From: Jim Mattson <jmattson@google.com>
To: Mohammed Gamal <mgamal@redhat.com>
Cc: kvm list <kvm@vger.kernel.org>,
Paolo Bonzini <pbonzini@redhat.com>,
LKML <linux-kernel@vger.kernel.org>,
Sean Christopherson <sean.j.christopherson@intel.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Joerg Roedel <joro@8bytes.org>
Subject: Re: [PATCH] KVM: x86: VMX: Make smaller physical guest address space support user-configurable
Date: Thu, 3 Sep 2020 10:57:58 -0700 [thread overview]
Message-ID: <CALMp9eTrc8_z3pKBtLVmbnMvC+KtzXMYbYTXZPPz5F0UWW8oNQ@mail.gmail.com> (raw)
In-Reply-To: <20200903141122.72908-1-mgamal@redhat.com>
On Thu, Sep 3, 2020 at 7:12 AM Mohammed Gamal <mgamal@redhat.com> wrote:
>
> This patch exposes allow_smaller_maxphyaddr to the user as a module parameter.
>
> Since smaller physical address spaces are only supported on VMX, the parameter
> is only exposed in the kvm_intel module.
> Modifications to VMX page fault and EPT violation handling will depend on whether
> that parameter is enabled.
>
> Also disable support by default, and let the user decide if they want to enable
> it.
>
> Signed-off-by: Mohammed Gamal <mgamal@redhat.com>
I think a smaller guest physical address width *should* be allowed.
However, perhaps the pedantic adherence to the architectural
specification could be turned on or off per-VM? And, if we're going to
be pedantic, I think we should go all the way and get MOV-to-CR3
correct.
Does the typical guest care about whether or not setting any of the
bits 51:46 in a PFN results in a fault?
next prev parent reply other threads:[~2020-09-03 17:58 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-03 14:11 [PATCH] KVM: x86: VMX: Make smaller physical guest address space support user-configurable Mohammed Gamal
2020-09-03 17:57 ` Jim Mattson [this message]
2020-09-03 18:03 ` Paolo Bonzini
2020-09-03 18:32 ` Jim Mattson
2020-09-03 20:02 ` Paolo Bonzini
2020-09-03 21:26 ` Jim Mattson
2020-09-23 13:45 ` Paolo Bonzini
[not found] ` <CALMp9eTHbhwfdq4Be=XcUG9z82KK8AapQeVmsdH=mGdQ_Yt2ug@mail.gmail.com>
2020-09-23 15:19 ` Paolo Bonzini
2020-09-28 15:34 ` Qian Cai
2020-09-29 11:59 ` Qian Cai
2020-09-29 12:26 ` Paolo Bonzini
2020-09-29 13:39 ` Qian Cai
2020-09-29 14:47 ` Paolo Bonzini
2020-10-02 17:28 ` Naresh Kamboju
2020-10-02 17:30 ` Paolo Bonzini
2021-01-16 0:08 ` Jim Mattson
2021-01-18 10:18 ` Mohammed Gamal
2021-06-21 18:01 ` Jim Mattson
2021-06-22 12:59 ` Mohammed Gamal
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