From: Paolo Bonzini <pbonzini@redhat.com>
To: Wanpeng Li <wanpeng.li@linux.intel.com>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>,
Gleb Natapov <gleb@kernel.org>,
hpa@zytor.com, x86@kernel.org, kvm@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/5] KVM: vmx: fix ept reserved bits for 1-GByte page
Date: Tue, 19 Aug 2014 08:11:39 +0200 [thread overview]
Message-ID: <53F2EA9B.5010208@redhat.com> (raw)
In-Reply-To: <20140819021741.GA2003@kernel>
Il 19/08/2014 04:17, Wanpeng Li ha scritto:
>>> >> - if (level == 1 || (level == 2 && (spte & (1ULL << 7)))) {
>>> >> + if (level == 1 || ((level == 3 || level == 2)
>>> >> + && (spte & (1ULL << 7)))) {
>> >
>> >This condition can be simplified by checking the return value of ept_rsvd_mask.
>> >If it includes 0x38, this is a large page.
Oops, a "not" was missing. If it includes 0x38, this is _not_ a large
page (it is a page directory / page directory pointer / PML4).
>> Otherwise it is a leaf page and
>> you can go down the "if".
> As you know, 5:3 bits which used for EPT MT are not reserved bits, so
> I fail to understand why check the return value of ept_rsvd_mask and
> it's a large page if includes 0x38. Could you eplain in more details? ;-)
A non-leaf page will always have 0x38 in the ept_rsvd_mask. A leaf page
will never have 0x38 in the ept_rsvd_mask.
Paolo
next prev parent reply other threads:[~2014-08-19 6:11 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-08-18 9:50 [PATCH 1/5] KVM: vmx: fix ept reserved bits for 1-GByte page Wanpeng Li
2014-08-18 9:50 ` [PATCH 2/5] KVM: x86: drop fpu_activate hook Wanpeng Li
2014-08-18 10:20 ` Paolo Bonzini
2014-08-18 10:26 ` Avi Kivity
2014-08-18 10:51 ` Paolo Bonzini
2014-08-18 11:15 ` Avi Kivity
2014-08-18 10:52 ` Paolo Bonzini
2014-08-18 9:50 ` [PATCH 3/5] KVM: vmx: don't vmx_segment_cache_clear twice in enter_pmode Wanpeng Li
2014-08-18 10:24 ` Paolo Bonzini
2014-08-18 9:50 ` [PATCH 4/5] KVM: x86: fix check legal type of Variable Range MTRRs Wanpeng Li
2014-08-18 10:28 ` Paolo Bonzini
2014-08-18 9:50 ` [PATCH 5/5] KVM: x86: #GP when attempts to write reserved bits " Wanpeng Li
2014-08-18 12:27 ` Wanpeng Li
2014-08-18 12:49 ` Paolo Bonzini
2014-08-18 10:18 ` [PATCH 1/5] KVM: vmx: fix ept reserved bits for 1-GByte page Paolo Bonzini
2014-08-19 2:17 ` Wanpeng Li
2014-08-19 6:11 ` Paolo Bonzini [this message]
2014-08-18 10:52 ` Xiao Guangrong
2014-08-18 11:18 ` Paolo Bonzini
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