From 6b08cd6328c58a2ae190c5ee03a2ffcab5ef828e Mon Sep 17 00:00:00 2001 From: Boris Ostrovsky Date: Mon, 10 Aug 2015 16:34:36 -0400 Subject: [PATCH] xen/PMU: Intercept PMU-related MSR and APIC accesses Provide interfaces for recognizing accesses to PMU-related MSRs and LVTPC APIC and process these accesses in Xen PMU code. (The interrupt handler performs XENPMU_flush right away in the beginning since no PMU emulation is available. It will be added with a later patch). Signed-off-by: Boris Ostrovsky Reviewed-by: David Vrabel Signed-off-by: David Vrabel --- arch/x86/xen/apic.c | 5 +- arch/x86/xen/enlighten.c | 11 ++-- arch/x86/xen/pmu.c | 95 +++++++++++++++++++++++++++++++++- arch/x86/xen/pmu.h | 4 ++ include/xen/interface/xenpmu.h | 2 + 5 files changed, 109 insertions(+), 8 deletions(-) diff --git a/arch/x86/xen/apic.c b/arch/x86/xen/apic.c index d03ebfa89b9f..acda713ab5be 100644 --- a/arch/x86/xen/apic.c +++ b/arch/x86/xen/apic.c @@ -7,6 +7,7 @@ #include #include #include "xen-ops.h" +#include "pmu.h" #include "smp.h" static unsigned int xen_io_apic_read(unsigned apic, unsigned reg) @@ -72,8 +73,10 @@ static u32 xen_apic_read(u32 reg) static void xen_apic_write(u32 reg, u32 val) { - if (reg == APIC_LVTPC) + if (reg == APIC_LVTPC) { + (void)pmu_apic_update(reg); return; + } /* Warn to see if there's any stray references */ WARN(1,"register: %x, value: %x\n", reg, val); diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index 19072f91a8e2..fdaba49f6759 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -1031,6 +1031,9 @@ static u64 xen_read_msr_safe(unsigned int msr, int *err) { u64 val; + if (pmu_msr_read(msr, &val, err)) + return val; + val = native_read_msr_safe(msr, err); switch (msr) { case MSR_IA32_APICBASE: @@ -1077,17 +1080,13 @@ static int xen_write_msr_safe(unsigned int msr, unsigned low, unsigned high) Xen console noise. */ default: - ret = native_write_msr_safe(msr, low, high); + if (!pmu_msr_write(msr, low, high, &ret)) + ret = native_write_msr_safe(msr, low, high); } return ret; } -unsigned long long xen_read_pmc(int counter) -{ - return 0; -} - void xen_setup_shared_info(void) { if (!xen_feature(XENFEAT_auto_translated_physmap)) { diff --git a/arch/x86/xen/pmu.c b/arch/x86/xen/pmu.c index a4a6e4f04f37..f92b908e005f 100644 --- a/arch/x86/xen/pmu.c +++ b/arch/x86/xen/pmu.c @@ -51,6 +51,8 @@ static __read_mostly int amd_num_counters; /* Alias registers (0x4c1) for full-width writes to PMCs */ #define MSR_PMC_ALIAS_MASK (~(MSR_IA32_PERFCTR0 ^ MSR_IA32_PMC0)) +#define INTEL_PMC_TYPE_SHIFT 30 + static __read_mostly int intel_num_arch_counters, intel_num_fixed_counters; @@ -167,6 +169,91 @@ static int is_intel_pmu_msr(u32 msr_index, int *type, int *index) } } +bool pmu_msr_read(unsigned int msr, uint64_t *val, int *err) +{ + + if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD) { + if (is_amd_pmu_msr(msr)) { + *val = native_read_msr_safe(msr, err); + return true; + } + } else { + int type, index; + + if (is_intel_pmu_msr(msr, &type, &index)) { + *val = native_read_msr_safe(msr, err); + return true; + } + } + + return false; +} + +bool pmu_msr_write(unsigned int msr, uint32_t low, uint32_t high, int *err) +{ + if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD) { + if (is_amd_pmu_msr(msr)) { + *err = native_write_msr_safe(msr, low, high); + return true; + } + } else { + int type, index; + + if (is_intel_pmu_msr(msr, &type, &index)) { + *err = native_write_msr_safe(msr, low, high); + return true; + } + } + + return false; +} + +static unsigned long long xen_amd_read_pmc(int counter) +{ + uint32_t msr; + int err; + + msr = amd_counters_base + (counter * amd_msr_step); + return native_read_msr_safe(msr, &err); +} + +static unsigned long long xen_intel_read_pmc(int counter) +{ + int err; + uint32_t msr; + + if (counter & (1<pmu.l.lapic_lvtpc = val; + ret = HYPERVISOR_xenpmu_op(XENPMU_lvtpc_set, NULL); + + return ret; +} + /* perf callbacks */ static int xen_is_in_guest(void) { @@ -239,7 +326,7 @@ static void xen_convert_regs(const struct xen_pmu_regs *xen_regs, irqreturn_t xen_pmu_irq_handler(int irq, void *dev_id) { - int ret = IRQ_NONE; + int err, ret = IRQ_NONE; struct pt_regs regs; const struct xen_pmu_data *xenpmu_data = get_xenpmu_data(); @@ -248,6 +335,12 @@ irqreturn_t xen_pmu_irq_handler(int irq, void *dev_id) return ret; } + err = HYPERVISOR_xenpmu_op(XENPMU_flush, NULL); + if (err) { + pr_warn_once("%s: failed hypercall, err: %d\n", __func__, err); + return ret; + } + xen_convert_regs(&xenpmu_data->pmu.r.regs, ®s, xenpmu_data->pmu.pmu_flags); if (x86_pmu.handle_irq(®s)) diff --git a/arch/x86/xen/pmu.h b/arch/x86/xen/pmu.h index a76d2cf83581..af5f0ad94078 100644 --- a/arch/x86/xen/pmu.h +++ b/arch/x86/xen/pmu.h @@ -7,5 +7,9 @@ irqreturn_t xen_pmu_irq_handler(int irq, void *dev_id); void xen_pmu_init(int cpu); void xen_pmu_finish(int cpu); bool is_xen_pmu(int cpu); +bool pmu_msr_read(unsigned int msr, uint64_t *val, int *err); +bool pmu_msr_write(unsigned int msr, uint32_t low, uint32_t high, int *err); +int pmu_apic_update(uint32_t reg); +unsigned long long xen_read_pmc(int counter); #endif /* __XEN_PMU_H */ diff --git a/include/xen/interface/xenpmu.h b/include/xen/interface/xenpmu.h index ca42301949b5..139efc91bceb 100644 --- a/include/xen/interface/xenpmu.h +++ b/include/xen/interface/xenpmu.h @@ -20,6 +20,8 @@ #define XENPMU_feature_set 3 #define XENPMU_init 4 #define XENPMU_finish 5 +#define XENPMU_lvtpc_set 6 +#define XENPMU_flush 7 /* ` } */ -- 2.20.1