Messages in this thread |  | | Date | Sat, 2 Apr 2022 20:58:38 +0800 | Subject | Re: [PATCH v7 3/8] KVM: VMX: Detect Tertiary VM-Execution control when setup VMCS config | From | Zeng Guang <> |
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On 4/1/2022 6:41 AM, Sean Christopherson wrote: > On Fri, Mar 04, 2022, Zeng Guang wrote: >> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c >> index c569dc2b9192..8a5713d49635 100644 >> --- a/arch/x86/kvm/vmx/vmx.c >> +++ b/arch/x86/kvm/vmx/vmx.c >> @@ -2422,6 +2422,21 @@ static __init int adjust_vmx_controls(u32 ctl_min, u32 ctl_opt, >> return 0; >> } >> >> +static __init int adjust_vmx_controls_64(u64 ctl_min, u64 ctl_opt, > I slightly prefer controls64 over controls_64. As usual, KVM is inconsistent as > a whole, but vmcs_read/write64 omit the underscore, so we can at least be somewhat > consistent within VMX. > >> + u32 msr, u64 *result) >> +{ >> + u64 allowed1; >> + >> + rdmsrl(msr, allowed1); >> + >> + /* Ensure minimum (required) set of control bits are supported. */ >> + if (ctl_min & ~allowed1) > Eh, just drop @ctl_min. Practically speaking, there is zero chance tertiary > controls or any other control of this nature will ever be mandatory. Secondary > controls would fall into the same boat, but specifying min=0 allows it to share > helpers, so it's the lesser of evils. > > With the error return gone, this can be > > static __init u64 adjust_vmx_controls64(u64 ctl_opt, u32 msr) > { > u64 allowed; > > rdmsrl(msr, allowed); > > return ctl_opt & allowed; > }
Make sense. I will change it. Thanks.
> Alternatively, we could take the control-to-modify directly and have no return, > but I like having the "u64 opt = ..." in the caller.
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