From: Sean Christopherson <seanjc@google.com>
To: "Chang S. Bae" <chang.seok.bae@intel.com>
Cc: kvm@vger.kernel.org, pbonzini@redhat.com,
linux-kernel@vger.kernel.org, yang.zhong@intel.com
Subject: Re: [RFC PATCH 1/2] KVM: x86: Add a new system attribute for dynamic XSTATE component
Date: Thu, 25 Aug 2022 21:54:10 +0000 [thread overview]
Message-ID: <YwfvgsNTz33dlwKP@google.com> (raw)
In-Reply-To: <e52f26d4-c52a-e20d-7bc0-663bb4979827@intel.com>
On Thu, Aug 25, 2022, Chang S. Bae wrote:
> On 8/25/2022 9:19 AM, Sean Christopherson wrote:
> >
> > Adding new uAPI and new exports to eliminate one line of userspace code is not a
> > good tradeoff. Am I missing something? This really seems like solution looking
> > for a problem.
>
> Well, then that's your call.
>
> Yeah, that simplification is really minor. With this, I would rather think
> KVM wants enforcement before relaying the request to the host. That
> enforcement is unthinkable without supported_xcr0.
My point is that KVM needs supported_xcr0 (or similar behavior) regardless of
whether or not the kernel further restricts feature usage.
> But it looks like userspace is somehow trusted here for KVM.
next prev parent reply other threads:[~2022-08-25 21:54 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-23 23:14 [RFC PATCH 0/2] KVM: x86: Add a new attribute to control dynamic XSTATE components Chang S. Bae
2022-08-23 23:14 ` [RFC PATCH 1/2] KVM: x86: Add a new system attribute for dynamic XSTATE component Chang S. Bae
2022-08-24 21:42 ` Sean Christopherson
2022-08-24 22:49 ` Chang S. Bae
2022-08-25 16:19 ` Sean Christopherson
2022-08-25 20:45 ` Chang S. Bae
2022-08-25 21:54 ` Sean Christopherson [this message]
2022-08-23 23:14 ` [RFC PATCH 2/2] selftests: kvm: Use the KVM API to enable dynamic XSTATE features Chang S. Bae
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