Messages in this thread | | | Date | Wed, 2 Nov 2022 08:28:14 -0700 | From | Josh Poimboeuf <> | Subject | Re: [PATCH 6/7] KVM: SVM: move MSR_IA32_SPEC_CTRL save/restore to assembly |
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On Fri, Oct 28, 2022 at 07:07:22PM -0400, Paolo Bonzini wrote: > +++ b/arch/x86/kvm/svm/svm.c > @@ -3918,10 +3918,21 @@ static noinstr void svm_vcpu_enter_exit(struct kvm_vcpu *vcpu) > struct vcpu_svm *svm = to_svm(vcpu); > unsigned long vmcb_pa = svm->current_vmcb->pa; > > + /* > + * For non-nested case: > + * If the L01 MSR bitmap does not intercept the MSR, then we need to > + * save it. > + * > + * For nested case: > + * If the L02 MSR bitmap does not intercept the MSR, then we need to > + * save it. > + */ > + bool spec_ctrl_intercepted = msr_write_intercepted(vcpu, MSR_IA32_SPEC_CTRL);
This triggers a warning:
vmlinux.o: warning: objtool: svm_vcpu_enter_exit+0x3d: call to svm_msrpm_offset() leaves .noinstr.text section
svm_vcpu_enter_exit() is noinstr, but it's calling msr_write_intercepted() which is not.
That's why in the VMX code I did the call to msr_write_intercepted() (in __vmx_vcpu_run_flags) before calling vmx_vcpu_enter_exit().
-- Josh
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