linux-kernel - Re: [PATCH v12 05/22] x86/virt/tdx: Add SEAMCALL infrastructure

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 for Android: free password hash cracker in your pocket

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

Message-ID: <8bce4a6c56b94acc96a08b3e63467788e5250a3a.camel@intel.com>
Date:   Wed, 28 Jun 2023 23:31:30 +0000
From:   "Huang, Kai" <kai.huang@...el.com>
To:     "kirill.shutemov@...ux.intel.com" <kirill.shutemov@...ux.intel.com>
CC:     "kvm@...r.kernel.org" <kvm@...r.kernel.org>,
        "x86@...nel.org" <x86@...nel.org>,
        "Raj, Ashok" <ashok.raj@...el.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>,
        "Christopherson,, Sean" <seanjc@...gle.com>,
        "Chatre, Reinette" <reinette.chatre@...el.com>,
        "pbonzini@...hat.com" <pbonzini@...hat.com>,
        "tglx@...utronix.de" <tglx@...utronix.de>,
        "linux-mm@...ck.org" <linux-mm@...ck.org>,
        "Yamahata, Isaku" <isaku.yamahata@...el.com>,
        "mingo@...hat.com" <mingo@...hat.com>,
        "Luck, Tony" <tony.luck@...el.com>,
        "hpa@...or.com" <hpa@...or.com>,
        "peterz@...radead.org" <peterz@...radead.org>,
        "nik.borisov@...e.com" <nik.borisov@...e.com>,
        "imammedo@...hat.com" <imammedo@...hat.com>,
        "Gao, Chao" <chao.gao@...el.com>, "bp@...en8.de" <bp@...en8.de>,
        "Brown, Len" <len.brown@...el.com>,
        "Shahar, Sagi" <sagis@...gle.com>,
        "sathyanarayanan.kuppuswamy@...ux.intel.com" 
        <sathyanarayanan.kuppuswamy@...ux.intel.com>,
        "Huang, Ying" <ying.huang@...el.com>,
        "Williams, Dan J" <dan.j.williams@...el.com>
Subject: Re: [PATCH v12 05/22] x86/virt/tdx: Add SEAMCALL infrastructure

On Wed, 2023-06-28 at 14:50 +0300, kirill.shutemov@...ux.intel.com wrote:
> On Wed, Jun 28, 2023 at 03:34:05AM +0000, Huang, Kai wrote:
> > On Wed, 2023-06-28 at 11:09 +0800, Chao Gao wrote:
> > > > +/*
> > > > + * Wrapper of __seamcall() to convert SEAMCALL leaf function error code
> > > > + * to kernel error code.  @seamcall_ret and @out contain the SEAMCALL
> > > > + * leaf function return code and the additional output respectively if
> > > > + * not NULL.
> > > > + */
> > > > +static int __always_unused seamcall(u64 fn, u64 rcx, u64 rdx, u64 r8, u64
> > > > r9,
> > > > +				    u64 *seamcall_ret,
> > > > +				    struct tdx_module_output *out)
> > > > +{
> > > > +	u64 sret;
> > > > +	int cpu;
> > > > +
> > > > +	/* Need a stable CPU id for printing error message */
> > > > +	cpu = get_cpu();
> > > > +	sret = __seamcall(fn, rcx, rdx, r8, r9, out);
> > > > +	put_cpu();
> > > > +
> > > > +	/* Save SEAMCALL return code if the caller wants it */
> > > > +	if (seamcall_ret)
> > > > +		*seamcall_ret = sret;
> > > 
> > > Hi Kai,
> > > 
> > > All callers in this series pass NULL for seamcall_ret. I am no sure if
> > > you keep it intentionally.
> > 
> > In this series all the callers doesn't need seamcall_ret.
> 
> I'm fine keeping it if it is needed by KVM TDX enabling. Otherwise, just
> drop it.

No problem I'll drop it.  KVM is using __seamcall() anyway.