a. call callbacks resume/checkpoint/suspend while secondary vm
status is consistent with primary
b. send dirty pfn list to primary when checkpoint under colo
c. send store gfn and console gfn to xl before resuming secondary vm
Signed-off-by: Yang Hongyang <hongyang.yang@easystack.cn>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Changlong Xie <xiecl.fnst@cn.fujitsu.com>
CC: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
read_record() could be used by primary to read dirty bitmap
record sent by secondary under COLO.
When used by xc save side, we need to pass the backchannel fd
instead of ctx->fd to read_record(), so we added a fd param to
it.
No functional changes.
CC: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Yang Hongyang <hongyang.yang@easystack.cn>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Changlong Xie <xiecl.fnst@cn.fujitsu.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
In COLO mode, both VMs are running, and are considered in sync if the
visible network traffic is identical. After some time, they fall out of
sync.
At this point, the two VMs have definitely diverged. Lets call the
primary dirty bitmap set A, while the secondary dirty bitmap set B.
Sets A and B are different.
Under normal migration, the page data for set A will be sent from the
primary to the secondary.
However, the set difference B - A (the one in B but not in A, lets
call this C) is out-of-date on the secondary (with respect to the
primary) and will not be sent by the primary (to secondary), as it
was not memory dirtied by the primary. The secondary needs C page data
to reconstruct an exact copy of the primary at the checkpoint.
The secondary cannot calculate C as it doesn't know A. Instead, the
secondary must send B to the primary, at which point the primary
calculates the union of A and B (lets call this D) which is all the
pages dirtied by both the primary and the secondary, and sends all page
data covered by D.
In the general case, D is a superset of both A and B. Without the
backchannel dirty bitmap, a COLO checkpoint can't reconstruct a valid
copy of the primary.
We transfer the dirty bitmap on libxc side, so we need to introduce back
channel to libxc.
Note: it is different from the paper. We change the original design to
the current one, according to our following concerns:
1. The original design needs extra memory on Secondary host. When there's
multiple backups on one host, the memory cost is high.
2. The memory cache code will be another 1k+, it will make the review
more time consuming.
Note: this patch merely adds new parameters to various prototypes and
functions. The new parameters are used in later patch called
"libxc/restore: send dirty pfn list to primary when checkpoint under
COLO".
Signed-off-by: Yang Hongyang <hongyang.yang@easystack.cn>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Changlong Xie <xiecl.fnst@cn.fujitsu.com>
CC: Ian Campbell <Ian.Campbell@citrix.com>
CC: Ian Jackson <Ian.Jackson@eu.citrix.com>
CC: Wei Liu <wei.liu2@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
By having the "num" argument before the page and error arrays we can
potentially use a variable-length-array argument ("int pages[num]") in
the function prototype.
However VLAs are a C99 feature and we are currently targetting C89 and
later, so we don't actually make use of this here, merely arrange that
we can switch to VLAs in the future without changing the function ABI.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
And require it be used instead of direct munmap.
This will allow e.g. Valgrind hooks to help track incorrect use of
foreign mappings.
Switch all uses of xenforeignmemory_map to use
xenforeignmemory_unmap, not that foreign mappings via the libxc compat
xc_map_foreign_* interface will not take advantage of this and will
need converting.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
libxenforeignmemory will provide a stable API and ABI for mapping
foreign domain memory (subject to appropriate privileges).
The new library exposes an interface equivalent to
xc_map_foreign_memory_bulk, which all the other
xc_map_foreign_memory_* functions (which remain in libxc) are
implemented in terms of.
Upon request (via #define XC_WANT_COMPAT_MAP_FOREIGN_API) libxenctrl
will provide a compat API for the old names. This is used by qemu-xen
and qemu-trad as well as various in tree things (which required
de-dupping various #includes in some too to get the #define before the
first).
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
[ ijc -- updated MINIOS_UPSTREAM_REVISION and QEMU_TRADITIONAL_REVISION ]
We will have a consistent state when a CHECKPOINT_END record
is received. After the first CHECKPOINT_END record is received,
we will buffer all records until the next CHECKPOINT_END record
is received. So if the checkpoint() callback returns XGR_CHECKPOINT_FAILOVER,
we only can do failover if ctx->restore.buffer_all_records is
true.
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
The original implementation of populate_pfns didn't consider the same
pfn can be present multiple times in the array. The mechanism to prevent
populating the same pfn multiple times only worked if the recurring pfn
appeared in different batches.
This bug is discovered by Linux 4.1 32 bit kernel save / restore test,
which has several ptes pointing to same pfn, which results in an array
containing recurring pfn. When libxc called x86_pv_localise_page, the
original implementation would populate the same pfn more than once.
The fix is to set bit in populated bitmap as we generate list of pfns to
be populated.
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Add further instructions to the libxc "Future Extensions" section, and
provide such a section for libxl.
In addition, drop the "In experimental __func__" IPRINTF()s from the
libxc implementations.
Finally, a correction to libxl's "Not Yet Included" section which
should have been amended in c/s 7eaec00 when libxl Remus support was
introduced into the protocol.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
CC: Ian Campbell <Ian.Campbell@citrix.com>
CC: Ian Jackson <Ian.Jackson@eu.citrix.com>
CC: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
And call it when a checkpoint record is found in the libxc stream.
Some parts of this patch have been based on patches from the COLO
series.
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Yang Hongyang <yanghy@cn.fujitsu.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Campbell <Ian.Campbell@citrix.com>
CC: Ian Jackson <Ian.Jackson@eu.citrix.com>
CC: Wei Liu <wei.liu2@citrix.com>
---
v3: Named constants for the API
v2: Borrow sufficient fragments from several COLO patches to get
BROKEN_CHANNEL and checkpoint failover to function.
Split read/handle qemu info. The receiving of qemu info
should be done while we receive the migration stream,
handle_qemu will be called when the stream complete.
Otherwise, it will break Remus because read_record()
won't read qemu info and stream_complete will be called
at failover.
Signed-off-by: Yang Hongyang <yanghy@cn.fujitsu.com>
CC: Ian Campbell <Ian.Campbell@citrix.com>
CC: Ian Jackson <Ian.Jackson@eu.citrix.com>
CC: Wei Liu <wei.liu2@citrix.com>
CC: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Restore a domain from the new format. This reads and validates the domain and
image header and loads the guest memory from the PAGE_DATA records, populating
the p2m as it does so.
This provides the xc_domain_restore2() function as an alternative to the
existing xc_domain_restore().
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Campbell <Ian.Campbell@citrix.com>
Restore the x86 PV specific parts. The X86_PV_INFO, the P2M_FRAMES,
SHARED_INFO, and VCPU context records.
The localise_page callback is called from the common PAGE_DATA code to convert
PFNs in page tables to MFNs.
Page tables are pinned and the guest's P2M is updated when the stream is
complete.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Campbell <Ian.Campbell@citrix.com>
For testing purposes, the environmental variable "XG_MIGRATION_V2" allows the
two save/restore codepaths to coexist, and have a runtime switch.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Campbell <Ian.Campbell@citrix.com>
Wei Liu
Wen Congyang
Ian Campbell
Andrew Cooper
Yang Hongyang