diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S index 6ad064c8cf35e6fdfc9c384212a6f76c780ffd69..bef8e2b202a8c0a608fb3dad7e38fb58889ee88e 100644 --- a/arch/x86/entry/entry_32.S +++ b/arch/x86/entry/entry_32.S @@ -902,6 +902,9 @@ BUILD_INTERRUPT3(hyperv_callback_vector, HYPERVISOR_CALLBACK_VECTOR, BUILD_INTERRUPT3(hyperv_reenlightenment_vector, HYPERV_REENLIGHTENMENT_VECTOR, hyperv_reenlightenment_intr) +BUILD_INTERRUPT3(hv_stimer0_callback_vector, HYPERV_STIMER0_VECTOR, + hv_stimer0_vector_handler) + #endif /* CONFIG_HYPERV */ ENTRY(page_fault) diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index 805f52703ee3377f88180eb3467a34bf2bc40e87..5a11e324eacca239ce594cd7759fd0626d57e553 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -1135,6 +1135,9 @@ apicinterrupt3 HYPERVISOR_CALLBACK_VECTOR \ apicinterrupt3 HYPERV_REENLIGHTENMENT_VECTOR \ hyperv_reenlightenment_vector hyperv_reenlightenment_intr + +apicinterrupt3 HYPERV_STIMER0_VECTOR \ + hv_stimer0_callback_vector hv_stimer0_vector_handler #endif /* CONFIG_HYPERV */ idtentry debug do_debug has_error_code=0 paranoid=1 shift_ist=DEBUG_STACK diff --git a/arch/x86/include/asm/hardirq.h b/arch/x86/include/asm/hardirq.h index 7c341a74ec8c49c090257d9aa192bc8f6afa9517..5ea2afd4c8719cea73919db1241cdb093119d03e 100644 --- a/arch/x86/include/asm/hardirq.h +++ b/arch/x86/include/asm/hardirq.h @@ -40,6 +40,7 @@ typedef struct { #endif #if IS_ENABLED(CONFIG_HYPERV) unsigned int irq_hv_reenlightenment_count; + unsigned int hyperv_stimer0_count; #endif } ____cacheline_aligned irq_cpustat_t; diff --git a/arch/x86/include/asm/irq_vectors.h b/arch/x86/include/asm/irq_vectors.h index e71c1120426bbc9652539cae486762dd98098f19..404c5fdff859ded0e55325ac601ced0332910aac 100644 --- a/arch/x86/include/asm/irq_vectors.h +++ b/arch/x86/include/asm/irq_vectors.h @@ -106,9 +106,10 @@ #if IS_ENABLED(CONFIG_HYPERV) #define HYPERV_REENLIGHTENMENT_VECTOR 0xee +#define HYPERV_STIMER0_VECTOR 0xed #endif -#define LOCAL_TIMER_VECTOR 0xed +#define LOCAL_TIMER_VECTOR 0xec #define NR_VECTORS 256 diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h index 25283f7eb299e06ab703c11f7a2f95c0425f6a95..e73c4d0c06adae0215e1799e93113405b31fcbf5 100644 --- a/arch/x86/include/asm/mshyperv.h +++ b/arch/x86/include/asm/mshyperv.h @@ -173,6 +173,19 @@ void hv_remove_kexec_handler(void); void hv_setup_crash_handler(void (*handler)(struct pt_regs *regs)); void hv_remove_crash_handler(void); +/* + * Routines for stimer0 Direct Mode handling. + * On x86/x64, there are no percpu actions to take. + */ +void hv_stimer0_vector_handler(struct pt_regs *regs); +void hv_stimer0_callback_vector(void); +int hv_setup_stimer0_irq(int *irq, int *vector, void (*handler)(void)); +void hv_remove_stimer0_irq(int irq); + +static inline void hv_enable_stimer0_percpu_irq(int irq) {} +static inline void hv_disable_stimer0_percpu_irq(int irq) {} + + #if IS_ENABLED(CONFIG_HYPERV) extern struct clocksource *hyperv_cs; extern void *hv_hypercall_pg; diff --git a/arch/x86/include/uapi/asm/hyperv.h b/arch/x86/include/uapi/asm/hyperv.h index 099414345865d588e6c55b63078f8b168fc8e907..6c0c3a3b631cdab34d6bf82bae79c34e64503b8f 100644 --- a/arch/x86/include/uapi/asm/hyperv.h +++ b/arch/x86/include/uapi/asm/hyperv.h @@ -77,6 +77,9 @@ /* Crash MSR available */ #define HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE (1 << 10) +/* stimer Direct Mode is available */ +#define HV_X64_STIMER_DIRECT_MODE_AVAILABLE (1 << 19) + /* * Feature identification: EBX indicates which flags were specified at * partition creation. The format is the same as the partition creation diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c index 9340f41ce8d3d374ff4453638d88759ec5f72064..4488cf0dd499aa589f2ba250198c8f9b2f0e43e7 100644 --- a/arch/x86/kernel/cpu/mshyperv.c +++ b/arch/x86/kernel/cpu/mshyperv.c @@ -37,6 +37,7 @@ EXPORT_SYMBOL_GPL(ms_hyperv); #if IS_ENABLED(CONFIG_HYPERV) static void (*vmbus_handler)(void); +static void (*hv_stimer0_handler)(void); static void (*hv_kexec_handler)(void); static void (*hv_crash_handler)(struct pt_regs *regs); @@ -69,6 +70,41 @@ void hv_remove_vmbus_irq(void) EXPORT_SYMBOL_GPL(hv_setup_vmbus_irq); EXPORT_SYMBOL_GPL(hv_remove_vmbus_irq); +/* + * Routines to do per-architecture handling of stimer0 + * interrupts when in Direct Mode + */ + +__visible void __irq_entry hv_stimer0_vector_handler(struct pt_regs *regs) +{ + struct pt_regs *old_regs = set_irq_regs(regs); + + entering_irq(); + inc_irq_stat(hyperv_stimer0_count); + if (hv_stimer0_handler) + hv_stimer0_handler(); + ack_APIC_irq(); + + exiting_irq(); + set_irq_regs(old_regs); +} + +int hv_setup_stimer0_irq(int *irq, int *vector, void (*handler)(void)) +{ + *vector = HYPERV_STIMER0_VECTOR; + *irq = 0; /* Unused on x86/x64 */ + hv_stimer0_handler = handler; + return 0; +} +EXPORT_SYMBOL_GPL(hv_setup_stimer0_irq); + +void hv_remove_stimer0_irq(int irq) +{ + /* We have no way to deallocate the interrupt gate */ + hv_stimer0_handler = NULL; +} +EXPORT_SYMBOL_GPL(hv_remove_stimer0_irq); + void hv_setup_kexec_handler(void (*handler)(void)) { hv_kexec_handler = handler; @@ -257,6 +293,10 @@ static void __init ms_hyperv_init_platform(void) alloc_intr_gate(HYPERV_REENLIGHTENMENT_VECTOR, hyperv_reenlightenment_vector); + /* Setup the IDT for stimer0 */ + if (ms_hyperv.misc_features & HV_X64_STIMER_DIRECT_MODE_AVAILABLE) + alloc_intr_gate(HYPERV_STIMER0_VECTOR, + hv_stimer0_callback_vector); #endif } diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c index 45fb4d2565f80a451b04fbf9976f69a165efb2d3..328d027d829d215ef3f3732c9b47d55641746746 100644 --- a/arch/x86/kernel/irq.c +++ b/arch/x86/kernel/irq.c @@ -150,6 +150,13 @@ int arch_show_interrupts(struct seq_file *p, int prec) irq_stats(j)->irq_hv_reenlightenment_count); seq_puts(p, " Hyper-V reenlightenment interrupts\n"); } + if (test_bit(HYPERV_STIMER0_VECTOR, system_vectors)) { + seq_printf(p, "%*s: ", prec, "HVS"); + for_each_online_cpu(j) + seq_printf(p, "%10u ", + irq_stats(j)->hyperv_stimer0_count); + seq_puts(p, " Hyper-V stimer0 interrupts\n"); + } #endif seq_printf(p, "%*s: %10u\n", prec, "ERR", atomic_read(&irq_err_count)); #if defined(CONFIG_X86_IO_APIC) diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c index 31142b72f1b951ad365a4532d146e4873eeaf652..b1f6793acf4c2ebd4ca7bd9cf2cc02e458c8a937 100644 --- a/drivers/hv/hv.c +++ b/drivers/hv/hv.c @@ -27,7 +27,7 @@ #include #include #include -#include +#include #include #include #include @@ -38,6 +38,17 @@ struct hv_context hv_context = { .synic_initialized = false, }; +/* + * If false, we're using the old mechanism for stimer0 interrupts + * where it sends a VMbus message when it expires. The old + * mechanism is used when running on older versions of Hyper-V + * that don't support Direct Mode. While Hyper-V provides + * four stimer's per CPU, Linux uses only stimer0. + */ +static bool direct_mode_enabled; +static int stimer0_irq; +static int stimer0_vector; + #define HV_TIMER_FREQUENCY (10 * 1000 * 1000) /* 100ns period */ #define HV_MAX_MAX_DELTA_TICKS 0xffffffff #define HV_MIN_DELTA_TICKS 1 @@ -53,6 +64,8 @@ int hv_init(void) if (!hv_context.cpu_context) return -ENOMEM; + direct_mode_enabled = ms_hyperv.misc_features & + HV_X64_STIMER_DIRECT_MODE_AVAILABLE; return 0; } @@ -91,6 +104,21 @@ int hv_post_message(union hv_connection_id connection_id, return status & 0xFFFF; } +/* + * ISR for when stimer0 is operating in Direct Mode. Direct Mode + * does not use VMbus or any VMbus messages, so process here and not + * in the VMbus driver code. + */ + +static void hv_stimer0_isr(void) +{ + struct hv_per_cpu_context *hv_cpu; + + hv_cpu = this_cpu_ptr(hv_context.cpu_context); + hv_cpu->clk_evt->event_handler(hv_cpu->clk_evt); + add_interrupt_randomness(stimer0_vector, 0); +} + static int hv_ce_set_next_event(unsigned long delta, struct clock_event_device *evt) { @@ -108,6 +136,8 @@ static int hv_ce_shutdown(struct clock_event_device *evt) { hv_init_timer(HV_X64_MSR_STIMER0_COUNT, 0); hv_init_timer_config(HV_X64_MSR_STIMER0_CONFIG, 0); + if (direct_mode_enabled) + hv_disable_stimer0_percpu_irq(stimer0_irq); return 0; } @@ -116,11 +146,26 @@ static int hv_ce_set_oneshot(struct clock_event_device *evt) { union hv_timer_config timer_cfg; + timer_cfg.as_uint64 = 0; timer_cfg.enable = 1; timer_cfg.auto_enable = 1; - timer_cfg.sintx = VMBUS_MESSAGE_SINT; + if (direct_mode_enabled) { + /* + * When it expires, the timer will directly interrupt + * on the specified hardware vector/IRQ. + */ + timer_cfg.direct_mode = 1; + timer_cfg.apic_vector = stimer0_vector; + hv_enable_stimer0_percpu_irq(stimer0_irq); + } else { + /* + * When it expires, the timer will generate a VMbus message, + * to be handled by the normal VMbus interrupt handler. + */ + timer_cfg.direct_mode = 0; + timer_cfg.sintx = VMBUS_MESSAGE_SINT; + } hv_init_timer_config(HV_X64_MSR_STIMER0_CONFIG, timer_cfg.as_uint64); - return 0; } @@ -191,6 +236,11 @@ int hv_synic_alloc(void) INIT_LIST_HEAD(&hv_cpu->chan_list); } + if (direct_mode_enabled && + hv_setup_stimer0_irq(&stimer0_irq, &stimer0_vector, + hv_stimer0_isr)) + goto err; + return 0; err: return -ENOMEM; @@ -292,6 +342,9 @@ void hv_synic_clockevents_cleanup(void) if (!(ms_hyperv.features & HV_X64_MSR_SYNTIMER_AVAILABLE)) return; + if (direct_mode_enabled) + hv_remove_stimer0_irq(stimer0_irq); + for_each_present_cpu(cpu) { struct hv_per_cpu_context *hv_cpu = per_cpu_ptr(hv_context.cpu_context, cpu); diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h index 22300ec7b5567478bbeb607b84a0c6f6cd94c785..36d34fe3ccb32b1ebf8bc5229a1adb13e1e2d12b 100644 --- a/drivers/hv/hyperv_vmbus.h +++ b/drivers/hv/hyperv_vmbus.h @@ -57,7 +57,9 @@ union hv_timer_config { u64 periodic:1; u64 lazy:1; u64 auto_enable:1; - u64 reserved_z0:12; + u64 apic_vector:8; + u64 direct_mode:1; + u64 reserved_z0:3; u64 sintx:4; u64 reserved_z1:44; };