From: Nuno Das Neves <nunodasne...@linux.microsoft.com> Sent: Friday, February
7, 2025 11:03 AM
>
> Move hv_current_partition_id and hv_get_partition_id() to hv_common.c,
> and call hv_get_partition_id() on arm64 in hyperv_init(). These aren't
> specific to x86_64 and will be needed by common code.
>
> Set hv_current_partition_id to HV_PARTITION_ID_SELF by default.
>
> Rename struct hv_get_partition_id to hv_output_get_partition_id, to
> make it distinct from the function hv_get_partition_id(), and match
> the original Hyper-V struct name.
>
> Remove the BUG()s. Failing to get the id need not crash the machine.
>
> Signed-off-by: Nuno Das Neves <nunodasne...@linux.microsoft.com>
Looks good now.
Reviewed-by: Michael Kelley <mhkli...@outlook.com>
> ---
> arch/arm64/hyperv/mshyperv.c | 3 +++
> arch/x86/hyperv/hv_init.c | 25 +------------------------
> arch/x86/include/asm/mshyperv.h | 2 --
> drivers/hv/hv_common.c | 22 ++++++++++++++++++++++
> include/asm-generic/mshyperv.h | 2 ++
> include/hyperv/hvgdk_mini.h | 2 +-
> 6 files changed, 29 insertions(+), 27 deletions(-)
>
> diff --git a/arch/arm64/hyperv/mshyperv.c b/arch/arm64/hyperv/mshyperv.c
> index fc49949b7df6..29fcfd595f48 100644
> --- a/arch/arm64/hyperv/mshyperv.c
> +++ b/arch/arm64/hyperv/mshyperv.c
> @@ -72,6 +72,9 @@ static int __init hyperv_init(void)
> return ret;
> }
>
> + if (ms_hyperv.priv_high & HV_ACCESS_PARTITION_ID)
> + hv_get_partition_id();
> +
> ms_hyperv_late_init();
>
> hyperv_initialized = true;
> diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
> index 173005e6a95d..9be1446f5bd3 100644
> --- a/arch/x86/hyperv/hv_init.c
> +++ b/arch/x86/hyperv/hv_init.c
> @@ -34,9 +34,6 @@
> #include <clocksource/hyperv_timer.h>
> #include <linux/highmem.h>
>
> -u64 hv_current_partition_id = ~0ull;
> -EXPORT_SYMBOL_GPL(hv_current_partition_id);
> -
> void *hv_hypercall_pg;
> EXPORT_SYMBOL_GPL(hv_hypercall_pg);
>
> @@ -393,24 +390,6 @@ static void __init hv_stimer_setup_percpu_clockev(void)
> old_setup_percpu_clockev();
> }
>
> -static void __init hv_get_partition_id(void)
> -{
> - struct hv_get_partition_id *output_page;
> - u64 status;
> - unsigned long flags;
> -
> - local_irq_save(flags);
> - output_page = *this_cpu_ptr(hyperv_pcpu_output_arg);
> - status = hv_do_hypercall(HVCALL_GET_PARTITION_ID, NULL, output_page);
> - if (!hv_result_success(status)) {
> - /* No point in proceeding if this failed */
> - pr_err("Failed to get partition ID: %lld\n", status);
> - BUG();
> - }
> - hv_current_partition_id = output_page->partition_id;
> - local_irq_restore(flags);
> -}
> -
> #if IS_ENABLED(CONFIG_HYPERV_VTL_MODE)
> static u8 __init get_vtl(void)
> {
> @@ -605,11 +584,9 @@ void __init hyperv_init(void)
>
> register_syscore_ops(&hv_syscore_ops);
>
> - if (cpuid_ebx(HYPERV_CPUID_FEATURES) & HV_ACCESS_PARTITION_ID)
> + if (ms_hyperv.priv_high & HV_ACCESS_PARTITION_ID)
> hv_get_partition_id();
>
> - BUG_ON(hv_root_partition && hv_current_partition_id == ~0ull);
> -
> #ifdef CONFIG_PCI_MSI
> /*
> * If we're running as root, we want to create our own PCI MSI domain.
> diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
> index f91ab1e75f9f..8d3ada3e8d0d 100644
> --- a/arch/x86/include/asm/mshyperv.h
> +++ b/arch/x86/include/asm/mshyperv.h
> @@ -43,8 +43,6 @@ extern bool hyperv_paravisor_present;
>
> extern void *hv_hypercall_pg;
>
> -extern u64 hv_current_partition_id;
> -
> extern union hv_ghcb * __percpu *hv_ghcb_pg;
>
> bool hv_isolation_type_snp(void);
> diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c
> index af5d1dc451f6..cb3ea49020ef 100644
> --- a/drivers/hv/hv_common.c
> +++ b/drivers/hv/hv_common.c
> @@ -31,6 +31,9 @@
> #include <hyperv/hvhdk.h>
> #include <asm/mshyperv.h>
>
> +u64 hv_current_partition_id = HV_PARTITION_ID_SELF;
> +EXPORT_SYMBOL_GPL(hv_current_partition_id);
> +
> /*
> * hv_root_partition, ms_hyperv and hv_nested are defined here with other
> * Hyper-V specific globals so they are shared across all architectures and
> are
> @@ -283,6 +286,25 @@ static inline bool hv_output_page_exists(void)
> return hv_root_partition || IS_ENABLED(CONFIG_HYPERV_VTL_MODE);
> }
>
> +void __init hv_get_partition_id(void)
> +{
> + struct hv_output_get_partition_id *output;
> + unsigned long flags;
> + u64 status, pt_id;
> +
> + local_irq_save(flags);
> + output = *this_cpu_ptr(hyperv_pcpu_input_arg);
> + status = hv_do_hypercall(HVCALL_GET_PARTITION_ID, NULL, &output);
> + pt_id = output->partition_id;
> + local_irq_restore(flags);
> +
> + if (hv_result_success(status))
> + hv_current_partition_id = pt_id;
> + else
> + pr_err("Hyper-V: failed to get partition ID: %#lx\n",
> + hv_result(status));
> +}
> +
> int __init hv_common_init(void)
> {
> int i;
> diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
> index a7bbe504e4f3..febeddf6cd8a 100644
> --- a/include/asm-generic/mshyperv.h
> +++ b/include/asm-generic/mshyperv.h
> @@ -58,6 +58,7 @@ struct ms_hyperv_info {
> };
> extern struct ms_hyperv_info ms_hyperv;
> extern bool hv_nested;
> +extern u64 hv_current_partition_id;
>
> extern void * __percpu *hyperv_pcpu_input_arg;
> extern void * __percpu *hyperv_pcpu_output_arg;
> @@ -207,6 +208,7 @@ extern u64 (*hv_read_reference_counter)(void);
> #define VP_INVAL U32_MAX
>
> int __init hv_common_init(void);
> +void __init hv_get_partition_id(void);
> void __init hv_common_free(void);
> void __init ms_hyperv_late_init(void);
> int hv_common_cpu_init(unsigned int cpu);
> diff --git a/include/hyperv/hvgdk_mini.h b/include/hyperv/hvgdk_mini.h
> index 155615175965..58895883f636 100644
> --- a/include/hyperv/hvgdk_mini.h
> +++ b/include/hyperv/hvgdk_mini.h
> @@ -182,7 +182,7 @@ struct hv_tsc_emulation_control { /*
> HV_TSC_INVARIANT_CONTROL */
>
> #endif /* CONFIG_X86 */
>
> -struct hv_get_partition_id { /* HV_OUTPUT_GET_PARTITION_ID */
> +struct hv_output_get_partition_id {
> u64 partition_id;
> } __packed;
>
> --
> 2.34.1
