Commit 11c39b5c authored by Ross Zwisler's avatar Ross Zwisler Committed by Michael S. Tsirkin
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nvdimm: make persistence option symbolic 



Replace the "nvdimm-cap" option which took numeric arguments such as "2"
with a more user friendly "nvdimm-persistence" option which takes symbolic
arguments "cpu" or "mem-ctrl".

Signed-off-by: default avatarRoss Zwisler <ross.zwisler@linux.intel.com>
Suggested-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Suggested-by: default avatarDan Williams <dan.j.williams@intel.com>
Reviewed-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent 0f3ef1c0

docs/nvdimm.txt

+12 −19
Original line number Diff line number Diff line
@@ -154,29 +154,22 @@ guest software that this vNVDIMM device contains a region that cannot 
accept persistent writes. In result, for example, the guest Linux

NVDIMM driver, marks such vNVDIMM device as read-only.



Platform Capabilities

---------------------

NVDIMM Persistence

------------------



ACPI 6.2 Errata A added support for a new Platform Capabilities Structure

which allows the platform to communicate what features it supports related to

NVDIMM data durability.  Users can provide a capabilities value to a guest via

the optional "nvdimm-cap" machine command line option:

NVDIMM data persistence.  Users can provide a persistence value to a guest via

the optional "nvdimm-persistence" machine command line option:



    -machine pc,accel=kvm,nvdimm,nvdimm-cap=2

    -machine pc,accel=kvm,nvdimm,nvdimm-persistence=cpu



This "nvdimm-cap" field is an integer, and is the combined value of the

various capability bits defined in table 5-137 of the ACPI 6.2 Errata A spec.

There are currently two valid values for this option:



Here is a quick summary of the three bits that are defined as of that spec:

"mem-ctrl" - The platform supports flushing dirty data from the memory

             controller to the NVDIMMs in the event of power loss.



Bit[0] - CPU Cache Flush to NVDIMM Durability on Power Loss Capable.

Bit[1] - Memory Controller Flush to NVDIMM Durability on Power Loss Capable.

         Note: If bit 0 is set to 1 then this bit shall be set to 1 as well.

Bit[2] - Byte Addressable Persistent Memory Hardware Mirroring Capable.



So, a "nvdimm-cap" value of 2 would mean that the platform supports Memory

Controller Flush on Power Loss, a value of 3 would mean that the platform

supports CPU Cache Flush and Memory Controller Flush on Power Loss, etc.



For a complete list of the flags available and for more detailed descriptions,

please consult the ACPI spec.
 
"cpu"      - The platform supports flushing dirty data from the CPU cache to

             the NVDIMMs in the event of power loss.  This implies that the

             platform also supports flushing dirty data through the memory

             controller on power loss.

hw/acpi/nvdimm.c

+2 −2
Original line number Diff line number Diff line
@@ -404,8 +404,8 @@ static GArray *nvdimm_build_device_structure(AcpiNVDIMMState *state) 
    }

    g_slist_free(device_list);



    if (state->capabilities) {

        nvdimm_build_structure_caps(structures, state->capabilities);

    if (state->persistence) {

        nvdimm_build_structure_caps(structures, state->persistence);

    }



    return structures;

hw/i386/pc.c

+17 −18
Original line number Diff line number Diff line
@@ -2181,31 +2181,30 @@ static void pc_machine_set_nvdimm(Object *obj, bool value, Error **errp) 
    pcms->acpi_nvdimm_state.is_enabled = value;

}



static void pc_machine_get_nvdimm_capabilities(Object *obj, Visitor *v,

                                               const char *name, void *opaque,

                                               Error **errp)

static char *pc_machine_get_nvdimm_persistence(Object *obj, Error **errp)

{

    PCMachineState *pcms = PC_MACHINE(obj);

    uint32_t value = pcms->acpi_nvdimm_state.capabilities;



    visit_type_uint32(v, name, &value, errp);

    return g_strdup(pcms->acpi_nvdimm_state.persistence_string);

}



static void pc_machine_set_nvdimm_capabilities(Object *obj, Visitor *v,

                                               const char *name, void *opaque,

static void pc_machine_set_nvdimm_persistence(Object *obj, const char *value,

                                               Error **errp)

{

    PCMachineState *pcms = PC_MACHINE(obj);

    Error *error = NULL;

    uint32_t value;



    visit_type_uint32(v, name, &value, &error);

    if (error) {

        error_propagate(errp, error);

        return;

    AcpiNVDIMMState *nvdimm_state = &pcms->acpi_nvdimm_state;



    if (strcmp(value, "cpu") == 0)

        nvdimm_state->persistence = 3;

    else if (strcmp(value, "mem-ctrl") == 0)

        nvdimm_state->persistence = 2;

    else {

        error_report("-machine nvdimm-persistence=%s: unsupported option", value);

        exit(EXIT_FAILURE);

    }



    pcms->acpi_nvdimm_state.capabilities = value;

    g_free(nvdimm_state->persistence_string);

    nvdimm_state->persistence_string = g_strdup(value);

}



static bool pc_machine_get_smbus(Object *obj, Error **errp)
@@ -2421,9 +2420,9 @@ static void pc_machine_class_init(ObjectClass *oc, void *data) 
    object_class_property_add_bool(oc, PC_MACHINE_NVDIMM,

        pc_machine_get_nvdimm, pc_machine_set_nvdimm, &error_abort);



    object_class_property_add(oc, PC_MACHINE_NVDIMM_CAP, "uint32",

        pc_machine_get_nvdimm_capabilities,

        pc_machine_set_nvdimm_capabilities, NULL, NULL, &error_abort);

    object_class_property_add_str(oc, PC_MACHINE_NVDIMM_PERSIST,

        pc_machine_get_nvdimm_persistence,

        pc_machine_set_nvdimm_persistence, &error_abort);



    object_class_property_add_bool(oc, PC_MACHINE_SMBUS,

        pc_machine_get_smbus, pc_machine_set_smbus, &error_abort);

include/hw/i386/pc.h

+1 −1
Original line number Diff line number Diff line
@@ -76,7 +76,7 @@ struct PCMachineState { 
#define PC_MACHINE_VMPORT           "vmport"

#define PC_MACHINE_SMM              "smm"

#define PC_MACHINE_NVDIMM           "nvdimm"

#define PC_MACHINE_NVDIMM_CAP       "nvdimm-cap"

#define PC_MACHINE_NVDIMM_PERSIST   "nvdimm-persistence"

#define PC_MACHINE_SMBUS            "smbus"

#define PC_MACHINE_SATA             "sata"

#define PC_MACHINE_PIT              "pit"

include/hw/mem/nvdimm.h

+2 −1
Original line number Diff line number Diff line
@@ -138,7 +138,8 @@ struct AcpiNVDIMMState { 
    /*

     * Platform capabilities, section 5.2.25.9 of ACPI 6.2 Errata A

     */

    int32_t capabilities;

    int32_t persistence;

    char    *persistence_string;

};

typedef struct AcpiNVDIMMState AcpiNVDIMMState;