[Qemu-devel] [RFC PATCH 6/9] pc: pass paravirt info for hotplug memory slots to BIOS

[Vasilis Liaskovitis]

 The numa_fw_cfg paravirt interface is extended to include SRAT information for
 all hotplug-able memslots. There are 3 words for each hotplug-able memory slot,
 denoting start address, size and node proximity. nb_numa_nodes is set to 1 by
 default (not 0), so that we always pass srat info to SeaBIOS.

 This information is used by Seabios to build hotplug memory device objects at 
runtime.

 Signed-off-by: Vasilis Liaskovitis <address@hidden>
---
 hw/pc.c |   59 +++++++++++++++++++++++++++++++++++++++++++++++++++++------
 vl.c    |    4 +++-
 2 files changed, 56 insertions(+), 7 deletions(-)

diff --git a/hw/pc.c b/hw/pc.c
index 67f0479..f1f550a 100644
--- a/hw/pc.c
+++ b/hw/pc.c
@@ -46,6 +46,7 @@
 #include "ui/qemu-spice.h"
 #include "memory.h"
 #include "exec-memory.h"
+#include "memslot.h"
 
 /* output Bochs bios info messages */
 //#define DEBUG_BIOS
@@ -592,12 +593,15 @@ int e820_add_entry(uint64_t address, uint64_t length, 
uint32_t type)
     return index;
 }
 
+static void bochs_bios_setup_hp_memslots(uint64_t *fw_cfg_slots);
+
 static void *bochs_bios_init(void)
 {
     void *fw_cfg;
     uint8_t *smbios_table;
     size_t smbios_len;
     uint64_t *numa_fw_cfg;
+    uint64_t *hp_memslots_fw_cfg;
     int i, j;
 
     register_ioport_write(0x400, 1, 2, bochs_bios_write, NULL);
@@ -630,28 +634,71 @@ static void *bochs_bios_init(void)
     fw_cfg_add_bytes(fw_cfg, FW_CFG_HPET, (uint8_t *)&hpet_cfg,
                      sizeof(struct hpet_fw_config));
     /* allocate memory for the NUMA channel: one (64bit) word for the number
-     * of nodes, one word for each VCPU->node and one word for each node to
-     * hold the amount of memory.
+     * of nodes, one word for the number of hotplug memory slots, one word
+     * for each VCPU->node, one word for each node to hold the amount of 
memory.
+     * Finally three words for each hotplug memory slot, denoting start 
address,
+     * size and node proximity.
      */
-    numa_fw_cfg = g_malloc0((1 + max_cpus + nb_numa_nodes) * 8);
+    numa_fw_cfg = g_malloc0((2 + max_cpus + nb_numa_nodes + 3 * 
nb_hp_memslots) * 8);
     numa_fw_cfg[0] = cpu_to_le64(nb_numa_nodes);
+    numa_fw_cfg[1] = cpu_to_le64(nb_hp_memslots);
+
     for (i = 0; i < max_cpus; i++) {
         for (j = 0; j < nb_numa_nodes; j++) {
             if (node_cpumask[j] & (1 << i)) {
-                numa_fw_cfg[i + 1] = cpu_to_le64(j);
+                numa_fw_cfg[i + 2] = cpu_to_le64(j);
                 break;
             }
         }
     }
     for (i = 0; i < nb_numa_nodes; i++) {
-        numa_fw_cfg[max_cpus + 1 + i] = cpu_to_le64(node_mem[i]);
+        numa_fw_cfg[max_cpus + 2 + i] = cpu_to_le64(node_mem[i]);
     }
+
+    hp_memslots_fw_cfg = numa_fw_cfg + 2 + max_cpus + nb_numa_nodes;
+    if (nb_hp_memslots)
+        bochs_bios_setup_hp_memslots(hp_memslots_fw_cfg);
+
     fw_cfg_add_bytes(fw_cfg, FW_CFG_NUMA, (uint8_t *)numa_fw_cfg,
-                     (1 + max_cpus + nb_numa_nodes) * 8);
+                     (2 + max_cpus + nb_numa_nodes + 3 * nb_hp_memslots) * 8);
 
     return fw_cfg;
 }
 
+static void bochs_bios_setup_hp_memslots(uint64_t *fw_cfg_slots)
+{
+    int i = 0;
+    Error *err = NULL;
+    DeviceState *dev;
+    MemSlotState *slot;
+    char *type;
+    BusState *bus = sysbus_get_default();
+
+    QTAILQ_FOREACH(dev, &bus->children, sibling) {
+        type = object_property_get_str(OBJECT(dev), "type", &err);
+        if (err) {
+            error_free(err);
+            fprintf(stderr, "error getting device type\n");
+            exit(1);
+        }
+
+        if (!strcmp(type, "memslot")) {
+            if (!dev->id) {
+                error_free(err);
+                fprintf(stderr, "error getting memslot device id\n");
+                exit(1);
+            }
+            if (!strcmp(dev->id, "initialslot")) continue;
+            slot = MEMSLOT(dev);
+            fw_cfg_slots[3 * slot->idx] = cpu_to_le64(slot->start);
+            fw_cfg_slots[3 * slot->idx + 1] = cpu_to_le64(slot->size);
+            fw_cfg_slots[3 * slot->idx + 2] = cpu_to_le64(slot->node);
+            i++;
+        }
+    }
+    assert(i == nb_hp_memslots);
+}
+
 static long get_file_size(FILE *f)
 {
     long where, size;
diff --git a/vl.c b/vl.c
index ae91a8a..50df453 100644
--- a/vl.c
+++ b/vl.c
@@ -3428,8 +3428,10 @@ int main(int argc, char **argv, char **envp)
 
     register_savevm_live(NULL, "ram", 0, 4, NULL, ram_save_live, NULL,
                          ram_load, NULL);
+    if (!nb_numa_nodes)
+        nb_numa_nodes = 1;
 
-    if (nb_numa_nodes > 0) {
+    {
         int i;
 
         if (nb_numa_nodes > MAX_NODES) {
-- 
1.7.9