Messages in this thread | | | From | Wanpeng Li <> | Date | Fri, 12 Jan 2018 09:49:58 +0800 | Subject | Re: [PATCH 4/8] kvm: vmx: Set IBPB when running a different VCPU |
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2018-01-09 20:03 GMT+08:00 Paolo Bonzini <pbonzini@redhat.com>: > > if (!already_loaded) { > @@ -4029,6 +4031,13 @@ static void free_loaded_vmcs(struct loaded_vmcs *loaded_vmcs) > free_vmcs(loaded_vmcs->vmcs); > loaded_vmcs->vmcs = NULL; > WARN_ON(loaded_vmcs->shadow_vmcs != NULL); > + > + /* > + * The VMCS could be recycled, causing a false negative in > + * vmx_vcpu_load; block speculative execution. > + */ > + if (have_spec_ctrl) > + wrmsrl(MSR_IA32_PRED_CMD, PRED_CMD_IBPB); > }
Intel guys told us the recycle is about the address of vmcs, not the content. Could you explain more why it matters?
Regards, Wanpeng Li
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