@@ -638,7 +638,9 @@ static void __vcpu_clear(void *arg)
vmcs_clear(vmx->vmcs);
if (per_cpu(current_vmcs, cpu) == vmx->vmcs)
per_cpu(current_vmcs, cpu) = NULL;
- list_del(&vmx->local_vcpus_link);
+ /* TODO: currently, local_vcpus_link is just for L1 VMCSs */
+ if (!is_guest_mode(&vmx->vcpu))
+ list_del(&vmx->local_vcpus_link);
vmx->vcpu.cpu = -1;
vmx->launched = 0;
}
@@ -1100,8 +1102,10 @@ static void vmx_vcpu_load(struct kvm_vcp
kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);
local_irq_disable();
- list_add(&vmx->local_vcpus_link,
- &per_cpu(vcpus_on_cpu, cpu));
+ /* TODO: currently, local_vcpus_link is just for L1 VMCSs */
+ if (!is_guest_mode(&vmx->vcpu))
+ list_add(&vmx->local_vcpus_link,
+ &per_cpu(vcpus_on_cpu, cpu));
local_irq_enable();
/*
@@ -1806,7 +1810,9 @@ static void vmclear_local_vcpus(void)
list_for_each_entry_safe(vmx, n, &per_cpu(vcpus_on_cpu, cpu),
local_vcpus_link)
- __vcpu_clear(vmx);
+ /* TODO: currently, local_vcpus_link is just for L1 VMCSs */
+ if (!is_guest_mode(&vmx->vcpu))
+ __vcpu_clear(vmx);
}
In VMX, before we bring down a CPU we must VMCLEAR all VMCSs loaded on it because (at least in theory) the processor might not have written all of its content back to memory. Since a patch from June 26, 2008, this is done using a per-cpu "vcpus_on_cpu" linked list of vcpus loaded on each CPU. The problem is that with nested VMX, we no longer have the concept of a vcpu being loaded on a cpu: A vcpu has multiple VMCSs (one for L1, others for each L2), and each of those may be have been last loaded on a different cpu. This trivial patch changes the code to keep on vcpus_on_cpu only L1 VMCSs. This fixes crashes on L1 shutdown caused by incorrectly maintaing the linked lists. It is not a complete solution, though. It doesn't flush the inactive L1 or L2 VMCSs loaded on a CPU which is being shutdown. Doing this correctly will probably require replacing the vcpu linked list by a link list of "saved_vcms" objects (VMCS, cpu and launched), and it is left as a TODO. Signed-off-by: Nadav Har'El <nyh@il.ibm.com> --- arch/x86/kvm/vmx.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html