All of lore.kernel.org
 help / color / mirror / Atom feed
From: Paolo Bonzini <pbonzini@redhat.com>
To: Vitaly Kuznetsov <vkuznets@redhat.com>, kvm@vger.kernel.org
Cc: Sean Christopherson <seanjc@google.com>,
	Wanpeng Li <wanpengli@tencent.com>,
	Jim Mattson <jmattson@google.com>,
	Maxim Levitsky <mlevitsk@redhat.com>,
	Cathy Avery <cavery@redhat.com>,
	Emanuele Giuseppe Esposito <eesposit@redhat.com>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH RFC] KVM: nSVM: Fix L1 state corruption upon return from SMM
Date: Wed, 23 Jun 2021 11:39:31 +0200	[thread overview]
Message-ID: <a3918bfa-7b4f-c31a-448a-aa22a44d4dfd@redhat.com> (raw)
In-Reply-To: <20210623074427.152266-1-vkuznets@redhat.com>

On 23/06/21 09:44, Vitaly Kuznetsov wrote:
> - RFC: I'm not 100% sure my 'smart' idea to use currently-unused HSAVE area
> is that smart. Also, we don't even seem to check that L1 set it up upon
> nested VMRUN so hypervisors which don't do that may remain broken. A very
> much needed selftest is also missing.

It's certainly a bit weird, but I guess it counts as smart too.  It 
needs a few more comments, but I think it's a good solution.

One could delay the backwards memcpy until vmexit time, but that would 
require a new flag so it's not worth it for what is a pretty rare and 
already expensive case.

Paolo


  reply	other threads:[~2021-06-23  9:39 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-23  7:44 [PATCH RFC] KVM: nSVM: Fix L1 state corruption upon return from SMM Vitaly Kuznetsov
2021-06-23  9:39 ` Paolo Bonzini [this message]
2021-06-23 11:39   ` Maxim Levitsky
2021-06-23 12:00     ` Paolo Bonzini
2021-06-23 13:01   ` Maxim Levitsky
2021-06-23 13:07     ` Maxim Levitsky
2021-06-23 13:32       ` Vitaly Kuznetsov
2021-06-23 14:41         ` Maxim Levitsky
2021-06-23 16:10           ` Sean Christopherson
2021-06-23 16:21             ` Sean Christopherson
2021-06-23 20:37               ` Paolo Bonzini
2021-06-24  7:41                 ` Vitaly Kuznetsov
2021-06-24  8:20                 ` Maxim Levitsky
2021-06-24 10:38                   ` Paolo Bonzini
2021-06-24 14:32                     ` Tom Lendacky
2021-06-24 15:36                       ` Maxim Levitsky
2021-06-23 13:21     ` Paolo Bonzini
2021-06-23 14:06       ` Maxim Levitsky

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=a3918bfa-7b4f-c31a-448a-aa22a44d4dfd@redhat.com \
    --to=pbonzini@redhat.com \
    --cc=cavery@redhat.com \
    --cc=eesposit@redhat.com \
    --cc=jmattson@google.com \
    --cc=kvm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mlevitsk@redhat.com \
    --cc=seanjc@google.com \
    --cc=vkuznets@redhat.com \
    --cc=wanpengli@tencent.com \
    /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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.