Before this patch:
1. Suspend
a. PVHVM and PV: we use the same way to suspend the guest (send the
suspend request to the guest). If the guest doesn't support evtchn, the
xenstore variant will be used, suspending the guest via XenBus control
node.
b. Pure HVM: we call xc_domain_shutdown(..., SHUTDOWN_suspend) to suspend
the guest.
2. Resume:
a. Fast path (fast=1)
Do not change the guest state. We call libxl__domain_resume(.., 1) which
calls xc_domain_resume(..., 1 /* fast=1*/) to resume the guest.
PV: Modify the return code to 1, and than call the domctl:
XEN_DOMCTL_resumedomain
PVHVM: same with PV
Pure HVM: Do nothing in modify_returncode, and than call the domctl:
XEN_DOMCTL_resumedomain
b. Slow path (fast=0)
Used when the guest's state have been changed. Will call
libxl__domain_resume(..., 0) to resume the guest.
PV: Update start info, and reset all secondary CPU states. Than call
the domctl: XEN_DOMCTL_resumedomain
PVHVM: Can not be resumed. You will get the following error message:
"Cannot resume uncooperative HVM guests"
Pure HVM: Same with PVHVM
After this patch:
1. Suspend
Unchanged.
2. Resume
a. Fast path
Unchanged.
b. Slow path
PV: Unchanged.
PVHVM: Call XEN_DOMCTL_resumedomain to resume the guest. Because we
don't modify the return code, PV drivers will disconnect
and reconnect.
The guest ends up doing the XENMAPSPACE_shared_info
XENMEM_add_to_physmap hypercall and resetting all of its CPU
states to point to the shared_info (except the ones past 32).
That is the Linux kernel does that - regardless whether the
SCHEDOP_shutdown:SHUTDOWN_suspend returns 1 or not.
Pure HVM: Call XEN_DOMCTL_resumedomain to resume the guest.
Under COLO, we will update the guest's state (modify memory, CPU registers,
device state etc). In this case, we cannot use the fast path to resume it.
Keep the return code 0, and use the slow path to resume the guest.
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Yang Hongyang <hongyang.yang@easystack.cn>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
[ wei: reformat commit message a bit ]
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Add cmdline switches to 'xl migrate-receive' command to specify
a domain-specific hotplug script to setup COLO proxy.
Add a new config var 'colo.default.agentscript' to xl.conf, that
allows the user to override the default global script used to
setup COLO proxy.
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>
Use qemu block replication as our block replication solution.
Note that guest must be paused before starting COLO, otherwise,
the disk won't be consistent between primary and secondary.
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Yang Hongyang <hongyang.yang@easystack.cn>
Signed-off-by: Changlong Xie <xiecl.fnst@cn.fujitsu.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
We will use qemu block replication, and qemu provides some qmp commands
to prepare replication, start replication, get replication error, and
stop replication. Introduce new API to execute these qmp commands.
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Changlong Xie <xiecl.fnst@cn.fujitsu.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Add a new option -c to the command 'xl remus'. If you want
to use COLO HA instead of Remus HA, please use -c option.
Update man pages to reflect the addition of a new option to
'xl remus' command.
Also add a new option --colo to the internal command 'xl migrate-receive'.
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Yang Hongyang <hongyang.yang@easystack.cn>
Signed-off-by: Changlong Xie <xiecl.fnst@cn.fujitsu.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
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>
We will do the following things again and again:
1. Suspend primary vm
a. Suspend primary vm
b. do postsuspend
c. Read CHECKPOINT_SVM_SUSPENDED sent by secondary
2. Checkpoint
a. Write emulator xenstore data and emulator context
b. Write checkpoint end record
3. Resume primary vm
a. Read CHECKPOINT_SVM_READY from slave
b. Do presume
c. Resume primary vm
d. Read CHECKPOINT_SVM_RESUMED from slave
4. Wait a new checkpoint
a. Wait a new checkpoint(not implemented)
b. Send CHECKPOINT_NEW to slave
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Yang Hongyang <hongyang.yang@easystack.cn>
Signed-off-by: Changlong Xie <xiecl.fnst@cn.fujitsu.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Secondary vm is running in colo mode. So we will do
the following things again and again:
1. Resume secondary vm
a. Send CHECKPOINT_SVM_READY to master.
b. If it is not the first resume, call libxl__checkpoint_devices_preresume().
c. If it is the first resume(resume right after live migration),
- call libxl__xc_domain_restore_done() to build the secondary vm.
- enable secondary vm's logdirty.
- call libxl__domain_resume() to resume secondary vm.
- call libxl__checkpoint_devices_setup() to setup checkpoint devices.
d. Send CHECKPOINT_SVM_RESUMED to master.
2. Wait a new checkpoint
a. Call libxl__checkpoint_devices_commit().
b. Read CHECKPOINT_NEW from master.
3. Suspend secondary vm
a. Suspend secondary vm.
b. Call libxl__checkpoint_devices_postsuspend().
c. Send CHECKPOINT_SVM_SUSPENDED to master.
4. Checkpoint
a. Read emulator xenstore data and emulator context
b. REC_TYPE_CHECKPOINT_END
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Yang Hongyang <hongyang.yang@easystack.cn>
Signed-off-by: Changlong Xie <xiecl.fnst@cn.fujitsu.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
This is used by primay to read records sent by secondary.
Note: The function libxl__stream_read_checkpoint_state() will be used
in later patches called "secondary vm suspend/resume/checkpoint code" and
"primary vm suspend/resume/checkpoint code".
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>
Add back channel support to write stream. If the write stream is
a back channel stream, this means the write stream is used by
Secondary to send some records back.
Note: The function libxl__stream_write_checkpoint_state() will be used
in later patches called "secondary vm suspend/resume/checkpoint code" and
"primary vm suspend/resume/checkpoint code".
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>
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>
In COLO mode, secondary needs to send the following data to primary:
1. In libxl
Secondary sends the following CHECKPOINT_CONTEXT to primary:
CHECKPOINT_SVM_SUSPENDED, CHECKPOINT_SVM_READY and CHECKPOINT_SVM_RESUMED
2. In libxc
Secondary sends the dirty pfn list to primary
But the io_fd only can be written in primary, and only can be read in
secondary. Save recv_fd in domain_suspend_state, and send_fd in
domain_create_state. Extend libxl_domain_create_restore API, add a
send_fd param to it. Add LIBXL_HAVE_CREATE_RESTORE_SEND_FD to indicate
the API change.
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Yang Hongyang <hongyang.yang@easystack.cn>
Signed-off-by: Changlong Xie <xiecl.fnst@cn.fujitsu.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Secondary vm is running in COLO mode, we need to send secondary
vm's dirty page information to primary host at checkpoint, so we
have to enable qemu logdirty on secondary.
libxl__domain_suspend_common_switch_qemu_logdirty() is to enable
qemu logdirty. But it uses libxl__domain_save_state, and calls
libxl__xc_domain_saverestore_async_callback_done() before exits.
This can not be used for secondary vm.
Update libxl__domain_suspend_common_switch_qemu_logdirty() to
introduce a new API libxl__domain_common_switch_qemu_logdirty().
This API only uses libxl__logdirty_switch, and calls
lds->callback before exits. This new API will be used by the patch:
secondary vm suspend/resume/checkpoint codes
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 Campbell <ian.campbell@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
In normal migration, the qemu state is passed to qemu as a parameter.
With COLO, secondary vm is running. So we will do the following steps
at every checkpoint:
1. suspend both primary vm and secondary vm
2. sync the state
3. resume both primary vm and secondary vm
Primary will send qemu's state in step2, and secondary's qemu should
read it and restore the state before it is resumed. We can not pass the
state to qemu as a parameter because secondary QEMU is already started
at this point, so we introduce libxl__qmp_restore() to do it.
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: Anthony Perard <anthony.perard@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
xc_domain_save() and xc_domain_restore's parameter will use this type,
so it should be public.
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
we call (init|cleanup)_subkind_nic and (init|cleanup)_subkind_drbd_disk
directly in checkpoint device. Move them to libxl_remus.c, Call them before
calling libxl__checkpoint_devices_setup() or after calling
libxl__checkpoint_devices_teardown().
it is pure refactoring and no functional changes.
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Yang Hongyang <hongyang.yang@easystack.cn>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Add a new structure remus state, and move concrete layer's private
member to remus state.
it is pure refactoring and no functional changes.
Init interval in libxl__remus_setup(). It is safe to move this initialisation,
because this value is only used for remus, and remus will use this value after
libxl__remus_setup().
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Yang Hongyang <hongyang.yang@easystack.cn>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Checkpoint device is an abstract layer to do checkpoint.
COLO can also use it to do checkpoint. But there are
still some codes in checkpoint device which touch remus.
This patch and:
tools/libxl: move remus state into a seperate structure
tools/libxl: seperate device init/cleanup from checkpoint device layer
will seperate remus from checkpoint device layer.
We use remus ops directly in checkpoint device. Store it
in checkpoint device state so that we do not aware of
remus_ops in the checkpoint device layer.
It is pure refactoring and no functional changes.
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Yang Hongyang <hongyang.yang@easystack.cn>
Acked-by:Ian Campbell <ian.campbell@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Introduce enum type libxl_checkpointed_stream in IDL.
rename the last argument of migrate_receive from "remus" to
"checkpointed" since the semantics of this parameter has
changed.
NOTE:
libxl_domain_restore_params and domain_create aren't changed here,
checkpointed_stream is still an int. Because we will pass the
value from libxl to libxc.
Signed-off-by: Yang Hongyang <hongyang.yang@easystack.cn>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Currently struct libxl__domain_suspend_state contains 2 type of states,
one is save state, another is suspend state. This patch separates those
two out.
The motivation of this is that COLO will need to do suspend/resume
continuously, we need a more common suspend state.
After this change, dss stands for libxl__domain_save_state,
dsps stands for libxl__domain_suspend_state.
Also introduce libxl__domain_suspend_init to initialise the
libxl__domain_suspend_state.
Signed-off-by: Yang Hongyang <hongyang.yang@easystack.cn>
Signed-off-by: Wen Congyang <wency@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>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
For example: if the secondary host is down, and we fail to send the data to
the secondary host. xc_domain_save() returns 0. So in the function
libxl__xc_domain_save_done(), rc is 0 (the helper program exits normally),
and retval is 0 (it is xc_domain_save()'s return value). In such case, we
just need to complete the stream.
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
[ ijc -- updated wording of comment as discussed ]
stream_continue() is used for migration to read emulator
xenstore data and emulator context. For remus, if we do
failover, we have read it in the checkpoint cycle, and
we only need to complete the stream.
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
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>
Currently, starting a datacopier requires a valid read and write fd, but this
is a problem when purely sending data from a local buffer to a writable fd.
The prefixdata mechanism already exists and works for inserting data from a
local buffer ahead of reading from the read fd.
Make the lack of a read fd non-fatal. A datacopier with no read fd, but some
prefixdata will write the prefixdata to the write fd and complete successfully.
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
[Rewrite commit message]
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
CC: Ian Campbell <Ian.Campbell@citrix.com>
CC: Ian Jackson <Ian.Jackson@eu.citrix.com>
CC: Wei Liu <wei.liu2@citrix.com>
In verify mode, we map the guest memory, and the guest page is
region_base + i * PAGE_SIZE. So we should csum page (region_base
+ i * PAGE_SIZE), not (region_base + (i+curbatch) * PAGE_SIZE)
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
In colo mode, secondary vm is running, so VM_ENTRY_INTR_INFO may
valid before restoring vmcs. If there is no pending event after
restoring vm, we should clear it.
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Also clear pending software exceptions.
Copy the fix to SVM as well.
Signed-off-by: Tim Deegan <tim@xen.org>
Acked-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>
commit de18e4c038 introduces a build error with
older gcc:
In file included from xl.c:31:
libxl.h:582: error: redefinition of typedef ‘libxl_ctx’
libxl.h:348: note: previous declaration of ‘libxl_ctx’ was here
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
[ ijc -- rewrote commit message ]
Wen Congyang