[PATCH v4 07/17] x86/hyperv: extract partition ID from Microsoft Hypervisor if necessary
From: Wei Liu <wei.liu@kernel.org>
Date: 2021-01-06 20:34:53
Also in:
linux-arch, lkml
Subsystem:
generic include/asm header files, hyper-v/azure core and drivers, the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Arnd Bergmann, "K. Y. Srinivasan", Haiyang Zhang, Wei Liu, Dexuan Cui, Long Li, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
We will need the partition ID for executing some hypercalls later. Signed-off-by: Lillian Grassin-Drake <redacted> Co-Developed-by: Sunil Muthuswamy <redacted> Signed-off-by: Wei Liu <wei.liu@kernel.org> --- v3: 1. Make hv_get_partition_id static. 2. Change code structure a bit. --- arch/x86/hyperv/hv_init.c | 27 +++++++++++++++++++++++++++ arch/x86/include/asm/mshyperv.h | 2 ++ include/asm-generic/hyperv-tlfs.h | 6 ++++++ 3 files changed, 35 insertions(+)
diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index 6f4cb40e53fe..fc9941bd8653 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c@@ -26,6 +26,9 @@ #include <linux/syscore_ops.h> #include <clocksource/hyperv_timer.h> +u64 hv_current_partition_id = ~0ull; +EXPORT_SYMBOL_GPL(hv_current_partition_id); + void *hv_hypercall_pg; EXPORT_SYMBOL_GPL(hv_hypercall_pg);
@@ -331,6 +334,25 @@ static struct syscore_ops hv_syscore_ops = { .resume = hv_resume, }; +static void __init hv_get_partition_id(void) +{ + struct hv_get_partition_id *output_page; + u16 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) & + HV_HYPERCALL_RESULT_MASK; + if (status != HV_STATUS_SUCCESS) { + /* No point in proceeding if this failed */ + pr_err("Failed to get partition ID: %d\n", status); + BUG(); + } + hv_current_partition_id = output_page->partition_id; + local_irq_restore(flags); +} + /* * This function is to be invoked early in the boot sequence after the * hypervisor has been detected.
@@ -426,6 +448,11 @@ void __init hyperv_init(void) register_syscore_ops(&hv_syscore_ops); + if (cpuid_ebx(HYPERV_CPUID_FEATURES) & HV_ACCESS_PARTITION_ID) + hv_get_partition_id(); + + BUG_ON(hv_root_partition && hv_current_partition_id == ~0ull); + return; remove_cpuhp_state:
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index 62d9390f1ddf..67f5d35a73d3 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h@@ -78,6 +78,8 @@ extern void *hv_hypercall_pg; extern void __percpu **hyperv_pcpu_input_arg; extern void __percpu **hyperv_pcpu_output_arg; +extern u64 hv_current_partition_id; + static inline u64 hv_do_hypercall(u64 control, void *input, void *output) { u64 input_address = input ? virt_to_phys(input) : 0;
diff --git a/include/asm-generic/hyperv-tlfs.h b/include/asm-generic/hyperv-tlfs.h
index e6903589a82a..87b1a79b19eb 100644
--- a/include/asm-generic/hyperv-tlfs.h
+++ b/include/asm-generic/hyperv-tlfs.h@@ -141,6 +141,7 @@ struct ms_hyperv_tsc_page { #define HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX 0x0013 #define HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX 0x0014 #define HVCALL_SEND_IPI_EX 0x0015 +#define HVCALL_GET_PARTITION_ID 0x0046 #define HVCALL_GET_VP_REGISTERS 0x0050 #define HVCALL_SET_VP_REGISTERS 0x0051 #define HVCALL_POST_MESSAGE 0x005c
@@ -407,6 +408,11 @@ struct hv_tlb_flush_ex { u64 gva_list[]; } __packed; +/* HvGetPartitionId hypercall (output only) */ +struct hv_get_partition_id { + u64 partition_id; +} __packed; + /* HvRetargetDeviceInterrupt hypercall */ union hv_msi_entry { u64 as_uint64;
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2.20.1