From mboxrd@z Thu Jan  1 00:00:00 1970
From: Joerg Roedel <joro@8bytes.org>
Subject: Re: [PATCH 35/62] x86/sev-es: Setup per-cpu GHCBs for the runtime
 handler
Date: Wed, 12 Feb 2020 16:16:13 +0100
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To: Andy Lutomirski <luto@kernel.org>
Cc: X86 ML <x86@kernel.org>, "H. Peter Anvin" <hpa@zytor.com>, Dave Hansen <dave.hansen@linux.intel.com>, Peter Zijlstra <peterz@infradead.org>, Thomas Hellstrom <thellstrom@vmware.com>, Jiri Slaby <jslaby@suse.cz>, Dan Williams <dan.j.williams@intel.com>, Tom Lendacky <thomas.lendacky@amd.com>, Juergen Gross <jgross@suse.com>, Kees Cook <keescook@chromium.org>, LKML <linux-kernel@vger.kernel.org>, kvm list <kvm@vger.kernel.org>, Linux Virtualization <virtualization@lists.linux-foundation.org>, Joerg Roedel <jroedel@suse.de>
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On Tue, Feb 11, 2020 at 02:46:11PM -0800, Andy Lutomirski wrote:
> On Tue, Feb 11, 2020 at 5:53 AM Joerg Roedel <joro@8bytes.org> wrote:
> > +/* Runtime GHCBs */
> > +static DEFINE_PER_CPU_DECRYPTED(struct ghcb, ghcb_page) __aligned(PAGE_SIZE);
> 
> Hmm.  This is a largeish amount of memory on large non-SEV-ES systems.
> Maybe store a pointer instead?  It would be even better if it could be
> DEFINE_PER_CPU like this but be discarded if we don't need it, but I
> don't think we have the infrastructure for that.

Yeah, discarding is not easily possible right now, but I changed it to
only store a pointer and allocating the pages only when running as an
SEV-ES guest.

Regards,

	Joerg