diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/hyperv/Makefile | 10 | ||||
| -rw-r--r-- | arch/x86/hyperv/hv_vtl.c | 30 | ||||
| -rw-r--r-- | arch/x86/hyperv/mshv-asm-offsets.c | 37 | ||||
| -rw-r--r-- | arch/x86/hyperv/mshv_vtl_asm.S | 116 | ||||
| -rw-r--r-- | arch/x86/include/asm/mshyperv.h | 34 |
5 files changed, 226 insertions, 1 deletions
diff --git a/arch/x86/hyperv/Makefile b/arch/x86/hyperv/Makefile index 6f5d97cddd80..56292102af62 100644 --- a/arch/x86/hyperv/Makefile +++ b/arch/x86/hyperv/Makefile @@ -1,7 +1,12 @@ # SPDX-License-Identifier: GPL-2.0-only obj-y := hv_init.o mmu.o nested.o irqdomain.o ivm.o obj-$(CONFIG_X86_64) += hv_apic.o -obj-$(CONFIG_HYPERV_VTL_MODE) += hv_vtl.o +obj-$(CONFIG_HYPERV_VTL_MODE) += hv_vtl.o mshv_vtl_asm.o + +$(obj)/mshv_vtl_asm.o: $(obj)/mshv-asm-offsets.h + +$(obj)/mshv-asm-offsets.h: $(obj)/mshv-asm-offsets.s FORCE + $(call filechk,offsets,__MSHV_ASM_OFFSETS_H__) ifdef CONFIG_X86_64 obj-$(CONFIG_PARAVIRT_SPINLOCKS) += hv_spinlock.o @@ -12,3 +17,6 @@ obj-$(CONFIG_PARAVIRT_SPINLOCKS) += hv_spinlock.o obj-$(CONFIG_CRASH_DUMP) += hv_crash.o hv_trampoline.o endif endif + +targets += mshv-asm-offsets.s +clean-files += mshv-asm-offsets.h diff --git a/arch/x86/hyperv/hv_vtl.c b/arch/x86/hyperv/hv_vtl.c index 042e8712d8de..c0edaed0efb3 100644 --- a/arch/x86/hyperv/hv_vtl.c +++ b/arch/x86/hyperv/hv_vtl.c @@ -9,12 +9,17 @@ #include <asm/apic.h> #include <asm/boot.h> #include <asm/desc.h> +#include <asm/fpu/api.h> +#include <asm/fpu/types.h> #include <asm/i8259.h> #include <asm/mshyperv.h> #include <asm/msr.h> #include <asm/realmode.h> #include <asm/reboot.h> +#include <asm/smap.h> +#include <linux/export.h> #include <../kernel/smpboot.h> +#include "../../kernel/fpu/legacy.h" extern struct boot_params boot_params; static struct real_mode_header hv_vtl_real_mode_header; @@ -249,3 +254,28 @@ int __init hv_vtl_early_init(void) return 0; } + +DEFINE_STATIC_CALL_NULL(__mshv_vtl_return_hypercall, void (*)(void)); + +void mshv_vtl_return_call_init(u64 vtl_return_offset) +{ + static_call_update(__mshv_vtl_return_hypercall, + (void *)((u8 *)hv_hypercall_pg + vtl_return_offset)); +} +EXPORT_SYMBOL(mshv_vtl_return_call_init); + +void mshv_vtl_return_call(struct mshv_vtl_cpu_context *vtl0) +{ + struct hv_vp_assist_page *hvp; + + hvp = hv_vp_assist_page[smp_processor_id()]; + hvp->vtl_ret_x64rax = vtl0->rax; + hvp->vtl_ret_x64rcx = vtl0->rcx; + + kernel_fpu_begin_mask(0); + fxrstor(&vtl0->fx_state); + __mshv_vtl_return_call(vtl0); + fxsave(&vtl0->fx_state); + kernel_fpu_end(); +} +EXPORT_SYMBOL(mshv_vtl_return_call); diff --git a/arch/x86/hyperv/mshv-asm-offsets.c b/arch/x86/hyperv/mshv-asm-offsets.c new file mode 100644 index 000000000000..882c1db6df16 --- /dev/null +++ b/arch/x86/hyperv/mshv-asm-offsets.c @@ -0,0 +1,37 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Generate definitions needed by assembly language modules. + * This code generates raw asm output which is post-processed to extract + * and format the required data. + * + * Copyright (c) 2025, Microsoft Corporation. + * + * Author: + * Naman Jain <namjain@microsoft.com> + */ +#define COMPILE_OFFSETS + +#include <linux/kbuild.h> +#include <asm/mshyperv.h> + +static void __used common(void) +{ + if (IS_ENABLED(CONFIG_HYPERV_VTL_MODE)) { + OFFSET(MSHV_VTL_CPU_CONTEXT_rax, mshv_vtl_cpu_context, rax); + OFFSET(MSHV_VTL_CPU_CONTEXT_rcx, mshv_vtl_cpu_context, rcx); + OFFSET(MSHV_VTL_CPU_CONTEXT_rdx, mshv_vtl_cpu_context, rdx); + OFFSET(MSHV_VTL_CPU_CONTEXT_rbx, mshv_vtl_cpu_context, rbx); + OFFSET(MSHV_VTL_CPU_CONTEXT_rbp, mshv_vtl_cpu_context, rbp); + OFFSET(MSHV_VTL_CPU_CONTEXT_rsi, mshv_vtl_cpu_context, rsi); + OFFSET(MSHV_VTL_CPU_CONTEXT_rdi, mshv_vtl_cpu_context, rdi); + OFFSET(MSHV_VTL_CPU_CONTEXT_r8, mshv_vtl_cpu_context, r8); + OFFSET(MSHV_VTL_CPU_CONTEXT_r9, mshv_vtl_cpu_context, r9); + OFFSET(MSHV_VTL_CPU_CONTEXT_r10, mshv_vtl_cpu_context, r10); + OFFSET(MSHV_VTL_CPU_CONTEXT_r11, mshv_vtl_cpu_context, r11); + OFFSET(MSHV_VTL_CPU_CONTEXT_r12, mshv_vtl_cpu_context, r12); + OFFSET(MSHV_VTL_CPU_CONTEXT_r13, mshv_vtl_cpu_context, r13); + OFFSET(MSHV_VTL_CPU_CONTEXT_r14, mshv_vtl_cpu_context, r14); + OFFSET(MSHV_VTL_CPU_CONTEXT_r15, mshv_vtl_cpu_context, r15); + OFFSET(MSHV_VTL_CPU_CONTEXT_cr2, mshv_vtl_cpu_context, cr2); + } +} diff --git a/arch/x86/hyperv/mshv_vtl_asm.S b/arch/x86/hyperv/mshv_vtl_asm.S new file mode 100644 index 000000000000..f595eefad9ab --- /dev/null +++ b/arch/x86/hyperv/mshv_vtl_asm.S @@ -0,0 +1,116 @@ +/* SPDX-License-Identifier: GPL-2.0 + * + * Assembly level code for mshv_vtl VTL transition + * + * Copyright (c) 2025, Microsoft Corporation. + * + * Author: + * Naman Jain <namjain@microsoft.com> + */ + +#include <linux/linkage.h> +#include <linux/static_call_types.h> +#include <asm/asm.h> +#include <asm/asm-offsets.h> +#include <asm/frame.h> +#include "mshv-asm-offsets.h" + + .text + .section .noinstr.text, "ax" +/* + * void __mshv_vtl_return_call(struct mshv_vtl_cpu_context *vtl0) + * + * This function is used to context switch between different Virtual Trust Levels. + * It is marked as 'noinstr' to prevent against instrumentation and debugging facilities. + * NMIs aren't a problem because the NMI handler saves/restores CR2 specifically to guard + * against #PFs in NMI context clobbering the guest state. + */ +SYM_FUNC_START(__mshv_vtl_return_call) + /* Push callee save registers */ + pushq %rbp + mov %rsp, %rbp + pushq %r12 + pushq %r13 + pushq %r14 + pushq %r15 + pushq %rbx + + /* register switch to VTL0 clobbers all registers except rax/rcx */ + mov %_ASM_ARG1, %rax + + /* grab rbx/rbp/rsi/rdi/r8-r15 */ + mov MSHV_VTL_CPU_CONTEXT_rbx(%rax), %rbx + mov MSHV_VTL_CPU_CONTEXT_rbp(%rax), %rbp + mov MSHV_VTL_CPU_CONTEXT_rsi(%rax), %rsi + mov MSHV_VTL_CPU_CONTEXT_rdi(%rax), %rdi + mov MSHV_VTL_CPU_CONTEXT_r8(%rax), %r8 + mov MSHV_VTL_CPU_CONTEXT_r9(%rax), %r9 + mov MSHV_VTL_CPU_CONTEXT_r10(%rax), %r10 + mov MSHV_VTL_CPU_CONTEXT_r11(%rax), %r11 + mov MSHV_VTL_CPU_CONTEXT_r12(%rax), %r12 + mov MSHV_VTL_CPU_CONTEXT_r13(%rax), %r13 + mov MSHV_VTL_CPU_CONTEXT_r14(%rax), %r14 + mov MSHV_VTL_CPU_CONTEXT_r15(%rax), %r15 + + mov MSHV_VTL_CPU_CONTEXT_cr2(%rax), %rdx + mov %rdx, %cr2 + mov MSHV_VTL_CPU_CONTEXT_rdx(%rax), %rdx + + /* stash host registers on stack */ + pushq %rax + pushq %rcx + + xor %ecx, %ecx + + /* make a hypercall to switch VTL */ + call STATIC_CALL_TRAMP_STR(__mshv_vtl_return_hypercall) + + /* stash guest registers on stack, restore saved host copies */ + pushq %rax + pushq %rcx + mov 16(%rsp), %rcx + mov 24(%rsp), %rax + + mov %rdx, MSHV_VTL_CPU_CONTEXT_rdx(%rax) + mov %cr2, %rdx + mov %rdx, MSHV_VTL_CPU_CONTEXT_cr2(%rax) + pop MSHV_VTL_CPU_CONTEXT_rcx(%rax) + pop MSHV_VTL_CPU_CONTEXT_rax(%rax) + add $16, %rsp + + /* save rbx/rbp/rsi/rdi/r8-r15 */ + mov %rbx, MSHV_VTL_CPU_CONTEXT_rbx(%rax) + mov %rbp, MSHV_VTL_CPU_CONTEXT_rbp(%rax) + mov %rsi, MSHV_VTL_CPU_CONTEXT_rsi(%rax) + mov %rdi, MSHV_VTL_CPU_CONTEXT_rdi(%rax) + mov %r8, MSHV_VTL_CPU_CONTEXT_r8(%rax) + mov %r9, MSHV_VTL_CPU_CONTEXT_r9(%rax) + mov %r10, MSHV_VTL_CPU_CONTEXT_r10(%rax) + mov %r11, MSHV_VTL_CPU_CONTEXT_r11(%rax) + mov %r12, MSHV_VTL_CPU_CONTEXT_r12(%rax) + mov %r13, MSHV_VTL_CPU_CONTEXT_r13(%rax) + mov %r14, MSHV_VTL_CPU_CONTEXT_r14(%rax) + mov %r15, MSHV_VTL_CPU_CONTEXT_r15(%rax) + + /* pop callee-save registers r12-r15, rbx */ + pop %rbx + pop %r15 + pop %r14 + pop %r13 + pop %r12 + + pop %rbp + RET +SYM_FUNC_END(__mshv_vtl_return_call) +/* + * Make sure that static_call_key symbol: __SCK____mshv_vtl_return_hypercall is accessible here. + * Below code is inspired from __ADDRESSABLE(sym) macro. Symbol name is kept simple, to avoid + * naming it something like "__UNIQUE_ID_addressable___SCK____mshv_vtl_return_hypercall_662.0" + * which would otherwise have been generated by the macro. + */ + .section .discard.addressable,"aw" + .align 8 + .type mshv_vtl_return_sym, @object + .size mshv_vtl_return_sym, 8 +mshv_vtl_return_sym: + .quad __SCK____mshv_vtl_return_hypercall diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h index 1342d55c2545..10037125099a 100644 --- a/arch/x86/include/asm/mshyperv.h +++ b/arch/x86/include/asm/mshyperv.h @@ -11,6 +11,7 @@ #include <asm/paravirt.h> #include <asm/msr.h> #include <hyperv/hvhdk.h> +#include <asm/fpu/types.h> /* * Hyper-V always provides a single IO-APIC at this MMIO address. @@ -269,13 +270,46 @@ static inline u64 hv_get_non_nested_msr(unsigned int reg) { return 0; } static inline int hv_apicid_to_vp_index(u32 apic_id) { return -EINVAL; } #endif /* CONFIG_HYPERV */ +struct mshv_vtl_cpu_context { + union { + struct { + u64 rax; + u64 rcx; + u64 rdx; + u64 rbx; + u64 cr2; + u64 rbp; + u64 rsi; + u64 rdi; + u64 r8; + u64 r9; + u64 r10; + u64 r11; + u64 r12; + u64 r13; + u64 r14; + u64 r15; + }; + u64 gp_regs[16]; + }; + + struct fxregs_state fx_state; +}; #ifdef CONFIG_HYPERV_VTL_MODE void __init hv_vtl_init_platform(void); int __init hv_vtl_early_init(void); +void mshv_vtl_return_call(struct mshv_vtl_cpu_context *vtl0); +void mshv_vtl_return_call_init(u64 vtl_return_offset); +void mshv_vtl_return_hypercall(void); +void __mshv_vtl_return_call(struct mshv_vtl_cpu_context *vtl0); #else static inline void __init hv_vtl_init_platform(void) {} static inline int __init hv_vtl_early_init(void) { return 0; } +static inline void mshv_vtl_return_call(struct mshv_vtl_cpu_context *vtl0) {} +static inline void mshv_vtl_return_call_init(u64 vtl_return_offset) {} +static inline void mshv_vtl_return_hypercall(void) {} +static inline void __mshv_vtl_return_call(struct mshv_vtl_cpu_context *vtl0) {} #endif #include <asm-generic/mshyperv.h> |