diff options
Diffstat (limited to 'hw/xen/xen-operations.c')
| -rw-r--r-- | hw/xen/xen-operations.c | 478 |
1 files changed, 478 insertions, 0 deletions
diff --git a/hw/xen/xen-operations.c b/hw/xen/xen-operations.c new file mode 100644 index 0000000000..4b78fbf4bd --- /dev/null +++ b/hw/xen/xen-operations.c @@ -0,0 +1,478 @@ +/* + * QEMU Xen backend support: Operations for true Xen + * + * Copyright © 2022 Amazon.com, Inc. or its affiliates. All Rights Reserved. + * + * Authors: David Woodhouse <dwmw2@infradead.org> + * + * 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/osdep.h" +#include "qemu/uuid.h" +#include "qapi/error.h" + +#include "hw/xen/xen_native.h" +#include "hw/xen/xen_backend_ops.h" + +/* + * If we have new enough libxenctrl then we do not want/need these compat + * interfaces, despite what the user supplied cflags might say. They + * must be undefined before including xenctrl.h + */ +#undef XC_WANT_COMPAT_EVTCHN_API +#undef XC_WANT_COMPAT_GNTTAB_API +#undef XC_WANT_COMPAT_MAP_FOREIGN_API + +#include <xenctrl.h> + +/* + * We don't support Xen prior to 4.2.0. + */ + +/* Xen 4.2 through 4.6 */ +#if CONFIG_XEN_CTRL_INTERFACE_VERSION < 40701 + +typedef xc_evtchn xenevtchn_handle; +typedef evtchn_port_or_error_t xenevtchn_port_or_error_t; + +#define xenevtchn_open(l, f) xc_evtchn_open(l, f); +#define xenevtchn_close(h) xc_evtchn_close(h) +#define xenevtchn_fd(h) xc_evtchn_fd(h) +#define xenevtchn_pending(h) xc_evtchn_pending(h) +#define xenevtchn_notify(h, p) xc_evtchn_notify(h, p) +#define xenevtchn_bind_interdomain(h, d, p) xc_evtchn_bind_interdomain(h, d, p) +#define xenevtchn_unmask(h, p) xc_evtchn_unmask(h, p) +#define xenevtchn_unbind(h, p) xc_evtchn_unbind(h, p) + +typedef xc_gnttab xengnttab_handle; + +#define xengnttab_open(l, f) xc_gnttab_open(l, f) +#define xengnttab_close(h) xc_gnttab_close(h) +#define xengnttab_set_max_grants(h, n) xc_gnttab_set_max_grants(h, n) +#define xengnttab_map_grant_ref(h, d, r, p) xc_gnttab_map_grant_ref(h, d, r, p) +#define xengnttab_unmap(h, a, n) xc_gnttab_munmap(h, a, n) +#define xengnttab_map_grant_refs(h, c, d, r, p) \ + xc_gnttab_map_grant_refs(h, c, d, r, p) +#define xengnttab_map_domain_grant_refs(h, c, d, r, p) \ + xc_gnttab_map_domain_grant_refs(h, c, d, r, p) + +typedef xc_interface xenforeignmemory_handle; + +#else /* CONFIG_XEN_CTRL_INTERFACE_VERSION >= 40701 */ + +#include <xenevtchn.h> +#include <xengnttab.h> +#include <xenforeignmemory.h> + +#endif + +/* Xen before 4.8 */ + +static int libxengnttab_fallback_grant_copy(xengnttab_handle *xgt, + bool to_domain, uint32_t domid, + XenGrantCopySegment segs[], + unsigned int nr_segs, Error **errp) +{ + uint32_t *refs = g_new(uint32_t, nr_segs); + int prot = to_domain ? PROT_WRITE : PROT_READ; + void *map; + unsigned int i; + int rc = 0; + + for (i = 0; i < nr_segs; i++) { + XenGrantCopySegment *seg = &segs[i]; + + refs[i] = to_domain ? seg->dest.foreign.ref : + seg->source.foreign.ref; + } + map = xengnttab_map_domain_grant_refs(xgt, nr_segs, domid, refs, prot); + if (!map) { + if (errp) { + error_setg_errno(errp, errno, + "xengnttab_map_domain_grant_refs failed"); + } + rc = -errno; + goto done; + } + + for (i = 0; i < nr_segs; i++) { + XenGrantCopySegment *seg = &segs[i]; + void *page = map + (i * XEN_PAGE_SIZE); + + if (to_domain) { + memcpy(page + seg->dest.foreign.offset, seg->source.virt, + seg->len); + } else { + memcpy(seg->dest.virt, page + seg->source.foreign.offset, + seg->len); + } + } + + if (xengnttab_unmap(xgt, map, nr_segs)) { + if (errp) { + error_setg_errno(errp, errno, "xengnttab_unmap failed"); + } + rc = -errno; + } + +done: + g_free(refs); + return rc; +} + +#if CONFIG_XEN_CTRL_INTERFACE_VERSION >= 40800 + +static int libxengnttab_backend_grant_copy(xengnttab_handle *xgt, + bool to_domain, uint32_t domid, + XenGrantCopySegment *segs, + uint32_t nr_segs, Error **errp) +{ + xengnttab_grant_copy_segment_t *xengnttab_segs; + unsigned int i; + int rc; + + xengnttab_segs = g_new0(xengnttab_grant_copy_segment_t, nr_segs); + + for (i = 0; i < nr_segs; i++) { + XenGrantCopySegment *seg = &segs[i]; + xengnttab_grant_copy_segment_t *xengnttab_seg = &xengnttab_segs[i]; + + if (to_domain) { + xengnttab_seg->flags = GNTCOPY_dest_gref; + xengnttab_seg->dest.foreign.domid = domid; + xengnttab_seg->dest.foreign.ref = seg->dest.foreign.ref; + xengnttab_seg->dest.foreign.offset = seg->dest.foreign.offset; + xengnttab_seg->source.virt = seg->source.virt; + } else { + xengnttab_seg->flags = GNTCOPY_source_gref; + xengnttab_seg->source.foreign.domid = domid; + xengnttab_seg->source.foreign.ref = seg->source.foreign.ref; + xengnttab_seg->source.foreign.offset = + seg->source.foreign.offset; + xengnttab_seg->dest.virt = seg->dest.virt; + } + + xengnttab_seg->len = seg->len; + } + + if (xengnttab_grant_copy(xgt, nr_segs, xengnttab_segs)) { + if (errp) { + error_setg_errno(errp, errno, "xengnttab_grant_copy failed"); + } + rc = -errno; + goto done; + } + + rc = 0; + for (i = 0; i < nr_segs; i++) { + xengnttab_grant_copy_segment_t *xengnttab_seg = &xengnttab_segs[i]; + + if (xengnttab_seg->status != GNTST_okay) { + if (errp) { + error_setg(errp, "xengnttab_grant_copy seg[%u] failed", i); + } + rc = -EIO; + break; + } + } + +done: + g_free(xengnttab_segs); + return rc; +} +#endif + +static xenevtchn_handle *libxenevtchn_backend_open(void) +{ + return xenevtchn_open(NULL, 0); +} + +struct evtchn_backend_ops libxenevtchn_backend_ops = { + .open = libxenevtchn_backend_open, + .close = xenevtchn_close, + .bind_interdomain = xenevtchn_bind_interdomain, + .unbind = xenevtchn_unbind, + .get_fd = xenevtchn_fd, + .notify = xenevtchn_notify, + .unmask = xenevtchn_unmask, + .pending = xenevtchn_pending, +}; + +static xengnttab_handle *libxengnttab_backend_open(void) +{ + return xengnttab_open(NULL, 0); +} + +static int libxengnttab_backend_unmap(xengnttab_handle *xgt, + void *start_address, uint32_t *refs, + uint32_t count) +{ + return xengnttab_unmap(xgt, start_address, count); +} + + +static struct gnttab_backend_ops libxengnttab_backend_ops = { + .features = XEN_GNTTAB_OP_FEATURE_MAP_MULTIPLE, + .open = libxengnttab_backend_open, + .close = xengnttab_close, + .grant_copy = libxengnttab_fallback_grant_copy, + .set_max_grants = xengnttab_set_max_grants, + .map_refs = xengnttab_map_domain_grant_refs, + .unmap = libxengnttab_backend_unmap, +}; + +#if CONFIG_XEN_CTRL_INTERFACE_VERSION < 40701 + +static void *libxenforeignmem_backend_map(uint32_t dom, void *addr, int prot, + size_t pages, xfn_pfn_t *pfns, + int *errs) +{ + if (errs) { + return xc_map_foreign_bulk(xen_xc, dom, prot, pfns, errs, pages); + } else { + return xc_map_foreign_pages(xen_xc, dom, prot, pfns, pages); + } +} + +static int libxenforeignmem_backend_unmap(void *addr, size_t pages) +{ + return munmap(addr, pages * XC_PAGE_SIZE); +} + +#else /* CONFIG_XEN_CTRL_INTERFACE_VERSION >= 40701 */ + +static void *libxenforeignmem_backend_map(uint32_t dom, void *addr, int prot, + size_t pages, xen_pfn_t *pfns, + int *errs) +{ + return xenforeignmemory_map2(xen_fmem, dom, addr, prot, 0, pages, pfns, + errs); +} + +static int libxenforeignmem_backend_unmap(void *addr, size_t pages) +{ + return xenforeignmemory_unmap(xen_fmem, addr, pages); +} + +#endif + +struct foreignmem_backend_ops libxenforeignmem_backend_ops = { + .map = libxenforeignmem_backend_map, + .unmap = libxenforeignmem_backend_unmap, +}; + +struct qemu_xs_handle { + struct xs_handle *xsh; + NotifierList notifiers; +}; + +static void watch_event(void *opaque) +{ + struct qemu_xs_handle *h = opaque; + + for (;;) { + char **v = xs_check_watch(h->xsh); + + if (!v) { + break; + } + + notifier_list_notify(&h->notifiers, v); + free(v); + } +} + +static struct qemu_xs_handle *libxenstore_open(void) +{ + struct xs_handle *xsh = xs_open(0); + struct qemu_xs_handle *h = g_new0(struct qemu_xs_handle, 1); + + if (!xsh) { + return NULL; + } + + h = g_new0(struct qemu_xs_handle, 1); + h->xsh = xsh; + + notifier_list_init(&h->notifiers); + qemu_set_fd_handler(xs_fileno(h->xsh), watch_event, NULL, h); + + return h; +} + +static void libxenstore_close(struct qemu_xs_handle *h) +{ + g_assert(notifier_list_empty(&h->notifiers)); + qemu_set_fd_handler(xs_fileno(h->xsh), NULL, NULL, NULL); + xs_close(h->xsh); + g_free(h); +} + +static char *libxenstore_get_domain_path(struct qemu_xs_handle *h, + unsigned int domid) +{ + return xs_get_domain_path(h->xsh, domid); +} + +static char **libxenstore_directory(struct qemu_xs_handle *h, + xs_transaction_t t, const char *path, + unsigned int *num) +{ + return xs_directory(h->xsh, t, path, num); +} + +static void *libxenstore_read(struct qemu_xs_handle *h, xs_transaction_t t, + const char *path, unsigned int *len) +{ + return xs_read(h->xsh, t, path, len); +} + +static bool libxenstore_write(struct qemu_xs_handle *h, xs_transaction_t t, + const char *path, const void *data, + unsigned int len) +{ + return xs_write(h->xsh, t, path, data, len); +} + +static bool libxenstore_create(struct qemu_xs_handle *h, xs_transaction_t t, + unsigned int owner, unsigned int domid, + unsigned int perms, const char *path) +{ + struct xs_permissions perms_list[] = { + { + .id = owner, + .perms = XS_PERM_NONE, + }, + { + .id = domid, + .perms = perms, + }, + }; + + if (!xs_mkdir(h->xsh, t, path)) { + return false; + } + + return xs_set_permissions(h->xsh, t, path, perms_list, + ARRAY_SIZE(perms_list)); +} + +static bool libxenstore_destroy(struct qemu_xs_handle *h, xs_transaction_t t, + const char *path) +{ + return xs_rm(h->xsh, t, path); +} + +struct qemu_xs_watch { + char *path; + char *token; + xs_watch_fn fn; + void *opaque; + Notifier notifier; +}; + +static void watch_notify(Notifier *n, void *data) +{ + struct qemu_xs_watch *w = container_of(n, struct qemu_xs_watch, notifier); + const char **v = data; + + if (!strcmp(w->token, v[XS_WATCH_TOKEN])) { + w->fn(w->opaque, v[XS_WATCH_PATH]); + } +} + +static struct qemu_xs_watch *new_watch(const char *path, xs_watch_fn fn, + void *opaque) +{ + struct qemu_xs_watch *w = g_new0(struct qemu_xs_watch, 1); + QemuUUID uuid; + + qemu_uuid_generate(&uuid); + + w->token = qemu_uuid_unparse_strdup(&uuid); + w->path = g_strdup(path); + w->fn = fn; + w->opaque = opaque; + w->notifier.notify = watch_notify; + + return w; +} + +static void free_watch(struct qemu_xs_watch *w) +{ + g_free(w->token); + g_free(w->path); + + g_free(w); +} + +static struct qemu_xs_watch *libxenstore_watch(struct qemu_xs_handle *h, + const char *path, xs_watch_fn fn, + void *opaque) +{ + struct qemu_xs_watch *w = new_watch(path, fn, opaque); + + notifier_list_add(&h->notifiers, &w->notifier); + + if (!xs_watch(h->xsh, path, w->token)) { + notifier_remove(&w->notifier); + free_watch(w); + return NULL; + } + + return w; +} + +static void libxenstore_unwatch(struct qemu_xs_handle *h, + struct qemu_xs_watch *w) +{ + xs_unwatch(h->xsh, w->path, w->token); + notifier_remove(&w->notifier); + free_watch(w); +} + +static xs_transaction_t libxenstore_transaction_start(struct qemu_xs_handle *h) +{ + return xs_transaction_start(h->xsh); +} + +static bool libxenstore_transaction_end(struct qemu_xs_handle *h, + xs_transaction_t t, bool abort) +{ + return xs_transaction_end(h->xsh, t, abort); +} + +struct xenstore_backend_ops libxenstore_backend_ops = { + .open = libxenstore_open, + .close = libxenstore_close, + .get_domain_path = libxenstore_get_domain_path, + .directory = libxenstore_directory, + .read = libxenstore_read, + .write = libxenstore_write, + .create = libxenstore_create, + .destroy = libxenstore_destroy, + .watch = libxenstore_watch, + .unwatch = libxenstore_unwatch, + .transaction_start = libxenstore_transaction_start, + .transaction_end = libxenstore_transaction_end, +}; + +void setup_xen_backend_ops(void) +{ +#if CONFIG_XEN_CTRL_INTERFACE_VERSION >= 40800 + xengnttab_handle *xgt = xengnttab_open(NULL, 0); + + if (xgt) { + if (xengnttab_grant_copy(xgt, 0, NULL) == 0) { + libxengnttab_backend_ops.grant_copy = libxengnttab_backend_grant_copy; + } + xengnttab_close(xgt); + } +#endif + xen_evtchn_ops = &libxenevtchn_backend_ops; + xen_gnttab_ops = &libxengnttab_backend_ops; + xen_foreignmem_ops = &libxenforeignmem_backend_ops; + xen_xenstore_ops = &libxenstore_backend_ops; +} |