Commit Graph

19 Commits

Author SHA1 Message Date
K. Y. Srinivasan 7f4f2302a1 Drivers: hv: Notify the host of permanent hot-add failures
If memory hot-add fails with the error -EEXIST, then this is a permanent
failure. Notify the host of this information, so the host will not attempt
hot-add again. If the failure were a transient failure, host will attempt
a hot-add after some delay.

In this version of the patch, I have added some additional comments
to clarify how the host treats different failure conditions.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-29 09:03:21 -07:00
K. Y. Srinivasan f766dc1ea5 Drivers: hv: balloon: Support 2M page allocations for ballooning
On Hyper-V it will be very efficient to use 2M allocations in the guest as this
makes the ballooning protocol with the host that much more efficient. Hyper-V
uses page ranges (start pfn : number of pages) to specify memory being moved
around and with 2M pages this encoding can be very efficient. However, when
memory is returned to the guest, the host does not guarantee any granularity.
To deal with this issue, split the page soon after a successful 2M allocation
so that this memory can potentially be freed as 4K pages.

If 2M allocations fail, we revert to 4K allocations.

In this version of the patch, based on the feedback from Michal Hocko
<mhocko@suse.cz>, I have added some additional commentary to the patch
description.

Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-29 09:03:21 -07:00
K. Y. Srinivasan 647965a268 Drivers: hv: balloon: Permit Linux to specify hot-add alignment requirements
Some Windows hosts permit the guest to specify memory hot-add alignment
requirements (if any). Linux currently requires a 128MB alignment on memory
segments that can be hot-added. Specify this alignment requirement to the
host.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-29 08:53:12 -07:00
Wei Yongjun a6025a2a86 Drivers: hv: balloon: make local functions static
local functions that could be static.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-25 13:31:24 -07:00
K. Y. Srinivasan 1cac8cd4d1 Drivers: hv: balloon: Implement hot-add functionality
Implement the memory hot-add functionality. With this, Linux guests can fully
participate in the Dynamic Memory protocol implemented in the Windows hosts.

In this version of the patch, based Olaf Herring's feedback, I have gotten
rid of the module level dependency on MEMORY_HOTPLUG. Instead the code within
the driver that depends on MEMORY_HOTPLUG has the appropriate compilation
switches. This would allow this driver to support pure ballooning in cases
where the kernel does not support memory hotplug.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-15 12:11:51 -07:00
K. Y. Srinivasan 0cf40a3e66 Drivers: hv: balloon: Make the balloon driver not unloadable
The balloon driver is stateful. For instance, it needs to keep track of pages
that have been ballooned out to properly post pressure reports. This state cannot
be re-constructed if the driver were to be unloaded and subsequently loaded.
Furthermore, as we support memory hot-add as part of this driver, this driver becomes
even more stateful and this state cannot be re-created. Make the balloon driver
unloadable to deal with this issue.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-15 12:11:50 -07:00
K. Y. Srinivasan c51af826cf Drivers: hv: balloon: Execute hot-add code in a separate context
Execute the hot-add operation in a separate work context.
This allows us to decouple the pressure reporting activity from the
"hot-add" activity. Testing has shown that this makes the guest more
responsive to hot add requests.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-15 12:11:50 -07:00
K. Y. Srinivasan 6571b2dab4 Drivers: hv: balloon: Execute balloon inflation in a separate context
Execute the balloon inflation operation in a separate work context.
This allows us to decouple the pressure reporting activity from the
ballooning activity. Testing has shown that this decoupling makes the
guest more reponsive.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-15 12:11:50 -07:00
K. Y. Srinivasan 7a64b864a0 Drivers: hv: balloon: Do not request completion notification
There is no need to request completion notification; get rid of it.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-15 12:11:50 -07:00
K. Y. Srinivasan 1c7db96f6f Drivers: hv: balloon: Prevent the host from ballooning the guest too low
Based on the amount of memory being managed set a floor on how low the
guest can be ballooned.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-08 15:42:01 -08:00
K. Y. Srinivasan e500d158fb Drivers: hv: balloon: Add a parameter to delay pressure reporting
Delay reporting memory pressure by a specified amount of time.
This addresses the problem where the host may take memory balancing
decisions based on incorrect memory pressure data that will be posted
as soon as the balloon driver is loaded.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-08 15:42:01 -08:00
K. Y. Srinivasan 0731572b6c Drivers: hv: balloon: Make adjustments to the pressure report
The host expects that the pressure report includes the pressure due to the
pages that have been ballooned. Make necessary adjustments to reflect that.
Also, include the free memory information in the pressure report.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-30 00:06:07 -05:00
Greg Kroah-Hartman 74790147fb Merge 3.8-rc5 into char-misc-next
This pulls in all of the 3.8-rc5 fixes into this branch so we can test easier.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-25 12:34:27 -08:00
K. Y. Srinivasan d13984e5c7 Drivers: hv: Use consolidated GUID definitions
Use the consolidated GUID definitions in the util and balloon drivers.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-25 11:17:31 -08:00
K. Y. Srinivasan 33080c1cda Drivers: hv: balloon: Fix a memory leak
The send buffer was being leaked; fix it.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Reported-by: Jason Wang <jasowang@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-17 11:58:00 -08:00
K. Y. Srinivasan 6427a0d771 Drivers: hv: balloon: Fix a bug in the definition of struct dm_info_msg
There is bug in the definition of struct dm_info_msg. This patch fixes
the definition of this structure and makes the corresponding adjustments.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-17 11:58:00 -08:00
Wei Yongjun 10d498b13f hv: hv_balloon: remove duplicated include from hv_balloon.c
Remove duplicated include.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Acked-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-17 10:41:46 -08:00
Greg Kroah-Hartman 989623c7d6 hv: hv_balloon: mark a function static
This resolves the following sparse warning:

drivers/hv/hv_balloon.c:548:6: sparse: symbol 'free_balloon_pages' was not declared. Should it be static?

Reported-by: Xie ChanglongX <changlongx.xie@intel.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-21 12:46:40 -08:00
K. Y. Srinivasan 9aa8b50b2b Drivers: hv: Add Hyper-V balloon driver
Add the basic balloon driver. Windows hosts dynamically manage the guest
memory allocation via a combination memory hot add and ballooning. Memory
hot add is used to grow the guest memory upto the maximum memory that can be
allocatted to the guest. Ballooning is used to both shrink as well as expand
up to the max memory. Supporting hot add needs additional support from the
host. We will support hot add when this support is available. For now,
by setting the VM startup memory to the VM  max memory, we can use
ballooning alone to dynamically manage memory allocation amongst
competing guests on a given host.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-15 15:42:09 -08:00