linux/Documentation/ABI/stable
Marek Marczykowski-Górecki 197ecb3802 xen/balloon: add runtime control for scrubbing ballooned out pages
Scrubbing pages on initial balloon down can take some time, especially
in nested virtualization case (nested EPT is slow). When HVM/PVH guest is
started with memory= significantly lower than maxmem=, all the extra
pages will be scrubbed before returning to Xen. But since most of them
weren't used at all at that point, Xen needs to populate them first
(from populate-on-demand pool). In nested virt case (Xen inside KVM)
this slows down the guest boot by 15-30s with just 1.5GB needed to be
returned to Xen.

Add runtime parameter to enable/disable it, to allow initially disabling
scrubbing, then enable it back during boot (for example in initramfs).
Such usage relies on assumption that a) most pages ballooned out during
initial boot weren't used at all, and b) even if they were, very few
secrets are in the guest at that time (before any serious userspace
kicks in).
Convert CONFIG_XEN_SCRUB_PAGES to CONFIG_XEN_SCRUB_PAGES_DEFAULT (also
enabled by default), controlling default value for the new runtime
switch.

Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2018-09-14 08:51:10 -04:00
..
firewire-cdev firewire: ABI documentation: libhinawa uses firewire-cdev 2016-03-12 10:55:46 +01:00
o2cb
syscalls
sysfs-acpi-pmprofile ACPI: Export FADT pm_profile integer value to userspace 2011-11-06 20:48:42 -05:00
sysfs-bus-firewire firewire: core: document is_local sysfs attribute 2012-06-30 10:49:06 +02:00
sysfs-bus-nvmem Documentation/ABI: document the nvmem sysfs files 2017-08-28 17:57:52 +02:00
sysfs-bus-usb docs-rst: fix usb cross-references 2017-04-11 14:41:29 -06:00
sysfs-bus-vmbus Drivers: hv: vmbus: add numa_node to sysfs 2018-07-29 08:09:56 +02:00
sysfs-bus-w1 w1: introduce an ability to specify microseconds bus scanning intervals 2015-05-24 12:08:59 -07:00
sysfs-bus-xen-backend xen: export device state to sysfs 2018-08-28 17:37:40 -04:00
sysfs-class-backlight backlight: add backlight type 2011-03-22 17:43:59 -07:00
sysfs-class-infiniband Documentation/ABI: update infiniband sysfs interfaces 2018-02-23 08:18:33 -07:00
sysfs-class-rfkill rfkill: Correctly document rkill subfolder range as >= 0 in sysfs-class-rfkill 2018-06-15 13:35:49 +02:00
sysfs-class-tpm Doc: ABI/stable: Fix typo in ABI/stable 2015-11-02 18:10:33 -07:00
sysfs-class-ubi UBI: Add ro-mode sysfs attribute 2016-05-24 15:15:26 +02:00
sysfs-class-udc Documentation: ABI: sysfs-class-udc: remove duplicated entry 2017-06-13 13:21:04 +03:00
sysfs-devices Documentation: fix admin-guide doc refs 2017-10-12 11:13:28 -06:00
sysfs-devices-node docs/admin-guide/mm: start moving here files from Documentation/vm 2018-04-27 17:02:48 -06:00
sysfs-devices-system-cpu powerpc: Document sysfs DSCR interface 2014-05-28 13:35:40 +10:00
sysfs-devices-system-xen_memory xen/balloon: add runtime control for scrubbing ballooned out pages 2018-09-14 08:51:10 -04:00
sysfs-driver-aspeed-vuart drivers/serial: Add driver for Aspeed virtual UART 2017-05-18 16:19:16 +02:00
sysfs-driver-dma-ioatdma dmaengine: ioatdma: Add ABI document 2017-08-21 21:40:40 +05:30
sysfs-driver-ib_srp IB/srp: Add multichannel support 2014-11-12 12:05:24 +01:00
sysfs-driver-mlxreg-io Documentation/ABI: Add new attribute for mlxreg-io sysfs interfaces 2018-08-01 17:41:31 -07:00
sysfs-driver-qla2xxx [SCSI] qla2xxx: Add firmware-dump kobject uevent notification. 2009-12-04 12:00:10 -06:00
sysfs-driver-usb-usbtmc USB: update usbtmc api documentation 2012-04-12 08:26:22 -07:00
sysfs-driver-w1_ds28e04 w1: Add 1-wire slave device driver for DS28E04-100 2012-06-13 16:47:10 -07:00
sysfs-driver-w1_ds28ea00 w1: Add support for DS28EA00 sequence to w1-therm 2015-05-24 12:08:59 -07:00
sysfs-firmware-efi-vars efivars: Add Documentation 2011-03-14 08:40:51 -07:00
sysfs-firmware-opal-dump powerpc/powernv Platform dump interface 2014-03-07 16:19:10 +11:00
sysfs-firmware-opal-elog Doc: ABI/stable: Fix typo in ABI/stable 2015-11-02 18:10:33 -07:00
sysfs-fs-orangefs Orangefs: kernel client part 6 2015-10-03 11:39:59 -04:00
sysfs-hypervisor-xen doc,xen: document hypervisor sysfs nodes for xen 2017-06-15 08:50:15 +02:00
sysfs-module ABI: Clarify when /sys/module/MODULENAME is created 2013-07-02 15:38:20 +09:30
sysfs-transport-srp scsi_transport_srp: Add periodic reconnect support 2013-11-08 14:43:16 -08:00
thermal-notification thermal: Add event notification to thermal framework 2011-01-12 00:08:35 -05:00
vdso doc: ABI: vdso: update parse_vdso.c reference 2017-03-13 17:13:22 -06:00