svn commit: r275675 - in head/sys: conf dev/xen/grant_table xen
Roger Pau Monné
royger at FreeBSD.org
Wed Dec 10 11:21:53 UTC 2014
Author: royger
Date: Wed Dec 10 11:21:52 2014
New Revision: 275675
URL: https://svnweb.freebsd.org/changeset/base/275675
Log:
xen: move grant table code
Mave the grant table code into the dev/xen folder in preparation for turning
it into a device using the newbus interface. This is just code motion, no
functional changes.
Sponsored by: Citrix Systems R&D
Added:
head/sys/dev/xen/grant_table/
head/sys/dev/xen/grant_table/grant_table.c
- copied unchanged from r275647, head/sys/xen/gnttab.c
Deleted:
head/sys/xen/gnttab.c
Modified:
head/sys/conf/files
Modified: head/sys/conf/files
==============================================================================
--- head/sys/conf/files Wed Dec 10 08:53:41 2014 (r275674)
+++ head/sys/conf/files Wed Dec 10 11:21:52 2014 (r275675)
@@ -2651,6 +2651,7 @@ dev/xen/blkback/blkback.c optional xen |
dev/xen/console/console.c optional xen | xenhvm
dev/xen/console/xencons_ring.c optional xen | xenhvm
dev/xen/control/control.c optional xen | xenhvm
+dev/xen/grant_table/grant_table.c optional xen | xenhvm
dev/xen/netback/netback.c optional xen | xenhvm
dev/xen/netfront/netfront.c optional xen | xenhvm
dev/xen/xenpci/xenpci.c optional xenpci
@@ -4000,7 +4001,6 @@ vm/vm_reserv.c standard
vm/vm_unix.c standard
vm/vm_zeroidle.c standard
vm/vnode_pager.c standard
-xen/gnttab.c optional xen | xenhvm
xen/features.c optional xen | xenhvm
xen/xenbus/xenbus_if.m optional xen | xenhvm
xen/xenbus/xenbus.c optional xen | xenhvm
Copied: head/sys/dev/xen/grant_table/grant_table.c (from r275647, head/sys/xen/gnttab.c)
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ head/sys/dev/xen/grant_table/grant_table.c Wed Dec 10 11:21:52 2014 (r275675, copy of r275647, head/sys/xen/gnttab.c)
@@ -0,0 +1,720 @@
+/******************************************************************************
+ * gnttab.c
+ *
+ * Two sets of functionality:
+ * 1. Granting foreign access to our memory reservation.
+ * 2. Accessing others' memory reservations via grant references.
+ * (i.e., mechanisms for both sender and recipient of grant references)
+ *
+ * Copyright (c) 2005, Christopher Clark
+ * Copyright (c) 2004, K A Fraser
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include "opt_pmap.h"
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/bus.h>
+#include <sys/conf.h>
+#include <sys/module.h>
+#include <sys/kernel.h>
+#include <sys/lock.h>
+#include <sys/malloc.h>
+#include <sys/mman.h>
+#include <sys/limits.h>
+#include <sys/rman.h>
+#include <machine/resource.h>
+
+#include <xen/xen-os.h>
+#include <xen/hypervisor.h>
+#include <machine/xen/synch_bitops.h>
+
+#include <xen/hypervisor.h>
+#include <xen/gnttab.h>
+
+#include <vm/vm.h>
+#include <vm/vm_kern.h>
+#include <vm/vm_extern.h>
+#include <vm/pmap.h>
+
+#define cmpxchg(a, b, c) atomic_cmpset_int((volatile u_int *)(a),(b),(c))
+
+/* External tools reserve first few grant table entries. */
+#define NR_RESERVED_ENTRIES 8
+#define GREFS_PER_GRANT_FRAME (PAGE_SIZE / sizeof(grant_entry_t))
+
+static grant_ref_t **gnttab_list;
+static unsigned int nr_grant_frames;
+static unsigned int boot_max_nr_grant_frames;
+static int gnttab_free_count;
+static grant_ref_t gnttab_free_head;
+static struct mtx gnttab_list_lock;
+
+#ifdef XENHVM
+/*
+ * Resource representing allocated physical address space
+ * for the grant table metainfo
+ */
+static struct resource *gnttab_pseudo_phys_res;
+
+/* Resource id for allocated physical address space. */
+static int gnttab_pseudo_phys_res_id;
+#endif
+
+static grant_entry_t *shared;
+
+static struct gnttab_free_callback *gnttab_free_callback_list = NULL;
+
+static int gnttab_expand(unsigned int req_entries);
+
+#define RPP (PAGE_SIZE / sizeof(grant_ref_t))
+#define gnttab_entry(entry) (gnttab_list[(entry) / RPP][(entry) % RPP])
+
+static int
+get_free_entries(int count, int *entries)
+{
+ int ref, error;
+ grant_ref_t head;
+
+ mtx_lock(&gnttab_list_lock);
+ if ((gnttab_free_count < count) &&
+ ((error = gnttab_expand(count - gnttab_free_count)) != 0)) {
+ mtx_unlock(&gnttab_list_lock);
+ return (error);
+ }
+ ref = head = gnttab_free_head;
+ gnttab_free_count -= count;
+ while (count-- > 1)
+ head = gnttab_entry(head);
+ gnttab_free_head = gnttab_entry(head);
+ gnttab_entry(head) = GNTTAB_LIST_END;
+ mtx_unlock(&gnttab_list_lock);
+
+ *entries = ref;
+ return (0);
+}
+
+static void
+do_free_callbacks(void)
+{
+ struct gnttab_free_callback *callback, *next;
+
+ callback = gnttab_free_callback_list;
+ gnttab_free_callback_list = NULL;
+
+ while (callback != NULL) {
+ next = callback->next;
+ if (gnttab_free_count >= callback->count) {
+ callback->next = NULL;
+ callback->fn(callback->arg);
+ } else {
+ callback->next = gnttab_free_callback_list;
+ gnttab_free_callback_list = callback;
+ }
+ callback = next;
+ }
+}
+
+static inline void
+check_free_callbacks(void)
+{
+ if (__predict_false(gnttab_free_callback_list != NULL))
+ do_free_callbacks();
+}
+
+static void
+put_free_entry(grant_ref_t ref)
+{
+
+ mtx_lock(&gnttab_list_lock);
+ gnttab_entry(ref) = gnttab_free_head;
+ gnttab_free_head = ref;
+ gnttab_free_count++;
+ check_free_callbacks();
+ mtx_unlock(&gnttab_list_lock);
+}
+
+/*
+ * Public grant-issuing interface functions
+ */
+
+int
+gnttab_grant_foreign_access(domid_t domid, unsigned long frame, int readonly,
+ grant_ref_t *result)
+{
+ int error, ref;
+
+ error = get_free_entries(1, &ref);
+
+ if (__predict_false(error))
+ return (error);
+
+ shared[ref].frame = frame;
+ shared[ref].domid = domid;
+ wmb();
+ shared[ref].flags = GTF_permit_access | (readonly ? GTF_readonly : 0);
+
+ if (result)
+ *result = ref;
+
+ return (0);
+}
+
+void
+gnttab_grant_foreign_access_ref(grant_ref_t ref, domid_t domid,
+ unsigned long frame, int readonly)
+{
+
+ shared[ref].frame = frame;
+ shared[ref].domid = domid;
+ wmb();
+ shared[ref].flags = GTF_permit_access | (readonly ? GTF_readonly : 0);
+}
+
+int
+gnttab_query_foreign_access(grant_ref_t ref)
+{
+ uint16_t nflags;
+
+ nflags = shared[ref].flags;
+
+ return (nflags & (GTF_reading|GTF_writing));
+}
+
+int
+gnttab_end_foreign_access_ref(grant_ref_t ref)
+{
+ uint16_t flags, nflags;
+
+ nflags = shared[ref].flags;
+ do {
+ if ( (flags = nflags) & (GTF_reading|GTF_writing) ) {
+ printf("%s: WARNING: g.e. still in use!\n", __func__);
+ return (0);
+ }
+ } while ((nflags = synch_cmpxchg(&shared[ref].flags, flags, 0)) !=
+ flags);
+
+ return (1);
+}
+
+void
+gnttab_end_foreign_access(grant_ref_t ref, void *page)
+{
+ if (gnttab_end_foreign_access_ref(ref)) {
+ put_free_entry(ref);
+ if (page != NULL) {
+ free(page, M_DEVBUF);
+ }
+ }
+ else {
+ /* XXX This needs to be fixed so that the ref and page are
+ placed on a list to be freed up later. */
+ printf("%s: WARNING: leaking g.e. and page still in use!\n",
+ __func__);
+ }
+}
+
+void
+gnttab_end_foreign_access_references(u_int count, grant_ref_t *refs)
+{
+ grant_ref_t *last_ref;
+ grant_ref_t head;
+ grant_ref_t tail;
+
+ head = GNTTAB_LIST_END;
+ tail = *refs;
+ last_ref = refs + count;
+ while (refs != last_ref) {
+
+ if (gnttab_end_foreign_access_ref(*refs)) {
+ gnttab_entry(*refs) = head;
+ head = *refs;
+ } else {
+ /*
+ * XXX This needs to be fixed so that the ref
+ * is placed on a list to be freed up later.
+ */
+ printf("%s: WARNING: leaking g.e. still in use!\n",
+ __func__);
+ count--;
+ }
+ refs++;
+ }
+
+ if (count != 0) {
+ mtx_lock(&gnttab_list_lock);
+ gnttab_free_count += count;
+ gnttab_entry(tail) = gnttab_free_head;
+ gnttab_free_head = head;
+ mtx_unlock(&gnttab_list_lock);
+ }
+}
+
+int
+gnttab_grant_foreign_transfer(domid_t domid, unsigned long pfn,
+ grant_ref_t *result)
+{
+ int error, ref;
+
+ error = get_free_entries(1, &ref);
+ if (__predict_false(error))
+ return (error);
+
+ gnttab_grant_foreign_transfer_ref(ref, domid, pfn);
+
+ *result = ref;
+ return (0);
+}
+
+void
+gnttab_grant_foreign_transfer_ref(grant_ref_t ref, domid_t domid,
+ unsigned long pfn)
+{
+ shared[ref].frame = pfn;
+ shared[ref].domid = domid;
+ wmb();
+ shared[ref].flags = GTF_accept_transfer;
+}
+
+unsigned long
+gnttab_end_foreign_transfer_ref(grant_ref_t ref)
+{
+ unsigned long frame;
+ uint16_t flags;
+
+ /*
+ * If a transfer is not even yet started, try to reclaim the grant
+ * reference and return failure (== 0).
+ */
+ while (!((flags = shared[ref].flags) & GTF_transfer_committed)) {
+ if ( synch_cmpxchg(&shared[ref].flags, flags, 0) == flags )
+ return (0);
+ cpu_relax();
+ }
+
+ /* If a transfer is in progress then wait until it is completed. */
+ while (!(flags & GTF_transfer_completed)) {
+ flags = shared[ref].flags;
+ cpu_relax();
+ }
+
+ /* Read the frame number /after/ reading completion status. */
+ rmb();
+ frame = shared[ref].frame;
+ KASSERT(frame != 0, ("grant table inconsistent"));
+
+ return (frame);
+}
+
+unsigned long
+gnttab_end_foreign_transfer(grant_ref_t ref)
+{
+ unsigned long frame = gnttab_end_foreign_transfer_ref(ref);
+
+ put_free_entry(ref);
+ return (frame);
+}
+
+void
+gnttab_free_grant_reference(grant_ref_t ref)
+{
+
+ put_free_entry(ref);
+}
+
+void
+gnttab_free_grant_references(grant_ref_t head)
+{
+ grant_ref_t ref;
+ int count = 1;
+
+ if (head == GNTTAB_LIST_END)
+ return;
+
+ ref = head;
+ while (gnttab_entry(ref) != GNTTAB_LIST_END) {
+ ref = gnttab_entry(ref);
+ count++;
+ }
+ mtx_lock(&gnttab_list_lock);
+ gnttab_entry(ref) = gnttab_free_head;
+ gnttab_free_head = head;
+ gnttab_free_count += count;
+ check_free_callbacks();
+ mtx_unlock(&gnttab_list_lock);
+}
+
+int
+gnttab_alloc_grant_references(uint16_t count, grant_ref_t *head)
+{
+ int ref, error;
+
+ error = get_free_entries(count, &ref);
+ if (__predict_false(error))
+ return (error);
+
+ *head = ref;
+ return (0);
+}
+
+int
+gnttab_empty_grant_references(const grant_ref_t *private_head)
+{
+
+ return (*private_head == GNTTAB_LIST_END);
+}
+
+int
+gnttab_claim_grant_reference(grant_ref_t *private_head)
+{
+ grant_ref_t g = *private_head;
+
+ if (__predict_false(g == GNTTAB_LIST_END))
+ return (g);
+ *private_head = gnttab_entry(g);
+ return (g);
+}
+
+void
+gnttab_release_grant_reference(grant_ref_t *private_head, grant_ref_t release)
+{
+
+ gnttab_entry(release) = *private_head;
+ *private_head = release;
+}
+
+void
+gnttab_request_free_callback(struct gnttab_free_callback *callback,
+ void (*fn)(void *), void *arg, uint16_t count)
+{
+
+ mtx_lock(&gnttab_list_lock);
+ if (callback->next)
+ goto out;
+ callback->fn = fn;
+ callback->arg = arg;
+ callback->count = count;
+ callback->next = gnttab_free_callback_list;
+ gnttab_free_callback_list = callback;
+ check_free_callbacks();
+ out:
+ mtx_unlock(&gnttab_list_lock);
+
+}
+
+void
+gnttab_cancel_free_callback(struct gnttab_free_callback *callback)
+{
+ struct gnttab_free_callback **pcb;
+
+ mtx_lock(&gnttab_list_lock);
+ for (pcb = &gnttab_free_callback_list; *pcb; pcb = &(*pcb)->next) {
+ if (*pcb == callback) {
+ *pcb = callback->next;
+ break;
+ }
+ }
+ mtx_unlock(&gnttab_list_lock);
+}
+
+
+static int
+grow_gnttab_list(unsigned int more_frames)
+{
+ unsigned int new_nr_grant_frames, extra_entries, i;
+
+ new_nr_grant_frames = nr_grant_frames + more_frames;
+ extra_entries = more_frames * GREFS_PER_GRANT_FRAME;
+
+ for (i = nr_grant_frames; i < new_nr_grant_frames; i++)
+ {
+ gnttab_list[i] = (grant_ref_t *)
+ malloc(PAGE_SIZE, M_DEVBUF, M_NOWAIT);
+
+ if (!gnttab_list[i])
+ goto grow_nomem;
+ }
+
+ for (i = GREFS_PER_GRANT_FRAME * nr_grant_frames;
+ i < GREFS_PER_GRANT_FRAME * new_nr_grant_frames - 1; i++)
+ gnttab_entry(i) = i + 1;
+
+ gnttab_entry(i) = gnttab_free_head;
+ gnttab_free_head = GREFS_PER_GRANT_FRAME * nr_grant_frames;
+ gnttab_free_count += extra_entries;
+
+ nr_grant_frames = new_nr_grant_frames;
+
+ check_free_callbacks();
+
+ return (0);
+
+grow_nomem:
+ for ( ; i >= nr_grant_frames; i--)
+ free(gnttab_list[i], M_DEVBUF);
+ return (ENOMEM);
+}
+
+static unsigned int
+__max_nr_grant_frames(void)
+{
+ struct gnttab_query_size query;
+ int rc;
+
+ query.dom = DOMID_SELF;
+
+ rc = HYPERVISOR_grant_table_op(GNTTABOP_query_size, &query, 1);
+ if ((rc < 0) || (query.status != GNTST_okay))
+ return (4); /* Legacy max supported number of frames */
+
+ return (query.max_nr_frames);
+}
+
+static inline
+unsigned int max_nr_grant_frames(void)
+{
+ unsigned int xen_max = __max_nr_grant_frames();
+
+ if (xen_max > boot_max_nr_grant_frames)
+ return (boot_max_nr_grant_frames);
+ return (xen_max);
+}
+
+#ifdef notyet
+/*
+ * XXX needed for backend support
+ *
+ */
+static int
+map_pte_fn(pte_t *pte, struct page *pmd_page,
+ unsigned long addr, void *data)
+{
+ unsigned long **frames = (unsigned long **)data;
+
+ set_pte_at(&init_mm, addr, pte, pfn_pte_ma((*frames)[0], PAGE_KERNEL));
+ (*frames)++;
+ return 0;
+}
+
+static int
+unmap_pte_fn(pte_t *pte, struct page *pmd_page,
+ unsigned long addr, void *data)
+{
+
+ set_pte_at(&init_mm, addr, pte, __pte(0));
+ return 0;
+}
+#endif
+
+#ifndef XENHVM
+
+static int
+gnttab_map(unsigned int start_idx, unsigned int end_idx)
+{
+ struct gnttab_setup_table setup;
+ u_long *frames;
+
+ unsigned int nr_gframes = end_idx + 1;
+ int i, rc;
+
+ frames = malloc(nr_gframes * sizeof(unsigned long), M_DEVBUF, M_NOWAIT);
+ if (!frames)
+ return (ENOMEM);
+
+ setup.dom = DOMID_SELF;
+ setup.nr_frames = nr_gframes;
+ set_xen_guest_handle(setup.frame_list, frames);
+
+ rc = HYPERVISOR_grant_table_op(GNTTABOP_setup_table, &setup, 1);
+ if (rc == -ENOSYS) {
+ free(frames, M_DEVBUF);
+ return (ENOSYS);
+ }
+ KASSERT(!(rc || setup.status),
+ ("unexpected result from grant_table_op"));
+
+ if (shared == NULL) {
+ vm_offset_t area;
+
+ area = kva_alloc(PAGE_SIZE * max_nr_grant_frames());
+ KASSERT(area, ("can't allocate VM space for grant table"));
+ shared = (grant_entry_t *)area;
+ }
+
+ for (i = 0; i < nr_gframes; i++)
+ PT_SET_MA(((caddr_t)shared) + i*PAGE_SIZE,
+ ((vm_paddr_t)frames[i]) << PAGE_SHIFT | PG_RW | PG_V);
+
+ free(frames, M_DEVBUF);
+
+ return (0);
+}
+
+int
+gnttab_resume(device_t dev)
+{
+
+ if (max_nr_grant_frames() < nr_grant_frames)
+ return (ENOSYS);
+ return (gnttab_map(0, nr_grant_frames - 1));
+}
+
+int
+gnttab_suspend(void)
+{
+ int i;
+
+ for (i = 0; i < nr_grant_frames; i++)
+ pmap_kremove((vm_offset_t) shared + i * PAGE_SIZE);
+
+ return (0);
+}
+
+#else /* XENHVM */
+
+static vm_paddr_t resume_frames;
+
+static int
+gnttab_map(unsigned int start_idx, unsigned int end_idx)
+{
+ struct xen_add_to_physmap xatp;
+ unsigned int i = end_idx;
+
+ /*
+ * Loop backwards, so that the first hypercall has the largest index,
+ * ensuring that the table will grow only once.
+ */
+ do {
+ xatp.domid = DOMID_SELF;
+ xatp.idx = i;
+ xatp.space = XENMAPSPACE_grant_table;
+ xatp.gpfn = (resume_frames >> PAGE_SHIFT) + i;
+ if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
+ panic("HYPERVISOR_memory_op failed to map gnttab");
+ } while (i-- > start_idx);
+
+ if (shared == NULL) {
+ vm_offset_t area;
+
+ area = kva_alloc(PAGE_SIZE * max_nr_grant_frames());
+ KASSERT(area, ("can't allocate VM space for grant table"));
+ shared = (grant_entry_t *)area;
+ }
+
+ for (i = start_idx; i <= end_idx; i++) {
+ pmap_kenter((vm_offset_t) shared + i * PAGE_SIZE,
+ resume_frames + i * PAGE_SIZE);
+ }
+
+ return (0);
+}
+
+int
+gnttab_resume(device_t dev)
+{
+ unsigned int max_nr_gframes, nr_gframes;
+
+ nr_gframes = nr_grant_frames;
+ max_nr_gframes = max_nr_grant_frames();
+ if (max_nr_gframes < nr_gframes)
+ return (ENOSYS);
+
+ if (!resume_frames) {
+ KASSERT(dev != NULL,
+ ("No resume frames and no device provided"));
+
+ gnttab_pseudo_phys_res = bus_alloc_resource(dev,
+ SYS_RES_MEMORY, &gnttab_pseudo_phys_res_id, 0, ~0,
+ PAGE_SIZE * max_nr_gframes, RF_ACTIVE);
+ if (gnttab_pseudo_phys_res == NULL)
+ panic("Unable to reserve physical memory for gnttab");
+ resume_frames = rman_get_start(gnttab_pseudo_phys_res);
+ }
+
+ return (gnttab_map(0, nr_gframes - 1));
+}
+
+#endif
+
+static int
+gnttab_expand(unsigned int req_entries)
+{
+ int error;
+ unsigned int cur, extra;
+
+ cur = nr_grant_frames;
+ extra = ((req_entries + (GREFS_PER_GRANT_FRAME-1)) /
+ GREFS_PER_GRANT_FRAME);
+ if (cur + extra > max_nr_grant_frames())
+ return (ENOSPC);
+
+ error = gnttab_map(cur, cur + extra - 1);
+ if (!error)
+ error = grow_gnttab_list(extra);
+
+ return (error);
+}
+
+int
+gnttab_init(device_t dev)
+{
+ int i;
+ unsigned int max_nr_glist_frames;
+ unsigned int nr_init_grefs;
+
+ if (!is_running_on_xen())
+ return (ENODEV);
+
+ nr_grant_frames = 1;
+ boot_max_nr_grant_frames = __max_nr_grant_frames();
+
+ /* Determine the maximum number of frames required for the
+ * grant reference free list on the current hypervisor.
+ */
+ max_nr_glist_frames = (boot_max_nr_grant_frames *
+ GREFS_PER_GRANT_FRAME /
+ (PAGE_SIZE / sizeof(grant_ref_t)));
+
+ gnttab_list = malloc(max_nr_glist_frames * sizeof(grant_ref_t *),
+ M_DEVBUF, M_NOWAIT);
+
+ if (gnttab_list == NULL)
+ return (ENOMEM);
+
+ for (i = 0; i < nr_grant_frames; i++) {
+ gnttab_list[i] = (grant_ref_t *)
+ malloc(PAGE_SIZE, M_DEVBUF, M_NOWAIT);
+ if (gnttab_list[i] == NULL)
+ goto ini_nomem;
+ }
+
+ if (gnttab_resume(dev))
+ return (ENODEV);
+
+ nr_init_grefs = nr_grant_frames * GREFS_PER_GRANT_FRAME;
+
+ for (i = NR_RESERVED_ENTRIES; i < nr_init_grefs - 1; i++)
+ gnttab_entry(i) = i + 1;
+
+ gnttab_entry(nr_init_grefs - 1) = GNTTAB_LIST_END;
+ gnttab_free_count = nr_init_grefs - NR_RESERVED_ENTRIES;
+ gnttab_free_head = NR_RESERVED_ENTRIES;
+
+ if (bootverbose)
+ printf("Grant table initialized\n");
+
+ return (0);
+
+ini_nomem:
+ for (i--; i >= 0; i--)
+ free(gnttab_list[i], M_DEVBUF);
+ free(gnttab_list, M_DEVBUF);
+ return (ENOMEM);
+
+}
+
+MTX_SYSINIT(gnttab, &gnttab_list_lock, "GNTTAB LOCK", MTX_DEF);
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