| /* |
| * 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); |
| } |
| |