From 32068f6527b8f1822a30671dedaf59c567325026 Mon Sep 17 00:00:00 2001 From: Olaf Hering <[mailto:olaf@aepfle.de]> Date: Sun, 3 Feb 2013 17:22:37 -0800 Subject: x86: Hyper-V: register clocksource only if its advertised Enable hyperv_clocksource only if its advertised as a feature. XenServer 6 returns the signature which is checked in ms_hyperv_platform(), but it does not offer all features. Currently the clocksource is enabled unconditionally in ms_hyperv_init_platform(), and the result is a hanging guest. Hyper-V spec Bit 1 indicates the availability of Partition Reference Counter. Register the clocksource only if this bit is set. The guest in question prints this in dmesg: [ 0.000000] Hypervisor detected: Microsoft HyperV [ 0.000000] HyperV: features 0x70, hints 0x0 This bug can be reproduced easily be setting 'viridian=1' in a HVM domU .cfg file. A workaround without this patch is to boot the HVM guest with 'clocksource=jiffies'. Signed-off-by: Olaf Hering Link: http://lkml.kernel.org/r/1359940959-32168-1-git-send-email-kys@microsoft.com Signed-off-by: K. Y. Srinivasan Cc: Cc: Greg KH Signed-off-by: H. Peter Anvin diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c index 0a630dd..646d192 100644 --- a/arch/x86/kernel/cpu/mshyperv.c +++ b/arch/x86/kernel/cpu/mshyperv.c @@ -68,7 +68,8 @@ static void __init ms_hyperv_init_platform(void) printk(KERN_INFO "HyperV: features 0x%x, hints 0x%x\n", ms_hyperv.features, ms_hyperv.hints); - clocksource_register_hz(&hyperv_cs, NSEC_PER_SEC/100); + if (ms_hyperv.features & HV_X64_MSR_TIME_REF_COUNT_AVAILABLE) + clocksource_register_hz(&hyperv_cs, NSEC_PER_SEC/100); } const __refconst struct hypervisor_x86 x86_hyper_ms_hyperv = { -- cgit v0.10.2 From db34bbb767bdfa1ebed7214b876fe01c5b7ee457 Mon Sep 17 00:00:00 2001 From: "K. Y. Srinivasan" Date: Sun, 3 Feb 2013 17:22:38 -0800 Subject: X86: Add a check to catch Xen emulation of Hyper-V Xen emulates Hyper-V to host enlightened Windows. Looks like this emulation may be turned on by default even for Linux guests. Check and fail Hyper-V detection if we are on Xen. [ hpa: the problem here is that Xen doesn't emulate Hyper-V well enough, and if the Xen support isn't compiled in, we end up stubling over the Hyper-V emulation and try to activate it -- and it fails. ] Signed-off-by: K. Y. Srinivasan Link: http://lkml.kernel.org/r/1359940959-32168-2-git-send-email-kys@microsoft.com Signed-off-by: H. Peter Anvin diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c index 646d192..4dab317 100644 --- a/arch/x86/kernel/cpu/mshyperv.c +++ b/arch/x86/kernel/cpu/mshyperv.c @@ -30,6 +30,13 @@ static bool __init ms_hyperv_platform(void) if (!boot_cpu_has(X86_FEATURE_HYPERVISOR)) return false; + /* + * Xen emulates Hyper-V to support enlightened Windows. + * Check to see first if we are on a Xen Hypervisor. + */ + if (xen_cpuid_base()) + return false; + cpuid(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS, &eax, &hyp_signature[0], &hyp_signature[1], &hyp_signature[2]); -- cgit v0.10.2 From bc2b0331e077f576369a2b6c75d15ed4de4ef91f Mon Sep 17 00:00:00 2001 From: "K. Y. Srinivasan" Date: Sun, 3 Feb 2013 17:22:39 -0800 Subject: X86: Handle Hyper-V vmbus interrupts as special hypervisor interrupts Starting with win8, vmbus interrupts can be delivered on any VCPU in the guest and furthermore can be concurrently active on multiple VCPUs. Support this interrupt delivery model by setting up a separate IDT entry for Hyper-V vmbus. interrupts. I would like to thank Jan Beulich and Thomas Gleixner , for their help. In this version of the patch, based on the feedback, I have merged the IDT vector for Xen and Hyper-V and made the necessary adjustments. Furhermore, based on Jan's feedback I have added the necessary compilation switches. Signed-off-by: K. Y. Srinivasan Link: http://lkml.kernel.org/r/1359940959-32168-3-git-send-email-kys@microsoft.com Signed-off-by: H. Peter Anvin diff --git a/arch/x86/include/asm/irq_vectors.h b/arch/x86/include/asm/irq_vectors.h index 1508e51..aac5fa6 100644 --- a/arch/x86/include/asm/irq_vectors.h +++ b/arch/x86/include/asm/irq_vectors.h @@ -109,8 +109,8 @@ #define UV_BAU_MESSAGE 0xf5 -/* Xen vector callback to receive events in a HVM domain */ -#define XEN_HVM_EVTCHN_CALLBACK 0xf3 +/* Vector on which hypervisor callbacks will be delivered */ +#define HYPERVISOR_CALLBACK_VECTOR 0xf3 /* * Local APIC timer IRQ vector is on a different priority level, diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h index 79ce568..c2934be 100644 --- a/arch/x86/include/asm/mshyperv.h +++ b/arch/x86/include/asm/mshyperv.h @@ -11,4 +11,8 @@ struct ms_hyperv_info { extern struct ms_hyperv_info ms_hyperv; +void hyperv_callback_vector(void); +void hyperv_vector_handler(struct pt_regs *regs); +void hv_register_vmbus_handler(int irq, irq_handler_t handler); + #endif diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c index 4dab317..a7d26d8 100644 --- a/arch/x86/kernel/cpu/mshyperv.c +++ b/arch/x86/kernel/cpu/mshyperv.c @@ -14,10 +14,15 @@ #include #include #include +#include +#include #include #include #include #include +#include +#include +#include struct ms_hyperv_info ms_hyperv; EXPORT_SYMBOL_GPL(ms_hyperv); @@ -77,6 +82,12 @@ static void __init ms_hyperv_init_platform(void) if (ms_hyperv.features & HV_X64_MSR_TIME_REF_COUNT_AVAILABLE) clocksource_register_hz(&hyperv_cs, NSEC_PER_SEC/100); +#if IS_ENABLED(CONFIG_HYPERV) + /* + * Setup the IDT for hypervisor callback. + */ + alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR, hyperv_callback_vector); +#endif } const __refconst struct hypervisor_x86 x86_hyper_ms_hyperv = { @@ -85,3 +96,36 @@ const __refconst struct hypervisor_x86 x86_hyper_ms_hyperv = { .init_platform = ms_hyperv_init_platform, }; EXPORT_SYMBOL(x86_hyper_ms_hyperv); + +#if IS_ENABLED(CONFIG_HYPERV) +static int vmbus_irq = -1; +static irq_handler_t vmbus_isr; + +void hv_register_vmbus_handler(int irq, irq_handler_t handler) +{ + vmbus_irq = irq; + vmbus_isr = handler; +} + +void hyperv_vector_handler(struct pt_regs *regs) +{ + struct pt_regs *old_regs = set_irq_regs(regs); + struct irq_desc *desc; + + irq_enter(); + exit_idle(); + + desc = irq_to_desc(vmbus_irq); + + if (desc) + generic_handle_irq_desc(vmbus_irq, desc); + + irq_exit(); + set_irq_regs(old_regs); +} +#else +void hv_register_vmbus_handler(int irq, irq_handler_t handler) +{ +} +#endif +EXPORT_SYMBOL_GPL(hv_register_vmbus_handler); diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S index 6ed91d9..8831176 100644 --- a/arch/x86/kernel/entry_32.S +++ b/arch/x86/kernel/entry_32.S @@ -1091,11 +1091,18 @@ ENTRY(xen_failsafe_callback) _ASM_EXTABLE(4b,9b) ENDPROC(xen_failsafe_callback) -BUILD_INTERRUPT3(xen_hvm_callback_vector, XEN_HVM_EVTCHN_CALLBACK, +BUILD_INTERRUPT3(xen_hvm_callback_vector, HYPERVISOR_CALLBACK_VECTOR, xen_evtchn_do_upcall) #endif /* CONFIG_XEN */ +#if IS_ENABLED(CONFIG_HYPERV) + +BUILD_INTERRUPT3(hyperv_callback_vector, HYPERVISOR_CALLBACK_VECTOR, + hyperv_vector_handler) + +#endif /* CONFIG_HYPERV */ + #ifdef CONFIG_FUNCTION_TRACER #ifdef CONFIG_DYNAMIC_FTRACE diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index cb3c591..048f224 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -1454,11 +1454,16 @@ ENTRY(xen_failsafe_callback) CFI_ENDPROC END(xen_failsafe_callback) -apicinterrupt XEN_HVM_EVTCHN_CALLBACK \ +apicinterrupt HYPERVISOR_CALLBACK_VECTOR \ xen_hvm_callback_vector xen_evtchn_do_upcall #endif /* CONFIG_XEN */ +#if IS_ENABLED(CONFIG_HYPERV) +apicinterrupt HYPERVISOR_CALLBACK_VECTOR \ + hyperv_callback_vector hyperv_vector_handler +#endif /* CONFIG_HYPERV */ + /* * Some functions should be protected against kprobes */ diff --git a/drivers/xen/events.c b/drivers/xen/events.c index 74d77df..22f77c5 100644 --- a/drivers/xen/events.c +++ b/drivers/xen/events.c @@ -1787,7 +1787,7 @@ void xen_callback_vector(void) int rc; uint64_t callback_via; if (xen_have_vector_callback) { - callback_via = HVM_CALLBACK_VECTOR(XEN_HVM_EVTCHN_CALLBACK); + callback_via = HVM_CALLBACK_VECTOR(HYPERVISOR_CALLBACK_VECTOR); rc = xen_set_callback_via(callback_via); if (rc) { printk(KERN_ERR "Request for Xen HVM callback vector" @@ -1798,8 +1798,9 @@ void xen_callback_vector(void) printk(KERN_INFO "Xen HVM callback vector for event delivery is " "enabled\n"); /* in the restore case the vector has already been allocated */ - if (!test_bit(XEN_HVM_EVTCHN_CALLBACK, used_vectors)) - alloc_intr_gate(XEN_HVM_EVTCHN_CALLBACK, xen_hvm_callback_vector); + if (!test_bit(HYPERVISOR_CALLBACK_VECTOR, used_vectors)) + alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR, + xen_hvm_callback_vector); } } #else -- cgit v0.10.2 From cb20e5f2c8d6ba7440a32f4d70c0755bceb36e78 Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin" Date: Tue, 12 Feb 2013 17:46:23 -0800 Subject: x86, hyperv: HYPERV depends on X86_LOCAL_APIC In order to compile in the special Hyper-V interrupt vector, we need infrastructure in arch/x86/apic/apic.c. At least for now, simply require CONFIG_X86_LOCAL_APIC in order to enable CONFIG_HYPERV. Link: http://lkml.kernel.org/r/tip-bc2b0331e077f576369a2b6c75d15ed4de4ef91f@git.kernel.org Cc: K. Y. Srinivasan Signed-off-by: H. Peter Anvin diff --git a/drivers/hv/Kconfig b/drivers/hv/Kconfig index b38ef6d..64630f1 100644 --- a/drivers/hv/Kconfig +++ b/drivers/hv/Kconfig @@ -2,7 +2,7 @@ menu "Microsoft Hyper-V guest support" config HYPERV tristate "Microsoft Hyper-V client drivers" - depends on X86 && ACPI && PCI + depends on X86 && ACPI && PCI && X86_LOCAL_APIC help Select this option to run Linux as a Hyper-V client operating system. -- cgit v0.10.2