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https://github.com/xen-project/xen.git
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Keir Fraser
92f5c346e7
The suspend event channel functions are arch independent code which xc_save uses. The changeset of 19382:a5f497f02e34 cause link error on ia64. This patch moves the functions into arch common file from x86 specific file xc_domain_save.c Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
118 lines
2.5 KiB
C
118 lines
2.5 KiB
C
/*
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* This file is subject to the terms and conditions of the GNU General
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* Public License. See the file "COPYING" in the main directory of
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* this archive for more details.
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*/
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#include "xc_private.h"
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#include "xenguest.h"
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#define SUSPEND_LOCK_FILE "/var/lib/xen/suspend_evtchn_lock.d"
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static int lock_suspend_event(void)
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{
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int fd, rc;
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mode_t mask;
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char buf[128];
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mask = umask(022);
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fd = open(SUSPEND_LOCK_FILE, O_CREAT | O_EXCL | O_RDWR, 0666);
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if (fd < 0)
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{
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ERROR("Can't create lock file for suspend event channel\n");
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return -EINVAL;
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}
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umask(mask);
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snprintf(buf, sizeof(buf), "%10ld", (long)getpid());
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rc = write_exact(fd, buf, strlen(buf));
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close(fd);
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return rc;
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}
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static int unlock_suspend_event(void)
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{
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int fd, pid, n;
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char buf[128];
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fd = open(SUSPEND_LOCK_FILE, O_RDWR);
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if (fd < 0)
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return -EINVAL;
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n = read(fd, buf, 127);
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close(fd);
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if (n > 0)
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{
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sscanf(buf, "%d", &pid);
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/* We are the owner, so we can simply delete the file */
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if (pid == getpid())
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{
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unlink(SUSPEND_LOCK_FILE);
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return 0;
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}
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}
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return -EPERM;
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}
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int xc_await_suspend(int xce, int suspend_evtchn)
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{
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int rc;
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do {
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rc = xc_evtchn_pending(xce);
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if (rc < 0) {
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ERROR("error polling suspend notification channel: %d", rc);
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return -1;
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}
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} while (rc != suspend_evtchn);
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/* harmless for one-off suspend */
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if (xc_evtchn_unmask(xce, suspend_evtchn) < 0)
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ERROR("failed to unmask suspend notification channel: %d", rc);
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return 0;
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}
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int xc_suspend_evtchn_release(int xce, int suspend_evtchn)
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{
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if (suspend_evtchn >= 0)
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xc_evtchn_unbind(xce, suspend_evtchn);
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return unlock_suspend_event();
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}
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int xc_suspend_evtchn_init(int xc, int xce, int domid, int port)
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{
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int rc, suspend_evtchn = -1;
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if (lock_suspend_event())
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return -EINVAL;
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suspend_evtchn = xc_evtchn_bind_interdomain(xce, domid, port);
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if (suspend_evtchn < 0) {
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ERROR("failed to bind suspend event channel: %d", suspend_evtchn);
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goto cleanup;
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}
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rc = xc_domain_subscribe_for_suspend(xc, domid, port);
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if (rc < 0) {
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ERROR("failed to subscribe to domain: %d", rc);
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goto cleanup;
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}
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/* event channel is pending immediately after binding */
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xc_await_suspend(xce, suspend_evtchn);
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return suspend_evtchn;
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cleanup:
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if (suspend_evtchn > 0)
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xc_suspend_evtchn_release(xce, suspend_evtchn);
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return -1;
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}
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