Once stop_machine() is gone from the CPU offline path, we won't be able
to depend on disabling preemption to prevent CPUs from going offline
from under us.
Use the get/put_online_cpus_atomic() APIs to prevent CPUs from going
offline, while invoking from atomic context.
Cc: Gleb Natapov <gleb@xxxxxxxxxx>
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: x86@xxxxxxxxxx
Cc: kvm@xxxxxxxxxxxxxxx
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@xxxxxxxxxxxxxxxxxx>
---
arch/x86/kvm/vmx.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 260a919..4e1e966 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -26,6 +26,7 @@
#include <linux/mm.h>
#include <linux/highmem.h>
#include <linux/sched.h>
+#include <linux/cpu.h>
#include <linux/moduleparam.h>
#include <linux/mod_devicetable.h>
#include <linux/ftrace_event.h>
@@ -7164,12 +7165,12 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id)
if (!vmm_exclusive)
kvm_cpu_vmxoff();
- cpu = get_cpu();
+ cpu = get_online_cpus_atomic();
vmx_vcpu_load(&vmx->vcpu, cpu);
vmx->vcpu.cpu = cpu;
err = vmx_vcpu_setup(vmx);
vmx_vcpu_put(&vmx->vcpu);
- put_cpu();
+ put_online_cpus_atomic();
if (err)
goto free_vmcs;
if (vm_need_virtualize_apic_accesses(kvm)) {
@@ -7706,12 +7707,12 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch)
vmx->nested.vmcs01_tsc_offset = vmcs_read64(TSC_OFFSET);
- cpu = get_cpu();
+ cpu = get_online_cpus_atomic();
vmx->loaded_vmcs = vmcs02;
vmx_vcpu_put(vcpu);
vmx_vcpu_load(vcpu, cpu);
vcpu->cpu = cpu;
- put_cpu();
+ put_online_cpus_atomic();
vmx_segment_cache_clear(vmx);
@@ -8023,12 +8024,12 @@ static void nested_vmx_vmexit(struct kvm_vcpu *vcpu)
leave_guest_mode(vcpu);
prepare_vmcs12(vcpu, vmcs12);
- cpu = get_cpu();
+ cpu = get_online_cpus_atomic();
vmx->loaded_vmcs = &vmx->vmcs01;
vmx_vcpu_put(vcpu);
vmx_vcpu_load(vcpu, cpu);
vcpu->cpu = cpu;
- put_cpu();
+ put_online_cpus_atomic();
vmx_segment_cache_clear(vmx);
--
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