diff options
Diffstat (limited to 'arch/x86/coco')
| -rw-r--r-- | arch/x86/coco/tdx/tdx.c | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/arch/x86/coco/tdx/tdx.c b/arch/x86/coco/tdx/tdx.c index ed7302581cc7..00ff0a830970 100644 --- a/arch/x86/coco/tdx/tdx.c +++ b/arch/x86/coco/tdx/tdx.c @@ -142,6 +142,44 @@ void __cpuidle tdx_safe_halt(void) WARN_ONCE(1, "HLT instruction emulation failed\n"); } +static bool read_msr(struct pt_regs *regs) +{ + struct tdx_hypercall_args args = { + .r10 = TDX_HYPERCALL_STANDARD, + .r11 = hcall_func(EXIT_REASON_MSR_READ), + .r12 = regs->cx, + }; + + /* + * Emulate the MSR read via hypercall. More info about ABI + * can be found in TDX Guest-Host-Communication Interface + * (GHCI), section titled "TDG.VP.VMCALL<Instruction.RDMSR>". + */ + if (__tdx_hypercall(&args, TDX_HCALL_HAS_OUTPUT)) + return false; + + regs->ax = lower_32_bits(args.r11); + regs->dx = upper_32_bits(args.r11); + return true; +} + +static bool write_msr(struct pt_regs *regs) +{ + struct tdx_hypercall_args args = { + .r10 = TDX_HYPERCALL_STANDARD, + .r11 = hcall_func(EXIT_REASON_MSR_WRITE), + .r12 = regs->cx, + .r13 = (u64)regs->dx << 32 | regs->ax, + }; + + /* + * Emulate the MSR write via hypercall. More info about ABI + * can be found in TDX Guest-Host-Communication Interface + * (GHCI) section titled "TDG.VP.VMCALL<Instruction.WRMSR>". + */ + return !__tdx_hypercall(&args, 0); +} + void tdx_get_ve_info(struct ve_info *ve) { struct tdx_module_output out; @@ -178,6 +216,10 @@ static bool virt_exception_kernel(struct pt_regs *regs, struct ve_info *ve) switch (ve->exit_reason) { case EXIT_REASON_HLT: return handle_halt(); + case EXIT_REASON_MSR_READ: + return read_msr(regs); + case EXIT_REASON_MSR_WRITE: + return write_msr(regs); default: pr_warn("Unexpected #VE: %lld\n", ve->exit_reason); return false; |