linux-kernel - [PATCH AUTOSEL 5.8 28/29] KVM: Check the allocation of pv cpu mask

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Date:   Mon, 14 Sep 2020 09:03:57 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Haiwei Li <lihaiwei@...cent.com>,
        Paolo Bonzini <pbonzini@...hat.com>,
        Sasha Levin <sashal@...nel.org>, kvm@...r.kernel.org
Subject: [PATCH AUTOSEL 5.8 28/29] KVM: Check the allocation of pv cpu mask

From: Haiwei Li <lihaiwei@...cent.com>

[ Upstream commit 0f990222108d214a0924d920e6095b58107d7b59 ]

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

Signed-off-by: Haiwei Li <lihaiwei@...cent.com>
Message-Id: <d59f05df-e6d3-3d31-a036-cc25a2b2f33f@...il.com>
Signed-off-by: Paolo Bonzini <pbonzini@...hat.com>
Signed-off-by: Sasha Levin <sashal@...nel.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