From: Sean Christopherson <seanjc@google.com>
To: Jim Mattson <jmattson@google.com>
Cc: Mahmoud Abumandour <ma.mandourr@gmail.com>,
Paolo Bonzini <pbonzini@redhat.com>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 0/2] KVM: nVMX: Don't let L2's LMSW modify CR0 bits owned by L1
Date: Fri, 30 Oct 2026 11:54:05 -0700 [thread overview]
Message-ID: <auTnzSiIihVgs8ha@google.com> (raw)
In-Reply-To: <CALMp9eS_XAyfRQ0aa7pGmC2t-=mbHA7rngWD9oqOB2U8AJZMsw@mail.gmail.com>
On Fri, Oct 30, 2026, Jim Mattson wrote:
> On Fri, Oct 30, 2026 at 11:51 AM Sean Christopherson <seanjc@google.com> wrote:
> >
> > On Thu, Oct 29, 2026, Mahmoud Abumandour wrote:
> > > When L2's LMSW exits to L0 but not to L1, KVM emulates it with
> > > kvm_lmsw(), which ignores vmcs12's CR0 guest/host mask, so L2 can change
> > > CR0 bits that L1 owns.
> > >
> > > v2:
> > > - Patch 2: order the CR0 store before FNOP and check L2's whole CR0.
> >
> > I'll send a v3, I already spent an absurd amount of time figuring all of this
> > out. I really hate x86 sometimes.
>
> You should redirect that emotion to KVM APIs!
Heh, saying I hate KVM's APIs sometimes would be a lie. I hate them all the time.
prev parent reply other threads:[~2026-10-30 18:54 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-30 3:29 [PATCH v2 0/2] KVM: nVMX: Don't let L2's LMSW modify CR0 bits owned by L1 Mahmoud Abumandour
2026-10-30 3:29 ` [PATCH v2 1/2] " Mahmoud Abumandour
2026-10-30 18:23 ` Sean Christopherson
2026-10-30 18:44 ` Sean Christopherson
2026-10-30 3:29 ` [PATCH v2 2/2] KVM: selftests: Verify that L2's LMSW leaves L1-owned CR0 bits alone Mahmoud Abumandour
2026-10-30 18:41 ` Sean Christopherson
2026-10-30 18:50 ` [PATCH v2 0/2] KVM: nVMX: Don't let L2's LMSW modify CR0 bits owned by L1 Sean Christopherson
2026-10-30 18:52 ` Jim Mattson
2026-10-30 18:54 ` Sean Christopherson [this message]
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=auTnzSiIihVgs8ha@google.com \
--to=seanjc@google.com \
--cc=jmattson@google.com \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=ma.mandourr@gmail.com \
--cc=pbonzini@redhat.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox