pci, pc, virtio, misc bugfixes

A bunch of bugfixes.
 
 Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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Merge remote-tracking branch 'remotes/mst/tags/for_upstream' into staging

pci, pc, virtio, misc bugfixes

A bunch of bugfixes.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

# gpg: Signature made Mon 29 Sep 2014 17:59:57 BST using RSA key ID D28D5469
# gpg: Good signature from "Michael S. Tsirkin <mst@kernel.org>"
# gpg:                 aka "Michael S. Tsirkin <mst@redhat.com>"

* remotes/mst/tags/for_upstream:
  vl: Adjust the place of calling mlockall to speedup VM's startup
  pc-dimm: Don't check dimm->node when there is non-NUMA config
  pci-hotplug-old: avoid losing error message
  Revert "virtio-pci: fix migration for pci bus master"
  loader: g_realloc(p, 0) frees and returns NULL, simplify

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

hw/mem/pc-dimm.c

@@ -252,7 +252,7 @@ static void pc_dimm_realize(DeviceState *dev, Error **errp)
         error_setg(errp, "'" PC_DIMM_MEMDEV_PROP "' property is not set");
         return;
     }
-    if (dimm->node >= nb_numa_nodes) {
+    if ((nb_numa_nodes > 0) && (dimm->node >= nb_numa_nodes)) {
         error_setg(errp, "'DIMM property " PC_DIMM_NODE_PROP " has value %"
                    PRIu32 "' which exceeds the number of numa nodes: %d",
                    dimm->node, nb_numa_nodes);

hw/pci/pci-hotplug-old.c

@@ -107,6 +107,7 @@ static int scsi_hot_add(Monitor *mon, DeviceState *adapter,
 {
     SCSIBus *scsibus;
     SCSIDevice *scsidev;
+    Error *local_err = NULL;
 
     scsibus = (SCSIBus *)
         object_dynamic_cast(OBJECT(QLIST_FIRST(&adapter->child_bus)),
@@ -127,8 +128,10 @@ static int scsi_hot_add(Monitor *mon, DeviceState *adapter,
     dinfo->unit = qemu_opt_get_number(dinfo->opts, "unit", -1);
     dinfo->bus = scsibus->busnr;
     scsidev = scsi_bus_legacy_add_drive(scsibus, dinfo->bdrv, dinfo->unit,
-                                        false, -1, NULL, NULL);
+                                        false, -1, NULL, &local_err);
     if (!scsidev) {
+        error_report("%s", error_get_pretty(local_err));
+        error_free(local_err);
         return -1;
     }
     dinfo->unit = scsidev->id;

hw/virtio/virtio-pci.c

@@ -86,6 +86,9 @@
  * 12 is historical, and due to x86 page size. */
 #define VIRTIO_PCI_QUEUE_ADDR_SHIFT    12
 
+/* Flags track per-device state like workarounds for quirks in older guests. */
+#define VIRTIO_PCI_FLAG_BUS_MASTER_BUG  (1 << 0)
+
 static void virtio_pci_bus_new(VirtioBusState *bus, size_t bus_size,
                                VirtIOPCIProxy *dev);
 
@@ -320,6 +323,14 @@ static void virtio_ioport_write(void *opaque, uint32_t addr, uint32_t val)
                                      proxy->pci_dev.config[PCI_COMMAND] |
                                      PCI_COMMAND_MASTER, 1);
         }
+
+        /* Linux before 2.6.34 sets the device as OK without enabling
+           the PCI device bus master bit. In this case we need to disable
+           some safety checks. */
+        if ((val & VIRTIO_CONFIG_S_DRIVER_OK) &&
+            !(proxy->pci_dev.config[PCI_COMMAND] & PCI_COMMAND_MASTER)) {
+            proxy->flags |= VIRTIO_PCI_FLAG_BUS_MASTER_BUG;
+        }
         break;
     case VIRTIO_MSI_CONFIG_VECTOR:
         msix_vector_unuse(&proxy->pci_dev, vdev->config_vector);
@@ -469,18 +480,13 @@ static void virtio_write_config(PCIDevice *pci_dev, uint32_t address,
     VirtIOPCIProxy *proxy = DO_UPCAST(VirtIOPCIProxy, pci_dev, pci_dev);
     VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
 
-    uint8_t cmd = proxy->pci_dev.config[PCI_COMMAND];
-
     pci_default_write_config(pci_dev, address, val, len);
 
     if (range_covers_byte(address, len, PCI_COMMAND) &&
         !(pci_dev->config[PCI_COMMAND] & PCI_COMMAND_MASTER) &&
-        (cmd & PCI_COMMAND_MASTER)) {
+        !(proxy->flags & VIRTIO_PCI_FLAG_BUS_MASTER_BUG)) {
-        /* Bus driver disables bus mastering - make it act
-         * as a kind of reset to render the device quiescent. */
         virtio_pci_stop_ioeventfd(proxy);
-        virtio_reset(vdev);
+        virtio_set_status(vdev, vdev->status & ~VIRTIO_CONFIG_S_DRIVER_OK);
-        msix_unuse_all_vectors(&proxy->pci_dev);
     }
 }
 
@@ -889,19 +895,11 @@ static void virtio_pci_vmstate_change(DeviceState *d, bool running)
     VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
 
     if (running) {
-        /* Linux before 2.6.34 drives the device without enabling
+        /* Try to find out if the guest has bus master disabled, but is
-           the PCI device bus master bit. Enable it automatically
+           in ready state. Then we have a buggy guest OS. */
-           for the guest. This is a PCI spec violation but so is
+        if ((vdev->status & VIRTIO_CONFIG_S_DRIVER_OK) &&
-           initiating DMA with bus master bit clear.
+            !(proxy->pci_dev.config[PCI_COMMAND] & PCI_COMMAND_MASTER)) {
-           Note: this only makes a difference when migrating
+            proxy->flags |= VIRTIO_PCI_FLAG_BUS_MASTER_BUG;
-           across QEMU versions from an old QEMU, as for new QEMU
-           bus master and driver bits are always in sync.
-           TODO: consider enabling conditionally for compat machine types. */
-        if (vdev->status & (VIRTIO_CONFIG_S_ACKNOWLEDGE |
-                            VIRTIO_CONFIG_S_DRIVER)) {
-            pci_default_write_config(&proxy->pci_dev, PCI_COMMAND,
-                                     proxy->pci_dev.config[PCI_COMMAND] |
-                                     PCI_COMMAND_MASTER, 1);
         }
         virtio_pci_start_ioeventfd(proxy);
     } else {
@@ -1042,6 +1040,7 @@ static void virtio_pci_reset(DeviceState *qdev)
     virtio_pci_stop_ioeventfd(proxy);
     virtio_bus_reset(bus);
     msix_unuse_all_vectors(&proxy->pci_dev);
+    proxy->flags &= ~VIRTIO_PCI_FLAG_BUS_MASTER_BUG;
 }
 
 static Property virtio_pci_properties[] = {

include/hw/elf_ops.h

@@ -147,7 +147,6 @@ static int glue(load_symbols, SZ)(struct elfhdr *ehdr, int fd, int must_swab,
         }
         i++;
     }
-    if (nsyms) {
     syms = g_realloc(syms, nsyms * sizeof(*syms));
 
     qsort(syms, nsyms, sizeof(*syms), glue(symcmp, SZ));
@@ -156,10 +155,6 @@ static int glue(load_symbols, SZ)(struct elfhdr *ehdr, int fd, int must_swab,
             syms[i].st_size = syms[i + 1].st_value - syms[i].st_value;
         }
     }
-    } else {
-        g_free(syms);
-        syms = NULL;
-    }
 
     /* String table */
     if (symtab->sh_link >= ehdr->e_shnum)

vl.c

@@ -134,6 +134,7 @@ const char* keyboard_layout = NULL;
 ram_addr_t ram_size;
 const char *mem_path = NULL;
 int mem_prealloc = 0; /* force preallocation of physical target memory */
+bool enable_mlock = false;
 int nb_nics;
 NICInfo nd_table[MAX_NICS];
 int autostart;
@@ -1421,12 +1422,8 @@ static void smp_parse(QemuOpts *opts)
 
 }
 
-static void configure_realtime(QemuOpts *opts)
+static void realtime_init(void)
 {
-    bool enable_mlock;
-
-    enable_mlock = qemu_opt_get_bool(opts, "mlock", true);
-
     if (enable_mlock) {
         if (os_mlock() < 0) {
             fprintf(stderr, "qemu: locking memory failed\n");
@@ -3974,7 +3971,7 @@ int main(int argc, char **argv, char **envp)
                 if (!opts) {
                     exit(1);
                 }
-                configure_realtime(opts);
+                enable_mlock = qemu_opt_get_bool(opts, "mlock", true);
                 break;
             case QEMU_OPTION_msg:
                 opts = qemu_opts_parse(qemu_find_opts("msg"), optarg, 0);
@@ -4442,6 +4439,8 @@ int main(int argc, char **argv, char **envp)
 
     machine_class->init(current_machine);
 
+    realtime_init();
+
     audio_init();
 
     cpu_synchronize_all_post_init();