From: Jim Mattson <jmattson@google.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: LKML <linux-kernel@vger.kernel.org>,
kvm list <kvm@vger.kernel.org>,
Sean Christopherson <sean.j.christopherson@intel.com>,
stable@vger.kernel.org
Subject: Re: [PATCH 2/5] KVM: x86: do not modify masked bits of shared MSRs
Date: Tue, 19 Nov 2019 11:00:28 -0800 [thread overview]
Message-ID: <CALMp9eTzAFYt1wkXT+OEx=vNs0rrCvp=8XG8Jbwwaj3mSPPF+Q@mail.gmail.com> (raw)
In-Reply-To: <1574101067-5638-3-git-send-email-pbonzini@redhat.com>
On Mon, Nov 18, 2019 at 10:17 AM Paolo Bonzini <pbonzini@redhat.com> wrote:
>
> "Shared MSRs" are guest MSRs that are written to the host MSRs but
> keep their value until the next return to userspace. They support
> a mask, so that some bits keep the host value, but this mask is
> only used to skip an unnecessary MSR write and the value written
> to the MSR is always the guest MSR.
>
> Fix this and, while at it, do not update smsr->values[slot].curr if
> for whatever reason the wrmsr fails. This should only happen due to
> reserved bits, so the value written to smsr->values[slot].curr
> will not match when the user-return notifier and the host value will
> always be restored. However, it is untidy and in rare cases this
> can actually avoid spurious WRMSRs on return to userspace.
>
> Cc: stable@vger.kernel.org
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
next prev parent reply other threads:[~2019-11-19 19:00 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-18 18:17 [PATCH 0/5] KVM: vmx: implement MSR_IA32_TSX_CTRL for guests Paolo Bonzini
2019-11-18 18:17 ` [PATCH 1/5] KVM: x86: fix presentation of TSX feature in ARCH_CAPABILITIES Paolo Bonzini
2019-11-18 19:39 ` Jim Mattson
2019-11-18 20:48 ` Jim Mattson
2019-11-22 20:15 ` Sean Christopherson
2019-11-18 18:17 ` [PATCH 2/5] KVM: x86: do not modify masked bits of shared MSRs Paolo Bonzini
2019-11-19 19:00 ` Jim Mattson [this message]
2019-11-18 18:17 ` [PATCH 3/5] KVM: x86: implement MSR_IA32_TSX_CTRL effect on CPUID Paolo Bonzini
2019-11-19 20:02 ` Jim Mattson
2019-11-18 18:17 ` [PATCH 4/5] KVM: vmx: implement MSR_IA32_TSX_CTRL disable RTM functionality Paolo Bonzini
2019-11-19 21:06 ` Jim Mattson
2019-11-20 12:21 ` Paolo Bonzini
2019-12-04 23:49 ` Jim Mattson
2019-12-05 10:16 ` Paolo Bonzini
2019-11-18 18:17 ` [PATCH 5/5] KVM: vmx: use MSR_IA32_TSX_CTRL to hard-disable TSX on guest that lack it Paolo Bonzini
2019-11-21 2:22 ` Eduardo Habkost
2019-11-21 9:05 ` 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='CALMp9eTzAFYt1wkXT+OEx=vNs0rrCvp=8XG8Jbwwaj3mSPPF+Q@mail.gmail.com' \
--to=jmattson@google.com \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=pbonzini@redhat.com \
--cc=sean.j.christopherson@intel.com \
--cc=stable@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;
as well as URLs for NNTP newsgroup(s).