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Date: Thu, 8 Aug 2019 12:45:58 +0200
From: =?UTF-8?B?Um9nZXIgUGF1IE1vbm7DqQ==?= <roger.pau@citrix.com>
To: Anthony PERARD <anthony.perard@citrix.com>
CC: <devel@edk2.groups.io>, Julien Grall <julien.grall@arm.com>,
	<xen-devel@lists.xenproject.org>, Jordan Justen <jordan.l.justen@intel.com>,
	Ard Biesheuvel <ard.biesheuvel@linaro.org>, Laszlo Ersek <lersek@redhat.com>
Subject: Re: [edk2-devel] [PATCH v4 22/35] OvmfPkg/XenPlatformPei: no hvmloader: get the E820 table via hypercall
Message-ID: <20190808104558.vm6dfic5dntjsnt4@Air-de-Roger>
References: <20190729153944.24239-1-anthony.perard@citrix.com>
 <20190729153944.24239-23-anthony.perard@citrix.com>
 <20190807150849.b6alhjw2lgcjpmxx@Air-de-Roger>
 <20190808104118.GS1242@perard.uk.xensource.com>
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On Thu, Aug 08, 2019 at 11:41:18AM +0100, Anthony PERARD wrote:
> On Wed, Aug 07, 2019 at 05:14:33PM +0200, Roger Pau Monné wrote:
> > On Mon, Jul 29, 2019 at 04:39:31PM +0100, Anthony PERARD wrote:
> > > When the Xen PVH entry point has been used, hvmloader hasn't run and
> > > hasn't prepared an E820 table. The only way left to get an E820 table
> > > is to ask Xen via an hypercall, the call can only be made once so keep
> > > the result cached for later.
> > 
> > I think we agreed that the above is not true, and that the memory
> > map can be fetched as many times as desired using the hypercall
> > interface.
> 
> Yes, I'll change the commit message. How about:
> 
>   When the Xen PVH entry point has been used, hvmloader hasn't run and
>   hasn't prepared an E820 table. The only way left to get an E820 table
>   is to ask Xen via an hypercall.  We keep the result cached to avoid
>   making a second hypercall which would give the same result.

LGTM, thanks.