From: Sean Christopherson <seanjc@google.com>
To: Borislav Petkov <bp@alien8.de>
Cc: Maxim Levitsky <mlevitsk@redhat.com>,
kvm@vger.kernel.org, Paolo Bonzini <pbonzini@redhat.com>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
linux-kernel@vger.kernel.org,
Peter Zijlstra <peterz@infradead.org>,
Thomas Gleixner <tglx@linutronix.de>,
Sandipan Das <sandipan.das@amd.com>,
Daniel Sneddon <daniel.sneddon@linux.intel.com>,
Jing Liu <jing2.liu@intel.com>,
Josh Poimboeuf <jpoimboe@kernel.org>,
Wyes Karny <wyes.karny@amd.com>, Babu Moger <babu.moger@amd.com>,
Pawan Gupta <pawan.kumar.gupta@linux.intel.com>,
Jim Mattson <jmattson@google.com>,
x86@kernel.org, Santosh Shukla <santosh.shukla@amd.com>
Subject: Re: [PATCH 06/13] KVM: SVM: Add VNMI bit definition
Date: Thu, 17 Nov 2022 20:33:44 +0000 [thread overview]
Message-ID: <Y3aaqJo7ckdUsyde@google.com> (raw)
In-Reply-To: <Y3ZqOvg2mlBmXAlW@zn.tnic>
On Thu, Nov 17, 2022, Borislav Petkov wrote:
> On Thu, Nov 17, 2022 at 04:42:57PM +0000, Sean Christopherson wrote:
> > Why? This is rarely run code, won't cpu_feature_enabled()
> > unnecessarily require patching?
>
> Because we want one single interface to test X86_FEATURE flags. And
> there's no need for the users to know whether it wants patching or not -
> we simply patch *everywhere* and that's it.
>
> > And while we're on the topic... https://lore.kernel.org/all/Y22IzA9DN%2FxYWgWN@google.com
>
> Because static_ or boot_ is not relevant to the user - all she
> wants to know is whether a cpu feature has been enabled. Thus
> cpu_feature_enabled().
>
> And yes, at the time I protested a little about unnecessary patching.
> And tglx said "Why not?". And I had no good answer to that. So we can
> just as well patch *everywhere*.
Ah, I missed that memo.
Paolo,
Since it sounds like static_cpu_has() is going the way of the dodo, and ditto for
boot_cpu_has() except for flows that don't play nice with patching (none of which
are in KVM), should we do a KVM-wide conversion to cpu_feature_enabled() at some
point in the near future?
next prev parent reply other threads:[~2022-11-17 20:33 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-17 14:32 [PATCH 00/13] SVM: vNMI (with my fixes) Maxim Levitsky
2022-11-17 14:32 ` [PATCH 01/13] KVM: nSVM: don't sync back tlb_ctl on nested VM exit Maxim Levitsky
2022-11-17 14:32 ` [PATCH 02/13] KVM: nSVM: don't call nested_sync_control_from_vmcb02 on each " Maxim Levitsky
2022-11-17 20:04 ` Sean Christopherson
2022-11-21 11:07 ` Maxim Levitsky
2022-11-21 17:51 ` Sean Christopherson
2022-11-17 14:32 ` [PATCH 03/13] KVM: nSVM: rename nested_sync_control_from_vmcb02 to nested_sync_int_ctl_from_vmcb02 Maxim Levitsky
2022-11-17 14:32 ` [PATCH 04/13] KVM: nSVM: clean up copying of int_ctl fields back to vmcb01/vmcb12 Maxim Levitsky
2022-11-17 20:15 ` Sean Christopherson
2022-11-21 11:10 ` Maxim Levitsky
2022-11-17 14:32 ` [PATCH 05/13] x86/cpu: Add CPUID feature bit for VNMI Maxim Levitsky
2022-11-17 14:32 ` [PATCH 06/13] KVM: SVM: Add VNMI bit definition Maxim Levitsky
2022-11-17 14:37 ` Borislav Petkov
2022-11-17 16:42 ` Sean Christopherson
2022-11-17 17:07 ` Borislav Petkov
2022-11-17 20:33 ` Sean Christopherson [this message]
2022-11-17 20:27 ` Sean Christopherson
2022-11-17 14:32 ` [PATCH 07/13] KVM: SVM: Add VNMI support in get/set_nmi_mask Maxim Levitsky
2022-11-17 18:54 ` Sean Christopherson
2022-11-21 12:36 ` Maxim Levitsky
2022-11-21 17:18 ` Sean Christopherson
2022-12-04 18:42 ` Maxim Levitsky
2022-12-06 18:27 ` Sean Christopherson
2022-11-17 14:32 ` [PATCH 08/13] KVM: SVM: Report NMI not allowed when Guest busy handling VNMI Maxim Levitsky
2022-11-17 14:32 ` [PATCH 09/13] KVM: SVM: allow NMI window with vNMI Maxim Levitsky
2022-11-17 18:21 ` Sean Christopherson
2022-11-21 13:40 ` Maxim Levitsky
2022-11-17 14:32 ` [PATCH 10/13] KVM: SVM: Add VNMI support in inject_nmi Maxim Levitsky
2022-11-21 17:12 ` Sean Christopherson
2022-11-17 14:32 ` [PATCH 11/13] KVM: nSVM: implement nested VNMI Maxim Levitsky
2022-11-17 14:32 ` [PATCH 12/13] KVM: nSVM: emulate VMEXIT_INVALID case for " Maxim Levitsky
2022-11-17 20:18 ` Sean Christopherson
2022-11-17 14:32 ` [PATCH 13/13] KVM: SVM: Enable VNMI feature Maxim Levitsky
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