From: Haiwei Li <lihaiwei.kernel@gmail.com>
To: Paolo Bonzini <pbonzini@redhat.com>,
linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
x86@kernel.org
Cc: sean.j.christopherson@intel.com, vkuznets@redhat.com,
wanpengli@tencent.com, jmattson@google.com, joro@8bytes.org,
tglx@linutronix.de, mingo@redhat.com, bp@alien8.de,
hpa@zytor.com, lihaiwei@tencent.com,
kernel test robot <lkp@intel.com>
Subject: Re: [PATCH 1/2] KVM: Fix the build error
Date: Wed, 23 Sep 2020 13:02:17 +0800 [thread overview]
Message-ID: <d5ff32e8-1dec-da50-0499-20db08e492fe@gmail.com> (raw)
In-Reply-To: <1810e3e5-8286-29e0-ff10-636d6c32df6d@redhat.com>
On 20/9/20 21:09, Paolo Bonzini wrote:
> On 14/09/20 11:11, lihaiwei.kernel@gmail.com wrote:
>> From: Haiwei Li <lihaiwei@tencent.com>
>>
>> When CONFIG_SMP is not set, an build error occurs with message "error:
>> use of undeclared identifier 'kvm_send_ipi_mask_allbutself'"
>>
>> Fixes: 0f990222108d ("KVM: Check the allocation of pv cpu mask", 2020-09-01)
>> Reported-by: kernel test robot <lkp@intel.com>
>> Signed-off-by: Haiwei Li <lihaiwei@tencent.com>
>> ---
>> arch/x86/kernel/kvm.c | 2 ++
>> 1 file changed, 2 insertions(+)
>>
>> diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
>> index 1b51b727b140..7e8be0421720 100644
>> --- a/arch/x86/kernel/kvm.c
>> +++ b/arch/x86/kernel/kvm.c
>> @@ -797,7 +797,9 @@ static __init int kvm_alloc_cpumask(void)
>> }
>> }
>>
>> +#if defined(CONFIG_SMP)
>> apic->send_IPI_mask_allbutself = kvm_send_ipi_mask_allbutself;
>> +#endif
>> pv_ops.mmu.flush_tlb_others = kvm_flush_tlb_others;
>> return 0;
>>
>>
>
> If CONFIG_SMP is not set you don't need kvm_alloc_cpumask or
> pv_ops.mmu.flush_tlb_others at all. Can you squash these two into the
> original patch and re-submit for 5.10?
Hi, Paolo
I'm a little confused. Function kvm_flush_tlb_others doesn't seem to be
related to CONFIG_SMP.
And my patch like:
---
arch/x86/kernel/kvm.c | 27 ++++++++++++++++++++++++---
1 file changed, 24 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index 9663ba31347c..1e5da6db519c 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -553,7 +553,6 @@ static void kvm_send_ipi_mask_allbutself(const
struct cpumask *mask, int vector)
static void kvm_setup_pv_ipi(void)
{
apic->send_IPI_mask = kvm_send_ipi_mask;
- apic->send_IPI_mask_allbutself = kvm_send_ipi_mask_allbutself;
pr_info("setup PV IPIs\n");
}
@@ -619,6 +618,11 @@ static void kvm_flush_tlb_others(const struct
cpumask *cpumask,
struct kvm_steal_time *src;
struct cpumask *flushmask = this_cpu_cpumask_var_ptr(__pv_cpu_mask);
+ if (unlikely(!flushmask)) {
+ native_flush_tlb_others(cpumask, info);
+ return;
+ }
+
cpumask_copy(flushmask, cpumask);
/*
* We have to call flush only on online vCPUs. And
@@ -765,6 +769,14 @@ static __init int activate_jump_labels(void)
}
arch_initcall(activate_jump_labels);
+static void kvm_free_cpumask(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;
@@ -783,11 +795,20 @@ 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;
}
+#if defined(CONFIG_SMP)
+ apic->send_IPI_mask_allbutself = kvm_send_ipi_mask_allbutself;
+#endif
return 0;
+
+zalloc_cpumask_fail:
+ kvm_free_cpumask();
+ return -ENOMEM;
}
arch_initcall(kvm_alloc_cpumask);
--
2.18.4
Do you have any suggestion? Thanks.
Haiwei
next prev parent reply other threads:[~2020-09-23 5:02 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-14 9:11 [PATCH 0/2] Fix the allocation of pv cpu mask lihaiwei.kernel
2020-09-14 9:11 ` [PATCH 1/2] KVM: Fix the build error lihaiwei.kernel
2020-09-20 13:09 ` Paolo Bonzini
2020-09-21 0:23 ` Haiwei Li
2020-09-23 5:02 ` Haiwei Li [this message]
2020-09-14 9:11 ` [PATCH 2/2] KVM: Check if __pv_cpu_mask was allocated instead of assigning ops too late lihaiwei.kernel
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