From mboxrd@z Thu Jan  1 00:00:00 1970
From: Radim =?utf-8?B?S3LEjW3DocWZ?= <rkrcmar@redhat.com>
Subject: Re: [PATCH 08/13] KVM: x86: stubs for SMM support
Date: Tue, 5 May 2015 20:48:14 +0200
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Cc: Paolo Bonzini <pbonzini@redhat.com>, linux-kernel@vger.kernel.org,
	kvm@vger.kernel.org, guangrong.xiao@linux.intel.com,
	Yang Zhang <yang.z.zhang@intel.com>, wanpeng.li@linux.intel.com
To: Bandan Das <bsd@redhat.com>
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2015-05-05 14:38-0400, Bandan Das:
> Radim Kr=C4=8Dm=C3=A1=C5=99 <rkrcmar@redhat.com> writes:
> ...
> >> +		break;
> >
> > (I'm not sure if this is supported if IA32_VMX_BASIC[49] =3D 0.
> >  34.15.6.4 Saving Guest State
> >    The SMM-transfer monitor (STM) can also discover the current val=
ue of
> >    the SMBASE register by using the RDMSR
> >
> >  but it's not possible to get into STM without having a support for=
 it
> >  noted in IA32_VMX_BASIC[49] and more magic we also don't emulate t=
o
> >  actually enable it.)
>=20
> Where does it mention IA32_VMX_BASIC[49] ? I only see "IA32_VMX_MISC[=
15] should be 1"
> in 34.15.6.4. Anyway, I think we should do what the spec says..

The relevant part is "SMM-transfer monitor (STM) can" -- you can't be
STM without IA32_VMX_MISC[15] and a bunch of other stuff.

Testing on real hardware would be the best way to tell ...
(Till we know, I'm okay with anything.)

> >> @@ -7208,6 +7240,8 @@ void kvm_vcpu_reset(struct kvm_vcpu *vcpu)
> >>  	vcpu->arch.regs_avail =3D ~0;
> >>  	vcpu->arch.regs_dirty =3D ~0;
> >> =20
> >> +	vcpu->arch.smbase =3D 0x30000;
> >
> > It's not reset on INIT, only on RESET.  (34.11 SMBASE RELOCATION)
> I remember mentioning it elsewhere - IMO kvm_vcpu_reset() and kvm_vcp=
u_init()
> should really be two different interfaces. I don't mean code duplicat=
ion - one
> can just call the other but different names will be of some help when=
 it comes
> to the million places where the spec mentions INIT and RESET have dif=
ferent
> behavior.

Agreed.