# HG changeset patch
# User Brendan Cully <brendan@xxxxxxxxx>
# Date 1240355510 25200
# Node ID b51238ea926948383500b94cd227321eb40a82dd
# Parent f5c0d3208d8ae9183391398d52c9be5969da24ec
Initiate failover if a packet is not received every 500ms.
This breaks checkpoints at lower frequencies, and should be made
configurable.
diff --git a/tools/libxc/xc_domain_restore.c b/tools/libxc/xc_domain_restore.c
--- a/tools/libxc/xc_domain_restore.c
+++ b/tools/libxc/xc_domain_restore.c
@@ -59,6 +59,51 @@
/* Address size of the guest, in bytes */
unsigned int guest_width;
+/* set when a consistent image is available */
+static int completed = 0;
+
+#define HEARTBEAT_MS 500
+
+# ifndef __MINIOS__
+static ssize_t read_exact_timed(int fd, void* buf, size_t size)
+{
+ size_t offset = 0;
+ ssize_t len;
+ struct timeval tv;
+ fd_set rfds;
+
+ while ( offset < size )
+ {
+ if (completed) {
+ /* expect a heartbeat every HEARBEAT_MS ms maximum */
+ tv.tv_sec = 0;
+ tv.tv_usec = HEARTBEAT_MS * 1000;
+
+ FD_ZERO(&rfds);
+ FD_SET(fd, &rfds);
+ len = select(fd + 1, &rfds, NULL, NULL, &tv);
+ if ( !FD_ISSET(fd, &rfds) ) {
+ fprintf(stderr, "read_exact_timed failed (select returned %zd)\n", len);
+ return -1;
+ }
+ }
+
+ len = read(fd, buf + offset, size - offset);
+ if ( (len == -1) && ((errno == EINTR) || (errno == EAGAIN)) )
+ continue;
+ if ( len <= 0 )
+ return -1;
+ offset += len;
+ }
+
+ return 0;
+}
+
+#define read_exact read_exact_timed
+
+#else
+#define read_exact_timed read_exact
+#endif
/*
** In the state file (or during transfer), all page-table pages are
** converted into a 'canonical' form where references to actual mfns
@@ -413,7 +458,9 @@
// DPRINTF("reading batch of %d pages\n", count);
if (!count) {
+ /*
DPRINTF("Last batch read\n");
+ */
return 0;
} else if (count == -1) {
DPRINTF("Entering page verify mode\n");
@@ -704,7 +751,8 @@
int xc_domain_restore(int xc_handle, int io_fd, uint32_t dom,
unsigned int store_evtchn, unsigned long *store_mfn,
unsigned int console_evtchn, unsigned long *console_mfn,
- unsigned int hvm, unsigned int pae)
+ unsigned int hvm, unsigned int pae,
+ int (*resume)(void*), void* resumedata)
{
DECLARE_DOMCTL;
int rc = 1, frc, i, j, n, m, pae_extended_cr3 = 0, ext_vcpucontext = 0;
@@ -752,7 +800,6 @@
/* Buffer for holding HVM context */
uint8_t *hvm_buf = NULL;
- int completed = 0;
pagebuf_t pagebuf;
tailbuf_t tailbuf, tmptail;
void* vcpup;
@@ -946,7 +993,9 @@
goto out;
}
+ /*
DPRINTF("Received all pages (%d races)\n", nraces);
+ */
if ( hvm )
{
@@ -1021,28 +1070,40 @@
/* Non-HVM guests only from here on */
if (!completed) {
+ int flags = 0;
+
if ( buffer_tail(&tailbuf, io_fd, max_vcpu_id, vcpumap,
ext_vcpucontext) < 0 ) {
ERROR ("error buffering image tail");
goto out;
}
+
completed = 1;
+ /* shift into nonblocking mode for the remainder */
+ if ((flags = fcntl(io_fd, F_GETFL, 0)) < 0)
+ flags = 0;
+ fcntl(io_fd, F_SETFL, flags | O_NONBLOCK);
}
-
+
+ /*
DPRINTF("Buffered checkpoint\n");
- if (pagebuf_get(&pagebuf, io_fd)) {
- ERROR("error when buffering batch, finishing\n");
- goto finish;
+ */
+ if (!resume(resumedata)) {
+ if (pagebuf_get(&pagebuf, io_fd)) {
+ ERROR("error when buffering batch, finishing\n");
+ goto finish;
+ }
+ memset(&tmptail, 0, sizeof(tmptail));
+ if ( buffer_tail(&tmptail, io_fd, max_vcpu_id, vcpumap,
+ ext_vcpucontext) < 0 ) {
+ ERROR ("error buffering image tail, finishing");
+ goto finish;
+ }
+ tailbuf_free(&tailbuf);
+ memcpy(&tailbuf, &tmptail, sizeof(tailbuf));
+
+ goto loadpages;
}
- if ( buffer_tail(&tmptail, io_fd, max_vcpu_id, vcpumap,
- ext_vcpucontext) < 0 ) {
- ERROR ("error buffering image tail, finishing");
- goto finish;
- }
- tailbuf_free(&tailbuf);
- memcpy(&tailbuf, &tmptail, sizeof(tailbuf));
-
- goto loadpages;
finish:
diff --git a/tools/libxc/xenguest.h b/tools/libxc/xenguest.h
--- a/tools/libxc/xenguest.h
+++ b/tools/libxc/xenguest.h
@@ -54,12 +54,16 @@
* @parm store_mfn returned with the mfn of the store page
* @parm hvm non-zero if this is a HVM restore
* @parm pae non-zero if this HVM domain has PAE support enabled
+ * @parm resume a function returning 1 to resume or 0 to expect
+ * another checkpoint
+ * @parm resumedata a void pointer to pass back to the resume function
* @return 0 on success, -1 on failure
*/
int xc_domain_restore(int xc_handle, int io_fd, uint32_t dom,
unsigned int store_evtchn, unsigned long *store_mfn,
unsigned int console_evtchn, unsigned long *console_mfn,
- unsigned int hvm, unsigned int pae);
+ unsigned int hvm, unsigned int pae,
+ int (*resume)(void*), void* resumedata);
/**
* This function will create a domain for a paravirtualized Linux
diff --git a/tools/python/xen/xend/XendCheckpoint.py
b/tools/python/xen/xend/XendCheckpoint.py
--- a/tools/python/xen/xend/XendCheckpoint.py
+++ b/tools/python/xen/xend/XendCheckpoint.py
@@ -318,7 +318,8 @@
restore_image.setCpuid()
- os.read(fd, 1) # Wait for source to close connection
+ #os.read(fd, 1) # Wait for source to close connection
+ # ^^ breaks failover, and I don't know why it's needed.
dominfo.completeRestore(handler.store_mfn, handler.console_mfn)
diff --git a/tools/xcutils/xc_restore.c b/tools/xcutils/xc_restore.c
--- a/tools/xcutils/xc_restore.c
+++ b/tools/xcutils/xc_restore.c
@@ -11,10 +11,59 @@
#include <stdlib.h>
#include <stdint.h>
#include <stdio.h>
+#include <string.h>
+#include <sys/select.h>
#include <xenctrl.h>
#include <xenguest.h>
+typedef struct {
+ int fd;
+} resume_t;
+
+static int resume(void* resumedata)
+{
+ fd_set rfds;
+ struct timeval tv;
+// char buf[64];
+ int rc;
+ resume_t* rd = resumedata;
+
+ FD_ZERO(&rfds);
+
+ do {
+ /* expect a heartbeat every 500ms maximum */
+ tv.tv_sec = 0;
+ tv.tv_usec = 500000;
+
+ FD_SET(rd->fd, &rfds);
+ rc = select(rd->fd + 1, &rfds, NULL, NULL, &tv);
+ if (!FD_ISSET(rd->fd, &rfds)) {
+ fprintf(stderr, "resume: heartbeat failed (select returned %d)\n", rc);
+ return -1;
+ }
+#if 0
+ rc = read(rd->fd, buf, 4);
+ if (rc == 4 && !strncmp(buf, "done", 4)) {
+ /*
+ fprintf(stderr, "resume: received 'done'\n");
+ */
+ return 0;
+ }
+ if (rc < 4 || strncmp(buf, "wait", 4)) {
+ if (rc >= 0)
+ buf[rc] = '\0';
+ else
+ buf[0] = '\0';
+ fprintf(stderr, "bad heartbeat response: %d, %s\n", rc, buf);
+ return -1;
+ }
+#endif
+ } while(0);
+
+ return 0;
+}
+
int
main(int argc, char **argv)
{
@@ -22,6 +71,7 @@
unsigned int hvm, pae, apic;
int xc_fd, io_fd, ret;
unsigned long store_mfn, console_mfn;
+ resume_t rdata;
if ( argc != 8 )
errx(1, "usage: %s iofd domid store_evtchn "
@@ -39,8 +89,11 @@
pae = atoi(argv[6]);
apic = atoi(argv[7]);
+ rdata.fd = io_fd;
+
ret = xc_domain_restore(xc_fd, io_fd, domid, store_evtchn, &store_mfn,
- console_evtchn, &console_mfn, hvm, pae);
+ console_evtchn, &console_mfn, hvm, pae,
+ resume, &rdata);
if ( ret == 0 )
{
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