On Mon, 1 Nov 2010, Alexander Graf wrote:
> Xenner emulates parts of libxc, so we can not use the real xen infrastructure
> when running xen pv guests without xen.
>
> This patch adds support for guest memory mapping.
>
> Signed-off-by: Alexander Graf <ag...@suse.de>
> ---
> hw/xenner_libxc_if.c | 124
> ++++++++++++++++++++++++++++++++++++++++++++++++++
> 1 files changed, 124 insertions(+), 0 deletions(-)
> create mode 100644 hw/xenner_libxc_if.c
>
> diff --git a/hw/xenner_libxc_if.c b/hw/xenner_libxc_if.c
> new file mode 100644
> index 0000000..7ccd3c0
> --- /dev/null
> +++ b/hw/xenner_libxc_if.c
> @@ -0,0 +1,124 @@
> +/*
> + * Copyright (C) Red Hat 2007
> + * Copyright (C) Novell Inc. 2010
> + *
> + * Author(s): Gerd Hoffmann <kra...@redhat.com>
> + * Alexander Graf <ag...@suse.de>
> + *
> + * Xenner Emulation -- memory management
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; under version 2 of the License.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License along
> + * with this program; if not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#include <sys/mman.h>
> +#include <xenctrl.h>
> +
> +#include "hw.h"
> +#include "xen_interfaces.h"
> +#include "xenner.h"
> +
> +/* ------------------------------------------------------------- */
> +
> +static int _qemu_open(void)
> +{
> + return 42;
> +}
Identifiers with leading underscore are reserved in this context.
> +
> +static int qemu_close(int xc_handle)
> +{
> + return 0;
> +}
> +
> +static void *qemu_map_foreign_range(int xc_handle, uint32_t dom,
> + int size, int prot, unsigned long mfn)
> +{
> + target_phys_addr_t addr, len;
> + void *ptr;
> +
> + addr = (target_phys_addr_t)mfn << PAGE_SHIFT;
> + len = size;
> + ptr = cpu_physical_memory_map(addr, &len, 1);
> +
> + if (len != size) {
> + fprintf(stderr, "%s: couldn't allocate %d bytes\n", __FUNCTION__,
> size);
> + return NULL;
> + }
> +
> + return ptr;
> +}
> +
> +static void *qemu_map_foreign_batch(int xc_handle, uint32_t dom, int prot,
> + xen_pfn_t *arr, int num)
> +{
> + ram_addr_t offset;
> + void *ptr;
> + int i;
> + target_phys_addr_t len = num * TARGET_PAGE_SIZE;
> +
> + char filename[] = "/dev/shm/qemu-vmcore.XXXXXX";
> + int rc, fd;
> +
> + fd = mkstemp(filename);
> + if (fd == -1) {
> + fprintf(stderr, "mkstemp(%s): %s\n", filename, strerror(errno));
> + return NULL;
> + };
> + unlink(filename);
> +
> + rc = ftruncate(fd, len);
> + if (rc != 0) {
> + fprintf(stderr, "ftruncate(0x%" PRIx64 "): %s\n",
> + (uint64_t)len, strerror(errno));
> + return NULL;
> + }
> +
> + ptr = mmap(NULL, len, PROT_WRITE | PROT_READ, MAP_SHARED | MAP_POPULATE,
> + fd, 0);
mmap can fail.
> +
> + for (i = 0; i < num; i++) {
> + void *map;
> + target_phys_addr_t pagelen = TARGET_PAGE_SIZE;
> +
> + printf("arr[%d] = %#lx\n", i, cpu_get_physical_page_desc(arr[i] <<
> PAGE_SHIFT));
> +
> + /* fetch the pointer in qemu's own virtual memory */
> + offset = cpu_get_physical_page_desc(arr[i] << PAGE_SHIFT);
> + map = cpu_physical_memory_map(offset, &pagelen, 1);
> +
> + /* copy current mem to new map */
> + memcpy(ptr + (i * TARGET_PAGE_SIZE), map, TARGET_PAGE_SIZE);
> +
> + if (mmap(map, TARGET_PAGE_SIZE, prot, MAP_SHARED | MAP_FIXED,
> + fd, i * TARGET_PAGE_SIZE) == (void*)-1) {
And what happens to ptr if it didn't fail and this mmap did?
> + fprintf(stderr, "%s: mmap(#%d, mfn 0x%lx): %s\n",
> + __FUNCTION__, i, arr[i], strerror(errno));
> + return NULL;
> + }
> + }
> +
> + return ptr;
> +}
> +
> +static void *qemu_map_foreign_pages(int xc_handle, uint32_t dom, int prot,
> + const xen_pfn_t *arr, int num)
> +{
> + return qemu_map_foreign_batch(xc_handle, dom, prot, (void*)arr, num);
> +}
> +
> +struct XenIfOps xc_xenner = {
> + .interface_open = _qemu_open,
> + .interface_close = qemu_close,
> + .map_foreign_range = qemu_map_foreign_range,
> + .map_foreign_batch = qemu_map_foreign_batch,
> + .map_foreign_pages = qemu_map_foreign_pages,
> +};
>
--
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