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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 68E7DC5475B for ; Mon, 11 Mar 2024 07:30:01 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rja5z-0004iz-QJ; Mon, 11 Mar 2024 03:29:15 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rja5y-0004in-Q8 for qemu-devel@nongnu.org; Mon, 11 Mar 2024 03:29:14 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rja5x-0003HI-3a for qemu-devel@nongnu.org; Mon, 11 Mar 2024 03:29:14 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1710142151; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=EF/lQ6AcWDo9er79rF8lhoXUfncFaGy7PoQxJj8hn1s=; b=UJh3f2S5OzP5Lj7SldBA/CJJm1q2PmeGI9yzKSPSiaeoluQbUswlXpdJ+6ZNhvfHlUacqW 3CmLHLN3yUERN4EE+auQX1g0Wvmp2UyrJxv1dJmHg41YhrpjON0u0M/CJuB+bgnYErWoNi iB2UFR1ndcns273bDt4zKErZQvkmbYE= 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-98-xybE5VPSMHCNtQSbpKXdXA-1; Mon, 11 Mar 2024 03:29:05 -0400 X-MC-Unique: xybE5VPSMHCNtQSbpKXdXA-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (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 88083185A789; Mon, 11 Mar 2024 07:29:04 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.39.192.138]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 437C71121306; Mon, 11 Mar 2024 07:29:04 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 34B9A21E6A24; Mon, 11 Mar 2024 08:29:03 +0100 (CET) From: Markus Armbruster To: Xiaoyao Li Cc: Paolo Bonzini , David Hildenbrand , Igor Mammedov , Eduardo Habkost , Marcel Apfelbaum , Philippe =?utf-8?Q?Mathieu-Daud=C3=A9?= , Yanan Wang , "Michael S. Tsirkin" , Richard Henderson , Ani Sinha , Peter Xu , Cornelia Huck , Daniel P. =?utf-8?Q?Berrang=C3=A9?= , Eric Blake , Marcelo Tosatti , kvm@vger.kernel.org, qemu-devel@nongnu.org, Michael Roth , Claudio Fontana , Gerd Hoffmann , Isaku Yamahata , Chenyi Qiang Subject: Re: [PATCH v5 52/65] i386/tdx: Wire TDX_REPORT_FATAL_ERROR with GuestPanic facility In-Reply-To: <95e623e1-ccf3-4d8f-9751-7767db100e2b@intel.com> (Xiaoyao Li's message of "Mon, 11 Mar 2024 09:28:37 +0800") References: <20240229063726.610065-1-xiaoyao.li@intel.com> <20240229063726.610065-53-xiaoyao.li@intel.com> <874jdr1wmt.fsf@pond.sub.org> <87y1au881k.fsf@pond.sub.org> <95e623e1-ccf3-4d8f-9751-7767db100e2b@intel.com> Date: Mon, 11 Mar 2024 08:29:03 +0100 Message-ID: <87plw1uszk.fsf@pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.3 Received-SPF: pass client-ip=170.10.133.124; envelope-from=armbru@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -30 X-Spam_score: -3.1 X-Spam_bar: --- X-Spam_report: (-3.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.945, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Xiaoyao Li writes: > On 3/7/2024 9:51 PM, Markus Armbruster wrote: >> Xiaoyao Li writes: >>=20 >>> On 2/29/2024 4:51 PM, Markus Armbruster wrote: >>>> Xiaoyao Li writes: >>>> >>>>> Integrate TDX's TDX_REPORT_FATAL_ERROR into QEMU GuestPanic facility >>>>> >>>>> Originated-from: Isaku Yamahata >>>>> Signed-off-by: Xiaoyao Li >>>>> --- >>>>> Changes in v5: >>>>> - mention additional error information in gpa when it presents; >>>>> - refine the documentation; (Markus) >>>>> >>>>> Changes in v4: >>>>> - refine the documentation; (Markus) >>>>> >>>>> Changes in v3: >>>>> - Add docmentation of new type and struct; (Daniel) >>>>> - refine the error message handling; (Daniel) >>>>> --- >>>>> qapi/run-state.json | 31 +++++++++++++++++++++-- >>>>> system/runstate.c | 58 +++++++++++++++++++++++++++++++++++++++= ++++ >>>>> target/i386/kvm/tdx.c | 24 +++++++++++++++++- >>>>> 3 files changed, 110 insertions(+), 3 deletions(-) >>>>> >>>>> diff --git a/qapi/run-state.json b/qapi/run-state.json >>>>> index dd0770b379e5..b71dd1884eb6 100644 >>>>> --- a/qapi/run-state.json >>>>> +++ b/qapi/run-state.json [...] >>>>> @@ -564,6 +567,30 @@ >>>>> 'psw-addr': 'uint64', >>>>> 'reason': 'S390CrashReason'}} >>>>> +## >>>>> +# @GuestPanicInformationTdx: >>>>> +# >>>>> +# TDX Guest panic information specific to TDX, as specified in the >>>>> +# "Guest-Hypervisor Communication Interface (GHCI) Specification", >>>>> +# section TDG.VP.VMCALL. >>>>> +# >>>>> +# @error-code: TD-specific error code >>>>> +# >>>>> +# @message: Human-readable error message provided by the guest. Not >>>>> +# to be trusted. >>>>> +# >>>>> +# @gpa: guest-physical address of a page that contains more verbose >>>>> +# error information, as zero-terminated string. Present when the >>>>> +# "GPA valid" bit (bit 63) is set in @error-code. >>>> >>>> Uh, peeking at GHCI Spec section 3.4 TDG.VP.VMCALL, I >>>> see operand R12 consists of >>>> >>>> bits name description >>>> 31:0 TD-specific error code TD-specific error code >>>> Panic =E2=80=93 0x0. >>>> Values =E2=80=93 0x1 to 0xFF= FFFFFF >>>> reserved. >>>> 62:32 TD-specific extended TD-specific extended error c= ode. >>>> error code TD software defined. >>>> 63 GPA Valid Set if the TD specified addi= tional >>>> information in the GPA param= eter >>>> (R13). >>>> Is @error-code all of R12, or just bits 31:0? >>>> If it's all of R12, description of @error-code as "TD-specific error >>>> code" is misleading. >>> >>> We pass all of R12 to @error_code. >>> >>> Here it wants to use "error_code" as generic as the whole R12. Do you h= ave any better description of it ? >>=20 >> Sadly, the spec is of no help: it doesn't name the entire thing, only >> the three sub-fields TD-specific error code, TD-specific extended error >> code, GPA valid. >>=20 >> We could take the hint, and provide the sub-fields instead: >>=20 >> * @error-code contains the TD-specific error code (bits 31:0) >>=20 >> * @extended-error-code contains the TD-specific extended error code >> (bits 62:32) >>=20 >> * we don't need @gpa-valid, because it's the same as "@gpa is present" >>=20 >> If we decide to keep the single member, we do need another name for it. >> @error-codes (plural) doesn't exactly feel wonderful, but it gives at >> least a subtle hint that it's not just *the* error code. > > The reason we only defined one single member, is that the=20 > extended-error-code is not used now, and I believe it won't be used in=20 > the near future. Aha! Then I recommend * @error-code contains the TD-specific error code (bits 31:0) * Omit bits 62:32 from the reply; if we later find an actual use for them, we can add a suitable member * Omit bit 63, because it's the same as "@gpa is present" > If no objection from others, I will use @error-codes (plural) in the=20 > next version. I recommend to keep the @error-code name, but narrow its value to the actual error code, i.e. bits 31:0. >>>> If it's just bits 31:0, then 'Present when the "GPA valid" bit (bit 63) >>>> is set in @error-code' is wrong. Could go with 'Only present when the >>>> guest provides this information'. [...]