RE: [Xen-devel] [PATCH 0/12] Add basic S3 support to Xen

["Tian, Kevin" <kevin.tian@xxxxxxxxx>]

A side-note is, logic in attached patch set has no impact on existing 
run-time features, which is only exercised in S3 suspend/resume
flow. :-)

Thanks,
Kevin

>-----Original Message-----
>Sent: 2007年5月15日 22:14
>To: xen-devel@xxxxxxxxxxxxxxxxxxx
>Subject: [Xen-devel] [PATCH 0/12] Add basic S3 support to Xen
>
>       Is now time for accepting new features? Here's updated S3
>patch set for Xen/dom0, based on latest 15017 changeset.
>Comments welcomed.
>
>=========================================
>Changes since last version:
>       - Rebase to latest 15017
>       - X86-64 support
>       - Force lazy context sync before cpu goes down
>       - S5 poweroff support
>       - Several bug fixes observed when running on different machines
>
>=========================================
>       Attached patch set is the first support to S3 (suspend to ram)
>on Xen environment. Totally 12 patches are attached. All files pulled
>from Linux are based on current xenlinux version (2.6.18).
>
>[Xen specific changes]
>[PATCH 1/12] Add suspend/resume to devices owned by Xen
>[PATCH 2/12] Pull necessary Linux PM files to Xen
>[PATCH 3/12] Provide basic Xen PM infrastructure
>[PATCH 4/12] PM interface between dom0 and Xen
>[PATCH 5/12] Add HVM support
>
>[Xenlinux specific changes]
>[PATCH 6/12] Make kthreads freezable
>[PATCH 7/12] Pull Linux PM files to sparse tree
>[PATCH 8/12] Enable ACPI sleep in Linux
>
>[Xen SMP related changes]
>[PATCH 9/12] Pull Linux CPU hotplug logic to Xen
>[PATCH 10/12] Add Xen CPU hotplug support
>[PATCH 11/12] Allow vcpu to pause self
>[PATCH 12/12] SMP support to Xen PM
>
>       For each patch mail, we also post in the body for easy review,
>except those simply pulling Linux files.
>
>       Thanks a lot to guidance from Jun Nakajima.
>
>=========================================
>       Some important notes are attached here, and it's better to read
>them carefully before you try it out, since Linux itself still has much
>thing to do for a stable PM support.
>
>#1. Ensure native linux (with same version as xenlinux) working on
>your environment first. Xen can never be more stable than native
>linux, thus please DO record all the information to make native Linux
>working stably, including kernel configuration changes, environmental
>setting, BIOS setting or any other tricky points you made. Then DO
>apply all these changes/settings to xen environment!!!
>
>#2. SATA driver suspend/resume was unstable in earlier linux
>version, which is said to have full support since 2.6.19. However in
>our side, SATA does work correctly if AHCI is disabled by configuring
>SATA as Enhanced/IDE mode for linux-2.6.18. If you see SATA failure
>unfortunately like "SATA: I/O request error", you have to switch to
>legacy IDE mode, and use traditional IDE drivers to operate disk.
>
>#3. VGA resume is the real boring issue, which may even crash the
>system on some boxes. The best case is that your BIOS support
>automatic VGA post after resume. If yes, congratulations! Or else,
>please read carefully linux-2.6.18/Documentation/power/video.txt,
>which lists some known workaround on some known types. Some
>supplements here:
>       a) Xen also support "acpi_sleep=" option. You can add it to the
>xenlinux cmdline if applied. We just verified "acpi_sleep=s3_bios",
>which works on one box but failed another. "acpi_sleep=s3_mode"
>seems no effect on either box we have.
>
>       b) On some boxes, VGA post have to be done in UP mode (For
>xen, it means UP-xenlinux), or else system may crash. S3_bios is a
>choice if applying to your box, since bios call is done in wakeup stub.
>Or else in case you have to use "vbetool post" from user space, one
>possible workaround is to manual unplug other cpus before suspend
>and re-plug them after VGA is resumed by:
>               #echo "0" > /sys/devices/system/cpu/cpuN/online
>               #echo "mem" > /sys/power/state
>               ----After resume to user space----
>               #vbetool post
>               ----Wait til VGA is fully resumed----
>               #echo "1" > /sys/devices/system/cpu/cpuN/online
>         I guess such issue may be related to vm86 emulation under
>SMP, for both Xen and Linux. But not sure for now. :-(
>
>#4. Some boxes fail to restart after trying S3, on both native and Xen.
>Need further investigation, which may come from some stale hardware
>State from previous S3 operation.
>
>       Just reiterative NOTE here, all above issues apply to both
>native
>Linux and Xen. So MAKE SURE you have a STABLE native result first.
>It's better to run some workload when testing stability. For example,
>kernel build is easy to trigger instability when VGA resume method is
>incorrect.
>
>Thanks,
>Ke/Kevin
>
>_______________________________________________
>Xen-devel mailing list
>Xen-devel@xxxxxxxxxxxxxxxxxxx
>http://lists.xensource.com/xen-devel

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel