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| author | Zhenzhong Duan <zhenzhong.duan@oracle.com> | 2019-07-11 20:02:09 +0800 |
|---|---|---|
| committer | Juergen Gross <jgross@suse.com> | 2019-07-17 08:09:58 +0200 |
| commit | 30978346372e5c43a652cfbd4533c6bd5427c33b (patch) | |
| tree | 0fb7e6a976d391af1469f7c4e210bef06e7ef5cb /Documentation/admin-guide/kernel-parameters.txt | |
| parent | 1b37683cda0217305837fd1b79e7c57104d4f983 (diff) | |
| download | lwn-30978346372e5c43a652cfbd4533c6bd5427c33b.tar.gz lwn-30978346372e5c43a652cfbd4533c6bd5427c33b.zip | |
x86: Add "nopv" parameter to disable PV extensions
In virtualization environment, PV extensions (drivers, interrupts,
timers, etc) are enabled in the majority of use cases which is the
best option.
However, in some cases (kexec not fully working, benchmarking)
we want to disable PV extensions. We have "xen_nopv" for that purpose
but only for XEN. For a consistent admin experience a common command
line parameter "nopv" set across all PV guest implementations is a
better choice.
There are guest types which just won't work without PV extensions,
like Xen PV, Xen PVH and jailhouse. add a "ignore_nopv" member to
struct hypervisor_x86 set to true for those guest types and call
the detect functions only if nopv is false or ignore_nopv is true.
Suggested-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Signed-off-by: Juergen Gross <jgross@suse.com>
Diffstat (limited to 'Documentation/admin-guide/kernel-parameters.txt')
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 99db4975e6b5..936e8e7e6474 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -5257,6 +5257,11 @@ improve timer resolution at the expense of processing more timer interrupts. + nopv= [X86,XEN,KVM,HYPER_V,VMWARE] + Disables the PV optimizations forcing the guest to run + as generic guest with no PV drivers. Currently support + XEN HVM, KVM, HYPER_V and VMWARE guest. + xirc2ps_cs= [NET,PCMCIA] Format: <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]] |