From 7051d5c872e3e708b2d4b2088215d6ab1b33de1b Mon Sep 17 00:00:00 2001 From: Andrew Cooper Date: Thu, 10 Oct 2013 12:23:10 +0100 Subject: tools/migrate: Fix regression when migrating from older version of Xen Commit 00a4b65f8534c9e6521eab2e6ce796ae36037774 Sep 7 2010 "libxc: provide notification of final checkpoint to restore end" broke migration from any version of Xen using tools from prior to that commit Older tools have no idea about an XC_SAVE_ID_LAST_CHECKPOINT, causing newer tools xc_domain_restore() to start reading the qemu save record, as ctx->last_checkpoint is 0. The failure looks like: xc: error: Max batch size exceeded (1970103633). Giving up. where 1970103633 = 0x756d6551 = *(uint32_t*)"Qemu" With this fix in place, the behaviour for normal migrations is reverted to how it was before the regression; the migration is considered non-checkpointed right from the start. A XC_SAVE_ID_LAST_CHECKPOINT chunk seen in the migration stream is a nop. For checkpointed migrations the behaviour is unchanged. Signed-off-by: Andrew Cooper Acked-by: Ian Campbell CC: Ian Jackson Acked-by: Shriram Rajagopalan (Remus bits) --- tools/libxc/xc_domain_restore.c | 3 ++- tools/libxc/xc_nomigrate.c | 2 +- tools/libxc/xenguest.h | 3 ++- 3 files changed, 5 insertions(+), 3 deletions(-) (limited to 'tools/libxc') diff --git a/tools/libxc/xc_domain_restore.c b/tools/libxc/xc_domain_restore.c index 939a76b47c..ecaf25deb4 100644 --- a/tools/libxc/xc_domain_restore.c +++ b/tools/libxc/xc_domain_restore.c @@ -1402,7 +1402,7 @@ int xc_domain_restore(xc_interface *xch, int io_fd, uint32_t dom, domid_t store_domid, unsigned int console_evtchn, unsigned long *console_mfn, domid_t console_domid, unsigned int hvm, unsigned int pae, int superpages, - int no_incr_generationid, + int no_incr_generationid, int checkpointed_stream, unsigned long *vm_generationid_addr, struct restore_callbacks *callbacks) { @@ -1474,6 +1474,7 @@ int xc_domain_restore(xc_interface *xch, int io_fd, uint32_t dom, ctx->superpages = superpages; ctx->hvm = hvm; + ctx->last_checkpoint = !checkpointed_stream; ctxt = xc_hypercall_buffer_alloc(xch, ctxt, sizeof(*ctxt)); diff --git a/tools/libxc/xc_nomigrate.c b/tools/libxc/xc_nomigrate.c index 73e7566639..fb6d53e522 100644 --- a/tools/libxc/xc_nomigrate.c +++ b/tools/libxc/xc_nomigrate.c @@ -35,7 +35,7 @@ int xc_domain_restore(xc_interface *xch, int io_fd, uint32_t dom, domid_t store_domid, unsigned int console_evtchn, unsigned long *console_mfn, domid_t console_domid, unsigned int hvm, unsigned int pae, int superpages, - int no_incr_generationid, + int no_incr_generationid, int checkpointed_stream, unsigned long *vm_generationid_addr, struct restore_callbacks *callbacks) { diff --git a/tools/libxc/xenguest.h b/tools/libxc/xenguest.h index c12091f52b..a0e30e1c98 100644 --- a/tools/libxc/xenguest.h +++ b/tools/libxc/xenguest.h @@ -114,6 +114,7 @@ struct restore_callbacks { * @parm pae non-zero if this HVM domain has PAE support enabled * @parm superpages non-zero to allocate guest memory with superpages * @parm no_incr_generationid non-zero if generation id is NOT to be incremented + * @parm checkpointed_stream non-zero if the far end of the stream is using checkpointing * @parm vm_generationid_addr returned with the address of the generation id buffer * @parm callbacks non-NULL to receive a callback to restore toolstack * specific data @@ -124,7 +125,7 @@ int xc_domain_restore(xc_interface *xch, int io_fd, uint32_t dom, domid_t store_domid, unsigned int console_evtchn, unsigned long *console_mfn, domid_t console_domid, unsigned int hvm, unsigned int pae, int superpages, - int no_incr_generationid, + int no_incr_generationid, int checkpointed_stream, unsigned long *vm_generationid_addr, struct restore_callbacks *callbacks); /** -- cgit v1.2.3