New NHM processors will support Pause-Loop Exiting by adding 2
VM-execution control fields:
PLE_Gap - upper bound on the amount of time between two successive
executions of PAUSE in a loop.
PLE_Window - upper bound on the amount of time a guest is allowed to
execute in a PAUSE loop
If the time, between this execution of PAUSE and previous one, exceeds
the PLE_Gap, processor consider this PAUSE belongs to a new loop.
Otherwise, processor determins the the total execution time of this
loop(since 1st PAUSE in this loop), and triggers a VM exit if total
time exceeds the PLE_Window.
* Refer SDM volume 3b section 21.6.13 & 22.1.3.
Pause-Loop Exiting can be used to detect Lock-Holder Preemption, where
one VP is sched-out after hold a spinlock, then other VPs for same
lock are sched-in to waste the CPU time.
Our tests indicate that most spinlocks are held for less than 2^12
cycles. Performance tests show that with 2X LP over-commitment we can
get +2% perf improvement for kernel build(Even more perf gain with
more LPs).
Signed-off-by: Zhai Edwin <edwin.zhai@intel.com>
There is a mistake to get the msix entry number. It should be
divide instead of modulus.
Signed-off-by: Yang Zhang <yang.zhang@intel.com>
Signed-off-by: Qing He <qing.he@intel.com>
The existing single page is not quite large enough to translate a
XENMEM_exchange hypercall with order=3D9. Since Linux uses
MAX_CONTIG_ORDER of 9 this seems like a reasonable upper bound to
support.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
pciback is used by VT-d to hide device for assigment. But in pv-ops
dom0, pciback is not supported yet. Fortunately, pci-stub module is
used to hide device in Linux for KVM VT-d device assignment and it's
included in pv-ops dom0. So can use pci-stub to hide devices for
assignment.
Device must be hidden before assignment. Control panel has checks if
devices can be assigned or not, and can list assignable devices via
reading devices owned by pciback. This patch changes the checks, and
also list assignable devices which are owned by pci-stub. Use pci-stub
to hide devices, and use this patch to pass checkes in control panel,
device assignemnt with VT-d works on Xen with pv-ops dom0.
Signed-off-by: Weidong Han <weidong.han@intel.com>
blktap2 devices use a regular 'phy' vbd blkback backend, causing
Blktap2Controller to trample the devices' parameters. This causes
problems with save/restore and managed domains, among other
things. This patch modifies Blktap2Controller to store both the vbd
and tap2 parameters in xenstore, and stops it from trampling the
device's config on device creation.
* store blktap2 parameters in xenstore
* restore blktap2 device config to original state once the underlying
* vbd
device is created (this fixes managed domains)
* use blktap2 parameters rather than vbd parameters when building
* blktap2
device configurations
* remove blktap2 specific code from XendConfig
Signed-off-by: Ryan O'Connor <rjo@cs.ubc.ca>
* seperate blktap1/blktap2 disk types
* use blktap1 when driver is not in explicit list of blktap2 drivers,
* rather than current check against list of blktap1 only drivers
* remove 'tapdisk' disk type (it is not a tapdisk disk type) and fix
* tapdisk disk type check in XenConfig
Signed-off-by: Ryan O'Connor <rjo@cs.ubc.ca>
softirqs. This fixes a bug where bailing into SCHEDULE_SOFTIRQ may not
actually return.
From: Ke Yu <ke.yu@intel.com>
Signed-off-by: Keir Fraser <keir.fraser@citrix.com>
The original user for this was domain destruction. Now that this is
preemptible all the way back up to dom0 userspace, asynchrony is
better iontroduced at that level, if at all, imo.
Signed-off-by: Keir Fraser <keir.fraser@citrix.com>
kexec has been failing (at least on 32on64, didn't try others) since
18771:8e18dd41c6c7 "x86: reduce GDT switching". Ensure that we are
using a known good GDT before attempting to switch to compatability
mode.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
* Interception should be standard part of HVM_TRAP_MASK
* Failed intercept should quietly forward #UD to the guest
Signed-off-by: Keir Fraser <keir.fraser@citrix.com>
blktap2 devices must be handled differently than blktap2
devices. blktap2 devices require a sysfs write to close the underlying
device, as well as extra sysfs writes when the domU is
paused/unpaused. The differences between blktap1 and blktap2 are great
enough to warrant the creation of a new device class, 'tap2', and
device controller for blktap2 devices.
* add a new device controller (Blktap2Controller) and device class
(tap2) for blktap2 devices
* move blktap2 specific code from DevController to Blktap2Controller
* if possible, check xenstore to determine block device class
* use vmpath (/vm/<uuid>/) when releasing devices
* modify linux hotplug cleanup script to handle blktap2 device
removal
Signed-off-by: Ryan O'Connor <rjo@cs.ubc.ca>
The trivial message is printed too many when xen boots and when we
create hvm guests with devices assigned.
Signed-off-by: Dexuan Cui <dexuan.cui@intel.com>
When MCE# happens, if the error has been contained/recovered by XEN
and it impacts one guest Domain(DOM0/HVM Guest/PV Guest), we will
inject the corresponding vMCE# into the impacted Domain. Guest OS will
go on its own recovery job if it has MCA handler.
Signed-off-by: Liping Ke <liping.ke@intel.com>
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
* Change default settings to relative pathes.
* Make xend to prepend install directory if entries have no absolute
* path
Signed-off-by: Christoph Egger <Christoph.Egger@amd.com>
don't use MAX_VCPUS, and use vcpu::max_vcpus.
The changeset of 2f9e1348aa98 introduced max_vcpus to allow more vcpus
per guest. This patch is ia64 counter part.
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
This patch removes the following warning.
> unwind.c:40:1: warning: "write_trylock" redefined
> In file included from xen/include/xen/sched.h:7,
> from unwind.c:33:
> xen/include/xen/spinlock.h:115:1: warning: this is the location of the previous definition
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
This patch changes fs-backend to use /var/lib/xen as default export
and check all the file names and paths given by the frontend against the
export path, so that the frontend can only operate under the export
directory.
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Attached patch fixes a bug introduced in c/s 19648.
32bit legacy guests have the sysenter/sysexit instructions available.
Therefore, we have to disable intercepts for the sysenter MSRs or the
guest stucks in an infinite loop of #GPs, otherwise.
For guests in 64bit mode and 32bit compat mode, sysenter/sysexit
instructions aren't available. The sysenter MSRs have to be
intercepted to make the instruction emulation working.
Signed-off-by: Christoph Egger <Christoph.Egger@amd.com>
Signed-off-by: Keir Fraser <keir.fraser@citrix.com>
Keir Fraser
Isaku Yamahata