linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Paolo Bonzini <pbonzini@redhat.com>
To: Tom Lendacky <thomas.lendacky@amd.com>,
	Sean Christopherson <seanjc@google.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	x86@kernel.org, Andy Lutomirski <luto@kernel.org>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	Peter Zijlstra <peterz@infradead.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>,
	Vitaly Kuznetsov <vkuznets@redhat.com>,
	Wanpeng Li <wanpengli@tencent.com>,
	Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
	linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
	Brijesh Singh <brijesh.singh@amd.com>
Subject: Re: [PATCH] x86/sev: Add AMD_SEV_ES_GUEST Kconfig for including SEV-ES support
Date: Mon, 18 Jan 2021 19:03:17 +0100	[thread overview]
Message-ID: <2d795f19-2ac8-ea74-4365-41ea07f8eeec@redhat.com> (raw)
In-Reply-To: <015821b1-9abc-caed-8af6-c44950bd04f0@amd.com>

On 16/01/21 06:40, Tom Lendacky wrote:
> 
>> Introduce a new Kconfig, AMD_SEV_ES_GUEST, to control the inclusion of
>> support for running as an SEV-ES guest.  Pivoting on AMD_MEM_ENCRYPT for
>> guest SEV-ES support is undesirable for host-only kernel builds as
>> AMD_MEM_ENCRYPT is also required to enable KVM/host support for SEV and
>> SEV-ES.
> 
> I believe only KVM_AMD_SEV is required to enable the KVM support to run 
> SEV and SEV-ES guests. The AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT setting is 
> only used to determine whether to enable the KVM SEV/SEV-ES support by 
> default on module load.

Right:

         if (IS_ENABLED(CONFIG_KVM_AMD_SEV) && sev) {
                 sev_hardware_setup();
         } else {
                 sev = false;
                 sev_es = false;
         }

I removed the addition to "config AMD_MEM_ENCRYPT_ from Sean's patch, 
but (despite merging it not once but twice) I don't really like the 
hidden dependency on AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT and thus 
AMD_MEM_ENCRYPT.  Is there any reason to not always enable sev/sev_es by 
default?

Paolo


  reply	other threads:[~2021-01-18 18:05 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-16  0:25 [PATCH] x86/sev: Add AMD_SEV_ES_GUEST Kconfig for including SEV-ES support Sean Christopherson
2021-01-16  5:40 ` Tom Lendacky
2021-01-18 18:03   ` Paolo Bonzini [this message]
2021-01-18 18:16     ` Tom Lendacky
2021-01-18 17:59 ` Paolo Bonzini
2021-01-18 20:26   ` Borislav Petkov
2021-01-18 20:30     ` Paolo Bonzini
2021-01-18 20:29 ` Borislav Petkov
2021-01-18 20:32   ` Paolo Bonzini
2021-01-18 20:47     ` Borislav Petkov
2021-01-19 16:23       ` Sean Christopherson
2021-01-19 17:09         ` Borislav Petkov
2021-01-19 17:12           ` Paolo Bonzini

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=2d795f19-2ac8-ea74-4365-41ea07f8eeec@redhat.com \
    --to=pbonzini@redhat.com \
    --cc=bp@alien8.de \
    --cc=brijesh.singh@amd.com \
    --cc=dave.hansen@linux.intel.com \
    --cc=hpa@zytor.com \
    --cc=jmattson@google.com \
    --cc=joro@8bytes.org \
    --cc=kvm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=luto@kernel.org \
    --cc=mingo@redhat.com \
    --cc=peterz@infradead.org \
    --cc=seanjc@google.com \
    --cc=tglx@linutronix.de \
    --cc=thomas.lendacky@amd.com \
    --cc=vkuznets@redhat.com \
    --cc=wanpengli@tencent.com \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).