From: Vitaly Kuznetsov <vkuznets@redhat.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Jim Mattson <jmattson@google.com>,
Sean Christopherson <sean.j.christopherson@intel.com>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
Liran Alon <liran.alon@oracle.com>
Subject: Re: [RFC] Revert "kvm: nVMX: Restrict VMX capability MSR changes"
Date: Mon, 20 Jan 2020 17:33:26 +0100 [thread overview]
Message-ID: <87k15mf5pl.fsf@vitty.brq.redhat.com> (raw)
In-Reply-To: <30525d58-10de-abb4-8dad-228da766ff82@redhat.com>
Paolo Bonzini <pbonzini@redhat.com> writes:
> On 20/01/20 16:11, Vitaly Kuznetsov wrote:
>>
>> RFC. I think the check for vmx->nested.vmxon is legitimate for everything
>> but restore so removing it (what I do with the revert) is likely a no-go.
>> I'd like to gather opinions on the proper fix: should we somehow check
>> that the vCPU is in 'restore' start (has never being run) and make
>> KVM_SET_MSRS pass or should we actually mandate that KVM_SET_NESTED_STATE
>> is run after KVM_SET_MSRS by userspace?
>>
>> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
>
> I think this should be fixed in QEMU, by doing KVM_SET_MSRS for feature
> MSRs way earlier. I'll do it since I'm currently working on a patch to
> add a KVM_SET_MSR for the microcode revision.
Works for me, thanks)
The bigger issue is that the vCPU setup sequence (like QEMU's
kvm_arch_put_registers()) effectively becomes an API convention and as
it gets more complex it would be great to document it for KVM.
--
Vitaly
next prev parent reply other threads:[~2020-01-20 16:33 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-20 15:11 [RFC] Revert "kvm: nVMX: Restrict VMX capability MSR changes" Vitaly Kuznetsov
2020-01-20 15:41 ` Paolo Bonzini
2020-01-20 16:33 ` Vitaly Kuznetsov [this message]
2020-01-20 16:40 ` Paolo Bonzini
2020-01-20 17:16 ` Liran Alon
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=87k15mf5pl.fsf@vitty.brq.redhat.com \
--to=vkuznets@redhat.com \
--cc=jmattson@google.com \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=liran.alon@oracle.com \
--cc=pbonzini@redhat.com \
--cc=sean.j.christopherson@intel.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.