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| author | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2014-07-11 11:51:35 -0400 |
|---|---|---|
| committer | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2014-07-14 12:21:59 -0400 |
| commit | 8d693b911bb9c57009c24cb1772d205b84c7985c (patch) | |
| tree | 4100eb4abefd72befda6445e6eda7bf0d4ceeb15 /Documentation/kernel-parameters.txt | |
| parent | 1795cd9b3a91d4b5473c97f491d63892442212ab (diff) | |
| download | lwn-8d693b911bb9c57009c24cb1772d205b84c7985c.tar.gz lwn-8d693b911bb9c57009c24cb1772d205b84c7985c.zip | |
xen: Introduce 'xen_nopv' to disable PV extensions for HVM guests.
By default when CONFIG_XEN and CONFIG_XEN_PVHVM kernels are
run, they will enable the PV extensions (drivers, interrupts, timers,
etc) - which is the best option for the majority of use cases.
However, in some cases (kexec not fully working, benchmarking)
we want to disable Xen PV extensions. As such introduce the
'xen_nopv' parameter that will do it.
This parameter is intended only for HVM guests as the Xen PV
guests MUST boot with PV extensions. However, even if you use
'xen_nopv' on Xen PV guests it will be ignored.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
---
[v2: s/off/xen_nopv/ per Boris Ostrovsky recommendation.]
[v3: Add Reviewed-by]
[v4: Clarify that this is only for HVM guests]
Diffstat (limited to 'Documentation/kernel-parameters.txt')
| -rw-r--r-- | Documentation/kernel-parameters.txt | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index c1b9aa8c5a52..403f927276cd 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -3691,6 +3691,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. Disables the ticketlock slowpath using Xen PV optimizations. + xen_nopv [X86] + Disables the PV optimizations forcing the HVM guest to + run as generic HVM guest with no PV drivers. + xirc2ps_cs= [NET,PCMCIA] Format: <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]] |