From: Paolo Bonzini <pbonzini@redhat.com>
To: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Cc: gleb@kernel.org, mtosatti@redhat.com, kvm@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/4] KVM: MMU: fix permission_fault()
Date: Tue, 29 Mar 2016 22:09:23 +0200 [thread overview]
Message-ID: <56FAE0F3.9090809@redhat.com> (raw)
In-Reply-To: <56FABECE.40601@linux.intel.com>
On 29/03/2016 19:43, Xiao Guangrong wrote:
> Based on the SDM:
> PK flag (bit 5).
> This flag is 1 if (1) IA32_EFER.LMA = CR4.PKE = 1; (2) the access
> causing the page-fault exception was a data access; (3) the linear
> address was a user-mode address with protection key i; and (5) the PKRU
> register (see Section 4.6.2) is such that either (a) ADi = 1; or (b) the
> following all hold: (i) WDi = 1; (ii) the access is a write access; and
> (iii) either CR0.WP = 1 or the access causing the page-fault exception
> was a user-mode access.
>
> So I think PKEY check and ordinary check are independent, i.e, PFEC.PKEY
> may be set even if the on permission on the page table is not adequate.
x86/access.flat is currently using the "other" definition, i.e., PFEC.PK
is only set if W=1 or CR0.WP=0 && PFEC.U=0 or PFEC.W=0. Can you use it
(with ept=1 of course) to check what the processor is doing?
Paolo
next prev parent reply other threads:[~2016-03-29 20:09 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-25 13:19 [PATCH 1/4] KVM: MMU: fix permission_fault() Xiao Guangrong
2016-03-25 13:19 ` [PATCH 2/4] KVM: MMU: simplify the logic of __mmu_unsync_walk() Xiao Guangrong
2016-03-25 13:19 ` [PATCH 3/4] KVM: MMU: reduce the size of mmu_page_path Xiao Guangrong
2016-03-25 13:45 ` Paolo Bonzini
2016-03-25 13:48 ` Xiao Guangrong
2016-03-25 13:56 ` Paolo Bonzini
2016-03-25 14:07 ` Xiao Guangrong
2016-03-25 14:22 ` Paolo Bonzini
2016-03-25 13:19 ` [PATCH 4/4] KVM: MMU: skip obsolete sp in for_each_gfn_*() Xiao Guangrong
2016-03-29 9:44 ` Paolo Bonzini
2016-03-25 13:35 ` [PATCH 1/4] KVM: MMU: fix permission_fault() Paolo Bonzini
2016-03-25 13:41 ` Xiao Guangrong
2016-03-25 13:50 ` Paolo Bonzini
2016-03-25 14:21 ` Paolo Bonzini
2016-03-29 17:43 ` Xiao Guangrong
2016-03-29 20:09 ` Paolo Bonzini [this message]
2016-03-30 1:56 ` Xiao Guangrong
2016-03-30 6:36 ` Paolo Bonzini
2016-03-30 6:39 ` Xiao Guangrong
2016-04-06 3:27 ` Xiao Guangrong
2016-04-06 8:17 ` Paolo Bonzini
2016-04-06 8:56 ` Paolo Bonzini
2016-04-06 15:09 ` Xiao Guangrong
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