KVM: Fix hotplug of CPUs

Both VMX and SVM require per-cpu memory allocation, which is done at module
init time, for only online cpus.

Backend was not allocating enough structure for all possible CPUs, so
new CPUs coming online could not be hardware enabled.

Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

2 files changed, 6 insertions, 4 deletions

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index d1036ce8917e..02a4269be645 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -482,7 +482,7 @@ static __init int svm_hardware_setup(void)
                 kvm_enable_efer_bits(EFER_SVME);
         }
 
-        for_each_online_cpu(cpu) {
+        for_each_possible_cpu(cpu) {
                 r = svm_cpu_init(cpu);
                 if (r)
                         goto err;
@@ -516,7 +516,7 @@ static __exit void svm_hardware_unsetup(void)
 {
         int cpu;
 
-        for_each_online_cpu(cpu)
+        for_each_possible_cpu(cpu)
                 svm_cpu_uninit(cpu);
 
         __free_pages(pfn_to_page(iopm_base >> PAGE_SHIFT), IOPM_ALLOC_ORDER);
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index a187570e4837..97f4265cda38 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -1350,15 +1350,17 @@ static void free_kvm_area(void)
 {
         int cpu;
 
-        for_each_online_cpu(cpu)
+        for_each_possible_cpu(cpu) {
                 free_vmcs(per_cpu(vmxarea, cpu));
+                per_cpu(vmxarea, cpu) = NULL;
+        }
 }
 
 static __init int alloc_kvm_area(void)
 {
         int cpu;
 
-        for_each_online_cpu(cpu) {
+        for_each_possible_cpu(cpu) {
                 struct vmcs *vmcs;
 
                 vmcs = alloc_vmcs_cpu(cpu);