From: David Matlack <dmatlack@google.com>
To: Sean Christopherson <seanjc@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
Jeremi Piotrowski <jpiotrowski@linux.microsoft.com>,
Ben Gardon <bgardon@google.com>
Subject: Re: [PATCH] KVM: x86: Preserve TDP MMU roots until they are explicitly invalidated
Date: Thu, 20 Apr 2023 13:34:51 -0700 [thread overview]
Message-ID: <ZEGh6zrhJX/SN9jp@google.com> (raw)
In-Reply-To: <20230413231251.1481410-1-seanjc@google.com>
On Thu, Apr 13, 2023 at 04:12:51PM -0700, Sean Christopherson wrote:
> Preserve TDP MMU roots until they are explicitly invalidated by gifting
> the TDP MMU itself a reference to a root when it is allocated. Keeping a
> reference in the TDP MMU fixes a flaw where the TDP MMU exhibits terrible
> performance, and can potentially even soft-hang a vCPU, if a vCPU
> frequently unloads its roots, e.g. when KVM is emulating SMI+RSM.
>
[...]
>
> Reported-by: Jeremi Piotrowski <jpiotrowski@linux.microsoft.com>
> Link: https://lore.kernel.org/all/959c5bce-beb5-b463-7158-33fc4a4f910c@linux.microsoft.com
> Link: https://lkml.kernel.org/r/20220209170020.1775368-1-pbonzini%40redhat.com
> Link: https://lore.kernel.org/all/20230322013731.102955-1-minipli@grsecurity.net
> Cc: David Matlack <dmatlack@google.com>
> Cc: Ben Gardon <bgardon@google.com>
> Cc: stable@vger.kernel.org
> Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: David Matlack <dmatlack@google.com>
next prev parent reply other threads:[~2023-04-20 20:35 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-04-13 23:12 [PATCH] KVM: x86: Preserve TDP MMU roots until they are explicitly invalidated Sean Christopherson
2023-04-14 11:58 ` Jeremi Piotrowski
2023-04-14 16:55 ` Sean Christopherson
2023-04-20 20:34 ` David Matlack [this message]
2023-04-20 23:05 ` 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=ZEGh6zrhJX/SN9jp@google.com \
--to=dmatlack@google.com \
--cc=bgardon@google.com \
--cc=jpiotrowski@linux.microsoft.com \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=pbonzini@redhat.com \
--cc=seanjc@google.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.