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Re: [Qemu-devel] [PATCH v6 1/1] Introduce "xen-load-devices-state"
From: |
Dr. David Alan Gilbert |
Subject: |
Re: [Qemu-devel] [PATCH v6 1/1] Introduce "xen-load-devices-state" |
Date: |
Mon, 13 Jun 2016 11:38:49 +0100 |
User-agent: |
Mutt/1.6.1 (2016-04-27) |
* Stefano Stabellini (address@hidden) wrote:
> On Fri, 3 Jun 2016, Anthony PERARD wrote:
> > On Fri, Jun 03, 2016 at 05:58:34PM +0800, Changlong Xie wrote:
> > > From: Wen Congyang <address@hidden>
> > >
> > > Introduce a "xen-load-devices-state" QAPI command that can be used to
> > > load the state of all devices, but not the RAM or the block devices of
> > > the VM.
> > >
> > > We only have hmp commands savevm/loadvm, and qmp commands
> > > xen-save-devices-state.
> > >
> > > We use this new command for COLO:
> > > 1. suspend both primary vm and secondary vm
> > > 2. sync the state
> > > 3. resume both primary vm and secondary vm
> > >
> > > In such case, we need to update all devices' state in any time.
> > >
> > > Signed-off-by: Wen Congyang <address@hidden>
> > > Signed-off-by: Changlong Xie <address@hidden>
> >
> > Reviewed-by: Anthony PERARD <address@hidden>
>
> David,
>
> can we still have your Ack on this patch?
Yes,
Reviewed-by: Dr. David Alan Gilbert <address@hidden>
Dave
>
>
> > > ---
> > > migration/savevm.c | 37 +++++++++++++++++++++++++++++++++++++
> > > qapi-schema.json | 14 ++++++++++++++
> > > qmp-commands.hx | 27 +++++++++++++++++++++++++++
> > > 3 files changed, 78 insertions(+)
> > >
> > > diff --git a/migration/savevm.c b/migration/savevm.c
> > > index 6c21231..ae2ef8b 100644
> > > --- a/migration/savevm.c
> > > +++ b/migration/savevm.c
> > > @@ -31,6 +31,7 @@
> > > #include "hw/boards.h"
> > > #include "hw/hw.h"
> > > #include "hw/qdev.h"
> > > +#include "hw/xen/xen.h"
> > > #include "net/net.h"
> > > #include "monitor/monitor.h"
> > > #include "sysemu/sysemu.h"
> > > @@ -1754,6 +1755,12 @@ qemu_loadvm_section_start_full(QEMUFile *f,
> > > MigrationIncomingState *mis)
> > > return -EINVAL;
> > > }
> > >
> > > + /* Validate if it is a device's state */
> > > + if (xen_enabled() && se->is_ram) {
> > > + error_report("loadvm: %s RAM loading not allowed on Xen", idstr);
> > > + return -EINVAL;
> > > + }
> > > +
> > > /* Add entry */
> > > le = g_malloc0(sizeof(*le));
> > >
> > > @@ -2064,6 +2071,36 @@ void qmp_xen_save_devices_state(const char
> > > *filename, Error **errp)
> > > }
> > > }
> > >
> > > +void qmp_xen_load_devices_state(const char *filename, Error **errp)
> > > +{
> > > + QEMUFile *f;
> > > + QIOChannelFile *ioc;
> > > + int ret;
> > > +
> > > + /* Guest must be paused before loading the device state; the RAM
> > > state
> > > + * will already have been loaded by xc
> > > + */
> > > + if (runstate_is_running()) {
> > > + error_setg(errp, "Cannot update device state while vm is
> > > running");
> > > + return;
> > > + }
> > > + vm_stop(RUN_STATE_RESTORE_VM);
> > > +
> > > + ioc = qio_channel_file_new_path(filename, O_RDONLY | O_BINARY, 0,
> > > errp);
> > > + if (!ioc) {
> > > + return;
> > > + }
> > > + f = qemu_fopen_channel_input(QIO_CHANNEL(ioc));
> > > +
> > > + migration_incoming_state_new(f);
> > > + ret = qemu_loadvm_state(f);
> > > + qemu_fclose(f);
> > > + if (ret < 0) {
> > > + error_setg(errp, QERR_IO_ERROR);
> > > + }
> > > + migration_incoming_state_destroy();
> > > +}
> > > +
> > > int load_vmstate(const char *name)
> > > {
> > > BlockDriverState *bs, *bs_vm_state;
> > > diff --git a/qapi-schema.json b/qapi-schema.json
> > > index 8483bdf..48c3a6f 100644
> > > --- a/qapi-schema.json
> > > +++ b/qapi-schema.json
> > > @@ -4201,6 +4201,20 @@
> > > 'data': [ 'none', 'record', 'play' ] }
> > >
> > > ##
> > > +# @xen-load-devices-state:
> > > +#
> > > +# Load the state of all devices from file. The RAM and the block devices
> > > +# of the VM are not loaded by this command.
> > > +#
> > > +# @filename: the file to load the state of the devices from as binary
> > > +# data. See xen-save-devices-state.txt for a description of the binary
> > > +# format.
> > > +#
> > > +# Since: 2.7
> > > +##
> > > +{ 'command': 'xen-load-devices-state', 'data': {'filename': 'str'} }
> > > +
> > > +##
> > > # @GICCapability:
> > > #
> > > # The struct describes capability for a specific GIC (Generic
> > > diff --git a/qmp-commands.hx b/qmp-commands.hx
> > > index 28801a2..780e7f2 100644
> > > --- a/qmp-commands.hx
> > > +++ b/qmp-commands.hx
> > > @@ -587,6 +587,33 @@ Example:
> > > EQMP
> > >
> > > {
> > > + .name = "xen-load-devices-state",
> > > + .args_type = "filename:F",
> > > + .mhandler.cmd_new = qmp_marshal_xen_load_devices_state,
> > > + },
> > > +
> > > +SQMP
> > > +xen-load-devices-state
> > > +----------------------
> > > +
> > > +Load the state of all devices from file. The RAM and the block devices
> > > +of the VM are not loaded by this command.
> > > +
> > > +Arguments:
> > > +
> > > +- "filename": the file to load the state of the devices from as binary
> > > +data. See xen-save-devices-state.txt for a description of the binary
> > > +format.
> > > +
> > > +Example:
> > > +
> > > +-> { "execute": "xen-load-devices-state",
> > > + "arguments": { "filename": "/tmp/resume" } }
> > > +<- { "return": {} }
> > > +
> > > +EQMP
> > > +
> > > + {
> > > .name = "xen-set-global-dirty-log",
> > > .args_type = "enable:b",
> > > .mhandler.cmd_new = qmp_marshal_xen_set_global_dirty_log,
> > > --
> > > 1.9.3
> > >
> > >
> > >
> >
> > --
> > Anthony PERARD
> >
--
Dr. David Alan Gilbert / address@hidden / Manchester, UK