From 8d693b911bb9c57009c24cb1772d205b84c7985c Mon Sep 17 00:00:00 2001 From: Konrad Rzeszutek Wilk Date: Fri, 11 Jul 2014 11:51:35 -0400 Subject: 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 Reviewed-by: David Vrabel --- [v2: s/off/xen_nopv/ per Boris Ostrovsky recommendation.] [v3: Add Reviewed-by] [v4: Clarify that this is only for HVM guests] --- Documentation/kernel-parameters.txt | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'Documentation') diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index c1b9aa8c5a5..403f927276c 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: ,,,,,[,[,[,]]] -- cgit v1.2.3-70-g09d2 From 8b63c998b31c69fff2c8c8c7e543e3142d9eea71 Mon Sep 17 00:00:00 2001 From: Konrad Rzeszutek Wilk Date: Mon, 14 Jul 2014 12:18:51 -0400 Subject: xen-pciback: Document the 'quirks' sysfs file Signed-off-by: Konrad Rzeszutek Wilk Signed-off-by: David Vrabel --- Documentation/ABI/testing/sysfs-driver-pciback | 13 +++++++++++++ 1 file changed, 13 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-driver-pciback (limited to 'Documentation') diff --git a/Documentation/ABI/testing/sysfs-driver-pciback b/Documentation/ABI/testing/sysfs-driver-pciback new file mode 100644 index 00000000000..6a733bfa37e --- /dev/null +++ b/Documentation/ABI/testing/sysfs-driver-pciback @@ -0,0 +1,13 @@ +What: /sys/bus/pci/drivers/pciback/quirks +Date: Oct 2011 +KernelVersion: 3.1 +Contact: xen-devel@lists.xenproject.org +Description: + If the permissive attribute is set, then writing a string in + the format of DDDD:BB:DD.F-REG:SIZE:MASK will allow the guest + to write and read from the PCI device. That is Domain:Bus: + Device.Function-Register:Size:Mask (Domain is optional). + For example: + #echo 00:19.0-E0:2:FF > /sys/bus/pci/drivers/pciback/quirks + will allow the guest to read and write to the configuration + register 0x0E. -- cgit v1.2.3-70-g09d2