From: Sean Christopherson <seanjc@google.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] KVM: x86/mmu: Calculate and check "full" mmu_role for nested MMU
Date: Fri, 11 Jun 2021 16:45:31 +0000 [thread overview]
Message-ID: <YMOTK7eYytpw58Vc@google.com> (raw)
In-Reply-To: <b2084f55-3ce5-57c4-f580-d6a2de6ce612@redhat.com>
On Fri, Jun 11, 2021, Paolo Bonzini wrote:
> On 11/06/21 00:00, Sean Christopherson wrote:
> > things like the number of levels in the guest's page tables are
> > surprisingly important when walking the guest page tables
>
> Along which path though? I would have naively expected those to be driven
> only by the context->root_level.
The functional code is driven by context->root_level, but if KVM doesn't include
the level in the mmu_role then it will fail to update context->root_level when
L2 changes from 32-bit PAE to 64-bit. If all the CR0/CR4/EFER bits remain the
same, only the level will differ. Without this patch, role.level is always '0'
for the nested MMU.
next prev parent reply other threads:[~2021-06-11 16:47 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-10 22:00 [PATCH] KVM: x86/mmu: Calculate and check "full" mmu_role for nested MMU Sean Christopherson
2021-06-11 8:57 ` Vitaly Kuznetsov
2021-06-11 14:22 ` Sean Christopherson
2021-06-11 19:51 ` Sean Christopherson
2021-06-11 16:02 ` Paolo Bonzini
2021-06-11 16:19 ` Paolo Bonzini
2021-06-11 16:45 ` Sean Christopherson [this message]
2021-06-11 16:49 ` 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=YMOTK7eYytpw58Vc@google.com \
--to=seanjc@google.com \
--cc=jmattson@google.com \
--cc=joro@8bytes.org \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=pbonzini@redhat.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox