linux-kernel - Re: [PATCH v12 07/22] x86/virt/tdx: Add skeleton to enable TDX on demand

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]

Date:   Fri, 30 Jun 2023 10:09:08 +0000
From:   "Huang, Kai" <kai.huang@...el.com>
To:     "peterz@...radead.org" <peterz@...radead.org>
CC:     "kvm@...r.kernel.org" <kvm@...r.kernel.org>,
        "Gao, Chao" <chao.gao@...el.com>,
        "Raj, Ashok" <ashok.raj@...el.com>,
        "Shahar, Sagi" <sagis@...gle.com>,
        "Hansen, Dave" <dave.hansen@...el.com>,
        "david@...hat.com" <david@...hat.com>,
        "bagasdotme@...il.com" <bagasdotme@...il.com>,
        "ak@...ux.intel.com" <ak@...ux.intel.com>,
        "Wysocki, Rafael J" <rafael.j.wysocki@...el.com>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "Chatre, Reinette" <reinette.chatre@...el.com>,
        "Christopherson,, Sean" <seanjc@...gle.com>,
        "pbonzini@...hat.com" <pbonzini@...hat.com>,
        "mingo@...hat.com" <mingo@...hat.com>,
        "Yamahata, Isaku" <isaku.yamahata@...el.com>,
        "nik.borisov@...e.com" <nik.borisov@...e.com>,
        "tglx@...utronix.de" <tglx@...utronix.de>,
        "Luck, Tony" <tony.luck@...el.com>,
        "kirill.shutemov@...ux.intel.com" <kirill.shutemov@...ux.intel.com>,
        "hpa@...or.com" <hpa@...or.com>,
        "imammedo@...hat.com" <imammedo@...hat.com>,
        "linux-mm@...ck.org" <linux-mm@...ck.org>,
        "bp@...en8.de" <bp@...en8.de>, "Brown, Len" <len.brown@...el.com>,
        "sathyanarayanan.kuppuswamy@...ux.intel.com" 
        <sathyanarayanan.kuppuswamy@...ux.intel.com>,
        "Huang, Ying" <ying.huang@...el.com>,
        "x86@...nel.org" <x86@...nel.org>,
        "Williams, Dan J" <dan.j.williams@...el.com>
Subject: Re: [PATCH v12 07/22] x86/virt/tdx: Add skeleton to enable TDX on
 demand

On Fri, 2023-06-30 at 11:22 +0200, Peter Zijlstra wrote:
> On Thu, Jun 29, 2023 at 12:15:13AM +0000, Huang, Kai wrote:
> 
> > > 	Can be called locally or through an IPI function call.
> > > 
> > 
> > Thanks.  As in another reply, if using spinlock is OK, then I think we can say
> > it will be called either locally or through an IPI function call.  Otherwise, we
> > do via a new separate function tdx_global_init() and no lock is needed in that
> > function.  The caller should call it properly.
> 
> IPI must use raw_spinlock_t. I'm ok with using raw_spinlock_t if there's
> actual need for that, but the code as presented didn't -- in comments or
> otherwise -- make it clear why it was as it was.

There's no hard requirement as I replied in another email.

Presumably you prefer the option to have a dedicated tdx_global_init() so we can
avoid the raw_spinlock_t?

Thanks.

> 
> TDX not specifying time constraints on the various TD/SEAM-CALLs is
> ofcourse sad, but alas.

Agreed.