Messages in this thread | | | From | Andy Lutomirski <> | Date | Mon, 14 Dec 2020 12:08:42 -0800 | Subject | Re: [PATCH v2] KVM: SVM: use vmsave/vmload for saving/restoring additional host state |
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On Mon, Dec 14, 2020 at 11:38 AM Sean Christopherson <seanjc@google.com> wrote: > > +Andy, who provided a lot of feedback on v1. > > > > > static unsigned long svm_get_rflags(struct kvm_vcpu *vcpu) > > @@ -3507,14 +3503,8 @@ static noinstr void svm_vcpu_enter_exit(struct kvm_vcpu *vcpu, > > > > __svm_vcpu_run(svm->vmcb_pa, (unsigned long *)&svm->vcpu.arch.regs); > > Tying in with avoiding svm->host_save_area, what about passing in the PA of the > save area and doing the vmload in __svm_vcpu_run()? One less instance of inline > assembly to stare at...
One potential side benefit is that we wouldn't execute any C code with the wrong MSR_GS_BASE, which avoids any concerns about instrumentation, stack protector, or some *SAN feature exploding due to a percpu memory not working.
--Andy
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