From mboxrd@z Thu Jan 1 00:00:00 1970 From: Xiao Guangrong Subject: [PATCH v5 13/13] docs: add NVDIMM ACPI documentation Date: Fri, 17 Jun 2016 19:08:16 +0800 Message-ID: <1466161696-99298-14-git-send-email-guangrong.xiao@linux.intel.com> References: <1466161696-99298-1-git-send-email-guangrong.xiao@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: kvm@vger.kernel.org, qemu-devel@nongnu.org, Xiao Guangrong To: mst@redhat.com Return-path: Received: from mga01.intel.com ([192.55.52.88]:64124 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933516AbcFQLT4 (ORCPT ); Fri, 17 Jun 2016 07:19:56 -0400 In-Reply-To: <1466161696-99298-1-git-send-email-guangrong.xiao@linux.intel.com> Sender: kvm-owner@vger.kernel.org List-ID: It describes the basic concepts of NVDIMM ACPI and the interfaces between QEMU and the ACPI BIOS Signed-off-by: Xiao Guangrong Reviewed-by: Stefan Hajnoczi Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- docs/specs/acpi_nvdimm.txt | 132 +++++++++++++++++++++++++++++++++++++= ++++++++ 1 file changed, 132 insertions(+) create mode 100644 docs/specs/acpi_nvdimm.txt diff --git a/docs/specs/acpi_nvdimm.txt b/docs/specs/acpi_nvdimm.txt new file mode 100644 index 0000000..0fdd251 --- /dev/null +++ b/docs/specs/acpi_nvdimm.txt @@ -0,0 +1,132 @@ +QEMU<->ACPI BIOS NVDIMM interface +--------------------------------- + +QEMU supports NVDIMM via ACPI. This document describes the basic conce= pts of +NVDIMM ACPI and the interface between QEMU and the ACPI BIOS. + +NVDIMM ACPI Background +---------------------- +NVDIMM is introduced in ACPI 6.0 which defines an NVDIMM root device u= nder +_SB scope with a _HID of =E2=80=9CACPI0012=E2=80=9D. For each NVDIMM p= resent or intended +to be supported by platform, platform firmware also exposes an ACPI +Namespace Device under the root device. + +The NVDIMM child devices under the NVDIMM root device are defined with= _ADR +corresponding to the NFIT device handle. The NVDIMM root device and th= e +NVDIMM devices can have device specific methods (_DSM) to provide addi= tional +functions specific to a particular NVDIMM implementation. + +This is an example from ACPI 6.0, a platform contains one NVDIMM: + +Scope (\_SB){ + Device (NVDR) // Root device + { + Name (_HID, =E2=80=9CACPI0012=E2=80=9D) + Method (_STA) {...} + Method (_FIT) {...} + Method (_DSM, ...) {...} + Device (NVD) + { + Name(_ADR, h) //where h is NFIT Device Handle for this NVDIMM + Method (_DSM, ...) {...} + } + } +} + +Method supported on both NVDIMM root device and NVDIMM device +_DSM (Device Specific Method) + It is a control method that enables devices to provide device speci= fic + control functions that are consumed by the device driver. + The NVDIMM DSM specification can be found at: + http://pmem.io/documents/NVDIMM_DSM_Interface_Example.pdf + + Arguments: + Arg0 =E2=80=93 A Buffer containing a UUID (16 Bytes) + Arg1 =E2=80=93 An Integer containing the Revision ID (4 Bytes) + Arg2 =E2=80=93 An Integer containing the Function Index (4 Bytes) + Arg3 =E2=80=93 A package containing parameters for the function spe= cified by the + UUID, Revision ID, and Function Index + + Return Value: + If Function Index =3D 0, a Buffer containing a function index bitfi= eld. + Otherwise, the return value and type depends on the UUID, revision = ID + and function index which are described in the DSM specification. + +Methods on NVDIMM ROOT Device +_FIT(Firmware Interface Table) + It evaluates to a buffer returning data in the format of a series o= f NFIT + Type Structure. + + Arguments: None + + Return Value: + A Buffer containing a list of NFIT Type structure entries. + + The detailed definition of the structure can be found at ACPI 6.0: = 5.2.25 + NVDIMM Firmware Interface Table (NFIT). + +QEMU NVDIMM Implemention +=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D +QEMU uses 4 bytes IO Port starting from 0x0a18 and a RAM-based memory = page +for NVDIMM ACPI. + +Memory: + QEMU uses BIOS Linker/loader feature to ask BIOS to allocate a memo= ry + page and dynamically patch its into a int32 object named "MEMA" in = ACPI. + + This page is RAM-based and it is used to transfer data between _DSM + method and QEMU. If ACPI has control, this pages is owned by ACPI w= hich + writes _DSM input data to it, otherwise, it is owned by QEMU which + emulates _DSM access and writes the output data to it. + + ACPI writes _DSM Input Data (based on the offset in the page): + [0x0 - 0x3]: 4 bytes, NVDIMM Device Handle, 0 is reserved for NVDIM= M + Root device. + [0x4 - 0x7]: 4 bytes, Revision ID, that is the Arg1 of _DSM method. + [0x8 - 0xB]: 4 bytes. Function Index, that is the Arg2 of _DSM meth= od. + [0xC - 0xFFF]: 4084 bytes, the Arg3 of _DSM method. + + QEMU Writes Output Data (based on the offset in the page): + [0x0 - 0x3]: 4 bytes, the length of result + [0x4 - 0xFFF]: 4092 bytes, the DSM result filled by QEMU + +IO Port 0x0a18 - 0xa1b: + ACPI writes the address of the memory page allocated by BIOS to thi= s + port then QEMU gets the control and fills the result in the memory = page. + + write Access: + [0x0a18 - 0xa1b]: 4 bytes, the address of the memory page allocated + by BIOS. + +_DSM process diagram: +--------------------- +"MEMA" indicates the address of memory page allocated by BIOS. + + +----------------------+=E2=80=89=E2=80=89 +----------------------= -+ +=E2=80=89|=E2=80=89=E2=80=89 1.=E2=80=89OSPM=E2=80=89=E2=80=89 = |=E2=80=89=E2=80=89=E2=80=89=E2=80=89=E2=80=89=E2=80=89| 2. OSPM = | +=E2=80=89|=E2=80=89save _DSM input data | | write "MEMA" to = | Exit to QEMU +=E2=80=89| to the page +----->| IO port 0x0a18 +------= ------+ +=E2=80=89| indicated by "MEMA" | | | = | +=E2=80=89+----------------------+ +-----------------------+ = | +=E2=80=89 = | +=E2=80=89 = v +=E2=80=89+------------- ----+ +-----------+ +------------= ------+--------+ +=E2=80=89| 5 QEMU | | 4 QEMU | | 3. Q= EMU | +=E2=80=89| write _DSM result | | emulate | | get _DSM in= put data from | + | to the page +<------+ _DSM +<-----+ the page indicated = by the | +=E2=80=89| | | | | value from = the IO port | + +--------+-----------+ +-----------+ +--------------------= -------+ + | + | Enter Guest + | + v + +--------------------------+ +--------------+ + | 6 OSPM | | 7 OSPM | + | result size is returned | | _DSM return | + | by reading DSM +----->+ | + | result from the page | | | + +--------------------------+ +--------------+ + + _FIT implementation + ------------------- + TODO (will fill it when nvdimm hotplug is introduced) --=20 1.8.3.1 From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54318) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bDrob-0002fs-Qa for qemu-devel@nongnu.org; Fri, 17 Jun 2016 07:20:00 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bDroa-0005pe-33 for qemu-devel@nongnu.org; Fri, 17 Jun 2016 07:19:57 -0400 Received: from mga04.intel.com ([192.55.52.120]:19212) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bDroZ-0005ky-OB for qemu-devel@nongnu.org; Fri, 17 Jun 2016 07:19:56 -0400 From: Xiao Guangrong Date: Fri, 17 Jun 2016 19:08:16 +0800 Message-Id: <1466161696-99298-14-git-send-email-guangrong.xiao@linux.intel.com> In-Reply-To: <1466161696-99298-1-git-send-email-guangrong.xiao@linux.intel.com> References: <1466161696-99298-1-git-send-email-guangrong.xiao@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Subject: [Qemu-devel] [PATCH v5 13/13] docs: add NVDIMM ACPI documentation List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: mst@redhat.com Cc: kvm@vger.kernel.org, qemu-devel@nongnu.org, Xiao Guangrong It describes the basic concepts of NVDIMM ACPI and the interfaces between QEMU and the ACPI BIOS Signed-off-by: Xiao Guangrong Reviewed-by: Stefan Hajnoczi Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- docs/specs/acpi_nvdimm.txt | 132 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 132 insertions(+) create mode 100644 docs/specs/acpi_nvdimm.txt diff --git a/docs/specs/acpi_nvdimm.txt b/docs/specs/acpi_nvdimm.txt new file mode 100644 index 0000000..0fdd251 --- /dev/null +++ b/docs/specs/acpi_nvdimm.txt @@ -0,0 +1,132 @@ +QEMU<->ACPI BIOS NVDIMM interface +--------------------------------- + +QEMU supports NVDIMM via ACPI. This document describes the basic concepts of +NVDIMM ACPI and the interface between QEMU and the ACPI BIOS. + +NVDIMM ACPI Background +---------------------- +NVDIMM is introduced in ACPI 6.0 which defines an NVDIMM root device under +_SB scope with a _HID of “ACPI0012”. For each NVDIMM present or intended +to be supported by platform, platform firmware also exposes an ACPI +Namespace Device under the root device. + +The NVDIMM child devices under the NVDIMM root device are defined with _ADR +corresponding to the NFIT device handle. The NVDIMM root device and the +NVDIMM devices can have device specific methods (_DSM) to provide additional +functions specific to a particular NVDIMM implementation. + +This is an example from ACPI 6.0, a platform contains one NVDIMM: + +Scope (\_SB){ + Device (NVDR) // Root device + { + Name (_HID, “ACPI0012”) + Method (_STA) {...} + Method (_FIT) {...} + Method (_DSM, ...) {...} + Device (NVD) + { + Name(_ADR, h) //where h is NFIT Device Handle for this NVDIMM + Method (_DSM, ...) {...} + } + } +} + +Method supported on both NVDIMM root device and NVDIMM device +_DSM (Device Specific Method) + It is a control method that enables devices to provide device specific + control functions that are consumed by the device driver. + The NVDIMM DSM specification can be found at: + http://pmem.io/documents/NVDIMM_DSM_Interface_Example.pdf + + Arguments: + Arg0 – A Buffer containing a UUID (16 Bytes) + Arg1 – An Integer containing the Revision ID (4 Bytes) + Arg2 – An Integer containing the Function Index (4 Bytes) + Arg3 – A package containing parameters for the function specified by the + UUID, Revision ID, and Function Index + + Return Value: + If Function Index = 0, a Buffer containing a function index bitfield. + Otherwise, the return value and type depends on the UUID, revision ID + and function index which are described in the DSM specification. + +Methods on NVDIMM ROOT Device +_FIT(Firmware Interface Table) + It evaluates to a buffer returning data in the format of a series of NFIT + Type Structure. + + Arguments: None + + Return Value: + A Buffer containing a list of NFIT Type structure entries. + + The detailed definition of the structure can be found at ACPI 6.0: 5.2.25 + NVDIMM Firmware Interface Table (NFIT). + +QEMU NVDIMM Implemention +======================== +QEMU uses 4 bytes IO Port starting from 0x0a18 and a RAM-based memory page +for NVDIMM ACPI. + +Memory: + QEMU uses BIOS Linker/loader feature to ask BIOS to allocate a memory + page and dynamically patch its into a int32 object named "MEMA" in ACPI. + + This page is RAM-based and it is used to transfer data between _DSM + method and QEMU. If ACPI has control, this pages is owned by ACPI which + writes _DSM input data to it, otherwise, it is owned by QEMU which + emulates _DSM access and writes the output data to it. + + ACPI writes _DSM Input Data (based on the offset in the page): + [0x0 - 0x3]: 4 bytes, NVDIMM Device Handle, 0 is reserved for NVDIMM + Root device. + [0x4 - 0x7]: 4 bytes, Revision ID, that is the Arg1 of _DSM method. + [0x8 - 0xB]: 4 bytes. Function Index, that is the Arg2 of _DSM method. + [0xC - 0xFFF]: 4084 bytes, the Arg3 of _DSM method. + + QEMU Writes Output Data (based on the offset in the page): + [0x0 - 0x3]: 4 bytes, the length of result + [0x4 - 0xFFF]: 4092 bytes, the DSM result filled by QEMU + +IO Port 0x0a18 - 0xa1b: + ACPI writes the address of the memory page allocated by BIOS to this + port then QEMU gets the control and fills the result in the memory page. + + write Access: + [0x0a18 - 0xa1b]: 4 bytes, the address of the memory page allocated + by BIOS. + +_DSM process diagram: +--------------------- +"MEMA" indicates the address of memory page allocated by BIOS. + + +----------------------+   +-----------------------+ + |   1. OSPM   |      | 2. OSPM | + | save _DSM input data | | write "MEMA" to | Exit to QEMU + | to the page +----->| IO port 0x0a18 +------------+ + | indicated by "MEMA" | | | | + +----------------------+ +-----------------------+ | +  | +  v + +------------- ----+ +-----------+ +------------------+--------+ + | 5 QEMU | | 4 QEMU | | 3. QEMU | + | write _DSM result | | emulate | | get _DSM input data from | + | to the page +<------+ _DSM +<-----+ the page indicated by the | + | | | | | value from the IO port | + +--------+-----------+ +-----------+ +---------------------------+ + | + | Enter Guest + | + v + +--------------------------+ +--------------+ + | 6 OSPM | | 7 OSPM | + | result size is returned | | _DSM return | + | by reading DSM +----->+ | + | result from the page | | | + +--------------------------+ +--------------+ + + _FIT implementation + ------------------- + TODO (will fill it when nvdimm hotplug is introduced) -- 1.8.3.1