From 57d276bbbd322409bb6f7c6446187a29953f8ded Mon Sep 17 00:00:00 2001 From: Michael Kelley Date: Wed, 4 Aug 2021 08:52:35 -0700 Subject: arm64: hyperv: Add Hyper-V hypercall and register access utilities hyperv-tlfs.h defines Hyper-V interfaces from the Hyper-V Top Level Functional Spec (TLFS), and #includes the architecture-independent part of hyperv-tlfs.h in include/asm-generic. The published TLFS is distinctly oriented to x86/x64, so the ARM64-specific hyperv-tlfs.h includes information for ARM64 that is not yet formally published. The TLFS is available here: docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/reference/tlfs mshyperv.h defines Linux-specific structures and routines for interacting with Hyper-V on ARM64, and #includes the architecture- independent part of mshyperv.h in include/asm-generic. Use these definitions to provide utility functions to make Hyper-V hypercalls and to get and set Hyper-V provided registers associated with a virtual processor. Signed-off-by: Michael Kelley Reviewed-by: Sunil Muthuswamy Acked-by: Marc Zyngier Acked-by: Mark Rutland Acked-by: Catalin Marinas Link: https://lore.kernel.org/r/1628092359-61351-2-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu --- arch/arm64/hyperv/Makefile | 2 + arch/arm64/hyperv/hv_core.c | 129 ++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 131 insertions(+) create mode 100644 arch/arm64/hyperv/Makefile create mode 100644 arch/arm64/hyperv/hv_core.c (limited to 'arch/arm64/hyperv') diff --git a/arch/arm64/hyperv/Makefile b/arch/arm64/hyperv/Makefile new file mode 100644 index 000000000000..1697d30ff106 --- /dev/null +++ b/arch/arm64/hyperv/Makefile @@ -0,0 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0 +obj-y := hv_core.o diff --git a/arch/arm64/hyperv/hv_core.c b/arch/arm64/hyperv/hv_core.c new file mode 100644 index 000000000000..4c5dc0f51b12 --- /dev/null +++ b/arch/arm64/hyperv/hv_core.c @@ -0,0 +1,129 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* + * Low level utility routines for interacting with Hyper-V. + * + * Copyright (C) 2021, Microsoft, Inc. + * + * Author : Michael Kelley + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* + * hv_do_hypercall- Invoke the specified hypercall + */ +u64 hv_do_hypercall(u64 control, void *input, void *output) +{ + struct arm_smccc_res res; + u64 input_address; + u64 output_address; + + input_address = input ? virt_to_phys(input) : 0; + output_address = output ? virt_to_phys(output) : 0; + + arm_smccc_1_1_hvc(HV_FUNC_ID, control, + input_address, output_address, &res); + return res.a0; +} +EXPORT_SYMBOL_GPL(hv_do_hypercall); + +/* + * hv_do_fast_hypercall8 -- Invoke the specified hypercall + * with arguments in registers instead of physical memory. + * Avoids the overhead of virt_to_phys for simple hypercalls. + */ + +u64 hv_do_fast_hypercall8(u16 code, u64 input) +{ + struct arm_smccc_res res; + u64 control; + + control = (u64)code | HV_HYPERCALL_FAST_BIT; + + arm_smccc_1_1_hvc(HV_FUNC_ID, control, input, &res); + return res.a0; +} +EXPORT_SYMBOL_GPL(hv_do_fast_hypercall8); + +/* + * Set a single VP register to a 64-bit value. + */ +void hv_set_vpreg(u32 msr, u64 value) +{ + struct arm_smccc_res res; + + arm_smccc_1_1_hvc(HV_FUNC_ID, + HVCALL_SET_VP_REGISTERS | HV_HYPERCALL_FAST_BIT | + HV_HYPERCALL_REP_COMP_1, + HV_PARTITION_ID_SELF, + HV_VP_INDEX_SELF, + msr, + 0, + value, + 0, + &res); + + /* + * Something is fundamentally broken in the hypervisor if + * setting a VP register fails. There's really no way to + * continue as a guest VM, so panic. + */ + BUG_ON(!hv_result_success(res.a0)); +} +EXPORT_SYMBOL_GPL(hv_set_vpreg); + +/* + * Get the value of a single VP register. One version + * returns just 64 bits and another returns the full 128 bits. + * The two versions are separate to avoid complicating the + * calling sequence for the more frequently used 64 bit version. + */ + +void hv_get_vpreg_128(u32 msr, struct hv_get_vp_registers_output *result) +{ + struct arm_smccc_1_2_regs args; + struct arm_smccc_1_2_regs res; + + args.a0 = HV_FUNC_ID; + args.a1 = HVCALL_GET_VP_REGISTERS | HV_HYPERCALL_FAST_BIT | + HV_HYPERCALL_REP_COMP_1; + args.a2 = HV_PARTITION_ID_SELF; + args.a3 = HV_VP_INDEX_SELF; + args.a4 = msr; + + /* + * Use the SMCCC 1.2 interface because the results are in registers + * beyond X0-X3. + */ + arm_smccc_1_2_hvc(&args, &res); + + /* + * Something is fundamentally broken in the hypervisor if + * getting a VP register fails. There's really no way to + * continue as a guest VM, so panic. + */ + BUG_ON(!hv_result_success(res.a0)); + + result->as64.low = res.a6; + result->as64.high = res.a7; +} +EXPORT_SYMBOL_GPL(hv_get_vpreg_128); + +u64 hv_get_vpreg(u32 msr) +{ + struct hv_get_vp_registers_output output; + + hv_get_vpreg_128(msr, &output); + + return output.as64.low; +} +EXPORT_SYMBOL_GPL(hv_get_vpreg); -- cgit v1.2.3