diff options
Diffstat (limited to 'target-ppc/kvm_ppc.c')
-rw-r--r-- | target-ppc/kvm_ppc.c | 110 |
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); +} + |