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: <SN6PR12MB276764F83F8849603A2F23478EAA9@SN6PR12MB2767.namprd12.prod.outlook.com>
Date:   Tue, 14 Jun 2022 17:16:53 +0000
From:   "Kalra, Ashish" <Ashish.Kalra@....com>
To:     Peter Gonda <pgonda@...gle.com>
CC:     Alper Gun <alpergun@...gle.com>,
        the arch/x86 maintainers <x86@...nel.org>,
        LKML <linux-kernel@...r.kernel.org>,
        kvm list <kvm@...r.kernel.org>,
        "linux-coco@...ts.linux.dev" <linux-coco@...ts.linux.dev>,
        "linux-mm@...ck.org" <linux-mm@...ck.org>,
        Linux Crypto Mailing List <linux-crypto@...r.kernel.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Joerg Roedel <jroedel@...e.de>,
        "Lendacky, Thomas" <Thomas.Lendacky@....com>,
        "H. Peter Anvin" <hpa@...or.com>, Ard Biesheuvel <ardb@...nel.org>,
        Paolo Bonzini <pbonzini@...hat.com>,
        Sean Christopherson <seanjc@...gle.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Andy Lutomirski <luto@...nel.org>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        Sergio Lopez <slp@...hat.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>,
        David Rientjes <rientjes@...gle.com>,
        Dov Murik <dovmurik@...ux.ibm.com>,
        Tobin Feldman-Fitzthum <tobin@....com>,
        Borislav Petkov <bp@...en8.de>,
        "Roth, Michael" <Michael.Roth@....com>,
        Vlastimil Babka <vbabka@...e.cz>,
        "Kirill A . Shutemov" <kirill@...temov.name>,
        Andi Kleen <ak@...ux.intel.com>,
        Tony Luck <tony.luck@...el.com>, Marc Orr <marcorr@...gle.com>,
        Sathyanarayanan Kuppuswamy 
        <sathyanarayanan.kuppuswamy@...ux.intel.com>
Subject: RE: [PATCH Part2 v5 23/45] KVM: SVM: Add KVM_SNP_INIT command

[AMD Official Use Only - General]

Hello Alper, Peter,

-----Original Message-----
From: Peter Gonda <pgonda@...gle.com> 
Sent: Tuesday, June 14, 2022 11:30 AM
To: Kalra, Ashish <Ashish.Kalra@....com>
Cc: Alper Gun <alpergun@...gle.com>; Brijesh Singh <brijesh.singh@....com>; the arch/x86 maintainers <x86@...nel.org>; LKML <linux-kernel@...r.kernel.org>; kvm list <kvm@...r.kernel.org>; linux-coco@...ts.linux.dev; linux-mm@...ck.org; Linux Crypto Mailing List <linux-crypto@...r.kernel.org>; Thomas Gleixner <tglx@...utronix.de>; Ingo Molnar <mingo@...hat.com>; Joerg Roedel <jroedel@...e.de>; Lendacky, Thomas <Thomas.Lendacky@....com>; H. Peter Anvin <hpa@...or.com>; Ard Biesheuvel <ardb@...nel.org>; Paolo Bonzini <pbonzini@...hat.com>; Sean Christopherson <seanjc@...gle.com>; Vitaly Kuznetsov <vkuznets@...hat.com>; Wanpeng Li <wanpengli@...cent.com>; Jim Mattson <jmattson@...gle.com>; Andy Lutomirski <luto@...nel.org>; Dave Hansen <dave.hansen@...ux.intel.com>; Sergio Lopez <slp@...hat.com>; Peter Zijlstra <peterz@...radead.org>; Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>; David Rientjes <rientjes@...gle.com>; Dov Murik <dovmurik@...ux.ibm.com>; Tobin Feldman-Fitzthum <tobin@....com>; Borislav Petkov <bp@...en8.de>; Roth, Michael <Michael.Roth@....com>; Vlastimil Babka <vbabka@...e.cz>; Kirill A . Shutemov <kirill@...temov.name>; Andi Kleen <ak@...ux.intel.com>; Tony Luck <tony.luck@...el.com>; Marc Orr <marcorr@...gle.com>; Sathyanarayanan Kuppuswamy <sathyanarayanan.kuppuswamy@...ux.intel.com>; Pavan Kumar Paluri <papaluri@....com>
Subject: Re: [PATCH Part2 v5 23/45] KVM: SVM: Add KVM_SNP_INIT command

On Tue, Jun 14, 2022 at 10:11 AM Kalra, Ashish <Ashish.Kalra@....com> wrote:
>
> [AMD Official Use Only - General]
>
>
> -----Original Message-----
> From: Peter Gonda <pgonda@...gle.com>
> Sent: Tuesday, June 14, 2022 10:38 AM
> To: Kalra, Ashish <Ashish.Kalra@....com>
> Cc: Alper Gun <alpergun@...gle.com>; Brijesh Singh 
> <brijesh.singh@....com>; Kalra, Ashish <Ashish.Kalra@....com>; the 
> arch/x86 maintainers <x86@...nel.org>; LKML 
> <linux-kernel@...r.kernel.org>; kvm list <kvm@...r.kernel.org>; 
> linux-coco@...ts.linux.dev; linux-mm@...ck.org; Linux Crypto Mailing 
> List <linux-crypto@...r.kernel.org>; Thomas Gleixner 
> <tglx@...utronix.de>; Ingo Molnar <mingo@...hat.com>; Joerg Roedel 
> <jroedel@...e.de>; Lendacky, Thomas <Thomas.Lendacky@....com>; H. 
> Peter Anvin <hpa@...or.com>; Ard Biesheuvel <ardb@...nel.org>; Paolo 
> Bonzini <pbonzini@...hat.com>; Sean Christopherson 
> <seanjc@...gle.com>; Vitaly Kuznetsov <vkuznets@...hat.com>; Wanpeng 
> Li <wanpengli@...cent.com>; Jim Mattson <jmattson@...gle.com>; Andy 
> Lutomirski <luto@...nel.org>; Dave Hansen 
> <dave.hansen@...ux.intel.com>; Sergio Lopez <slp@...hat.com>; Peter 
> Zijlstra <peterz@...radead.org>; Srinivas Pandruvada 
> <srinivas.pandruvada@...ux.intel.com>; David Rientjes 
> <rientjes@...gle.com>; Dov Murik <dovmurik@...ux.ibm.com>; Tobin 
> Feldman-Fitzthum <tobin@....com>; Borislav Petkov <bp@...en8.de>; 
> Roth, Michael <Michael.Roth@....com>; Vlastimil Babka 
> <vbabka@...e.cz>; Kirill A . Shutemov <kirill@...temov.name>; Andi 
> Kleen <ak@...ux.intel.com>; Tony Luck <tony.luck@...el.com>; Marc Orr 
> <marcorr@...gle.com>; Sathyanarayanan Kuppuswamy 
> <sathyanarayanan.kuppuswamy@...ux.intel.com>; Pavan Kumar Paluri 
> <papaluri@....com>
> Subject: Re: [PATCH Part2 v5 23/45] KVM: SVM: Add KVM_SNP_INIT command
>
> On Mon, Jun 13, 2022 at 6:21 PM Ashish Kalra <ashkalra@....com> wrote:
> >
> >
> > On 6/13/22 23:33, Alper Gun wrote:
> > > On Mon, Jun 13, 2022 at 4:15 PM Ashish Kalra <ashkalra@....com> wrote:
> > >> Hello Alper,
> > >>
> > >> On 6/13/22 20:58, Alper Gun wrote:
> > >>> static int sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd
> > >>> *argp)
> > >>>>    {
> > >>>> +       bool es_active = (argp->id == KVM_SEV_ES_INIT || 
> > >>>> + argp->id == KVM_SEV_SNP_INIT);
> > >>>>           struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
> > >>>> -       bool es_active = argp->id == KVM_SEV_ES_INIT;
> > >>>> +       bool snp_active = argp->id == KVM_SEV_SNP_INIT;
> > >>>>           int asid, ret;
> > >>>>
> > >>>>           if (kvm->created_vcpus) @@ -249,12 +269,22 @@ static 
> > >>>> int sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp)
> > >>>>                   return ret;
> > >>>>
> > >>>>           sev->es_active = es_active;
> > >>>> +       sev->snp_active = snp_active;
> > >>>>           asid = sev_asid_new(sev);
> > >>>>           if (asid < 0)
> > >>>>                   goto e_no_asid;
> > >>>>           sev->asid = asid;
> > >>>>
> > >>>> -       ret = sev_platform_init(&argp->error);
> > >>>> +       if (snp_active) {
> > >>>> +               ret = verify_snp_init_flags(kvm, argp);
> > >>>> +               if (ret)
> > >>>> +                       goto e_free;
> > >>>> +
> > >>>> +               ret = sev_snp_init(&argp->error);
> > >>>> +       } else {
> > >>>> +               ret = sev_platform_init(&argp->error);
> > >>> After SEV INIT_EX support patches, SEV may be initialized in the platform late.
> > >>> In my tests, if SEV has not been initialized in the platform 
> > >>> yet, SNP VMs fail with SEV_DF_FLUSH required error. I tried 
> > >>> calling SEV_DF_FLUSH right after the SNP platform init but this 
> > >>> time it failed later on the SNP launch update command with 
> > >>> SEV_RET_INVALID_PARAM error. Looks like there is another 
> > >>> dependency on SEV platform initialization.
> > >>>
> > >>> Calling sev_platform_init for SNP VMs fixes the problem in our tests.
> > >> Trying to get some more context for this issue.
> > >>
> > >> When you say after SEV_INIT_EX support patches, SEV may be 
> > >> initialized in the platform late, do you mean sev_pci_init()->sev_snp_init() ...
> > >> sev_platform_init() code path has still not executed on the host BSP ?
> > >>
> > > Correct, INIT_EX requires the file system to be ready and there is 
> > > a ccp module param to call it only when needed.
> > >
> > > MODULE_PARM_DESC(psp_init_on_probe, " if true, the PSP will be 
> > > initialized on module init. Else the PSP will be initialized on 
> > > the first command requiring it");
> > >
> > > If this module param is false, it won't initialize SEV on the 
> > > platform until the first SEV VM.
> > >
> > Ok, that makes sense.
> >
> > So the fix will be to call sev_platform_init() unconditionally here 
> > in sev_guest_init(), and both sev_snp_init() and sev_platform_init() 
> > are protected from being called again, so there won't be any issues 
> > if these functions are invoked again at SNP/SEV VM launch if they 
> > have been invoked earlier during module init.
>
> >That's one solution. I don't know if there is a downside to the system for enabling SEV if SNP is being enabled but another solution could be to just directly place a DF_FLUSH command instead of calling sev_platform_init().
>
> Actually sev_platform_init() is already called on module init if psp_init_on_probe is not false. Only need to ensure that SNP firmware is initialized first with SNP_INIT command.

> But if psp_init_on_probe is false, sev_platform_init() isn't called down this path. Alper has suggested we always call sev_platform_init() but we could just place an SEV_DF_FLUSH command instead. Or am I still missing something?

>After SEV INIT_EX support patches, SEV may be initialized in the platform late.
> In my tests, if SEV has not been initialized in the platform 
> yet, SNP VMs fail with SEV_DF_FLUSH required error. I tried 
> calling SEV_DF_FLUSH right after the SNP platform init.

Are you getting the DLFLUSH_REQUIRED error after the SNP activate command ?

Also did you use the SEV_DF_FLUSH command or the SNP_DF_FLUSH command ?

With SNP you need to use SNP_DF_FLUSH command.

Thanks,
Ashish

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ