I am attaching a clocksource driver for HyperV. Signed-off-by: K. Y. Srinivasan <ksrinivasan at novell.com> -------------- next part -------------- An embedded and charset-unspecified text was scrubbed... Name: hyperv_clocksource.patch Url: http://lists.linux-foundation.org/pipermail/virtualization/attachments/20100405/80968881/attachment-0001.txt
I am attaching a clocksource driver for HyperV. Signed-off-by: K. Y. Srinivasan <ksrinivasan at novell.com> -------------- next part -------------- An embedded and charset-unspecified text was scrubbed... Name: hyperv_clocksource.patch Url: http://lists.linux-foundation.org/pipermail/virtualization/attachments/20100405/127f1113/attachment.txt
>>> On 4/5/2010 at 5:36 PM, in message < 4BBA57FB.2000406 at goop.org >, JeremyFitzhardinge < jeremy at goop.org > wrote:> On 04/05/2010 01:30 PM, Ky Srinivasan wrote: >> +static cycle_t read_hv_clock(struct clocksource *arg) >> +{ >> + cycle_t current_tick; >> + /* >> + * Read the partition counter to get the current tick count. This count >> + * is set to 0 when the partition is created and is incremented in >> + * 100 nanosecond units. >> + */ >> + rdmsrl(HV_X64_MSR_TIME_REF_COUNT, current_tick); >> + return current_tick; >> +} >> + >> +static struct clocksource clocksource_hyperv = { >> + .name = "hyperv_clocksource", >> > > Seems like a redundantly long name; any use of this string is going to > be in a context where it is obviously a clocksource. How about just > "hyperv"> >> + .rating = 400, /* use this when running on Hyperv*/ >> + .read = read_hv_clock, >> + .mask = CLOCKSOURCE_MASK(64), >> + .shift = HV_CLOCK_SHIFT, >> +}; >> + >> +static struct dmi_system_id __initconst >> +hv_timesource_dmi_table[] __maybe_unused = { >> + { >> + .ident = "Hyper-V", >> + .matches = { >> + DMI_MATCH(DMI_SYS_VENDOR, "Microsoft Corporation"), >> + DMI_MATCH(DMI_PRODUCT_NAME, "Virtual Machine"), >> + DMI_MATCH(DMI_BOARD_NAME, "Virtual Machine"), >> + }, >> + }, >> + { }, >> +}; >> +MODULE_DEVICE_TABLE(dmi, hv_timesource_dmi_table); >> > > So you use the DMI signatures to determine whether the module is needed, > but cpuid to work out if the feature is present? > >> + >> +static struct pci_device_id __initconst >> +hv_timesource_pci_table[] __maybe_unused = { >> + { PCI_DEVICE(0x1414, 0x5353) }, /* VGA compatible controller */ >> + { 0 } >> +}; >> +MODULE_DEVICE_TABLE(pci, hv_timesource_pci_table); >> > > And/or PCI? > > Seems a bit... ad-hoc? Is this the official way to determine the > presence of Hyper-V?The presence of HyperV and our ability to use the partition-wide counter obviously is checked via probing the cpuid leaves. The DMI/PCI signatures are used in auto-loading these modules.> >> + >> + >> +static int __init hv_detect_hyperv(void) >> > > This looks generally useful. Should it be hidden away in the > clocksource driver, or in some common hyper-v code? Do other hyper-v > drivers have versions of this?Good point. Right now, I can think of multiple drivers replicating this code. We could include hyperV detection code in cpu/hypervisor.c . I will spin up a patch for doing that shortly.> >> +{ >> + u32 eax, ebx, ecx, edx; >> + static char hyp_signature[20]; >> > 20? static? > >> + >> + cpuid(1,&eax,&ebx,&ecx,&edx); >> + if (!(ecx& HV_HYPERVISOR_PRESENT_BIT)) { >> + printk(KERN_WARNING >> + "Not on a Hypervisor\n"); >> > This just looks like noise, especially since it doesn't identify what is > generating the message. And if you compile this code in as =y > (non-modular) then it will complain every boot. > >> + return 1; >> + } >> + cpuid(HV_CPUID_SIGNATURE,&eax,&ebx,&ecx,&edx); >> + *(u32 *)(hyp_signature + 0) = ebx; >> + *(u32 *)(hyp_signature + 4) = ecx; >> + *(u32 *)(hyp_signature + 8) = edx; >> + hyp_signature[12] = 0; >> + >> + if ((eax< HV_CPUID_MIN) || (strcmp("Microsoft Hv", hyp_signature))) { >> > > memcmp, surely? > >> + printk(KERN_WARNING >> + "Not on HyperV; signature %s, eax %x\n", >> + hyp_signature, eax); >> + return 1; >> + } >> + /* >> + * Extract the features, recommendations etc. >> + */ >> + cpuid(HV_CPUID_FEATURES,&eax,&ebx,&ecx,&edx); >> + if (!(eax& 0x10)) { >> + printk(KERN_WARNING "HyperV Time Ref Counter not available!\n"); >> + return 1; >> + } >> + >> + cpuid(HV_CPUID_RECOMMENDATIONS,&eax,&ebx,&ecx,&edx); >> + printk(KERN_INFO "HyperV recommendations: %x\n", eax); >> + printk(KERN_INFO "HyperV spin count: %x\n", ebx); >> + return 0; >> +} >> + >> + >> +static int __init init_hv_clocksource(void) >> +{ >> + if (hv_detect_hyperv()) >> + return -ENODEV;>> + /* >> + * The time ref counter in HyperV is in 100ns units. >> + * The definition of mult is: >> + * mult/2^shift = ns/cyc = 100 >> + * mult = (100<< shift) >> + */ >> + clocksource_hyperv.mult = (100<< HV_CLOCK_SHIFT); >> > > Why not initialize this in the structure? It's just 100<<22 isn't it? > >> + printk(KERN_INFO "Registering HyperV clock source\n"); >> + return clocksource_register(&clocksource_hyperv); >> +} >> + >> +module_init(init_hv_clocksource); >> +MODULE_DESCRIPTION("HyperV based clocksource"); >> +MODULE_AUTHOR("K. Y. Srinivasan< ksrinivasan at novell.com >"); >> +MODULE_LICENSE("GPL"); >> Index: linux/drivers/staging/hv/Makefile >> ==================================================================>> --- linux.orig/drivers/staging/hv/Makefile 2010-04-05 13:02:06.000000000 -0600 >> +++ linux/drivers/staging/hv/Makefile 2010-04-05 13:02:13.000000000 -0600 >> @@ -1,4 +1,4 @@ >> -obj-$(CONFIG_HYPERV) += hv_vmbus.o >> +obj-$(CONFIG_HYPERV) += hv_vmbus.o hv_timesource.o >> obj-$(CONFIG_HYPERV_STORAGE) += hv_storvsc.o >> obj-$(CONFIG_HYPERV_BLOCK) += hv_blkvsc.o >> obj-$(CONFIG_HYPERV_NET) += hv_netvsc.o >>Jeremy, thank you for your comments. I am attaching the next version of this patch that addresses the comments I have gotten thus far. Regards, K. Y -------------- next part -------------- An embedded and charset-unspecified text was scrubbed... Name: hyperv_clocksource.patch Url: http://lists.linux-foundation.org/pipermail/virtualization/attachments/20100407/511182a8/attachment-0001.txt
>>> On 4/5/2010 at 5:36 PM, in message < 4BBA57FB.2000406 at goop.org >, JeremyFitzhardinge < jeremy at goop.org > wrote:> On 04/05/2010 01:30 PM, Ky Srinivasan wrote: >> +static cycle_t read_hv_clock(struct clocksource *arg) >> +{ >> + cycle_t current_tick; >> + /* >> + * Read the partition counter to get the current tick count. This count >> + * is set to 0 when the partition is created and is incremented in >> + * 100 nanosecond units. >> + */ >> + rdmsrl(HV_X64_MSR_TIME_REF_COUNT, current_tick); >> + return current_tick; >> +} >> + >> +static struct clocksource clocksource_hyperv = { >> + .name = "hyperv_clocksource", >> > > Seems like a redundantly long name; any use of this string is going to > be in a context where it is obviously a clocksource. How about just > "hyperv"> >> + .rating = 400, /* use this when running on Hyperv*/ >> + .read = read_hv_clock, >> + .mask = CLOCKSOURCE_MASK(64), >> + .shift = HV_CLOCK_SHIFT, >> +}; >> + >> +static struct dmi_system_id __initconst >> +hv_timesource_dmi_table[] __maybe_unused = { >> + { >> + .ident = "Hyper-V", >> + .matches = { >> + DMI_MATCH(DMI_SYS_VENDOR, "Microsoft Corporation"), >> + DMI_MATCH(DMI_PRODUCT_NAME, "Virtual Machine"), >> + DMI_MATCH(DMI_BOARD_NAME, "Virtual Machine"), >> + }, >> + }, >> + { }, >> +}; >> +MODULE_DEVICE_TABLE(dmi, hv_timesource_dmi_table); >> > > So you use the DMI signatures to determine whether the module is needed, > but cpuid to work out if the feature is present? > >> + >> +static struct pci_device_id __initconst >> +hv_timesource_pci_table[] __maybe_unused = { >> + { PCI_DEVICE(0x1414, 0x5353) }, /* VGA compatible controller */ >> + { 0 } >> +}; >> +MODULE_DEVICE_TABLE(pci, hv_timesource_pci_table); >> > > And/or PCI? > > Seems a bit... ad-hoc? Is this the official way to determine the > presence of Hyper-V?The presence of HyperV and our ability to use the partition-wide counter obviously is checked via probing the cpuid leaves. The DMI/PCI signatures are used in auto-loading these modules.> >> + >> + >> +static int __init hv_detect_hyperv(void) >> > > This looks generally useful. Should it be hidden away in the > clocksource driver, or in some common hyper-v code? Do other hyper-v > drivers have versions of this?Good point. Right now, I can think of multiple drivers replicating this code. We could include hyperV detection code in cpu/hypervisor.c . I will spin up a patch for doing that shortly.> >> +{ >> + u32 eax, ebx, ecx, edx; >> + static char hyp_signature[20]; >> > 20? static? > >> + >> + cpuid(1,&eax,&ebx,&ecx,&edx); >> + if (!(ecx& HV_HYPERVISOR_PRESENT_BIT)) { >> + printk(KERN_WARNING >> + "Not on a Hypervisor\n"); >> > This just looks like noise, especially since it doesn't identify what is > generating the message. And if you compile this code in as =y > (non-modular) then it will complain every boot. > >> + return 1; >> + } >> + cpuid(HV_CPUID_SIGNATURE,&eax,&ebx,&ecx,&edx); >> + *(u32 *)(hyp_signature + 0) = ebx; >> + *(u32 *)(hyp_signature + 4) = ecx; >> + *(u32 *)(hyp_signature + 8) = edx; >> + hyp_signature[12] = 0; >> + >> + if ((eax< HV_CPUID_MIN) || (strcmp("Microsoft Hv", hyp_signature))) { >> > > memcmp, surely? > >> + printk(KERN_WARNING >> + "Not on HyperV; signature %s, eax %x\n", >> + hyp_signature, eax); >> + return 1; >> + } >> + /* >> + * Extract the features, recommendations etc. >> + */ >> + cpuid(HV_CPUID_FEATURES,&eax,&ebx,&ecx,&edx); >> + if (!(eax& 0x10)) { >> + printk(KERN_WARNING "HyperV Time Ref Counter not available!\n"); >> + return 1; >> + } >> + >> + cpuid(HV_CPUID_RECOMMENDATIONS,&eax,&ebx,&ecx,&edx); >> + printk(KERN_INFO "HyperV recommendations: %x\n", eax); >> + printk(KERN_INFO "HyperV spin count: %x\n", ebx); >> + return 0; >> +} >> + >> + >> +static int __init init_hv_clocksource(void) >> +{ >> + if (hv_detect_hyperv()) >> + return -ENODEV;>> + /* >> + * The time ref counter in HyperV is in 100ns units. >> + * The definition of mult is: >> + * mult/2^shift = ns/cyc = 100 >> + * mult = (100<< shift) >> + */ >> + clocksource_hyperv.mult = (100<< HV_CLOCK_SHIFT); >> > > Why not initialize this in the structure? It's just 100<<22 isn't it? > >> + printk(KERN_INFO "Registering HyperV clock source\n"); >> + return clocksource_register(&clocksource_hyperv); >> +} >> + >> +module_init(init_hv_clocksource); >> +MODULE_DESCRIPTION("HyperV based clocksource"); >> +MODULE_AUTHOR("K. Y. Srinivasan< ksrinivasan at novell.com >"); >> +MODULE_LICENSE("GPL"); >> Index: linux/drivers/staging/hv/Makefile >> ==================================================================>> --- linux.orig/drivers/staging/hv/Makefile 2010-04-05 13:02:06.000000000 -0600 >> +++ linux/drivers/staging/hv/Makefile 2010-04-05 13:02:13.000000000 -0600 >> @@ -1,4 +1,4 @@ >> -obj-$(CONFIG_HYPERV) += hv_vmbus.o >> +obj-$(CONFIG_HYPERV) += hv_vmbus.o hv_timesource.o >> obj-$(CONFIG_HYPERV_STORAGE) += hv_storvsc.o >> obj-$(CONFIG_HYPERV_BLOCK) += hv_blkvsc.o >> obj-$(CONFIG_HYPERV_NET) += hv_netvsc.o >>Jeremy, thank you for your comments. I am attaching the next version of this patch that addresses the comments I have gotten thus far. Regards, K. Y -------------- next part -------------- An embedded and charset-unspecified text was scrubbed... Name: hyperv_clocksource.patch Url: http://lists.linux-foundation.org/pipermail/virtualization/attachments/20100407/6d2169ac/attachment.txt