/*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to
* deal in the Software without restriction, including without limitation the
* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*/
#ifndef __XEN_PUBLIC_HVM_HVM_OP_H__
#define __XEN_PUBLIC_HVM_HVM_OP_H__
/* Get/set subcommands: the second argument of the hypercall is a
* pointer to a xen_hvm_param struct. */
#define HVMOP_set_param 0
#define HVMOP_get_param 1
struct xen_hvm_param {
domid_t domid; /* IN */
uint32_t index; /* IN */
uint64_t value; /* IN/OUT */
};
DEFINE_GUEST_HANDLE_STRUCT(xen_hvm_param);
/* Hint from PV drivers for pagetable destruction. */
#define HVMOP_pagetable_dying 9
struct xen_hvm_pagetable_dying {
/* Domain with a pagetable about to be destroyed. */
domid_t domid;
/* guest physical address of the toplevel pagetable dying */
aligned_u64 gpa;
};
typedef struct xen_hvm_pagetable_dying xen_hvm_pagetable_dying_t;
DEFINE_GUEST_HANDLE_STRUCT(xen_hvm_pagetable_dying_t);
enum hvmmem_type_t {
HVMMEM_ram_rw, /* Normal read/write guest RAM */
HVMMEM_ram_ro, /* Read-only; writes are discarded */
HVMMEM_mmio_dm, /* Reads and write go to the device model */
};
#define HVMOP_get_mem_type 15
/* Return hvmmem_type_t for the specified pfn. */
struct xen_hvm_get_mem_type {
/* Domain to be queried. */
domid_t domid;
/* OUT variable. */
uint16_t mem_type;
uint16_t pad[2]; /* align next field on 8-byte boundary */
/* IN variable. */
uint64_t pfn;
};
DEFINE_GUEST_HANDLE_STRUCT(xen_hvm_get_mem_type);
#endif /* __XEN_PUBLIC_HVM_HVM_OP_H__ */
rch' size='10' name='q' value=''/>
cpufreq: intel_pstate: Disable energy efficiency optimization
Some Kabylake desktop processors may not reach max turbo when running in
HWP mode, even if running under sustained 100% utilization.
This occurs when the HWP.EPP (Energy Performance Preference) is set to
"balance_power" (0x80) -- the default on most systems.
It occurs because the platform BIOS may erroneously enable an
energy-efficiency setting -- MSR_IA32_POWER_CTL BIT-EE, which is not
recommended to be enabled on this SKU.
On the failing systems, this BIOS issue was not discovered when the
desktop motherboard was tested with Windows, because the BIOS also
neglects to provide the ACPI/CPPC table, that Windows requires to enable
HWP, and so Windows runs in legacy P-state mode, where this setting has
no effect.
Linux' intel_pstate driver does not require ACPI/CPPC to enable HWP, and
so it runs in HWP mode, exposing this incorrect BIOS configuration.
There are several ways to address this problem.
First, Linux can also run in legacy P-state mode on this system.
As intel_pstate is how Linux enables HWP, booting with
"intel_pstate=disable"
will run in acpi-cpufreq/ondemand legacy p-state mode.
Or second, the "performance" governor can be used with intel_pstate,
which will modify HWP.EPP to 0.
Or third, starting in 4.10, the
/sys/devices/system/cpu/cpufreq/policy*/energy_performance_preference
attribute in can be updated from "balance_power" to "performance".
Or fourth, apply this patch, which fixes the erroneous setting of
MSR_IA32_POWER_CTL BIT_EE on this model, allowing the default
configuration to function as designed.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Reviewed-by: Len Brown <len.brown@intel.com>
Cc: 4.6+ <stable@vger.kernel.org> # 4.6+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>