From: Paolo Bonzini <pbonzini@redhat.com>
To: Maxim Levitsky <mlevitsk@redhat.com>,
Sean Christopherson <sean.j.christopherson@intel.com>
Cc: kvm@vger.kernel.org,
"maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)"
<x86@kernel.org>,
linux-kernel@vger.kernel.org, Joerg Roedel <joro@8bytes.org>,
Thomas Gleixner <tglx@linutronix.de>,
Wanpeng Li <wanpengli@tencent.com>,
"H. Peter Anvin" <hpa@zytor.com>, Borislav Petkov <bp@alien8.de>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Ingo Molnar <mingo@redhat.com>, Jim Mattson <jmattson@google.com>
Subject: Re: [PATCH] kvm: x86: rewrite kvm_spec_ctrl_valid_bits
Date: Tue, 7 Jul 2020 19:26:02 +0200 [thread overview]
Message-ID: <ed934ade-f377-4de1-55bb-d0c1a2770be0@redhat.com> (raw)
In-Reply-To: <f3c243b06b5acfea9ed4e4242d8287c7169ef1be.camel@redhat.com>
On 07/07/20 13:35, Maxim Levitsky wrote:
> After thinking about this, I am thinking that we should apply similiar logic
> as done with the 'cpu-pm' related features.
> This way the user can choose between passing through the IA32_SPEC_CTRL,
> (and in this case, we can since the user choose it, pass it right away, and thus
> avoid using kvm_spec_ctrl_valid_bits completely), and between correctness,
> in which case we can always emulate this msr, and therefore check all the bits,
> both regard to guest and host supported values.
Unfortunately, passing it through is just too slow. So I think it's
overkill. There's two ways to deal with badly-behaved guests blocking
migration: 1) hide SPEC_CTRL altogether 2) kill them when migration
fails; both are acceptable depending on the situation.
Paolo
> Does this makes sense, or do you think that this is overkill?
next prev parent reply other threads:[~2020-07-07 17:26 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-02 17:44 [PATCH] kvm: x86: rewrite kvm_spec_ctrl_valid_bits Maxim Levitsky
2020-07-02 18:16 ` Sean Christopherson
2020-07-05 9:40 ` Maxim Levitsky
2020-07-07 6:11 ` Sean Christopherson
2020-07-07 8:04 ` Paolo Bonzini
2020-07-07 8:14 ` Sean Christopherson
2020-07-07 8:17 ` Paolo Bonzini
2020-07-07 8:26 ` Sean Christopherson
2020-07-07 8:56 ` Wanpeng Li
2020-07-07 11:35 ` Maxim Levitsky
2020-07-07 17:26 ` Paolo Bonzini [this message]
2020-07-07 17:27 ` Sean Christopherson
2020-07-07 11:30 ` Maxim Levitsky
2020-07-07 17:26 ` Paolo Bonzini
2020-07-08 11:57 ` [PATCH] kvm: x86: replace kvm_spec_ctrl_test_value with runtime test on the host Maxim Levitsky
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