/* * 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 CONFIG_FDT int kvmppc_read_host_property(const char *node_path, const char *prop, void *val, size_t len) { char *path; FILE *f; int ret = 0; int pathlen; pathlen = snprintf(NULL, 0, "%s/%s/%s", PROC_DEVTREE_PATH, node_path, prop) + 1; path = g_malloc(pathlen); 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); 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_ns(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 = get_ticks_per_sec() / 10; kvmppc_timer = qemu_new_timer_ns(vm_clock, &kvmppc_timer_hack, NULL); qemu_mod_timer(kvmppc_timer, qemu_get_clock_ns(vm_clock) + kvmppc_timer_rate); }