kvm.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Sean Christopherson <seanjc@google.com>
To: Alexander Graf <graf@amazon.com>
Cc: "Alex Williamson" <alex.williamson@redhat.com>,
	"Radim Krčmář" <rkrcmar@redhat.com>,
	kvm@vger.kernel.org, "Xiao Guangrong" <guangrong.xiao@gmail.com>,
	"Chandrasekaran, Siddharth" <sidcha@amazon.de>,
	"Paolo Bonzini" <pbonzini@redhat.com>
Subject: Re: [PATCH v2 11/27] KVM: x86/mmu: Zap only the relevant pages when removing a memslot
Date: Thu, 20 Oct 2022 20:37:48 +0000	[thread overview]
Message-ID: <Y1GxnGo3A8UF3iTt@google.com> (raw)
In-Reply-To: <590c9312-a21f-8569-9da3-34508300afcc@amazon.com>

On Thu, Oct 20, 2022, Alexander Graf wrote:
> On 26.06.20 19:32, Sean Christopherson wrote:
> > /cast <thread necromancy>
> > 
> > On Tue, Aug 20, 2019 at 01:03:19PM -0700, Sean Christopherson wrote:
> 
> [...]
> 
> > I don't think any of this explains the pass-through GPU issue.  But, we
> > have a few use cases where zapping the entire MMU is undesirable, so I'm
> > going to retry upstreaming this patch as with per-VM opt-in.  I wanted to
> > set the record straight for posterity before doing so.
> 
> Hey Sean,
> 
> Did you ever get around to upstream or rework the zap optimization? The way
> I read current upstream, a memslot change still always wipes all SPTEs, not
> only the ones that were changed.

Nope, I've more or less given up hope on zapping only the deleted/moved memslot.
TDX (and SNP?) will preserve SPTEs for guest private memory, but they're very
much a special case.  

Do you have use case and/or issue that doesn't play nice with the "zap all" behavior?

  reply	other threads:[~2022-10-20 20:37 UTC|newest]

Thread overview: 38+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-02-05 20:54 [PATCH v2 00/27] KVM: x86/mmu: Remove fast invalidate mechanism Sean Christopherson
2019-02-05 20:54 ` [PATCH v2 01/27] KVM: Call kvm_arch_memslots_updated() before updating memslots Sean Christopherson
2019-02-06  9:12   ` Cornelia Huck
2019-02-12 12:36 ` [PATCH v2 00/27] KVM: x86/mmu: Remove fast invalidate mechanism Paolo Bonzini
     [not found] ` <20190205210137.1377-11-sean.j.christopherson@intel.com>
2019-08-13 16:04   ` [PATCH v2 11/27] KVM: x86/mmu: Zap only the relevant pages when removing a memslot Alex Williamson
2019-08-13 17:04     ` Sean Christopherson
2019-08-13 17:57       ` Alex Williamson
2019-08-13 19:33         ` Alex Williamson
2019-08-13 20:19           ` Sean Christopherson
2019-08-13 20:37             ` Paolo Bonzini
2019-08-13 21:14               ` Alex Williamson
2019-08-13 21:15                 ` Paolo Bonzini
2019-08-13 22:10                   ` Alex Williamson
2019-08-15 14:46                 ` Sean Christopherson
2019-08-15 15:23             ` Alex Williamson
2019-08-15 16:00               ` Sean Christopherson
2019-08-15 18:16                 ` Alex Williamson
2019-08-15 19:25                   ` Sean Christopherson
2019-08-15 20:11                     ` Alex Williamson
2019-08-19 16:03               ` Paolo Bonzini
2019-08-20 20:03                 ` Sean Christopherson
2019-08-20 20:42                   ` Alex Williamson
2019-08-20 21:02                     ` Sean Christopherson
2019-08-21 19:08                       ` Alex Williamson
2019-08-21 19:35                         ` Alex Williamson
2019-08-21 20:30                           ` Sean Christopherson
2019-08-23  2:25                             ` Sean Christopherson
2019-08-23 22:05                               ` Alex Williamson
2019-08-21 20:10                         ` Sean Christopherson
2019-08-26  7:36                           ` Tian, Kevin
2019-08-26 14:56                           ` Sean Christopherson
2020-06-26 17:32                   ` Sean Christopherson
2022-10-20 18:31                     ` Alexander Graf
2022-10-20 20:37                       ` Sean Christopherson [this message]
2022-10-20 21:06                         ` Alexander Graf
2022-10-21 19:40                           ` Sean Christopherson
2022-10-24  6:12                             ` Alexander Graf
2022-10-24 15:55                               ` Sean Christopherson

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=Y1GxnGo3A8UF3iTt@google.com \
    --to=seanjc@google.com \
    --cc=alex.williamson@redhat.com \
    --cc=graf@amazon.com \
    --cc=guangrong.xiao@gmail.com \
    --cc=kvm@vger.kernel.org \
    --cc=pbonzini@redhat.com \
    --cc=rkrcmar@redhat.com \
    --cc=sidcha@amazon.de \
    /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).