4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Roger Pau Monne <roger.pau@xxxxxxxxxx> [ 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@xxxxxxxxxx> Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx> Reviewed-by: Juergen Gross <jgross@xxxxxxxx> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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; }