From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BDFC7C77B71 for ; Tue, 25 Apr 2023 20:07:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236230AbjDYUHv (ORCPT ); Tue, 25 Apr 2023 16:07:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35140 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235372AbjDYUHv (ORCPT ); Tue, 25 Apr 2023 16:07:51 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 435EEA5E0; Tue, 25 Apr 2023 13:07:50 -0700 (PDT) From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1682453268; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=4O15691mL3gwOERb5M8WwZ/BXXDNqH0+MWC0TCs50QE=; b=Bwuzz8Nz/BV6G/VL2bb+kha7mVj8/IRkuvbsjwjzk4USnPr2OW7n7gum3YLTay29fSKm4l VIaAVviF4DxNGn2wYM6o0v57oY64CRe+VgXsYQv76pd/utkcrBMIA+Hlh315Cm54VqTo7K atpyanHwbqEDa1wx0+1kk6JnSgmhiayROO89bvR9xqhG5h5fXOyJHuELCWZOaAN84arMeq GGcJ4Ir8foJBLeP8ch9gHIy9jvOiKYJ4asV3QtfyaAgXR2pzDWC3evufPz0x9jkOlulsT0 C2Q9I3DEe4BIAOmlzxJr0oVN2tLwYUOfQk+hTo1aBm1XqujojvIZxEYvbxiQIw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1682453268; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=4O15691mL3gwOERb5M8WwZ/BXXDNqH0+MWC0TCs50QE=; b=RrFYGWkb9+Sr7TGoFVSkR/dCgulbRZuvJgUFeQBLzx1gsWc2Iv3HT6T4XcF1FLb33wIMzq mCdHr2bCd+lRBoCA== To: Sean Christopherson Cc: Andrew Cooper , Paul Menzel , linux-kernel@vger.kernel.org, x86@kernel.org, David Woodhouse , Brian Gerst , Arjan van de Veen , Paolo Bonzini , Paul McKenney , Tom Lendacky , Oleksandr Natalenko , "Guilherme G. Piccoli" , Piotr Gorski , David Woodhouse , Usama Arif , =?utf-8?B?SsO8cmdlbiBHcm/Dnw==?= , Boris Ostrovsky , xen-devel@lists.xenproject.org, Russell King , Arnd Bergmann , linux-arm-kernel@lists.infradead.org, Catalin Marinas , Will Deacon , Guo Ren , linux-csky@vger.kernel.org, Thomas Bogendoerfer , linux-mips@vger.kernel.org, "James E. J. Bottomley" , Helge Deller , linux-parisc@vger.kernel.org, Paul Walmsley , Palmer Dabbelt , linux-riscv@lists.infradead.org, Mark Rutland , Sabin Rapan Subject: Re: [patch 00/37] cpu/hotplug, x86: Reworked parallel CPU bringup In-Reply-To: <87v8hq35sk.ffs@tglx> References: <87r0sh4m7a.ffs@tglx> <8592a301-9933-1cad-bd61-8d97e7c7493b@molgen.mpg.de> <87a5z443g2.ffs@tglx> <877cu83v45.ffs@tglx> <874jpc3s3r.ffs@tglx> <0f5463fd-9c4a-6361-adbb-dd89dbb9138d@citrix.com> <871qkf3qek.ffs@tglx> <26d385da-2ede-5d73-2959-84c8f7d89e03@citrix.com> <87y1mm3iqz.ffs@tglx> <87v8hq35sk.ffs@tglx> Date: Tue, 25 Apr 2023 22:07:47 +0200 Message-ID: <87r0s7zpws.ffs@tglx> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-parisc@vger.kernel.org On Thu, Apr 20 2023 at 17:57, Thomas Gleixner wrote: > On Thu, Apr 20 2023 at 07:51, Sean Christopherson wrote: > Something like the completely untested below should just work whatever > APIC ID the BIOS decided to dice. > > That might just work on SEV too without that GHCB muck, but what do I > know. It does not. RDMSR(X2APIC_ID) is trapped via #VC which cannot be handled at that point. Unfortunately the GHCB protocol does not provide a RDMSR mechanism similar to the CPUID mechanism. Neither does the secure firmware enforce CPUID(0xb):APICID to real APIC ID consistency. So the hypervisor can dice the APIC IDs as long as they are consistent with the provided ACPI/MADT table. So no parallel startup for SEV for now. Thanks, tglx