From: Sean Christopherson <sean.j.christopherson@intel.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
Jan Kiszka <jan.kiszka@siemens.com>,
Xiaoyao Li <xiaoyao.li@intel.com>
Subject: Re: [PATCH 3/6] KVM: x86: Add dedicated emulator helper for grabbing CPUID.maxphyaddr
Date: Tue, 3 Mar 2020 08:28:08 -0800 [thread overview]
Message-ID: <20200303162808.GJ1439@linux.intel.com> (raw)
In-Reply-To: <de2ed4e9-409a-6cb1-e295-ea946be11e82@redhat.com>
On Tue, Mar 03, 2020 at 09:48:03AM +0100, Paolo Bonzini wrote:
> On 02/03/20 20:57, Sean Christopherson wrote:
> > Add a helper to retrieve cpuid_maxphyaddr() instead of manually
> > calculating the value in the emulator via raw CPUID output. In addition
> > to consolidating logic, this also paves the way toward simplifying
> > kvm_cpuid(), whose somewhat confusing return value exists purely to
> > support the emulator's maxphyaddr calculation.
> >
> > No functional change intended.
>
> I don't think this is a particularly useful change. Yes, it's not
> intuitive but is it more than a matter of documentation (and possibly
> moving the check_cr_write snippet into a separate function)?
I really don't like duplicating the maxphyaddr logic. I'm paranoid
something will come along and change the "effective" maxphyaddr and we'll
forget all about the emulator, e.g. SEV, TME and paravirt XO all dance
around maxphyaddr.
next prev parent reply other threads:[~2020-03-03 16:28 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-02 19:57 [PATCH 0/6] KVM: x86: CPUID emulation and tracing fixes Sean Christopherson
2020-03-02 19:57 ` [PATCH 1/6] KVM: x86: Fix tracing of CPUID.function when function is out-of-range Sean Christopherson
2020-03-02 20:26 ` Jan Kiszka
2020-03-02 20:49 ` Sean Christopherson
2020-03-02 20:59 ` Jan Kiszka
2020-03-03 2:27 ` Xiaoyao Li
2020-03-03 3:45 ` Sean Christopherson
2020-03-03 4:02 ` Xiaoyao Li
2020-03-03 4:12 ` Sean Christopherson
2020-03-03 4:30 ` Xiaoyao Li
2020-03-03 2:50 ` Xiaoyao Li
2020-03-03 4:08 ` Sean Christopherson
2020-03-03 4:16 ` Xiaoyao Li
2020-03-02 19:57 ` [PATCH 2/6] KVM: x86: Fix CPUID range check for Centaur and Hypervisor ranges Sean Christopherson
2020-03-02 21:59 ` Jim Mattson
2020-03-03 0:57 ` Sean Christopherson
2020-03-03 3:25 ` Jim Mattson
2020-03-03 4:25 ` Jim Mattson
2020-03-03 4:58 ` Sean Christopherson
2020-03-03 17:42 ` Jim Mattson
2020-03-03 18:01 ` Sean Christopherson
2020-03-03 18:08 ` Jim Mattson
2020-03-04 11:18 ` Paolo Bonzini
2020-03-02 19:57 ` [PATCH 3/6] KVM: x86: Add dedicated emulator helper for grabbing CPUID.maxphyaddr Sean Christopherson
2020-03-03 8:48 ` Paolo Bonzini
2020-03-03 9:48 ` Jan Kiszka
2020-03-03 10:14 ` Paolo Bonzini
2020-03-04 20:47 ` Sean Christopherson
2020-03-03 16:28 ` Sean Christopherson [this message]
2020-03-03 17:21 ` Paolo Bonzini
2020-03-02 19:57 ` [PATCH 4/6] KVM: x86: Drop return value from kvm_cpuid() Sean Christopherson
2020-03-02 19:57 ` [PATCH 5/6] KVM: x86: Rename "found" variable in kvm_cpuid() to "exact_entry_exists" Sean Christopherson
2020-03-02 20:20 ` Jan Kiszka
2020-03-02 20:35 ` Sean Christopherson
2020-03-02 20:48 ` Jan Kiszka
2020-03-02 19:57 ` [PATCH 6/6] KVM: x86: Add requested index to the CPUID tracepoint Sean Christopherson
2020-03-07 9:48 ` Jan Kiszka
2020-03-10 4:00 ` Sean Christopherson
2020-03-03 8:48 ` [PATCH 0/6] KVM: x86: CPUID emulation and tracing fixes Paolo Bonzini
2020-03-03 16:38 ` Sean Christopherson
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