From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received-SPF: Pass (sender SPF authorized) identity=mailfrom; client-ip=192.55.52.136; helo=mga12.intel.com; envelope-from=michael.d.kinney@intel.com; receiver=edk2-devel@lists.01.org Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id D6591223648BB for ; Tue, 30 Jan 2018 13:21:19 -0800 (PST) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 30 Jan 2018 13:26:54 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.46,436,1511856000"; d="scan'208";a="26012339" Received: from orsmsx106.amr.corp.intel.com ([10.22.225.133]) by fmsmga004.fm.intel.com with ESMTP; 30 Jan 2018 13:26:54 -0800 Received: from orsmsx116.amr.corp.intel.com (10.22.240.14) by ORSMSX106.amr.corp.intel.com (10.22.225.133) with Microsoft SMTP Server (TLS) id 14.3.319.2; Tue, 30 Jan 2018 13:26:53 -0800 Received: from orsmsx113.amr.corp.intel.com ([169.254.9.97]) by ORSMSX116.amr.corp.intel.com ([169.254.7.69]) with mapi id 14.03.0319.002; Tue, 30 Jan 2018 13:26:53 -0800 From: "Kinney, Michael D" To: Laszlo Ersek , edk2-devel-01 , "Kinney, Michael D" CC: "Ni, Ruiyu" , Paolo Bonzini , "Yao, Jiewen" , "Dong, Eric" Thread-Topic: [edk2] [PATCH 1/3] UefiCpuPkg/PiSmmCpuDxeSmm: update comments in IA32 SmmStartup() Thread-Index: AQHTmd/MCkuvve09PEGT8wX9DIo2RaOMqXnggACV9oD//33u0IAALa2g Date: Tue, 30 Jan 2018 21:26:53 +0000 Message-ID: References: <20180130153348.31992-1-lersek@redhat.com> <20180130153348.31992-2-lersek@redhat.com> <31138ce7-0637-a755-ec57-e36ab812f259@redhat.com> In-Reply-To: Accept-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: dlp-product: dlpe-windows dlp-version: 11.0.0.116 dlp-reaction: no-action x-originating-ip: [10.22.254.138] MIME-Version: 1.0 Subject: Re: [PATCH 1/3] UefiCpuPkg/PiSmmCpuDxeSmm: update comments in IA32 SmmStartup() X-BeenThere: edk2-devel@lists.01.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: EDK II Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 30 Jan 2018 21:21:20 -0000 Content-Language: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Laszlo, Maybe we can add a macro to help: #define PATCH_X86_ASM(Label,Type,Value) *((Type *)(&Label) - 1) =3D (Type= )(Value) PATCH_X86_ASM (gSmmCr0, UINT32, AsmReadCr0()); Mike > -----Original Message----- > From: Kinney, Michael D > Sent: Tuesday, January 30, 2018 12:31 PM > To: Laszlo Ersek ; edk2-devel-01 > ; Kinney, Michael D > > Cc: Ni, Ruiyu ; Paolo Bonzini > ; Yao, Jiewen > ; Dong, Eric > Subject: RE: [edk2] [PATCH 1/3] > UefiCpuPkg/PiSmmCpuDxeSmm: update comments in IA32 > SmmStartup() >=20 > Laszlo, >=20 > We have already used this technique in other NASM files > to remove DBs. >=20 > Let us know if you have suggestions on how to make the > C code that performs the patches easier to read and > maintain. >=20 > Mike >=20 > > -----Original Message----- > > From: edk2-devel [mailto:edk2-devel- > bounces@lists.01.org] > > On Behalf Of Laszlo Ersek > > Sent: Tuesday, January 30, 2018 10:17 AM > > To: Kinney, Michael D ; > edk2- > > devel-01 > > Cc: Ni, Ruiyu ; Paolo Bonzini > > ; Yao, Jiewen > > ; Dong, Eric > > > Subject: Re: [edk2] [PATCH 1/3] > > UefiCpuPkg/PiSmmCpuDxeSmm: update comments in IA32 > > SmmStartup() > > > > On 01/30/18 18:22, Kinney, Michael D wrote: > > > Laszlo, > > > > > > The DBs can be removed if the label is moved after > > > the instruction and the patch is done to the label > > > minus the size of the patch value. > > > > Indeed I haven't thought of this. > > > > If I understand correctly, it means > > > > extern UINT8 gSmmCr0; > > > > *(UINT32*)(&gSmmCr0 - sizeof (UINT32)) =3D > > (UINT32)AsmReadCr0 (); > > > > TBH, the DB feels less ugly to me than this :) > > > > Still, if you think it would be an acceptable price to > > pay for removing > > the remaining DBs, I can respin. > > > > Thanks > > Laszlo > > > > >> -----Original Message----- > > >> From: edk2-devel [mailto:edk2-devel- > > bounces@lists.01.org] > > >> On Behalf Of Laszlo Ersek > > >> Sent: Tuesday, January 30, 2018 7:34 AM > > >> To: edk2-devel-01 > > >> Cc: Ni, Ruiyu ; Yao, Jiewen > > >> ; Dong, Eric > > ; > > >> Paolo Bonzini > > >> Subject: [edk2] [PATCH 1/3] > UefiCpuPkg/PiSmmCpuDxeSmm: > > >> update comments in IA32 SmmStartup() > > >> > > >> The gSmmCr3, gSmmCr4, gSmmCr0 and gSmmJmpAddr global > > >> variables are used > > >> for patching assembly instructions, thus we can > never > > >> remove the DB > > >> encodings for those instructions. At least we should > > add > > >> the intended > > >> meanings in comments. > > >> > > >> This patch only changes comments. > > >> > > >> Cc: Eric Dong > > >> Cc: Jian J Wang > > >> Cc: Jiewen Yao > > >> Cc: Paolo Bonzini > > >> Cc: Ruiyu Ni > > >> Contributed-under: TianoCore Contribution Agreement > > 1.1 > > >> Signed-off-by: Laszlo Ersek > > >> --- > > >> UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmmInit.nasm | 8 > ++++- > > --- > > >> 1 file changed, 4 insertions(+), 4 deletions(-) > > >> > > >> diff --git > > a/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmmInit.nasm > > >> b/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmmInit.nasm > > >> index e96dd8d2392a..08534dba64b7 100644 > > >> --- a/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmmInit.nasm > > >> +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmmInit.nasm > > >> @@ -44,34 +44,34 @@ global ASM_PFX(SmmStartup) > > >> ASM_PFX(SmmStartup): > > >> DB 0x66 > > >> mov eax, 0x80000001 ; read > > >> capability > > >> cpuid > > >> DB 0x66 > > >> mov ebx, edx ; rdmsr > will > > >> change edx. keep it in ebx. > > >> - DB 0x66, 0xb8 > > >> + DB 0x66, 0xb8 ; mov eax, > > imm32 > > >> ASM_PFX(gSmmCr3): DD 0 > > >> mov cr3, eax > > >> DB 0x67, 0x66 > > >> lgdt [cs:ebp + (ASM_PFX(gcSmiInitGdtr) - > > >> ASM_PFX(SmmStartup))] > > >> - DB 0x66, 0xb8 > > >> + DB 0x66, 0xb8 ; mov eax, > > imm32 > > >> ASM_PFX(gSmmCr4): DD 0 > > >> mov cr4, eax > > >> DB 0x66 > > >> mov ecx, 0xc0000080 ; IA32_EFER > > MSR > > >> rdmsr > > >> DB 0x66 > > >> test ebx, BIT20 ; check NXE > > >> capability > > >> jz .1 > > >> or ah, BIT3 ; set NXE > bit > > >> wrmsr > > >> .1: > > >> - DB 0x66, 0xb8 > > >> + DB 0x66, 0xb8 ; mov eax, > > imm32 > > >> ASM_PFX(gSmmCr0): DD 0 > > >> DB 0xbf, PROTECT_MODE_DS, 0 ; mov di, > > >> PROTECT_MODE_DS > > >> mov cr0, eax > > >> - DB 0x66, 0xea ; jmp far > > >> [ptr48] > > >> + DB 0x66, 0xea ; jmp far > > >> [ptr48] > > >> ASM_PFX(gSmmJmpAddr): > > >> DD @32bit > > >> DW PROTECT_MODE_CS > > >> @32bit: > > >> mov ds, edi > > >> mov es, edi > > >> -- > > >> 2.14.1.3.gb7cf6e02401b > > >> > > >> > > >> _______________________________________________ > > >> edk2-devel mailing list > > >> edk2-devel@lists.01.org > > >> https://lists.01.org/mailman/listinfo/edk2-devel > > > > _______________________________________________ > > edk2-devel mailing list > > edk2-devel@lists.01.org > > https://lists.01.org/mailman/listinfo/edk2-devel