On 20/9/20 21:09, Paolo Bonzini wrote:
On 14/09/20 11:11, lihaiwei.kernel@xxxxxxxxx wrote:
From: Haiwei Li <lihaiwei@xxxxxxxxxxx>
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@xxxxxxxxx>
Signed-off-by: Haiwei Li <lihaiwei@xxxxxxxxxxx>
---
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
