[SOLVED] [REQUEST] paravirtualization in next kernel 3.10.x rebuild, please

zerouno · 08-12-2013, 05:53 PM

I'm a vmware user.

After any kernel upgrade I must rebuild the vmware kernel modules to user vmware.

But with 3.10.5 is needed to recompile the kernel adding at least
CONFIG_PARAVIRT_SPINLOCKS=y
(and related)

It's possible to add this feature in next kernel rebuilds?

I dont know how many config options should to be added in .config, but with an only small test, the following configurarion works. (x86_64)

Code:

# diff -u /boot/config-generic-3.10.5 .config
--- /boot/config-generic-3.10.5 2013-08-04 22:33:23.000000000 +0200
+++ .config     2013-08-12 22:46:32.352253231 +0200
@@ -332,7 +332,15 @@
 CONFIG_X86_INTEL_LPSS=y
 CONFIG_X86_SUPPORTS_MEMORY_FAILURE=y
 CONFIG_SCHED_OMIT_FRAME_POINTER=y
-# CONFIG_HYPERVISOR_GUEST is not set
+CONFIG_HYPERVISOR_GUEST=y
+CONFIG_PARAVIRT=y
+# CONFIG_PARAVIRT_DEBUG is not set
+CONFIG_PARAVIRT_SPINLOCKS=y
+# CONFIG_XEN is not set
+# CONFIG_XEN_PRIVILEGED_GUEST is not set
+CONFIG_KVM_GUEST=y
+# CONFIG_PARAVIRT_TIME_ACCOUNTING is not set
+CONFIG_PARAVIRT_CLOCK=y
 CONFIG_NO_BOOTMEM=y
 CONFIG_MEMTEST=y
 # CONFIG_MK8 is not set
@@ -1636,6 +1644,7 @@
 CONFIG_SENSORS_APDS990X=m
 CONFIG_HMC6352=m
 CONFIG_DS1682=m
+# CONFIG_VMWARE_BALLOON is not set
 CONFIG_BMP085=y
 CONFIG_BMP085_I2C=m
 CONFIG_PCH_PHUB=m
@@ -5107,6 +5116,7 @@
 #
 # Microsoft Hyper-V guest support
 #
+# CONFIG_HYPERV is not set
 CONFIG_STAGING=y
 # CONFIG_ET131X is not set
 # CONFIG_SLICOSS is not set

CONFIG_PARAVIRT_SPINLOCKS=y
is needed to solve this problem:
vmci: Unknown symbol pv_lock_ops (err 0)

pv_lock_ops is defined in ./arch/x86/kernel/paravirt-spinlocks.c

guanx · 08-12-2013, 06:07 PM

“Unfortunately the downside is an up to 5% performance hit on native kernels, with various workloads.”

zerouno · 08-12-2013, 06:25 PM

even when the feature is not used?

isn't possible to build it as module?

hf2046 · 08-13-2013, 07:22 AM

Quote:

Originally Posted by zerouno

even when the feature is not used?

That's what the kernel help documentation says.

Quote:

Originally Posted by zerouno

isn't possible to build it as module?

Nope.

zerouno · 08-13-2013, 07:25 AM

ok
thanx

rouvas · 08-14-2013, 01:40 AM

Perhaps a choice could be offered at installation time.
It should be noted, that running virtualized loads is an increasingly popular method of server utilization.
I think a method for efficiently accomodating virtualized loads should be offered.
Another alternative, could be a clear README-style document that would explain the required steps. Something along the lines of "booting with LVM" document.

solarfields · 08-14-2013, 09:25 AM

or may be a yet another kernel choice in addition to huge and generic or a ready config file in /extra?

zerouno · 10-16-2013, 07:24 AM

today changelog

Quote:

The kernels were rebuilt to fix a regression that
occurred when the 3.10.0 kernel changed CONFIG_PARAVIRT_GUEST to
CONFIG_HYPERVISOR_GUEST, which caused some previously included VMWare and
Hyper-V drivers to not be built. These are the changed kernel options:
HYPERVISOR_GUEST n -> y
+FB_HYPERV n
+HID_HYPERV_MOUSE m
+HYPERV m
+HYPERV_BALLOON m
+HYPERV_NET m
+HYPERV_STORAGE m
+HYPERV_UTILS m
+PARAVIRT n
+VMWARE_BALLOON m
+XEN_PRIVILEGED_GUEST n

volkerdi · 10-16-2013, 09:04 AM

These are device drivers that we had before. Note that CONFIG_PARAVIRT is not set.

zerouno · 10-16-2013, 09:21 AM

The important think is that now I can build succesfully vmware modules. I need it only for that (so I don't need to rebuild the kernel at every upgrade).

Thankyou.

mostlyharmless · 10-16-2013, 11:27 AM

Hmm, looks like I'll have to do a kernel recompile to install Xen as dom0. Is there a performance penalty for making
+XEN_PRIVILEGED_GUEST y
as well as the other Xen kernel options? I'm guessing the answer is yes or they would be enabled..

eRJe · 11-26-2013, 10:21 AM

I'm installing Slackware 14.1 on a VMware ESXi 5.5 host. First time installation I created a "other Linux 64bit" VM and kept all the default settings. This worked out fine. Now I'm trying to use different SCSI settings by choosing paravirtualization. I read this will improve performance and cost less CPU. But now the drive that I want to install the fresh Slackware on, won't show up in /dev. I assume this is because of choosing paravirtualization and the option not being enabled in the huge kernel?

Are there other options I should consider enabling to improve performance?

Thanks,
Robbert