| Message ID | 1598287583-71762-8-git-send-email-mikelley@microsoft.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Enable Linux guests on Hyper-V on ARM64 | expand |
On Mon, Aug 24, 2020 at 6:48 PM Michael Kelley <mikelley@microsoft.com> wrote: > > /* > + * This function is invoked via the ACPI clocksource probe mechanism. We > + * don't actually use any values from the ACPI GTDT table, but we set up > + * the Hyper-V synthetic clocksource and do other initialization for > + * interacting with Hyper-V the first time. Using early_initcall to invoke > + * this function is too late because interrupts are already enabled at that > + * point, and hv_init_clocksource() must run before interrupts are enabled. > + * > + * 1. Setup the guest ID. > + * 2. Get features and hints info from Hyper-V > + * 3. Setup per-cpu VP indices. > + * 4. Initialize the Hyper-V clocksource. > + */ > + > +static int __init hyperv_init(struct acpi_table_header *table) > +{ > + struct hv_get_vp_registers_output result; > + u32 a, b, c, d; > + u64 guest_id; > + int i, cpuhp; > + > + /* > + * If we're in a VM on Hyper-V, the ACPI hypervisor_id field will > + * have the string "MsHyperV". > + */ > + if (strncmp((char *)&acpi_gbl_FADT.hypervisor_id, "MsHyperV", 8)) > + return -EINVAL; > + > + /* Setup the guest ID */ > + guest_id = generate_guest_id(0, LINUX_VERSION_CODE, 0); > + hv_set_vpreg(HV_REGISTER_GUEST_OSID, guest_id); > + > + /* Get the features and hints from Hyper-V */ > + hv_get_vpreg_128(HV_REGISTER_FEATURES, &result); > + ms_hyperv.features = result.as32.a; > + ms_hyperv.misc_features = result.as32.c; > + > + hv_get_vpreg_128(HV_REGISTER_ENLIGHTENMENTS, &result); > + ms_hyperv.hints = result.as32.a; > + > + pr_info("Hyper-V: Features 0x%x, hints 0x%x, misc 0x%x\n", > + ms_hyperv.features, ms_hyperv.hints, ms_hyperv.misc_features); > + > + /* > + * If Hyper-V has crash notifications, set crash_kexec_post_notifiers > + * so that we will report the panic to Hyper-V before running kdump. > + */ > + if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) > + crash_kexec_post_notifiers = true; > + > + /* Get information about the Hyper-V host version */ > + hv_get_vpreg_128(HV_REGISTER_HYPERVISOR_VERSION, &result); > + a = result.as32.a; > + b = result.as32.b; > + c = result.as32.c; > + d = result.as32.d; > + pr_info("Hyper-V: Host Build %d.%d.%d.%d-%d-%d\n", > + b >> 16, b & 0xFFFF, a, d & 0xFFFFFF, c, d >> 24); > + > + /* Allocate and initialize percpu VP index array */ > + hv_vp_index = kmalloc_array(num_possible_cpus(), sizeof(*hv_vp_index), > + GFP_KERNEL); > + if (!hv_vp_index) > + return -ENOMEM; > + > + for (i = 0; i < num_possible_cpus(); i++) > + hv_vp_index[i] = VP_INVAL; > + > + cpuhp = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, > + "arm64/hyperv_init:online", hv_cpu_init, NULL); > + if (cpuhp < 0) > + goto free_vp_index; > + > + hv_init_clocksource(); > + if (hv_stimer_alloc()) > + goto remove_cpuhp_state; > + > + hyperv_initialized = true; > + return 0; > + > +remove_cpuhp_state: > + cpuhp_remove_state(cpuhp); > +free_vp_index: > + kfree(hv_vp_index); > + hv_vp_index = NULL; > + return -EINVAL; > +} > +TIMER_ACPI_DECLARE(hyperv, ACPI_SIG_GTDT, hyperv_init); I think this has come up before, and I still don't consider it an acceptable hack to hook platform initialization code into the timer code. Please split out the timer into a standalone driver in drivers/clocksource that can get reviewed by the clocksource maintainers. Arnd
From: Arnd Bergmann <arnd@arndb.de> Sent: Monday, August 24, 2020 11:34 AM > > On Mon, Aug 24, 2020 at 6:48 PM Michael Kelley <mikelley@microsoft.com> wrote: > > > > /* > > + * This function is invoked via the ACPI clocksource probe mechanism. We > > + * don't actually use any values from the ACPI GTDT table, but we set up > > + * the Hyper-V synthetic clocksource and do other initialization for > > + * interacting with Hyper-V the first time. Using early_initcall to invoke > > + * this function is too late because interrupts are already enabled at that > > + * point, and hv_init_clocksource() must run before interrupts are enabled. > > + * > > + * 1. Setup the guest ID. > > + * 2. Get features and hints info from Hyper-V > > + * 3. Setup per-cpu VP indices. > > + * 4. Initialize the Hyper-V clocksource. > > + */ > > + > > +static int __init hyperv_init(struct acpi_table_header *table) > > +{ > > + struct hv_get_vp_registers_output result; > > + u32 a, b, c, d; > > + u64 guest_id; > > + int i, cpuhp; > > + > > + /* > > + * If we're in a VM on Hyper-V, the ACPI hypervisor_id field will > > + * have the string "MsHyperV". > > + */ > > + if (strncmp((char *)&acpi_gbl_FADT.hypervisor_id, "MsHyperV", 8)) > > + return -EINVAL; > > + > > + /* Setup the guest ID */ > > + guest_id = generate_guest_id(0, LINUX_VERSION_CODE, 0); > > + hv_set_vpreg(HV_REGISTER_GUEST_OSID, guest_id); > > + > > + /* Get the features and hints from Hyper-V */ > > + hv_get_vpreg_128(HV_REGISTER_FEATURES, &result); > > + ms_hyperv.features = result.as32.a; > > + ms_hyperv.misc_features = result.as32.c; > > + > > + hv_get_vpreg_128(HV_REGISTER_ENLIGHTENMENTS, &result); > > + ms_hyperv.hints = result.as32.a; > > + > > + pr_info("Hyper-V: Features 0x%x, hints 0x%x, misc 0x%x\n", > > + ms_hyperv.features, ms_hyperv.hints, ms_hyperv.misc_features); > > + > > + /* > > + * If Hyper-V has crash notifications, set crash_kexec_post_notifiers > > + * so that we will report the panic to Hyper-V before running kdump. > > + */ > > + if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) > > + crash_kexec_post_notifiers = true; > > + > > + /* Get information about the Hyper-V host version */ > > + hv_get_vpreg_128(HV_REGISTER_HYPERVISOR_VERSION, &result); > > + a = result.as32.a; > > + b = result.as32.b; > > + c = result.as32.c; > > + d = result.as32.d; > > + pr_info("Hyper-V: Host Build %d.%d.%d.%d-%d-%d\n", > > + b >> 16, b & 0xFFFF, a, d & 0xFFFFFF, c, d >> 24); > > + > > + /* Allocate and initialize percpu VP index array */ > > + hv_vp_index = kmalloc_array(num_possible_cpus(), sizeof(*hv_vp_index), > > + GFP_KERNEL); > > + if (!hv_vp_index) > > + return -ENOMEM; > > + > > + for (i = 0; i < num_possible_cpus(); i++) > > + hv_vp_index[i] = VP_INVAL; > > + > > + cpuhp = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, > > + "arm64/hyperv_init:online", hv_cpu_init, NULL); > > + if (cpuhp < 0) > > + goto free_vp_index; > > + > > + hv_init_clocksource(); > > + if (hv_stimer_alloc()) > > + goto remove_cpuhp_state; > > + > > + hyperv_initialized = true; > > + return 0; > > + > > +remove_cpuhp_state: > > + cpuhp_remove_state(cpuhp); > > +free_vp_index: > > + kfree(hv_vp_index); > > + hv_vp_index = NULL; > > + return -EINVAL; > > +} > > +TIMER_ACPI_DECLARE(hyperv, ACPI_SIG_GTDT, hyperv_init); > > I think this has come up before, and I still don't consider it an acceptable > hack to hook platform initialization code into the timer code. > > Please split out the timer into a standalone driver in drivers/clocksource > that can get reviewed by the clocksource maintainers. I see two related topics here. First, the Hyper-V clocksource driver is drivers/clocksource/hyperv_timer.c. The code is architecture independent and is used today on the x86 side and for ARM64 in this patch series. A few architecture specific calls are satisfied by code under arch/x86, and in this patch series, under arch/arm64. Is there some aspect of this driver that needs reconsideration? I just want to make sure to understand what you are getting at. Second is the question of where/how to do Hyper-V specific initialization. I agree that hanging it off the timer initialization isn't a great approach. Should I add a Hyper-V specific initialization call at the appropriate point in the ARM64 init sequence? The x86 side has some structure for handling multiple hypervisors, and the Hyper-V initialization code naturally plugs into that structure. I'm certainly open to suggestions on the best way to handle it for ARM64. Michael > > Arnd
On Tue, Aug 25, 2020 at 11:20 PM Michael Kelley <mikelley@microsoft.com> wrote: > From: Arnd Bergmann <arnd@arndb.de> Sent: Monday, August 24, 2020 11:34 AM > > On Mon, Aug 24, 2020 at 6:48 PM Michael Kelley <mikelley@microsoft.com> wrote: > > > > I think this has come up before, and I still don't consider it an acceptable > > hack to hook platform initialization code into the timer code. > > > > Please split out the timer into a standalone driver in drivers/clocksource > > that can get reviewed by the clocksource maintainers. > > I see two related topics here. Agreed > First, the Hyper-V clocksource driver is > drivers/clocksource/hyperv_timer.c. The code is architecture independent > and is used today on the x86 side and for ARM64 in this patch series. A few > architecture specific calls are satisfied by code under arch/x86, and in this > patch series, under arch/arm64. Is there some aspect of this driver that > needs reconsideration? I just want to make sure to understand what you > are getting at. For the clocksource driver, I would like to see the arm64 specific bits (the code you add in arch/arm64 that are only relevant to this driver) moved out of arch/arm64 and into drivers/clocksource, in whatever form the clocksource maintainers prefer. I would suggest having a separate file that can get linked along with the architecture-independent part of that driver. > Second is the question of where/how to do Hyper-V specific initialization. > I agree that hanging it off the timer initialization isn't a great approach. > Should I add a Hyper-V specific initialization call at the appropriate point > in the ARM64 init sequence? The x86 side has some structure for handling > multiple hypervisors, and the Hyper-V initialization code naturally plugs into > that structure. I'm certainly open to suggestions on the best way to handle > it for ARM64. Yes, that is where I was getting at. Maybe the x86 abstraction for handling multiple hypervisors can be lifted out of arch/x86/ into common code? Arnd
diff --git a/arch/arm64/hyperv/hv_core.c b/arch/arm64/hyperv/hv_core.c index 966d815..831a69c 100644 --- a/arch/arm64/hyperv/hv_core.c +++ b/arch/arm64/hyperv/hv_core.c @@ -18,10 +18,41 @@ #include <linux/slab.h> #include <linux/hyperv.h> #include <linux/arm-smccc.h> +#include <linux/vmalloc.h> +#include <linux/acpi.h> +#include <linux/module.h> +#include <linux/cpuhotplug.h> +#include <linux/psci.h> #include <asm-generic/bug.h> #include <asm/hyperv-tlfs.h> #include <asm/mshyperv.h> +#include <asm/sysreg.h> +#include <clocksource/hyperv_timer.h> +static bool hyperv_initialized; + +struct ms_hyperv_info ms_hyperv __ro_after_init; +EXPORT_SYMBOL_GPL(ms_hyperv); + +u32 *hv_vp_index; +EXPORT_SYMBOL_GPL(hv_vp_index); + +u32 hv_max_vp_index; +EXPORT_SYMBOL_GPL(hv_max_vp_index); + +static int hv_cpu_init(unsigned int cpu) +{ + u64 msr_vp_index; + + msr_vp_index = hv_get_vpreg(HV_REGISTER_VPINDEX); + + hv_vp_index[smp_processor_id()] = msr_vp_index; + + if (msr_vp_index > hv_max_vp_index) + hv_max_vp_index = msr_vp_index; + + return 0; +} /* * Functions for allocating and freeing memory with size and @@ -67,6 +98,107 @@ void hv_free_hyperv_page(unsigned long addr) /* + * This function is invoked via the ACPI clocksource probe mechanism. We + * don't actually use any values from the ACPI GTDT table, but we set up + * the Hyper-V synthetic clocksource and do other initialization for + * interacting with Hyper-V the first time. Using early_initcall to invoke + * this function is too late because interrupts are already enabled at that + * point, and hv_init_clocksource() must run before interrupts are enabled. + * + * 1. Setup the guest ID. + * 2. Get features and hints info from Hyper-V + * 3. Setup per-cpu VP indices. + * 4. Initialize the Hyper-V clocksource. + */ + +static int __init hyperv_init(struct acpi_table_header *table) +{ + struct hv_get_vp_registers_output result; + u32 a, b, c, d; + u64 guest_id; + int i, cpuhp; + + /* + * If we're in a VM on Hyper-V, the ACPI hypervisor_id field will + * have the string "MsHyperV". + */ + if (strncmp((char *)&acpi_gbl_FADT.hypervisor_id, "MsHyperV", 8)) + return -EINVAL; + + /* Setup the guest ID */ + guest_id = generate_guest_id(0, LINUX_VERSION_CODE, 0); + hv_set_vpreg(HV_REGISTER_GUEST_OSID, guest_id); + + /* Get the features and hints from Hyper-V */ + hv_get_vpreg_128(HV_REGISTER_FEATURES, &result); + ms_hyperv.features = result.as32.a; + ms_hyperv.misc_features = result.as32.c; + + hv_get_vpreg_128(HV_REGISTER_ENLIGHTENMENTS, &result); + ms_hyperv.hints = result.as32.a; + + pr_info("Hyper-V: Features 0x%x, hints 0x%x, misc 0x%x\n", + ms_hyperv.features, ms_hyperv.hints, ms_hyperv.misc_features); + + /* + * If Hyper-V has crash notifications, set crash_kexec_post_notifiers + * so that we will report the panic to Hyper-V before running kdump. + */ + if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) + crash_kexec_post_notifiers = true; + + /* Get information about the Hyper-V host version */ + hv_get_vpreg_128(HV_REGISTER_HYPERVISOR_VERSION, &result); + a = result.as32.a; + b = result.as32.b; + c = result.as32.c; + d = result.as32.d; + pr_info("Hyper-V: Host Build %d.%d.%d.%d-%d-%d\n", + b >> 16, b & 0xFFFF, a, d & 0xFFFFFF, c, d >> 24); + + /* Allocate and initialize percpu VP index array */ + hv_vp_index = kmalloc_array(num_possible_cpus(), sizeof(*hv_vp_index), + GFP_KERNEL); + if (!hv_vp_index) + return -ENOMEM; + + for (i = 0; i < num_possible_cpus(); i++) + hv_vp_index[i] = VP_INVAL; + + cpuhp = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, + "arm64/hyperv_init:online", hv_cpu_init, NULL); + if (cpuhp < 0) + goto free_vp_index; + + hv_init_clocksource(); + if (hv_stimer_alloc()) + goto remove_cpuhp_state; + + hyperv_initialized = true; + return 0; + +remove_cpuhp_state: + cpuhp_remove_state(cpuhp); +free_vp_index: + kfree(hv_vp_index); + hv_vp_index = NULL; + return -EINVAL; +} +TIMER_ACPI_DECLARE(hyperv, ACPI_SIG_GTDT, hyperv_init); + +/* + * This routine is called before kexec/kdump, it does the required cleanup. + */ +void hyperv_cleanup(void) +{ + /* Reset our OS id */ + hv_set_vpreg(HV_REGISTER_GUEST_OSID, 0); + +} +EXPORT_SYMBOL_GPL(hyperv_cleanup); + + +/* * hv_do_hypercall- Invoke the specified hypercall */ u64 hv_do_hypercall(u64 control, void *input, void *output) @@ -291,3 +423,15 @@ void hyperv_report_panic_msg(phys_addr_t pa, size_t size) (HV_CRASH_CTL_CRASH_NOTIFY | HV_CRASH_CTL_CRASH_NOTIFY_MSG)); } EXPORT_SYMBOL_GPL(hyperv_report_panic_msg); + +bool hv_is_hyperv_initialized(void) +{ + return hyperv_initialized; +} +EXPORT_SYMBOL_GPL(hv_is_hyperv_initialized); + +bool hv_is_hibernation_supported(void) +{ + return false; +} +EXPORT_SYMBOL_GPL(hv_is_hibernation_supported);
Add ARM64-specific code to initialize the Hyper-V hypervisor when booting as a guest VM. Provide functions and data structures indicating hypervisor status that are needed by VMbus driver. This code is built only when CONFIG_HYPERV is enabled. Signed-off-by: Michael Kelley <mikelley@microsoft.com> --- arch/arm64/hyperv/hv_core.c | 144 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 144 insertions(+)