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[xen master] cpufreq: Add Hardware P-State (HWP) driver



commit 99c4570f820969adbd798c3eba4eed3917ebe774
Author:     Jason Andryuk <jandryuk@xxxxxxxxx>
AuthorDate: Mon Aug 7 14:51:10 2023 -0400
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Wed Aug 23 10:06:24 2023 +0200

    cpufreq: Add Hardware P-State (HWP) driver
    
    From the Intel SDM: "Hardware-Controlled Performance States (HWP), which
    autonomously selects performance states while utilizing OS supplied
    performance guidance hints."
    
    Enable HWP to run in autonomous mode by poking the correct MSRs.  HWP is
    disabled by default, and cpufreq=hwp enables it.
    
    cpufreq= parsing is expanded to allow cpufreq=hwp;xen.  This allows
    trying HWP and falling back to xen if not available.  Only hwp and xen
    are supported for this fallback feature.  hdc is a sub-option under hwp
    (i.e.  cpufreq=hwp,hdc=0) as is verbose.
    
    There is no interface to configure - xen_sysctl_pm_op/xenpm will
    be extended to configure in subsequent patches.  It will run with the
    default values, which should be the default 0x80 (out of 0x0-0xff)
    energy/performance preference.
    
    Unscientific powertop measurement of an mostly idle, customized OpenXT
    install:
    A 10th gen 6-core laptop showed battery discharge drop from ~9.x to
    ~7.x watts.
    A 8th gen 4-core laptop dropped from ~10 to ~9
    
    Power usage depends on many factors, especially display brightness, but
    this does show a power saving in balanced mode when CPU utilization is
    low.
    
    HWP isn't compatible with an external governor - it doesn't take
    explicit frequency requests.  Therefore a minimal internal governor,
    hwp, is also added as a placeholder.
    
    While adding to the xen-command-line.pandoc entry, un-nest verbose from
    minfreq.  They are independent.
    
    With cpufreq=hwp,verbose, HWP prints processor capabilities that are not
    used by the code, like HW_FEEDBACK.  This is done because otherwise
    there isn't a convenient way to query the information.
    
    Xen doesn't use the HWP interrupt, so it is disabled like in the Linux
    pstate driver.
    
    Signed-off-by: Jason Andryuk <jandryuk@xxxxxxxxx>
    Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
---
 docs/misc/xen-command-line.pandoc     |  20 +-
 xen/arch/x86/acpi/cpufreq/Makefile    |   1 +
 xen/arch/x86/acpi/cpufreq/cpufreq.c   |  21 +-
 xen/arch/x86/acpi/cpufreq/hwp.c       | 524 ++++++++++++++++++++++++++++++++++
 xen/arch/x86/include/asm/cpufeature.h |  12 +-
 xen/arch/x86/include/asm/msr-index.h  |  15 +-
 xen/drivers/cpufreq/cpufreq.c         |  59 +++-
 xen/include/acpi/cpufreq/cpufreq.h    |  10 +
 xen/include/public/sysctl.h           |   2 +
 9 files changed, 649 insertions(+), 15 deletions(-)

diff --git a/docs/misc/xen-command-line.pandoc 
b/docs/misc/xen-command-line.pandoc
index 4872b9098e..5f388eb560 100644
--- a/docs/misc/xen-command-line.pandoc
+++ b/docs/misc/xen-command-line.pandoc
@@ -499,7 +499,7 @@ If set, force use of the performance counters for oprofile, 
rather than detectin
 available support.
 
 ### cpufreq
-> `= none | {{ <boolean> | xen } 
[:[powersave|performance|ondemand|userspace][,<maxfreq>][,[<minfreq>][,[verbose]]]]}
 | dom0-kernel`
+> `= none | {{ <boolean> | xen } { 
[:[powersave|performance|ondemand|userspace][,[<maxfreq>]][,[<minfreq>]]] } 
[,verbose]} | dom0-kernel | hwp[:[<hdc>][,verbose]]`
 
 > Default: `xen`
 
@@ -510,6 +510,24 @@ choice of `dom0-kernel` is deprecated and not supported by 
all Dom0 kernels.
 * `<maxfreq>` and `<minfreq>` are integers which represent max and min 
processor frequencies
   respectively.
 * `verbose` option can be included as a string or also as `verbose=<integer>`
+  for `xen`.  It is a boolean for `hwp`.
+* `hwp` selects Hardware-Controlled Performance States (HWP) on supported Intel
+  hardware.  HWP is a Skylake+ feature which provides better CPU power
+  management.  The default is disabled.  If `hwp` is selected, but hardware
+  support is not available, Xen will fallback to cpufreq=xen.
+* `<hdc>` is a boolean to enable Hardware Duty Cycling (HDC).  HDC enables the
+  processor to autonomously force physical package components into idle state.
+  The default is enabled, but the option only applies when `hwp` is enabled.
+
+There is also support for `;`-separated fallback options:
+`cpufreq=hwp;xen,verbose`.  This first tries `hwp` and falls back to `xen` if
+unavailable.  Note: The `verbose` suboption is handled globally.  Setting it
+for either the primary or fallback option applies to both irrespective of where
+it is specified.
+
+Note: grub2 requires to escape or quote ';', so `"cpufreq=hwp;xen"` should be
+specified within double quotes inside grub.cfg.  Refer to the grub2
+documentation for more information.
 
 ### cpuid (x86)
 > `= List of comma separated booleans`
diff --git a/xen/arch/x86/acpi/cpufreq/Makefile 
b/xen/arch/x86/acpi/cpufreq/Makefile
index f75da9b9ca..db83aa6b14 100644
--- a/xen/arch/x86/acpi/cpufreq/Makefile
+++ b/xen/arch/x86/acpi/cpufreq/Makefile
@@ -1,2 +1,3 @@
 obj-y += cpufreq.o
+obj-y += hwp.o
 obj-y += powernow.o
diff --git a/xen/arch/x86/acpi/cpufreq/cpufreq.c 
b/xen/arch/x86/acpi/cpufreq/cpufreq.c
index f1cc473b4f..61b62c370a 100644
--- a/xen/arch/x86/acpi/cpufreq/cpufreq.c
+++ b/xen/arch/x86/acpi/cpufreq/cpufreq.c
@@ -642,7 +642,26 @@ static int __init cf_check cpufreq_driver_init(void)
         switch ( boot_cpu_data.x86_vendor )
         {
         case X86_VENDOR_INTEL:
-            ret = cpufreq_register_driver(&acpi_cpufreq_driver);
+            ret = -ENOENT;
+
+            for ( unsigned int i = 0; i < cpufreq_xen_cnt; i++ )
+            {
+                switch ( cpufreq_xen_opts[i] )
+                {
+                case CPUFREQ_xen:
+                    ret = cpufreq_register_driver(&acpi_cpufreq_driver);
+                    break;
+                case CPUFREQ_hwp:
+                    ret = hwp_register_driver();
+                    break;
+                case CPUFREQ_none:
+                    ret = 0;
+                    break;
+                }
+
+                if ( ret != -ENODEV )
+                    break;
+            }
             break;
 
         case X86_VENDOR_AMD:
diff --git a/xen/arch/x86/acpi/cpufreq/hwp.c b/xen/arch/x86/acpi/cpufreq/hwp.c
new file mode 100644
index 0000000000..932786ccca
--- /dev/null
+++ b/xen/arch/x86/acpi/cpufreq/hwp.c
@@ -0,0 +1,524 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * hwp.c cpufreq driver to run Intel Hardware P-States (HWP)
+ *
+ * Copyright (C) 2021 Jason Andryuk <jandryuk@xxxxxxxxx>
+ */
+
+#include <xen/cpumask.h>
+#include <xen/init.h>
+#include <xen/param.h>
+#include <xen/xmalloc.h>
+#include <asm/msr.h>
+#include <acpi/cpufreq/cpufreq.h>
+
+static bool __ro_after_init feature_hwp_notification;
+static bool __ro_after_init feature_hwp_activity_window;
+
+static bool __ro_after_init feature_hdc;
+
+static bool __ro_after_init opt_cpufreq_hdc = true;
+
+union hwp_request
+{
+    struct
+    {
+        unsigned int min_perf:8;
+        unsigned int max_perf:8;
+        unsigned int desired:8;
+        unsigned int energy_perf:8;
+        unsigned int activity_window:10;
+        bool package_control:1;
+        unsigned int :16;
+        bool activity_window_valid:1;
+        bool energy_perf_valid:1;
+        bool desired_valid:1;
+        bool max_perf_valid:1;
+        bool min_perf_valid:1;
+    };
+    uint64_t raw;
+};
+
+struct hwp_drv_data
+{
+    union
+    {
+        uint64_t hwp_caps;
+        struct
+        {
+            unsigned int highest:8;
+            unsigned int guaranteed:8;
+            unsigned int most_efficient:8;
+            unsigned int lowest:8;
+            unsigned int :32;
+        } hw;
+    };
+    union hwp_request curr_req;
+    int ret;
+    uint16_t activity_window;
+    uint8_t minimum;
+    uint8_t maximum;
+    uint8_t desired;
+    uint8_t energy_perf;
+};
+static DEFINE_PER_CPU_READ_MOSTLY(struct hwp_drv_data *, hwp_drv_data);
+
+#define hwp_err(cpu, fmt, args...) \
+    printk(XENLOG_ERR "HWP: CPU%u error: " fmt, cpu, ## args)
+#define hwp_info(fmt, args...)    printk(XENLOG_INFO "HWP: " fmt, ## args)
+#define hwp_verbose(fmt, args...)                         \
+({                                                        \
+    if ( cpufreq_verbose )                                \
+        printk(XENLOG_DEBUG "HWP: " fmt, ## args);        \
+})
+
+static int cf_check hwp_governor(struct cpufreq_policy *policy,
+                                 unsigned int event)
+{
+    int ret;
+
+    if ( policy == NULL )
+        return -EINVAL;
+
+    switch ( event )
+    {
+    case CPUFREQ_GOV_START:
+    case CPUFREQ_GOV_LIMITS:
+        ret = 0;
+        break;
+
+    case CPUFREQ_GOV_STOP:
+    default:
+        ret = -EINVAL;
+        break;
+    }
+
+    return ret;
+}
+
+static bool __init hwp_handle_option(const char *s, const char *end)
+{
+    int ret;
+
+    ret = parse_boolean("verbose", s, end);
+    if ( ret >= 0 )
+    {
+        cpufreq_verbose = ret;
+        return true;
+    }
+
+    ret = parse_boolean("hdc", s, end);
+    if ( ret >= 0 )
+    {
+        opt_cpufreq_hdc = ret;
+        return true;
+    }
+
+    return false;
+}
+
+int __init hwp_cmdline_parse(const char *s, const char *e)
+{
+    do
+    {
+        const char *end = strpbrk(s, ",;");
+
+        if ( !hwp_handle_option(s, end) )
+        {
+            printk(XENLOG_WARNING "cpufreq/hwp: option '%.*s' not 
recognized\n",
+                   (int)((end ?: e) - s), s);
+
+            return -EINVAL;
+        }
+
+        s = end ? ++end : end;
+    } while ( s && s < e );
+
+    return 0;
+}
+
+static struct cpufreq_governor cpufreq_gov_hwp =
+{
+    .name          = "hwp",
+    .governor      = hwp_governor,
+};
+
+static int __init cf_check cpufreq_gov_hwp_init(void)
+{
+    if ( !cpufreq_governor_internal )
+        return 0;
+
+    return cpufreq_register_governor(&cpufreq_gov_hwp);
+}
+__initcall(cpufreq_gov_hwp_init);
+
+static bool __init hwp_available(void)
+{
+    unsigned int eax;
+
+    if ( boot_cpu_data.cpuid_level < CPUID_PM_LEAF )
+    {
+        hwp_verbose("cpuid_level (%#x) lacks HWP support\n",
+                    boot_cpu_data.cpuid_level);
+
+        return false;
+    }
+
+    if ( boot_cpu_data.cpuid_level < 0x16 )
+    {
+        hwp_info("HWP disabled: cpuid_level %#x < 0x16 lacks CPU freq info\n",
+                 boot_cpu_data.cpuid_level);
+
+        return false;
+    }
+
+    eax = cpuid_eax(CPUID_PM_LEAF);
+
+    hwp_verbose("%d notify: %d act-window: %d energy-perf: %d pkg-level: %d 
peci: %d\n",
+                !!(eax & CPUID6_EAX_HWP),
+                !!(eax & CPUID6_EAX_HWP_NOTIFICATION),
+                !!(eax & CPUID6_EAX_HWP_ACTIVITY_WINDOW),
+                !!(eax & CPUID6_EAX_HWP_ENERGY_PERFORMANCE_PREFERENCE),
+                !!(eax & CPUID6_EAX_HWP_PACKAGE_LEVEL_REQUEST),
+                !!(eax & CPUID6_EAX_HWP_PECI));
+
+    if ( !(eax & CPUID6_EAX_HWP) )
+        return false;
+
+    if ( !(eax & CPUID6_EAX_HWP_ENERGY_PERFORMANCE_PREFERENCE) )
+    {
+        hwp_verbose("disabled: No energy/performance preference available");
+
+        return false;
+    }
+
+    feature_hwp_notification    = eax & CPUID6_EAX_HWP_NOTIFICATION;
+    feature_hwp_activity_window = eax & CPUID6_EAX_HWP_ACTIVITY_WINDOW;
+    feature_hdc                 = eax & CPUID6_EAX_HDC;
+
+    hwp_verbose("Hardware Duty Cycling (HDC) %ssupported%s\n",
+                feature_hdc ? "" : "not ",
+                feature_hdc ? opt_cpufreq_hdc ? ", enabled" : ", disabled"
+                            : "");
+
+    hwp_verbose("HW_FEEDBACK %ssupported\n",
+                (eax & CPUID6_EAX_HW_FEEDBACK) ? "" : "not ");
+
+    hwp_info("Using HWP for cpufreq\n");
+
+    return true;
+}
+
+static int cf_check hwp_cpufreq_verify(struct cpufreq_policy *policy)
+{
+    struct hwp_drv_data *data = per_cpu(hwp_drv_data, policy->cpu);
+
+    if ( !feature_hwp_activity_window && data->activity_window )
+    {
+        hwp_verbose("HWP activity window not supported\n");
+
+        return -EINVAL;
+    }
+
+    return 0;
+}
+
+static void cf_check hwp_write_request(void *info)
+{
+    const struct cpufreq_policy *policy = info;
+    struct hwp_drv_data *data = this_cpu(hwp_drv_data);
+    union hwp_request hwp_req = data->curr_req;
+
+    data->ret = 0;
+
+    BUILD_BUG_ON(sizeof(hwp_req) != sizeof(hwp_req.raw));
+    if ( wrmsr_safe(MSR_HWP_REQUEST, hwp_req.raw) )
+    {
+        hwp_verbose("CPU%u: error wrmsr_safe(MSR_HWP_REQUEST, %lx)\n",
+                    policy->cpu, hwp_req.raw);
+        rdmsr_safe(MSR_HWP_REQUEST, data->curr_req.raw);
+        data->ret = -EINVAL;
+    }
+}
+
+static int cf_check hwp_cpufreq_target(struct cpufreq_policy *policy,
+                                       unsigned int target_freq,
+                                       unsigned int relation)
+{
+    unsigned int cpu = policy->cpu;
+    struct hwp_drv_data *data = per_cpu(hwp_drv_data, cpu);
+    /* Zero everything to ensure reserved bits are zero... */
+    union hwp_request hwp_req = { .raw = 0 };
+
+    /* .. and update from there */
+    hwp_req.min_perf = data->minimum;
+    hwp_req.max_perf = data->maximum;
+    hwp_req.desired = data->desired;
+    hwp_req.energy_perf = data->energy_perf;
+    if ( feature_hwp_activity_window )
+        hwp_req.activity_window = data->activity_window;
+
+    if ( hwp_req.raw == data->curr_req.raw )
+        return 0;
+
+    data->curr_req = hwp_req;
+
+    on_selected_cpus(cpumask_of(cpu), hwp_write_request, policy, 1);
+
+    return data->ret;
+}
+
+static bool hdc_set_pkg_hdc_ctl(unsigned int cpu, bool val)
+{
+    uint64_t msr;
+
+    if ( rdmsr_safe(MSR_PKG_HDC_CTL, msr) )
+    {
+        hwp_err(cpu, "rdmsr_safe(MSR_PKG_HDC_CTL)\n");
+        return false;
+    }
+
+    if ( val )
+        msr |= PKG_HDC_CTL_HDC_PKG_ENABLE;
+    else
+        msr &= ~PKG_HDC_CTL_HDC_PKG_ENABLE;
+
+    if ( wrmsr_safe(MSR_PKG_HDC_CTL, msr) )
+    {
+        hwp_err(cpu, "wrmsr_safe(MSR_PKG_HDC_CTL): %016lx\n", msr);
+        return false;
+    }
+
+    return true;
+}
+
+static bool hdc_set_pm_ctl1(unsigned int cpu, bool val)
+{
+    uint64_t msr;
+
+    if ( rdmsr_safe(MSR_PM_CTL1, msr) )
+    {
+        hwp_err(cpu, "rdmsr_safe(MSR_PM_CTL1)\n");
+        return false;
+    }
+
+    if ( val )
+        msr |= PM_CTL1_HDC_ALLOW_BLOCK;
+    else
+        msr &= ~PM_CTL1_HDC_ALLOW_BLOCK;
+
+    if ( wrmsr_safe(MSR_PM_CTL1, msr) )
+    {
+        hwp_err(cpu, "wrmsr_safe(MSR_PM_CTL1): %016lx\n", msr);
+        return false;
+    }
+
+    return true;
+}
+
+static void hwp_get_cpu_speeds(struct cpufreq_policy *policy)
+{
+    uint32_t base_khz, max_khz, bus_khz, edx;
+
+    cpuid(0x16, &base_khz, &max_khz, &bus_khz, &edx);
+
+    /*
+     * Zero values are acceptable - they are not used for calculations
+     * and only returned to userspace.
+     */
+    policy->cpuinfo.perf_freq = base_khz * 1000;
+    policy->cpuinfo.min_freq = base_khz * 1000;
+    policy->cpuinfo.max_freq = max_khz * 1000;
+    policy->min = base_khz * 1000;
+    policy->max = max_khz * 1000;
+    policy->cur = 0;
+}
+
+static void cf_check hwp_init_msrs(void *info)
+{
+    struct cpufreq_policy *policy = info;
+    struct hwp_drv_data *data = this_cpu(hwp_drv_data);
+    uint64_t val;
+
+    /*
+     * Package level MSR, but we don't have a good idea of packages here, so
+     * just do it everytime.
+     */
+    if ( rdmsr_safe(MSR_PM_ENABLE, val) )
+    {
+        hwp_err(policy->cpu, "rdmsr_safe(MSR_PM_ENABLE)\n");
+        data->curr_req.raw = -1;
+        return;
+    }
+
+    /* Ensure we don't generate interrupts */
+    if ( feature_hwp_notification )
+        wrmsr_safe(MSR_HWP_INTERRUPT, 0);
+
+    if ( !(val & PM_ENABLE_HWP_ENABLE) )
+    {
+        val |= PM_ENABLE_HWP_ENABLE;
+        if ( wrmsr_safe(MSR_PM_ENABLE, val) )
+        {
+            hwp_err(policy->cpu, "wrmsr_safe(MSR_PM_ENABLE, %lx)\n", val);
+            data->curr_req.raw = -1;
+            return;
+        }
+    }
+
+    if ( rdmsr_safe(MSR_HWP_CAPABILITIES, data->hwp_caps) )
+    {
+        hwp_err(policy->cpu, "rdmsr_safe(MSR_HWP_CAPABILITIES)\n");
+        goto error;
+    }
+
+    if ( rdmsr_safe(MSR_HWP_REQUEST, data->curr_req.raw) )
+    {
+        hwp_err(policy->cpu, "rdmsr_safe(MSR_HWP_REQUEST)\n");
+        goto error;
+    }
+
+    /* Check for turbo support. */
+    intel_feature_detect(policy);
+
+    if ( feature_hdc &&
+         (!hdc_set_pkg_hdc_ctl(policy->cpu, opt_cpufreq_hdc) ||
+          !hdc_set_pm_ctl1(policy->cpu, opt_cpufreq_hdc)) )
+    {
+        hwp_err(policy->cpu, "Disabling HDC support\n");
+        feature_hdc = false;
+    }
+
+    hwp_get_cpu_speeds(policy);
+
+    return;
+
+ error:
+    data->curr_req.raw = -1;
+    val &= ~PM_ENABLE_HWP_ENABLE;
+    if ( wrmsr_safe(MSR_PM_ENABLE, val) )
+        hwp_err(policy->cpu, "wrmsr_safe(MSR_PM_ENABLE, %lx)\n", val);
+}
+
+static int cf_check hwp_cpufreq_cpu_init(struct cpufreq_policy *policy)
+{
+    static bool __read_mostly first_run = true;
+    static union hwp_request initial_req;
+    unsigned int cpu = policy->cpu;
+    struct hwp_drv_data *data;
+
+    data = xzalloc(struct hwp_drv_data);
+    if ( !data )
+        return -ENOMEM;
+
+    policy->governor = &cpufreq_gov_hwp;
+
+    per_cpu(hwp_drv_data, cpu) = data;
+
+    on_selected_cpus(cpumask_of(cpu), hwp_init_msrs, policy, 1);
+
+    if ( data->curr_req.raw == -1 )
+    {
+        hwp_err(cpu, "Could not initialize HWP properly\n");
+        per_cpu(hwp_drv_data, cpu) = NULL;
+        xfree(data);
+        return -ENODEV;
+    }
+
+    data->minimum = data->curr_req.min_perf;
+    data->maximum = data->curr_req.max_perf;
+    data->desired = data->curr_req.desired;
+    data->energy_perf = data->curr_req.energy_perf;
+    data->activity_window = data->curr_req.activity_window;
+
+    if ( first_run )
+    {
+        hwp_verbose("CPU%u: HWP_CAPABILITIES: %016lx\n", cpu, data->hwp_caps);
+        initial_req = data->curr_req;
+    }
+
+    if ( first_run || data->curr_req.raw != initial_req.raw )
+    {
+        hwp_verbose("CPU%u: rdmsr HWP_REQUEST %016lx\n", cpu,
+                    data->curr_req.raw);
+        first_run = false;
+    }
+
+    return 0;
+}
+
+static int cf_check hwp_cpufreq_cpu_exit(struct cpufreq_policy *policy)
+{
+    struct hwp_drv_data *data = per_cpu(hwp_drv_data, policy->cpu);
+
+    per_cpu(hwp_drv_data, policy->cpu) = NULL;
+    xfree(data);
+
+    return 0;
+}
+
+/*
+ * The SDM reads like turbo should be disabled with MSR_IA32_PERF_CTL and
+ * PERF_CTL_TURBO_DISENGAGE, but that does not seem to actually work, at least
+ * with testing on i7-10810U and i7-8550U.  MSR_MISC_ENABLE and
+ * MISC_ENABLE_TURBO_DISENGAGE is what Linux uses and seems to work.
+ */
+static void cf_check hwp_set_misc_turbo(void *info)
+{
+    const struct cpufreq_policy *policy = info;
+    struct hwp_drv_data *data = per_cpu(hwp_drv_data, policy->cpu);
+    uint64_t msr;
+
+    data->ret = 0;
+
+    if ( rdmsr_safe(MSR_IA32_MISC_ENABLE, msr) )
+    {
+        hwp_verbose("CPU%u: error rdmsr_safe(MSR_IA32_MISC_ENABLE)\n",
+                    policy->cpu);
+        data->ret = -EACCES;
+
+        return;
+    }
+
+    if ( policy->turbo == CPUFREQ_TURBO_ENABLED )
+        msr &= ~MSR_IA32_MISC_ENABLE_TURBO_DISENGAGE;
+    else
+        msr |= MSR_IA32_MISC_ENABLE_TURBO_DISENGAGE;
+
+    if ( wrmsr_safe(MSR_IA32_MISC_ENABLE, msr) )
+    {
+        hwp_verbose("CPU%u: error wrmsr_safe(MSR_IA32_MISC_ENABLE): %016lx\n",
+                    policy->cpu, msr);
+        data->ret = -EACCES;
+    }
+}
+
+static int cf_check hwp_cpufreq_update(int cpuid, struct cpufreq_policy 
*policy)
+{
+    on_selected_cpus(cpumask_of(cpuid), hwp_set_misc_turbo, policy, 1);
+
+    return per_cpu(hwp_drv_data, cpuid)->ret;
+}
+
+static const struct cpufreq_driver __initconstrel hwp_cpufreq_driver =
+{
+    .name   = XEN_HWP_DRIVER_NAME,
+    .verify = hwp_cpufreq_verify,
+    .target = hwp_cpufreq_target,
+    .init   = hwp_cpufreq_cpu_init,
+    .exit   = hwp_cpufreq_cpu_exit,
+    .update = hwp_cpufreq_update,
+};
+
+int __init hwp_register_driver(void)
+{
+    int ret;
+
+    if ( !hwp_available() )
+        return -ENODEV;
+
+    ret = cpufreq_register_driver(&hwp_cpufreq_driver);
+    cpufreq_governor_internal = (ret == 0);
+
+    return ret;
+}
diff --git a/xen/arch/x86/include/asm/cpufeature.h 
b/xen/arch/x86/include/asm/cpufeature.h
index 835fcdb27c..0825343945 100644
--- a/xen/arch/x86/include/asm/cpufeature.h
+++ b/xen/arch/x86/include/asm/cpufeature.h
@@ -52,8 +52,16 @@ static inline bool boot_cpu_has(unsigned int feat)
     return cpu_has(&boot_cpu_data, feat);
 }
 
-#define CPUID_PM_LEAF                    6
-#define CPUID6_ECX_APERFMPERF_CAPABILITY 0x1
+#define CPUID_PM_LEAF                                6
+#define CPUID6_EAX_HWP                               BIT(7, U)
+#define CPUID6_EAX_HWP_NOTIFICATION                  BIT(8, U)
+#define CPUID6_EAX_HWP_ACTIVITY_WINDOW               BIT(9, U)
+#define CPUID6_EAX_HWP_ENERGY_PERFORMANCE_PREFERENCE BIT(10, U)
+#define CPUID6_EAX_HWP_PACKAGE_LEVEL_REQUEST         BIT(11, U)
+#define CPUID6_EAX_HDC                               BIT(13, U)
+#define CPUID6_EAX_HWP_PECI                          BIT(16, U)
+#define CPUID6_EAX_HW_FEEDBACK                       BIT(19, U)
+#define CPUID6_ECX_APERFMPERF_CAPABILITY             BIT(0, U)
 
 /* CPUID level 0x00000001.edx */
 #define cpu_has_fpu             1
diff --git a/xen/arch/x86/include/asm/msr-index.h 
b/xen/arch/x86/include/asm/msr-index.h
index 8df52eda88..0684ca9e21 100644
--- a/xen/arch/x86/include/asm/msr-index.h
+++ b/xen/arch/x86/include/asm/msr-index.h
@@ -156,6 +156,13 @@
 
 #define MSR_PKRS                            0x000006e1
 
+#define MSR_PM_ENABLE                       0x00000770
+#define  PM_ENABLE_HWP_ENABLE               BIT(0, ULL)
+
+#define MSR_HWP_CAPABILITIES                0x00000771
+#define MSR_HWP_INTERRUPT                   0x00000773
+#define MSR_HWP_REQUEST                     0x00000774
+
 #define MSR_X2APIC_FIRST                    0x00000800
 #define MSR_X2APIC_LAST                     0x000008ff
 
@@ -170,6 +177,11 @@
 #define  PASID_PASID_MASK                   0x000fffff
 #define  PASID_VALID                        (_AC(1, ULL) << 31)
 
+#define MSR_PKG_HDC_CTL                     0x00000db0
+#define  PKG_HDC_CTL_HDC_PKG_ENABLE         BIT(0, ULL)
+#define MSR_PM_CTL1                         0x00000db1
+#define  PM_CTL1_HDC_ALLOW_BLOCK            BIT(0, ULL)
+
 #define MSR_UARCH_MISC_CTRL                 0x00001b01
 #define  UARCH_CTRL_DOITM                   (_AC(1, ULL) <<  0)
 
@@ -473,7 +485,8 @@
 #define MSR_IA32_MISC_ENABLE_MONITOR_ENABLE (1<<18)
 #define MSR_IA32_MISC_ENABLE_LIMIT_CPUID  (1<<22)
 #define MSR_IA32_MISC_ENABLE_XTPR_DISABLE (1<<23)
-#define MSR_IA32_MISC_ENABLE_XD_DISABLE   (_AC(1, ULL) << 34)
+#define MSR_IA32_MISC_ENABLE_XD_DISABLE      (_AC(1, ULL) << 34)
+#define MSR_IA32_MISC_ENABLE_TURBO_DISENGAGE (_AC(1, ULL) << 38)
 
 #define MSR_IA32_TSC_DEADLINE          0x000006E0
 #define MSR_IA32_ENERGY_PERF_BIAS      0x000001b0
diff --git a/xen/drivers/cpufreq/cpufreq.c b/xen/drivers/cpufreq/cpufreq.c
index fdc245eb4e..6e5c400849 100644
--- a/xen/drivers/cpufreq/cpufreq.c
+++ b/xen/drivers/cpufreq/cpufreq.c
@@ -64,12 +64,19 @@ LIST_HEAD_READ_MOSTLY(cpufreq_governor_list);
 /* set xen as default cpufreq */
 enum cpufreq_controller cpufreq_controller = FREQCTL_xen;
 
-static int __init cpufreq_cmdline_parse(const char *s);
+enum cpufreq_xen_opt __initdata cpufreq_xen_opts[2] = { CPUFREQ_xen,
+                                                        CPUFREQ_none };
+unsigned int __initdata cpufreq_xen_cnt = 1;
+
+static int __init cpufreq_cmdline_parse(const char *s, const char *e);
 
 static int __init cf_check setup_cpufreq_option(const char *str)
 {
-    const char *arg = strpbrk(str, ",:");
+    const char *arg = strpbrk(str, ",:;");
     int choice;
+    int ret = -EINVAL;
+
+    cpufreq_xen_cnt = 0;
 
     if ( !arg )
         arg = strchr(str, '\0');
@@ -90,15 +97,45 @@ static int __init cf_check setup_cpufreq_option(const char 
*str)
         return 0;
     }
 
-    if ( choice > 0 || !cmdline_strcmp(str, "xen") )
+    do
     {
-        xen_processor_pmbits |= XEN_PROCESSOR_PM_PX;
-        cpufreq_controller = FREQCTL_xen;
-        if ( *arg && *(arg + 1) )
-            return cpufreq_cmdline_parse(arg + 1);
-    }
+        const char *end = strchr(str, ';');
+
+        if ( end == NULL )
+            end = strchr(str, '\0');
+
+        arg = strpbrk(str, ",:");
+        if ( !arg || arg > end )
+            arg = strchr(str, '\0');
+
+        if ( cpufreq_xen_cnt == ARRAY_SIZE(cpufreq_xen_opts) )
+            return -E2BIG;
+
+        if ( choice > 0 || !cmdline_strcmp(str, "xen") )
+        {
+            xen_processor_pmbits |= XEN_PROCESSOR_PM_PX;
+            cpufreq_controller = FREQCTL_xen;
+            cpufreq_xen_opts[cpufreq_xen_cnt++] = CPUFREQ_xen;
+            ret = 0;
+            if ( arg[0] && arg[1] )
+                ret = cpufreq_cmdline_parse(arg + 1, end);
+        }
+        else if ( choice < 0 && !cmdline_strcmp(str, "hwp") )
+        {
+            xen_processor_pmbits |= XEN_PROCESSOR_PM_PX;
+            cpufreq_controller = FREQCTL_xen;
+            cpufreq_xen_opts[cpufreq_xen_cnt++] = CPUFREQ_hwp;
+            ret = 0;
+            if ( arg[0] && arg[1] )
+                ret = hwp_cmdline_parse(arg + 1, end);
+        }
+        else
+            ret = -EINVAL;
+
+        str = *end ? ++end : end;
+    } while ( choice < 0 && ret == 0 && *str );
 
-    return (choice < 0) ? -EINVAL : 0;
+    return (choice < 0) ? ret : 0;
 }
 custom_param("cpufreq", setup_cpufreq_option);
 
@@ -577,7 +614,7 @@ static int __init cpufreq_handle_common_option(const char 
*name, const char *val
     return 0;
 }
 
-static int __init cpufreq_cmdline_parse(const char *s)
+static int __init cpufreq_cmdline_parse(const char *s, const char *e)
 {
     static struct cpufreq_governor *__initdata cpufreq_governors[] =
     {
@@ -593,6 +630,8 @@ static int __init cpufreq_cmdline_parse(const char *s)
     int rc = 0;
 
     strlcpy(buf, s, sizeof(buf));
+    if (e - s < sizeof(buf))
+        buf[e - s] = '\0';
     do {
         char *val, *end = strchr(str, ',');
         unsigned int i;
diff --git a/xen/include/acpi/cpufreq/cpufreq.h 
b/xen/include/acpi/cpufreq/cpufreq.h
index 482ea5b0de..cfe975814e 100644
--- a/xen/include/acpi/cpufreq/cpufreq.h
+++ b/xen/include/acpi/cpufreq/cpufreq.h
@@ -24,6 +24,13 @@ DECLARE_PER_CPU(spinlock_t, cpufreq_statistic_lock);
 
 extern bool_t cpufreq_verbose;
 
+enum cpufreq_xen_opt {
+    CPUFREQ_none,
+    CPUFREQ_xen,
+    CPUFREQ_hwp,
+};
+extern enum cpufreq_xen_opt cpufreq_xen_opts[2];
+extern unsigned int cpufreq_xen_cnt;
 struct cpufreq_governor;
 
 struct acpi_cpufreq_data {
@@ -245,4 +252,7 @@ void cpufreq_dbs_timer_resume(void);
 
 void intel_feature_detect(struct cpufreq_policy *policy);
 
+int hwp_cmdline_parse(const char *s, const char *e);
+int hwp_register_driver(void);
+
 #endif /* __XEN_CPUFREQ_PM_H__ */
diff --git a/xen/include/public/sysctl.h b/xen/include/public/sysctl.h
index c11c0b1a6c..5a30b16fcf 100644
--- a/xen/include/public/sysctl.h
+++ b/xen/include/public/sysctl.h
@@ -296,6 +296,8 @@ struct xen_ondemand {
     uint32_t up_threshold;
 };
 
+#define XEN_HWP_DRIVER_NAME "hwp"
+
 /*
  * cpufreq para name of this structure named
  * same as sysfs file name of native linux
--
generated by git-patchbot for /home/xen/git/xen.git#master



 


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