From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail02.groups.io (mail02.groups.io [66.175.222.108]) by spool.mail.gandi.net (Postfix) with ESMTPS id 1C6C5D80D5A for ; Fri, 1 Mar 2024 13:01:05 +0000 (UTC) DKIM-Signature: a=rsa-sha256; bh=9L9Fzl2l2WTcPVLvBpxrUW7WRma0JiusMJ8sgq2X9qE=; c=relaxed/simple; d=groups.io; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From:In-Reply-To:Precedence:List-Subscribe:List-Help:Sender:List-Id:Mailing-List:Delivered-To:Reply-To:List-Unsubscribe-Post:List-Unsubscribe:Content-Language:Content-Type:Content-Transfer-Encoding; s=20140610; t=1709298064; v=1; b=ataORv35tfe9DyR/iZrWDuFl3i6z5EYHgok7bTAwb1OVLrQ2BJB9u9DG3DNeVmvThz8CNXr8 2HemqKnN3oPHPZKPeKTgcX8sS2YAHzRJNfQHhyiTOkwIAxxzBMYEPLAiaTDagutpHaFGVLivQat 1Vvq2CU2w6tz7tTUJdLhLLCE= X-Received: by 127.0.0.2 with SMTP id ufNXYY7687511xWSbOHXq4aF; Fri, 01 Mar 2024 05:01:04 -0800 X-Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by mx.groups.io with SMTP id smtpd.web10.21966.1709298064071096434 for ; Fri, 01 Mar 2024 05:01:04 -0800 X-Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-475-x7FhgBqkMc2-PsLM550lnQ-1; Fri, 01 Mar 2024 08:00:59 -0500 X-MC-Unique: x7FhgBqkMc2-PsLM550lnQ-1 X-Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 72E0585A599; Fri, 1 Mar 2024 13:00:58 +0000 (UTC) X-Received: from [10.39.194.215] (unknown [10.39.194.215]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 9E1C34D905; Fri, 1 Mar 2024 13:00:56 +0000 (UTC) Message-ID: Date: Fri, 1 Mar 2024 14:00:55 +0100 MIME-Version: 1.0 Subject: Re: [edk2-devel] [PATCH v2 09/10] OvmfPkg/ResetVector: leave SEV VC handler installed longer To: devel@edk2.groups.io, kraxel@redhat.com Cc: Jiewen Yao , Oliver Steffen , Michael Roth , Erdem Aktas , Min Xu , Ard Biesheuvel , Tom Lendacky References: <20240301074402.98625-1-kraxel@redhat.com> <20240301074402.98625-10-kraxel@redhat.com> From: "Laszlo Ersek" In-Reply-To: <20240301074402.98625-10-kraxel@redhat.com> X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Precedence: Bulk List-Subscribe: List-Help: Sender: devel@edk2.groups.io List-Id: Mailing-List: list devel@edk2.groups.io; contact devel+owner@edk2.groups.io Reply-To: devel@edk2.groups.io,lersek@redhat.com List-Unsubscribe-Post: List-Unsubscribe=One-Click List-Unsubscribe: X-Gm-Message-State: rQlRS1gkcFyhDasoqGcfemzwx7686176AA= Content-Language: en-US Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-GND-Status: LEGIT Authentication-Results: spool.mail.gandi.net; dkim=pass header.d=groups.io header.s=20140610 header.b=ataORv35; spf=pass (spool.mail.gandi.net: domain of bounce@groups.io designates 66.175.222.108 as permitted sender) smtp.mailfrom=bounce@groups.io; dmarc=fail reason="SPF not aligned (relaxed), DKIM not aligned (relaxed)" header.from=redhat.com (policy=none) On 3/1/24 08:44, Gerd Hoffmann wrote: > When running in SEV mode keep the VC handler installed. > Add a function to uninstall it later. >=20 > This allows using the cpuid instruction in SetCr3ForPageTables64, > which is needed to check for la57 & 1G page support. >=20 > Signed-off-by: Gerd Hoffmann > --- > OvmfPkg/ResetVector/Ia32/AmdSev.asm | 12 ++++++++++-- > OvmfPkg/ResetVector/Ia32/PageTables64.asm | 1 + > OvmfPkg/ResetVector/Main.asm | 4 ++++ > 3 files changed, 15 insertions(+), 2 deletions(-) >=20 > diff --git a/OvmfPkg/ResetVector/Ia32/AmdSev.asm b/OvmfPkg/ResetVector/Ia= 32/AmdSev.asm > index 23e4c5ebbe92..cbb86871636f 100644 > --- a/OvmfPkg/ResetVector/Ia32/AmdSev.asm > +++ b/OvmfPkg/ResetVector/Ia32/AmdSev.asm > @@ -320,9 +320,9 @@ NoSevEsVcHlt: > NoSevPass: > xor eax, eax > =20 > -SevExit: > ; > - ; Clear exception handlers and stack > + ; When NOT running in SEV mode: clear exception handlers and stack h= ere. > + ; Otherwise: SevClearVcHandlerAndStack must be called later. > ; > push eax > mov eax, ADDR_OF(IdtrClear) > @@ -330,8 +330,16 @@ SevExit: > pop eax > mov esp, 0 > =20 > +SevExit: > OneTimeCallRet CheckSevFeatures > =20 > +SevClearVcHandlerAndStack: > + ; Clear exception handlers and stack > + mov eax, ADDR_OF(IdtrClear) > + lidt [cs:eax] > + mov esp, 0 > + OneTimeCallRet SevClearVcHandlerAndStack > + > ; Start of #VC exception handling routines > ; > =20 > diff --git a/OvmfPkg/ResetVector/Ia32/PageTables64.asm b/OvmfPkg/ResetVec= tor/Ia32/PageTables64.asm > index b922c845f297..29ce155eed8d 100644 > --- a/OvmfPkg/ResetVector/Ia32/PageTables64.asm > +++ b/OvmfPkg/ResetVector/Ia32/PageTables64.asm > @@ -254,6 +254,7 @@ SevInit: > CreatePageTables4Level edx > ; Clear the C-bit from the GHCB page if the SEV-ES is enabled. > OneTimeCall SevClearPageEncMaskForGhcbPage > + OneTimeCall SevClearVcHandlerAndStack > jmp SetCr3 > =20 > TdxBspInit: > diff --git a/OvmfPkg/ResetVector/Main.asm b/OvmfPkg/ResetVector/Main.asm > index 46cfa87c4c0a..88b25db3bc9e 100644 > --- a/OvmfPkg/ResetVector/Main.asm > +++ b/OvmfPkg/ResetVector/Main.asm > @@ -80,7 +80,11 @@ SearchBfv: > ; Set the OVMF/SEV work area as appropriate. > ; > OneTimeCall CheckSevFeatures > + cmp byte[WORK_AREA_GUEST_TYPE], 1 > + jnz NoSevIa32 > + OneTimeCall SevClearVcHandlerAndStack > =20 > +NoSevIa32: > ; > ; Restore initial EAX value into the EAX register > ; Did you miss Tom's review under v1? https://edk2.groups.io/g/devel/message/116176 The patch is identical to its v1 counterpart, which should not be a problem in itself (Tom mentioned a small, *optional*, simplification, IIUC); however, I don't understand why you didn't pick up Tom's R-b. I'm ready to merge this (adding Tom's R-b, if you, Gerd, confirm that that's what you want). Having deferred to Tom's judgement on this: Acked-by: Laszlo Ersek -=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#116250): https://edk2.groups.io/g/devel/message/116250 Mute This Topic: https://groups.io/mt/104660115/7686176 Group Owner: devel+owner@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [rebecca@openfw.io] -=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-