[Qemu-devel] [PATCH v7 29/35] nvdimm acpi: support function 0

[Xiao Guangrong <guangrong.xiao@linux.intel.com>]

__DSM is defined in ACPI 6.0: 9.14.1 _DSM (Device Specific Method)

Function 0 is a query function. We do not support any function on root
device and only 3 functions are support for NVDIMM device, Get Namespace
Label Size, Get Namespace Label Data and Set Namespace Label Data, that
means we currently only allow to access device's Label Namespace

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
---
 hw/acpi/aml-build.c         |   2 +-
 hw/acpi/nvdimm.c            | 158 +++++++++++++++++++++++++++++++++++++++++++-
 include/hw/acpi/aml-build.h |   1 +
 3 files changed, 159 insertions(+), 2 deletions(-)

diff --git a/hw/acpi/aml-build.c b/hw/acpi/aml-build.c
index 8bee8b2..90229c5 100644
--- a/hw/acpi/aml-build.c
+++ b/hw/acpi/aml-build.c
@@ -231,7 +231,7 @@ static void build_extop_package(GArray *package, uint8_t op)
     build_prepend_byte(package, 0x5B); /* ExtOpPrefix */
 }
 
-static void build_append_int_noprefix(GArray *table, uint64_t value, int size)
+void build_append_int_noprefix(GArray *table, uint64_t value, int size)
 {
     int i;
 
diff --git a/hw/acpi/nvdimm.c b/hw/acpi/nvdimm.c
index e179a72..3895ad8 100644
--- a/hw/acpi/nvdimm.c
+++ b/hw/acpi/nvdimm.c
@@ -212,6 +212,22 @@ static uint32_t nvdimm_slot_to_dcr_index(int slot)
     return nvdimm_slot_to_spa_index(slot) + 1;
 }
 
+static NVDIMMDevice
+*nvdimm_get_device_by_handle(GSList *list, uint32_t handle)
+{
+    for (; list; list = list->next) {
+        NVDIMMDevice *nvdimm = list->data;
+        int slot = object_property_get_int(OBJECT(nvdimm), DIMM_SLOT_PROP,
+                                           NULL);
+
+        if (nvdimm_slot_to_handle(slot) == handle) {
+            return nvdimm;
+        }
+    }
+
+    return NULL;
+}
+
 /* ACPI 6.0: 5.2.25.1 System Physical Address Range Structure */
 static void
 nvdimm_build_structure_spa(GArray *structures, NVDIMMDevice *nvdimm)
@@ -368,6 +384,29 @@ static void nvdimm_build_nfit(GSList *device_list, GArray *table_offsets,
     g_array_free(structures, true);
 }
 
+/* define NVDIMM DSM return status codes according to DSM Spec Rev1. */
+enum {
+    /* Common return status codes. */
+    /* Success */
+    NVDIMM_DSM_STATUS_SUCCESS = 0,
+    /* Not Supported */
+    NVDIMM_DSM_STATUS_NOT_SUPPORTED = 1,
+
+    /* NVDIMM Root Device _DSM function return status codes*/
+    /* Invalid Input Parameters */
+    NVDIMM_DSM_ROOT_DEV_STATUS_INVALID_PARAS = 2,
+    /* Function-Specific Error */
+    NVDIMM_DSM_ROOT_DEV_STATUS_FUNCTION_SPECIFIC_ERROR = 3,
+
+    /* NVDIMM Device (non-root) _DSM function return status codes*/
+    /* Non-Existing Memory Device */
+    NVDIMM_DSM_DEV_STATUS_NON_EXISTING_MEM_DEV = 2,
+    /* Invalid Input Parameters */
+    NVDIMM_DSM_DEV_STATUS_INVALID_PARAS = 3,
+    /* Vendor Specific Error */
+    NVDIMM_DSM_DEV_STATUS_VENDOR_SPECIFIC_ERROR = 4,
+};
+
 struct NvdimmDsmIn {
     uint32_t handle;
     uint32_t revision;
@@ -377,10 +416,127 @@ struct NvdimmDsmIn {
 } QEMU_PACKED;
 typedef struct NvdimmDsmIn NvdimmDsmIn;
 
+static void nvdimm_dsm_write_status(GArray *out, uint32_t status)
+{
+    status = cpu_to_le32(status);
+    build_append_int_noprefix(out, status, sizeof(status));
+}
+
+static void nvdimm_dsm_root(NvdimmDsmIn *in, GArray *out)
+{
+    uint32_t status = NVDIMM_DSM_STATUS_NOT_SUPPORTED;
+
+    /*
+     * Query command implemented per ACPI Specification, it is defined in
+     * ACPI 6.0: 9.14.1 _DSM (Device Specific Method).
+     */
+    if (in->function == 0x0) {
+        /*
+         * Set it to zero to indicate no function is supported for NVDIMM
+         * root.
+         */
+        uint64_t cmd_list = cpu_to_le64(0);
+
+        build_append_int_noprefix(out, cmd_list, sizeof(cmd_list));
+        return;
+    }
+
+    nvdimm_debug("Return status %#x.\n", status);
+    nvdimm_dsm_write_status(out, status);
+}
+
+static void nvdimm_dsm_device(NvdimmDsmIn *in, GArray *out)
+{
+    GSList *list = nvdimm_get_plugged_device_list();
+    NVDIMMDevice *nvdimm = nvdimm_get_device_by_handle(list, in->handle);
+    uint32_t status = NVDIMM_DSM_DEV_STATUS_NON_EXISTING_MEM_DEV;
+    uint64_t cmd_list;
+
+    if (!nvdimm) {
+        goto set_status_free;
+    }
+
+    /* Encode DSM function according to DSM Spec Rev1. */
+    switch (in->function) {
+    /* see comments in nvdimm_dsm_root(). */
+    case 0x0:
+        cmd_list = cpu_to_le64(0x1 /* Bit 0 indicates whether there is
+                                      support for any functions other
+                                      than function 0.
+                                    */                               |
+                               1 << 4 /* Get Namespace Label Size */ |
+                               1 << 5 /* Get Namespace Label Data */ |
+                               1 << 6 /* Set Namespace Label Data */);
+        build_append_int_noprefix(out, cmd_list, sizeof(cmd_list));
+        goto free;
+    default:
+        status = NVDIMM_DSM_STATUS_NOT_SUPPORTED;
+    };
+
+set_status_free:
+    nvdimm_debug("Return status %#x.\n", status);
+    nvdimm_dsm_write_status(out, status);
+free:
+    g_slist_free(list);
+}
+
 static uint64_t
 nvdimm_dsm_read(void *opaque, hwaddr addr, unsigned size)
 {
-    return 0;
+    AcpiNVDIMMState *state = opaque;
+    MemoryRegion *dsm_ram_mr = &state->ram_mr;
+    NvdimmDsmIn *in;
+    GArray *out;
+    void *dsm_ram_addr;
+    uint32_t buf_size;
+
+    assert(memory_region_size(dsm_ram_mr) >= sizeof(NvdimmDsmIn));
+    dsm_ram_addr = memory_region_get_ram_ptr(dsm_ram_mr);
+
+    /*
+     * The DSM memory is mapped to guest address space so an evil guest
+     * can change its content while we are doing DSM emulation. Avoid
+     * this by copying DSM memory to QEMU local memory.
+     */
+    in = g_malloc(memory_region_size(dsm_ram_mr));
+    memcpy(in, dsm_ram_addr, memory_region_size(dsm_ram_mr));
+
+    le32_to_cpus(&in->revision);
+    le32_to_cpus(&in->function);
+    le32_to_cpus(&in->handle);
+
+    nvdimm_debug("Revision %#x Handler %#x Function %#x.\n", in->revision,
+                 in->handle, in->function);
+
+    out = g_array_new(false, true /* clear */, 1);
+
+    if (in->revision != 0x1 /* Current we support DSM Spec Rev1. */) {
+        nvdimm_debug("Revision %#x is not supported, expect %#x.\n",
+                      in->revision, 0x1);
+        nvdimm_dsm_write_status(out, NVDIMM_DSM_STATUS_NOT_SUPPORTED);
+        goto exit;
+    }
+
+    /* Handle 0 is reserved for NVDIMM Root Device. */
+    if (!in->handle) {
+        nvdimm_dsm_root(in, out);
+        goto exit;
+    }
+
+    nvdimm_dsm_device(in, out);
+
+exit:
+    assert(out->len <= memory_region_size(dsm_ram_mr));
+
+    /* Write output result to dsm memory. */
+    memcpy(dsm_ram_addr, out->data, out->len);
+    memory_region_set_dirty(dsm_ram_mr, 0, out->len);
+
+    buf_size = cpu_to_le32(out->len);
+
+    g_free(in);
+    g_array_free(out, true);
+    return buf_size;
 }
 
 static void
diff --git a/include/hw/acpi/aml-build.h b/include/hw/acpi/aml-build.h
index 00cf40e..2c80043 100644
--- a/include/hw/acpi/aml-build.h
+++ b/include/hw/acpi/aml-build.h
@@ -281,6 +281,7 @@ Aml *aml_create_field(Aml *srcbuf, Aml *index, Aml *len, const char *name);
 Aml *aml_concatenate(Aml *source1, Aml *source2, Aml *target);
 Aml *aml_object_type(Aml *object);
 
+void build_append_int_noprefix(GArray *table, uint64_t value, int size);
 void
 build_header(GArray *linker, GArray *table_data,
              AcpiTableHeader *h, const char *sig, int len, uint8_t rev);
-- 
1.8.3.1