From: Yang Zhang <yang.zhang.wz@gmail.com>
To: Paolo Bonzini <pbonzini@redhat.com>,
linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Subject: Re: [RFC PATCH 4/4] KVM: vmx: add support for emulating UMIP
Date: Wed, 13 Jul 2016 17:54:24 +0800 [thread overview]
Message-ID: <9d4f7e9c-3468-3cf7-e1e8-2a9352a72c93@gmail.com> (raw)
In-Reply-To: <b28bc6d9-ce39-e024-c6f1-51b756c72e45@redhat.com>
On 2016/7/13 17:35, Paolo Bonzini wrote:
>
>
> On 13/07/2016 11:21, Yang Zhang wrote:
>>>
>>> + if ((cr4 & X86_CR4_UMIP) && !boot_cpu_has(X86_FEATURE_UMIP)) {
>>> + vmcs_set_bits(SECONDARY_VM_EXEC_CONTROL,
>>> + SECONDARY_EXEC_DESC);
>>> + hw_cr4 &= ~X86_CR4_UMIP;
>>> + } else
>>> + vmcs_clear_bits(SECONDARY_VM_EXEC_CONTROL,
>>> + SECONDARY_EXEC_DESC);
>>> +
>>
>> Since the faults based on privilege level have priority over VM exits.
>> So we don't need to enable/disable SECONDARY_EXEC_DESC dynamically.
>> Instead, we can set it unconditionally.
>
> I'm setting it dynamically because it slows down LGDT, LLDT, LIDT and LTR.
You are right. And SGDT, SIDT, SLDT, SMSW, STR also will be intercepted
even in CPL 0 if we don't disable it.
--
Yang
Alibaba Cloud Computing
next prev parent reply other threads:[~2016-07-13 9:54 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-12 19:20 [RFC PATCH 0/4] KVM: Emulate UMIP (or almost do so) Paolo Bonzini
2016-07-12 19:20 ` [RFC PATCH 1/4] x86: add UMIP feature and CR4 bit Paolo Bonzini
2016-07-12 19:20 ` [RFC PATCH 2/4] KVM: x86: emulate sldt and str Paolo Bonzini
2016-07-12 19:20 ` [RFC PATCH 3/4] KVM: x86: add support for emulating UMIP Paolo Bonzini
2016-07-13 20:03 ` Radim Krčmář
2016-07-14 7:00 ` Paolo Bonzini
2016-07-14 12:24 ` Radim Krčmář
2016-07-12 19:20 ` [RFC PATCH 4/4] KVM: vmx: " Paolo Bonzini
2016-07-13 9:21 ` Yang Zhang
2016-07-13 9:35 ` Paolo Bonzini
2016-07-13 9:54 ` Yang Zhang [this message]
2016-07-13 9:35 ` Paolo Bonzini
2016-07-13 10:02 ` Yang Zhang
2016-07-13 10:21 ` Paolo Bonzini
2016-07-13 20:30 ` Radim Krčmář
2016-07-14 8:09 ` Paolo Bonzini
2016-07-14 12:36 ` Radim Krčmář
2016-07-14 12:54 ` Paolo Bonzini
2016-07-31 2:32 ` Wanpeng Li
2016-08-01 15:01 ` Paolo Bonzini
2016-08-02 1:05 ` Wanpeng Li
2016-07-13 8:29 ` [RFC PATCH 0/4] KVM: Emulate UMIP (or almost do so) Yang Zhang
2016-07-13 9:34 ` Paolo Bonzini
2016-12-13 4:03 ` Li, Liang Z
2016-12-13 11:03 ` Paolo Bonzini
2017-03-01 9:04 ` Yu Zhang
2017-03-06 21:07 ` Paolo Bonzini
2017-03-10 8:02 ` Yu Zhang
2017-03-10 8:36 ` Paolo Bonzini
2017-03-10 9:31 ` Yu Zhang
2017-03-10 11:28 ` Yu Zhang
2017-03-10 15:00 ` 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=9d4f7e9c-3468-3cf7-e1e8-2a9352a72c93@gmail.com \
--to=yang.zhang.wz@gmail.com \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--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;
as well as URLs for NNTP newsgroup(s).