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
+---------------------
+
+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:
+
+ -machine pc,accel=kvm,nvdimm,nvdimm-cap=2
+
+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.
+
+Here is a quick summary of the three bits that are defined as of that spec:
+
+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.
typedef struct NvdimmNfitControlRegion NvdimmNfitControlRegion;
/*
+ * NVDIMM Platform Capabilities Structure
+ *
+ * Defined in section 5.2.25.9 of ACPI 6.2 Errata A, September 2017
+ */
+struct NvdimmNfitPlatformCaps {
+ uint16_t type;
+ uint16_t length;
+ uint8_t highest_cap;
+ uint8_t reserved[3];
+ uint32_t capabilities;
+ uint8_t reserved2[4];
+} QEMU_PACKED;
+typedef struct NvdimmNfitPlatformCaps NvdimmNfitPlatformCaps;
+
+/*
* Module serial number is a unique number for each device. We use the
* slot id of NVDIMM device to generate this number so that each device
* associates with a different number.
JEDEC Annex L Release 3. */);
}
-static GArray *nvdimm_build_device_structure(void)
+/*
+ * ACPI 6.2 Errata A: 5.2.25.9 NVDIMM Platform Capabilities Structure
+ */
+static void
+nvdimm_build_structure_caps(GArray *structures, uint32_t capabilities)
+{
+ NvdimmNfitPlatformCaps *nfit_caps;
+
+ nfit_caps = acpi_data_push(structures, sizeof(*nfit_caps));
+
+ nfit_caps->type = cpu_to_le16(7 /* NVDIMM Platform Capabilities */);
+ nfit_caps->length = cpu_to_le16(sizeof(*nfit_caps));
+ nfit_caps->highest_cap = 31 - clz32(capabilities);
+ nfit_caps->capabilities = cpu_to_le32(capabilities);
+}
+
+static GArray *nvdimm_build_device_structure(AcpiNVDIMMState *state)
{
GSList *device_list = nvdimm_get_device_list();
GArray *structures = g_array_new(false, true /* clear */, 1);
}
g_slist_free(device_list);
+ if (state->capabilities) {
+ nvdimm_build_structure_caps(structures, state->capabilities);
+ }
+
return structures;
}
fit_buf->fit = g_array_new(false, true /* clear */, 1);
}
-static void nvdimm_build_fit_buffer(NvdimmFitBuffer *fit_buf)
+static void nvdimm_build_fit_buffer(AcpiNVDIMMState *state)
{
+ NvdimmFitBuffer *fit_buf = &state->fit_buf;
+
g_array_free(fit_buf->fit, true);
- fit_buf->fit = nvdimm_build_device_structure();
+ fit_buf->fit = nvdimm_build_device_structure(state);
fit_buf->dirty = true;
}
void nvdimm_plug(AcpiNVDIMMState *state)
{
- nvdimm_build_fit_buffer(&state->fit_buf);
+ nvdimm_build_fit_buffer(state);
}
static void nvdimm_build_nfit(AcpiNVDIMMState *state, GArray *table_offsets,
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)
+{
+ PCMachineState *pcms = PC_MACHINE(obj);
+ uint32_t value = pcms->acpi_nvdimm_state.capabilities;
+
+ visit_type_uint32(v, name, &value, errp);
+}
+
+static void pc_machine_set_nvdimm_capabilities(Object *obj, Visitor *v,
+ const char *name, void *opaque,
+ 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;
+ }
+
+ pcms->acpi_nvdimm_state.capabilities = value;
+}
+
static bool pc_machine_get_smbus(Object *obj, Error **errp)
{
PCMachineState *pcms = PC_MACHINE(obj);
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_bool(oc, PC_MACHINE_SMBUS,
pc_machine_get_smbus, pc_machine_set_smbus, &error_abort);
#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_SMBUS "smbus"
#define PC_MACHINE_SATA "sata"
#define PC_MACHINE_PIT "pit"
/* the IO region used by OSPM to transfer control to QEMU. */
MemoryRegion io_mr;
+
+ /*
+ * Platform capabilities, section 5.2.25.9 of ACPI 6.2 Errata A
+ */
+ int32_t capabilities;
};
typedef struct AcpiNVDIMMState AcpiNVDIMMState;