linux-kernel - Re: [RFC PATCH v5 042/104] KVM: x86/mmu: Track shadow MMIO value/mask on a per-VM basis

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <7db9977ef1ec3f67ea2da1599f168825d7173111.camel@intel.com>
Date:   Sat, 09 Apr 2022 11:34:07 +1200
From:   Kai Huang <kai.huang@...el.com>
To:     Isaku Yamahata <isaku.yamahata@...il.com>
Cc:     isaku.yamahata@...el.com, kvm@...r.kernel.org,
        linux-kernel@...r.kernel.org, Paolo Bonzini <pbonzini@...hat.com>,
        Jim Mattson <jmattson@...gle.com>, erdemaktas@...gle.com,
        Connor Kuehl <ckuehl@...hat.com>,
        Sean Christopherson <seanjc@...gle.com>
Subject: Re: [RFC PATCH v5 042/104] KVM: x86/mmu: Track shadow MMIO
 value/mask on a per-VM basis

On Fri, 2022-04-08 at 12:12 -0700, Isaku Yamahata wrote:
> > > -	shadow_present_mask	= has_exec_only ? 0ull :
> > > VMX_EPT_READABLE_MASK;
> > > +	shadow_present_mask	=
> > > +		(has_exec_only ? 0ull : VMX_EPT_READABLE_MASK) |
> > > init_value;
> > 
> > This change doesn't seem make any sense.  Why should "Suppress #VE" bit be
> > set
> > for a present PTE?
> 
> Because W or NX violation also needs #VE.  Although the name uses present,
> it's
> actually readable.

Yeah I forgot this.  Thanks!

-- 
Thanks,
-Kai