Kroah-Hartman
2020-09-21T16:44:11Z

From: Haiwei Li <lihaiwei@tencent.com>

[ Upstream commit 0f990222108d214a0924d920e6095b58107d7b59 ]

check the allocation of per-cpu __pv_cpu_mask. Initialize ops only when
successful.

Signed-off-by: Haiwei Li <lihaiwei@tencent.com>
Message-Id: <d59f05df-e6d3-3d31-a036-cc25a2b2f33f@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/x86/kernel/kvm.c | 22 +++++++++++++++++++---
1 file changed, 19 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index df63786e7bfa4..d6219f3181d63 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -638,7 +638,6 @@ 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");
}
@@ -750,6 +749,14 @@ 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;
@@ -768,11 +775,20 @@ static __init int kvm_alloc_cpumask(void)

if (alloc)
for_each_possible_cpu(cpu) {
- zalloc_cpumask_var_node(per_cpu_ptr(&__pv_cpu_mask, cpu),
- GFP_KERNEL, cpu_to_node(cpu));
+ if (!zalloc_cpumask_var_node(
+ per_cpu_ptr(&__pv_cpu_mask, cpu),
+ GFP_KERNEL, cpu_to_node(cpu))) {
+ goto zalloc_cpumask_fail;
+ }
}

+ 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);

--
2.25.1