4.18-stable review patch. If anyone has any objections, please let me know.
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From: Roger Pau Monne roger.pau@citrix.com
[ Upstream commit 3596924a233e45aa918c961a902170fc4916461b ]
The current balloon code tries to calculate a delta factor for the balloon target when running in HVM mode in order to account for memory used by the firmware.
This workaround for memory accounting doesn't work properly on a PVH Dom0, that has a static-max value different from the target value even at startup. Note that this is not a problem for DomUs because guests are started with a static-max value that matches the amount of RAM in the memory map.
Fix this by forcefully setting target_diff for Dom0, regardless of it's mode.
Reported-by: Gabriel Bercarug bercarug@amazon.com Signed-off-by: Roger Pau Monné roger.pau@citrix.com Reviewed-by: Juergen Gross jgross@suse.com Signed-off-by: Boris Ostrovsky boris.ostrovsky@oracle.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/xen/xen-balloon.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/xen/xen-balloon.c +++ b/drivers/xen/xen-balloon.c @@ -81,7 +81,7 @@ static void watch_target(struct xenbus_w static_max = new_target; else static_max >>= PAGE_SHIFT - 10; - target_diff = xen_pv_domain() ? 0 + target_diff = (xen_pv_domain() || xen_initial_domain()) ? 0 : static_max - balloon_stats.target_pages; }