Re: [Qemu-devel] [PATCH 4/5] x86: Allow physical address bits to be set

From: Eduardo Habkost <ehabkost@redhat.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Dr. David Alan Gilbert (git)" <dgilbert@redhat.com>,
	qemu-devel@nongnu.org, aarcange@redhat.com
Subject: Re: [Qemu-devel] [PATCH 4/5] x86: Allow physical address bits to be set
Date: Thu, 16 Jun 2016 15:09:51 -0300	[thread overview]
Message-ID: <20160616180951.GR18662@thinpad.lan.raisama.net> (raw)
In-Reply-To: <f374818a-753c-d67a-37bb-275f616d1e76@redhat.com>

On Thu, Jun 16, 2016 at 07:26:01PM +0200, Paolo Bonzini wrote:
> 
> 
> On 16/06/2016 19:12, Dr. David Alan Gilbert (git) wrote:
> >          if (env->features[FEAT_8000_0001_EDX] & CPUID_EXT2_LM) {
> > -            /* 64 bit processor */
> > -/* XXX: The physical address space is limited to 42 bits in exec.c. */
> > -            *eax = 0x00003028; /* 48 bits virtual, 40 bits physical */
> > +            /* 64 bit processor, 48 bits virtual, configurable
> > +             * physical bits.
> > +             */
> > +            *eax = 0x00003000 + cpu->phys_bits;
> 
> This probably ought to be range checked in realize.  I think you can
> also implement the magic 0 value there and have a bit less indentation.

Yes, please. We should move everything that requires looking at
the host inside realize. Close to the "if (cpu->host_features)"
check.

> 
> In addition, "-cpu host" should have phys-bits=0.

Yes.

-- 
Eduardo