Re: [Qemu-devel] [PATCH 31/35] pc: ACPI BIOS: implement memory hotplug interface

["Michael S. Tsirkin" <mst@redhat.com>]

On Fri, Apr 04, 2014 at 03:36:56PM +0200, Igor Mammedov wrote:
> - provides static SSDT object for memory hotplug
> - SSDT template for memory devices and runtime generator
>   of them in SSDT table.
> 
> Signed-off-by: Vasilis Liaskovitis <vasilis.liaskovitis@profitbricks.com>
> Signed-off-by: Igor Mammedov <imammedo@redhat.com>
> ---
>  hw/i386/Makefile.objs |   3 +-
>  hw/i386/acpi-build.c  |  37 ++++++++++++
>  hw/i386/ssdt-mem.dsl  |  75 +++++++++++++++++++++++
>  hw/i386/ssdt-misc.dsl | 163 ++++++++++++++++++++++++++++++++++++++++++++++++++
>  4 files changed, 277 insertions(+), 1 deletion(-)
>  create mode 100644 hw/i386/ssdt-mem.dsl
> 
> diff --git a/hw/i386/Makefile.objs b/hw/i386/Makefile.objs
> index 3df1612..fd04fc2 100644
> --- a/hw/i386/Makefile.objs
> +++ b/hw/i386/Makefile.objs
> @@ -9,7 +9,8 @@ obj-y += acpi-build.o
>  obj-y += bios-linker-loader.o
>  hw/i386/acpi-build.o: hw/i386/acpi-build.c hw/i386/acpi-dsdt.hex \
>  	hw/i386/ssdt-proc.hex hw/i386/ssdt-pcihp.hex hw/i386/ssdt-misc.hex \
> -	hw/i386/acpi-dsdt.hex hw/i386/q35-acpi-dsdt.hex
> +	hw/i386/acpi-dsdt.hex hw/i386/q35-acpi-dsdt.hex \
> +	hw/i386/q35-acpi-dsdt.hex hw/i386/ssdt-mem.hex
>  
>  iasl-option=$(shell if test -z "`$(1) $(2) 2>&1 > /dev/null`" \
>      ; then echo "$(2)"; else echo "$(3)"; fi ;)
> diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
> index a5d3fbf..6649480 100644
> --- a/hw/i386/acpi-build.c
> +++ b/hw/i386/acpi-build.c
> @@ -37,6 +37,7 @@
>  #include "bios-linker-loader.h"
>  #include "hw/loader.h"
>  #include "hw/isa/isa.h"
> +#include "hw/acpi/memory_hotplug.h"
>  
>  /* Supported chipsets: */
>  #include "hw/acpi/piix4.h"
> @@ -664,6 +665,14 @@ static inline char acpi_get_hex(uint32_t val)
>  #define ACPI_PCIQXL_SIZEOF (*ssdt_pciqxl_end - *ssdt_pciqxl_start)
>  #define ACPI_PCIQXL_AML (ssdp_pcihp_aml + *ssdt_pciqxl_start)
>  
> +#include "hw/i386/ssdt-mem.hex"
> +
> +/* 0x5B 0x82 DeviceOp PkgLength NameString DimmID */
> +#define ACPI_MEM_OFFSET_HEX (*ssdt_mem_name - *ssdt_mem_start + 2)
> +#define ACPI_MEM_OFFSET_ID (*ssdt_mem_id - *ssdt_mem_start + 7)
> +#define ACPI_MEM_SIZEOF (*ssdt_mem_end - *ssdt_mem_start)
> +#define ACPI_MEM_AML (ssdm_mem_aml + *ssdt_mem_start)
> +
>  #define ACPI_SSDT_SIGNATURE 0x54445353 /* SSDT */
>  #define ACPI_SSDT_HEADER_LENGTH 36
>  
> @@ -999,6 +1008,8 @@ build_ssdt(GArray *table_data, GArray *linker,
>             AcpiCpuInfo *cpu, AcpiPmInfo *pm, AcpiMiscInfo *misc,
>             PcPciInfo *pci, PcGuestInfo *guest_info)
>  {
> +    MachineState *machine = MACHINE(qdev_get_machine());
> +    uint32_t nr_mem = machine->init_args.ram_slots;
>      unsigned acpi_cpus = guest_info->apic_id_limit;
>      int ssdt_start = table_data->len;
>      uint8_t *ssdt_ptr;
> @@ -1027,6 +1038,9 @@ build_ssdt(GArray *table_data, GArray *linker,
>      ACPI_BUILD_SET_LE(ssdt_ptr, sizeof(ssdp_misc_aml),
>                        ssdt_isa_pest[0], 16, misc->pvpanic_port);
>  
> +    ACPI_BUILD_SET_LE(ssdt_ptr, sizeof(ssdp_misc_aml),
> +                      ssdt_mctrl_nr_slots[0], 32, nr_mem);
> +
>      {
>          GArray *sb_scope = build_alloc_array();
>          uint8_t op = 0x10; /* ScopeOp */
> @@ -1080,6 +1094,29 @@ build_ssdt(GArray *table_data, GArray *linker,
>              build_free_array(package);
>          }
>  
> +        if (nr_mem) {
> +            /*
> +             * current device naming scheme dosen't support

doesn't

> +             * more that 256 memory devices
> +             */
> +            assert(nr_mem <= 256);
> +            /* build memory devices */
> +            for (i = 0; i < nr_mem; i++) {
> +                char id[3];
> +                uint8_t *mem = acpi_data_push(sb_scope, ACPI_MEM_SIZEOF);
> +
> +                snprintf(id, sizeof(id), "%02X", i);
> +                memcpy(mem, ACPI_MEM_AML, ACPI_MEM_SIZEOF);
> +                memcpy(mem + ACPI_MEM_OFFSET_HEX, id, 2);
> +                memcpy(mem + ACPI_MEM_OFFSET_ID, id, 2);
> +            }
> +
> +            /* build Method(MTFY, 2) {
> +             *     If (LEqual(Arg0, 0x00)) {Notify(MP00, Arg1)} ...
> +             */
> +            build_append_notify_method(sb_scope, "MTFY", "MP%0.02X", nr_mem);
> +        }
> +
>          {
>              AcpiBuildPciBusHotplugState hotplug_state;
>              Object *pci_host;
> diff --git a/hw/i386/ssdt-mem.dsl b/hw/i386/ssdt-mem.dsl
> new file mode 100644
> index 0000000..7f68750
> --- /dev/null
> +++ b/hw/i386/ssdt-mem.dsl
> @@ -0,0 +1,75 @@
> +/*
> + * Memory hotplug ACPI DSDT static objects definitions
> + *
> + * Copyright ProfitBricks GmbH 2012
> + * Copyright (C) 2013 Red Hat Inc
> + *
> + * This library is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU Lesser General Public
> + * License as published by the Free Software Foundation; either
> + * version 2 of the License, or (at your option) any later version.
> + *
> + * This library is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> + * Lesser General Public License for more details.
> + *
> + * You should have received a copy of the GNU Lesser General Public
> + * License along with this library; if not, see <http://www.gnu.org/licenses/>
> + */
> +
> +/* This file is the basis for the ssdt_mem[] variable in src/acpi.c.
> + * It defines the contents of the memory device object.  At
> + * runtime, a dynamically generated SSDT will contain one copy of this
> + * AML snippet for every possible memory device in the system.  The
> + * objects will be placed in the \_SB_ namespace.
> + *
> + * In addition to the aml code generated from this file, the
> + * src/acpi.c file creates a MTFY method with an entry for each memdevice:
> + *     Method(MTFY, 2) {
> + *         If (LEqual(Arg0, 0x00)) { Notify(MP00, Arg1) }
> + *         If (LEqual(Arg0, 0x01)) { Notify(MP01, Arg1) }
> + *         ...
> + *     }
> + */
> +ACPI_EXTRACT_ALL_CODE ssdm_mem_aml
> +
> +DefinitionBlock ("ssdt-mem.aml", "SSDT", 0x02, "BXPC", "CSSDT", 0x1)
> +{
> +
> +    External(\_SB.MHPD.MCRS, MethodObj)
> +    External(\_SB.MHPD.MRST, MethodObj)
> +    External(\_SB.MHPD.MOST, MethodObj)
> +    External(\_SB.MHPD.MPXM, MethodObj)
> +
> +    Scope(\_SB) {
> +/*  v------------------ DO NOT EDIT ------------------v */
> +        ACPI_EXTRACT_DEVICE_START ssdt_mem_start
> +        ACPI_EXTRACT_DEVICE_END ssdt_mem_end
> +        ACPI_EXTRACT_DEVICE_STRING ssdt_mem_name
> +        Device(MPAA) {
> +            ACPI_EXTRACT_NAME_STRING ssdt_mem_id
> +            Name(_UID, "0xAA")
> +/*  ^------------------ DO NOT EDIT ------------------^
> + * Don't change the above without also updating the C code.
> + */
> +            Name(_HID, EISAID("PNP0C80"))
> +
> +            Method(_CRS, 0) {
> +                Return(\_SB.MHPD.MCRS(_UID))
> +            }
> +
> +            Method(_STA, 0) {
> +                Return(\_SB.MHPD.MRST(_UID))
> +            }
> +
> +            Method(_PXM, 0) {
> +                Return(\_SB.MHPD.MPXM(_UID))
> +            }
> +
> +            Method(_OST, 3) {
> +                \_SB.MHPD.MOST(_UID, Arg0, Arg1, Arg2)
> +            }
> +        }
> +    }
> +}
> diff --git a/hw/i386/ssdt-misc.dsl b/hw/i386/ssdt-misc.dsl
> index a4484b8..d1caaed 100644
> --- a/hw/i386/ssdt-misc.dsl
> +++ b/hw/i386/ssdt-misc.dsl
> @@ -12,6 +12,7 @@
>   * You should have received a copy of the GNU General Public License along
>   * with this program; if not, see <http://www.gnu.org/licenses/>.
>   */
> +#include "hw/acpi/acpi_defs.h"
>  
>  ACPI_EXTRACT_ALL_CODE ssdp_misc_aml
>  
> @@ -116,4 +117,166 @@ DefinitionBlock ("ssdt-misc.aml", "SSDT", 0x01, "BXPC", "BXSSDTSUSP", 0x1)
>              }
>          }
>      }
> +
> +    External(MTFY, MethodObj)
> +    Scope(\_SB) {
> +        Device(MHPD) {
> +            Name(_HID, "ACPI0004")
> +            Name(_UID, "Memory hotplug resources")
> +
> +            ACPI_EXTRACT_NAME_DWORD_CONST ssdt_mctrl_nr_slots
> +            Name(MDNR, 0x12345678)

Let's define some macros and use descriptive names - is this one
MEMORY_DIMM_NUMBER?

Same for other ACPI names below.

> +
> +            /* Memory hotplug IO registers */
> +            OperationRegion(HPMR, SystemIO, ACPI_MEMORY_HOTPLUG_BASE,
> +                            ACPI_MEMORY_HOTPLUG_IO_LEN)
> +
> +            Name(_CRS, ResourceTemplate() {
> +                IO(Decode16, ACPI_MEMORY_HOTPLUG_BASE, ACPI_MEMORY_HOTPLUG_BASE,
> +                   0, ACPI_MEMORY_HOTPLUG_IO_LEN, IO)
> +            })
> +
> +            Method(_STA, 0) {
> +                If (LEqual(MDNR, Zero)) {
> +                    Return(0x0)
> +                }
> +                /* present, functioning, decoding, not shown in UI */
> +                Return(0xB)
> +            }
> +
> +            Field(HPMR, DWordAcc, NoLock, Preserve) {
> +                MRBL, 32, // DIMM start addr Low word, read only
> +                MRBH, 32, // DIMM start addr Hi word, read only
> +                MRLL, 32, // DIMM size Low word, read only
> +                MRLH, 32, // DIMM size Hi word, read only
> +                MPX, 32,  // DIMM node proximity, read only
> +            }
> +            Field(HPMR, ByteAcc, NoLock, Preserve) {
> +                Offset(20),
> +                MES,  1, // 1 if DIMM enabled used by _STA, read only
> +                MINS, 1, // (read) 1 if DIMM has a insert event. (write) 1 after MTFY() to clear event
> +            }
> +
> +            Mutex (MLCK, 0)
> +            Field (HPMR, DWordAcc, NoLock, Preserve) {
> +                MSEL, 32,  // DIMM selector, write only
> +                MOEV, 32,  // _OST event code, write only
> +                MOSC, 32,  // _OST status code, write only
> +            }
> +
> +            Method(MESC, 0, Serialized) {

Why is this one serialized? Shouldn't be necessary since
you use explicit locking, right?

> +                If (LEqual(MDNR, Zero)) {
> +                     Return(Zero)
> +                }
> +
> +                Store(Zero, Local0) // Mem devs iterrator
> +                Acquire(MLCK, 0xFFFF)
> +                while (LLess(Local0, MDNR)) {
> +                    Store(Local0, MSEL) // select Local0 DIMM
> +                    If (LEqual(MINS, One)) { // Memory device needs check

This works because MINS is a 1 bit fields.
OK but please use a name that reflects this fact.

> +                        MTFY(Local0, 1)
> +                        Store(1, MINS)
> +                    }
> +                    // TODO: handle memory eject request
> +                    Add(Local0, One, Local0) // goto next DIMM
> +                }
> +                Release(MLCK)
> +                Return(One)
> +            }
> +
> +            Method(MRST, 1) {
> +                Store(Zero, Local0)
> +
> +                Acquire(MLCK, 0xFFFF)
> +                Store(ToInteger(Arg0), MSEL) // select DIMM
> +
> +                If (LEqual(MES, One)) {
> +                    Store(0xF, Local0)
> +                }
> +
> +                Release(MLCK)
> +                Return(Local0)
> +            }
> +
> +            Method(MCRS, 1, Serialized) {
> +                Acquire(MLCK, 0xFFFF)
> +                Store(ToInteger(Arg0), MSEL) // select DIMM
> +
> +                Name(MR64, ResourceTemplate() {
> +                    QWordMemory(ResourceProducer, PosDecode, MinFixed, MaxFixed,
> +                    Cacheable, ReadWrite,
> +                    0x0000000000000000,        // Address Space Granularity
> +                    0x0000000000000000,        // Address Range Minimum
> +                    0xFFFFFFFFFFFFFFFE,        // Address Range Maximum
> +                    0x0000000000000000,        // Address Translation Offset
> +                    0xFFFFFFFFFFFFFFFF,        // Address Length
> +                    ,, MW64, AddressRangeMemory, TypeStatic)
> +                })
> +
> +                CreateDWordField(MR64, 14, MINL)
> +                CreateDWordField(MR64, 18, MINH)
> +                CreateDWordField(MR64, 38, LENL)
> +                CreateDWordField(MR64, 42, LENH)
> +                CreateDWordField(MR64, 22, MAXL)
> +                CreateDWordField(MR64, 26, MAXH)
> +
> +                Store(MRBH, MINH)
> +                Store(MRBL, MINL)
> +                Store(MRLH, LENH)
> +                Store(MRLL, LENL)
> +
> +                // 64-bit math: MAX = MIN + LEN - 1
> +                Add(MINL, LENL, MAXL)
> +                Add(MINH, LENH, MAXH)
> +                If (LLess(MAXL, MINL)) {
> +                    Add(MAXH, One, MAXH)
> +                }
> +                If (LLess(MAXL, One)) {
> +                    Subtract(MAXH, One, MAXH)
> +                }
> +                Subtract(MAXL, One, MAXL)
> +
> +                If (LEqual(MAXH, Zero)){
> +                    Name(MR32, ResourceTemplate() {
> +                        DWordMemory(ResourceProducer, PosDecode, MinFixed, MaxFixed,
> +                        Cacheable, ReadWrite,
> +                        0x00000000,        // Address Space Granularity
> +                        0x00000000,        // Address Range Minimum
> +                        0xFFFFFFFE,        // Address Range Maximum
> +                        0x00000000,        // Address Translation Offset
> +                        0xFFFFFFFF,        // Address Length
> +                        ,, MW32, AddressRangeMemory, TypeStatic)
> +                    })
> +                    CreateDWordField(MR32, MW32._MIN, MIN)
> +                    CreateDWordField(MR32, MW32._MAX, MAX)
> +                    CreateDWordField(MR32, MW32._LEN, LEN)
> +                    Store(MINL, MIN)
> +                    Store(MAXL, MAX)
> +                    Store(LENL, LEN)
> +
> +                    Release(MLCK)
> +                    Return(MR32)
> +                }
> +
> +                Release(MLCK)
> +                Return(MR64)
> +            }
> +
> +            Method(MPXM, 1) {
> +                Acquire(MLCK, 0xFFFF)
> +                Store(ToInteger(Arg0), MSEL) // select DIMM
> +                Store(MPX, Local0)
> +                Release(MLCK)
> +                Return(Local0)
> +            }
> +
> +            Method(MOST, 4) {
> +                Acquire(MLCK, 0xFFFF)
> +                Store(ToInteger(Arg0), MSEL) // select DIMM
> +                Store(Arg1, MOEV)
> +                Store(Arg2, MOSC)
> +                Release(MLCK)
> +            }
> +        } // Device()
> +    } // Scope()
>  }
> -- 
> 1.9.0