target-ppc: Enable KVM for ppcemb.

Implement hooks called by generic KVM code.

Also add code that will copy the host's CPU and timebase frequencies to the
guest, which is necessary on KVM because the guest can directly access the
timebase.

Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com>
Acked-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6065 c046a42c-6fe2-441c-8c8c-71466251a162

1 files changed, 110 insertions, 0 deletions

diff --git a/target-ppc/kvm_ppc.c b/target-ppc/kvm_ppc.c
new file mode 100644
index 0000000000..0caa5b98c7
--- /dev/null
+++ b/target-ppc/kvm_ppc.c
@@ -0,0 +1,110 @@
+/*
+ * PowerPC KVM support
+ *
+ * Copyright IBM Corp. 2008
+ *
+ * Authors:
+ *  Hollis Blanchard <hollisb@us.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#include "qemu-common.h"
+#include "qemu-timer.h"
+#include "kvm_ppc.h"
+#include "device_tree.h"
+
+#define PROC_DEVTREE_PATH "/proc/device-tree"
+
+static QEMUTimer *kvmppc_timer;
+static unsigned int kvmppc_timer_rate;
+
+#ifdef HAVE_FDT
+static int kvmppc_read_host_property(const char *node_path, const char *prop,
+                                     void *val, size_t len)
+{
+    char *path;
+    FILE *f;
+    int ret;
+    int pathlen;
+
+    pathlen = snprintf(NULL, 0, "%s/%s/%s", PROC_DEVTREE_PATH, node_path, prop)
+              + 1;
+    path = qemu_malloc(pathlen);
+    if (path == NULL) {
+        ret = -ENOMEM;
+        goto out;
+    }
+
+    snprintf(path, pathlen, "%s/%s/%s", PROC_DEVTREE_PATH, node_path, prop);
+
+    f = fopen(path, "rb");
+    if (f == NULL) {
+        ret = errno;
+        goto free;
+    }
+
+    len = fread(val, len, 1, f);
+    if (len != 1) {
+        ret = ferror(f);
+        goto close;
+    }
+
+close:
+    fclose(f);
+free:
+    free(path);
+out:
+    return ret;
+}
+
+static int kvmppc_copy_host_cell(void *fdt, const char *node, const char *prop)
+{
+    uint32_t cell;
+    int ret;
+
+    ret = kvmppc_read_host_property(node, prop, &cell, sizeof(cell));
+    if (ret < 0) {
+        fprintf(stderr, "couldn't read host %s/%s\n", node, prop);
+        goto out;
+    }
+
+    ret = qemu_devtree_setprop_cell(fdt, node, prop, cell);
+    if (ret < 0) {
+        fprintf(stderr, "couldn't set guest %s/%s\n", node, prop);
+        goto out;
+    }
+
+out:
+    return ret;
+}
+
+void kvmppc_fdt_update(void *fdt)
+{
+    /* Copy data from the host device tree into the guest. Since the guest can
+     * directly access the timebase without host involvement, we must expose
+     * the correct frequencies. */
+    kvmppc_copy_host_cell(fdt, "/cpus/cpu@0", "clock-frequency");
+    kvmppc_copy_host_cell(fdt, "/cpus/cpu@0", "timebase-frequency");
+}
+#endif
+
+static void kvmppc_timer_hack(void *opaque)
+{
+    qemu_service_io();
+    qemu_mod_timer(kvmppc_timer, qemu_get_clock(vm_clock) + kvmppc_timer_rate);
+}
+
+void kvmppc_init(void)
+{
+    /* XXX The only reason KVM yields control back to qemu is device IO. Since
+     * an idle guest does no IO, qemu's device model will never get a chance to
+     * run. So, until Qemu gains IO threads, we create this timer to ensure
+     * that the device model gets a chance to run. */
+    kvmppc_timer_rate = ticks_per_sec / 10;
+    kvmppc_timer = qemu_new_timer(vm_clock, &kvmppc_timer_hack, NULL);
+    qemu_mod_timer(kvmppc_timer, qemu_get_clock(vm_clock) + kvmppc_timer_rate);
+}
+