From: "Radim Krčmář" <rkrcmar@redhat.com>
To: Jim Mattson <jmattson@google.com>
Cc: kvm@vger.kernel.org
Subject: Re: [PATCH 1/3] kvm: vmx: Do not disable intercepts for BNDCFGS
Date: Wed, 24 May 2017 17:05:36 +0200 [thread overview]
Message-ID: <20170524150536.GB7778@potion> (raw)
In-Reply-To: <20170523185254.98780-1-jmattson@google.com>
2017-05-23 11:52-0700, Jim Mattson:
> The MSR permission bitmaps are shared by all VMs. However, some VMs
> may not be configured to support MPX, even when the host does. If the
> host supports VMX and the guest does not, we should intercept accesses
> to the BNDCFGS MSR, so that we can synthesize a #GP
> fault. Furthermore, if the host does not support MPX and the
> "ignore_msrs" kvm kernel parameter is set, then we should intercept
> accesses to the BNDCFGS MSR, so that we can skip over the rdmsr/wrmsr
> without raising a #GP fault.
>
> Fixes: da8999d31818fdc8 ("KVM: x86: Intel MPX vmx and msr handle")
> Signed-off-by: Jim Mattson <jmattson@google.com>
> ---
IIUC, we don't even need faster accesses as BNDCFGS MSR should usually
be written once per boot and never read,
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
next prev parent reply other threads:[~2017-05-24 15:05 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-23 18:52 [PATCH 1/3] kvm: vmx: Do not disable intercepts for BNDCFGS Jim Mattson
2017-05-23 18:52 ` [PATCH 2/3] kvm: vmx: Guest BNDCFGS requires guest MPX support Jim Mattson
2017-05-24 13:08 ` kbuild test robot
2017-05-24 16:22 ` [PATCH 2/3 v2] kvm: x86: " Jim Mattson
2017-05-24 17:28 ` Radim Krčmář
2017-05-24 17:40 ` Jim Mattson
2017-05-24 17:49 ` [PATCH 2/3 v3] " Jim Mattson
2017-05-24 18:22 ` Radim Krčmář
2017-05-23 18:52 ` [PATCH 3/3] kvm: vmx: Check value written to IA32_BNDCFGS Jim Mattson
2017-05-24 15:09 ` Radim Krčmář
2017-05-24 15:05 ` Radim Krčmář [this message]
2017-06-07 14:31 ` [PATCH 1/3] kvm: vmx: Do not disable intercepts for BNDCFGS Radim Krčmář
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=20170524150536.GB7778@potion \
--to=rkrcmar@redhat.com \
--cc=jmattson@google.com \
--cc=kvm@vger.kernel.org \
/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