linux-kernel - Re: [RFC PATCH v2 38/69] KVM: x86: Add option to force LAPIC expiration wait

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: <YO3832IMZH/ZLZ4Z@google.com>
Date:   Tue, 13 Jul 2021 20:51:43 +0000
From:   Sean Christopherson <seanjc@...gle.com>
To:     Paolo Bonzini <pbonzini@...hat.com>
Cc:     isaku.yamahata@...el.com, Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        "H . Peter Anvin" <hpa@...or.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Joerg Roedel <joro@...tes.org>, erdemaktas@...gle.com,
        Connor Kuehl <ckuehl@...hat.com>, x86@...nel.org,
        linux-kernel@...r.kernel.org, kvm@...r.kernel.org,
        isaku.yamahata@...il.com,
        Sean Christopherson <sean.j.christopherson@...el.com>
Subject: Re: [RFC PATCH v2 38/69] KVM: x86: Add option to force LAPIC
 expiration wait

On Tue, Jul 06, 2021, Paolo Bonzini wrote:
> On 03/07/21 00:04, isaku.yamahata@...el.com wrote:
> > From: Sean Christopherson <sean.j.christopherson@...el.com>
> > 
> > Add an option to skip the IRR check in kvm_wait_lapic_expire().  This
> > will be used by TDX to wait if there is an outstanding notification for
> > a TD, i.e. a virtual interrupt is being triggered via posted interrupt
> > processing.  KVM TDX doesn't emulate PI processing, i.e. there will
> > never be a bit set in IRR/ISR, so the default behavior for APICv of
> > querying the IRR doesn't work as intended.
> > 
> > Signed-off-by: Sean Christopherson <sean.j.christopherson@...el.com>
> > Signed-off-by: Isaku Yamahata <isaku.yamahata@...el.com>
> 
> Is there a better (existing after the previous patches) flag to test, or
> possibly can it use vm_type following the suggestion I gave for patch 28?

Not sure if there's a "better" flag, but there's most definitely a flag somewhere
that will suffice :-)