From mboxrd@z Thu Jan  1 00:00:00 1970
From: Nadav Amit <nadav.amit@gmail.com>
Subject: Re: x86: Question regarding the reset value of LINT0
Date: Sun, 12 Apr 2015 21:29:48 +0300
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Cc: Bandan Das <bsd@redhat.com>, Avi Kivity <avi.kivity@gmail.com>,
	Jan Kiszka <jan.kiszka@siemens.com>,
	kvm list <kvm@vger.kernel.org>
To: Paolo Bonzini <pbonzini@redhat.com>
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Paolo Bonzini <pbonzini@redhat.com> wrote:

>=20
>=20
> On 09/04/2015 21:17, Bandan Das wrote:
>>> Excluding (1) all of the other issues are related to the VM BIOS. P=
erhaps
>>> KVM should somehow realize which VM BIOS runs? (yes, it sounds just=
 as bad.)
>>=20
>> How about renaming the toggle Avi mentioned above to something more =
generic
>> (KVM_DISABLE_LEGACY_QUIRKS ?) and grouping all the issues together ?=
 Modern userspace
>> will always enable it and get the new correct behavior. When more ca=
ses are discovered,
>> KVM can just add them to the list.
>=20
> It can be a VM capability (KVM_FIRMWARE_QUIRKS?) that is enabled via
> KVM_ENABLE_CAP.
>=20
> The first argument in struct kvm_enable_cap can be used to add more
> quirks in the future.  For now, an argument of zero could be used to:
>=20
> 1) set up LINT0 correctly
>=20
> 2) set up CD and NW correctly in svm_set_cr0
>=20
> AFAIK the MTRR issue in SeaBIOS was not fixed.  For that, QEMU could
> write to MSR_MTRRcap with KVM_SET_MSR.
>=20
> Setting the "accessed" bit in vmx_set_segment is IMHO harmless, and w=
e
> might as well do it even if !enable_unrestricted_guest.

Ok. I=E2=80=99ll send an updated version (as well as updated version of=
 the
init/reset issues) in the next few days.

Nadav