diff options
author | Kirill A. Shutemov <kirill.shutemov@linux.intel.com> | 2023-03-21 03:35:11 +0300 |
---|---|---|
committer | Dave Hansen <dave.hansen@linux.intel.com> | 2023-03-22 21:36:05 +0300 |
commit | 7a3a401874bea02f568aa416ac29170d8cde0dc2 (patch) | |
tree | 6a54f38698e90f3c2c8f3771f662ddb02ed4d822 | |
parent | e8d018dd0257f744ca50a729e3d042cf2ec9da65 (diff) | |
download | linux-7a3a401874bea02f568aa416ac29170d8cde0dc2.tar.xz |
x86/tdx: Drop flags from __tdx_hypercall()
After TDX_HCALL_ISSUE_STI got dropped, the only flag left is
TDX_HCALL_HAS_OUTPUT. The flag indicates if the caller wants to see
tdx_hypercall_args updated based on the hypercall output.
Drop the flags and provide __tdx_hypercall_ret() that matches
TDX_HCALL_HAS_OUTPUT semantics.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/all/20230321003511.9469-1-kirill.shutemov%40linux.intel.com
-rw-r--r-- | arch/x86/boot/compressed/tdx.c | 4 | ||||
-rw-r--r-- | arch/x86/coco/tdx/tdcall.S | 66 | ||||
-rw-r--r-- | arch/x86/coco/tdx/tdx.c | 18 | ||||
-rw-r--r-- | arch/x86/include/asm/shared/tdx.h | 5 |
4 files changed, 51 insertions, 42 deletions
diff --git a/arch/x86/boot/compressed/tdx.c b/arch/x86/boot/compressed/tdx.c index 918a7606f53c..2d81d3cc72a1 100644 --- a/arch/x86/boot/compressed/tdx.c +++ b/arch/x86/boot/compressed/tdx.c @@ -26,7 +26,7 @@ static inline unsigned int tdx_io_in(int size, u16 port) .r14 = port, }; - if (__tdx_hypercall(&args, TDX_HCALL_HAS_OUTPUT)) + if (__tdx_hypercall_ret(&args)) return UINT_MAX; return args.r11; @@ -43,7 +43,7 @@ static inline void tdx_io_out(int size, u16 port, u32 value) .r15 = value, }; - __tdx_hypercall(&args, 0); + __tdx_hypercall(&args); } static inline u8 tdx_inb(u16 port) diff --git a/arch/x86/coco/tdx/tdcall.S b/arch/x86/coco/tdx/tdcall.S index 6a255e6809bc..b193c0a1d8db 100644 --- a/arch/x86/coco/tdx/tdcall.S +++ b/arch/x86/coco/tdx/tdcall.S @@ -85,12 +85,12 @@ SYM_FUNC_START(__tdx_module_call) SYM_FUNC_END(__tdx_module_call) /* - * __tdx_hypercall() - Make hypercalls to a TDX VMM using TDVMCALL leaf - * of TDCALL instruction + * TDX_HYPERCALL - Make hypercalls to a TDX VMM using TDVMCALL leaf of TDCALL + * instruction * * Transforms values in function call argument struct tdx_hypercall_args @args * into the TDCALL register ABI. After TDCALL operation, VMM output is saved - * back in @args. + * back in @args, if \ret is 1. * *------------------------------------------------------------------------- * TD VMCALL ABI: @@ -105,26 +105,18 @@ SYM_FUNC_END(__tdx_module_call) * specification. Non zero value indicates vendor * specific ABI. * R11 - VMCALL sub function number - * RBX, RBP, RDI, RSI - Used to pass VMCALL sub function specific arguments. + * RBX, RDX, RDI, RSI - Used to pass VMCALL sub function specific arguments. * R8-R9, R12-R15 - Same as above. * * Output Registers: * * RAX - TDCALL instruction status (Not related to hypercall * output). - * R10 - Hypercall output error code. - * R11-R15 - Hypercall sub function specific output values. + * RBX, RDX, RDI, RSI - Hypercall sub function specific output values. + * R8-R15 - Same as above. * - *------------------------------------------------------------------------- - * - * __tdx_hypercall() function ABI: - * - * @args (RDI) - struct tdx_hypercall_args for input and output - * @flags (RSI) - TDX_HCALL_* flags - * - * On successful completion, return the hypercall error code. */ -SYM_FUNC_START(__tdx_hypercall) +.macro TDX_HYPERCALL ret:req FRAME_BEGIN /* Save callee-saved GPRs as mandated by the x86_64 ABI */ @@ -134,9 +126,8 @@ SYM_FUNC_START(__tdx_hypercall) push %r12 push %rbx - /* Free RDI and RSI to be used as TDVMCALL arguments */ + /* Free RDI to be used as TDVMCALL arguments */ movq %rdi, %rax - push %rsi /* Copy hypercall registers from arg struct: */ movq TDX_HYPERCALL_r8(%rax), %r8 @@ -171,14 +162,11 @@ SYM_FUNC_START(__tdx_hypercall) * and are handled by callers. */ testq %rax, %rax - jne .Lpanic + jne .Lpanic\@ pop %rax - /* Copy hypercall result registers to arg struct if needed */ - testq $TDX_HCALL_HAS_OUTPUT, (%rsp) - jz .Lout - + .if \ret movq %r8, TDX_HYPERCALL_r8(%rax) movq %r9, TDX_HYPERCALL_r9(%rax) movq %r10, TDX_HYPERCALL_r10(%rax) @@ -191,7 +179,8 @@ SYM_FUNC_START(__tdx_hypercall) movq %rsi, TDX_HYPERCALL_rsi(%rax) movq %rbx, TDX_HYPERCALL_rbx(%rax) movq %rdx, TDX_HYPERCALL_rdx(%rax) -.Lout: + .endif + /* TDVMCALL leaf return code is in R10 */ movq %r10, %rax @@ -208,9 +197,6 @@ SYM_FUNC_START(__tdx_hypercall) xor %rdi, %rdi xor %rdx, %rdx - /* Remove TDX_HCALL_* flags from the stack */ - pop %rsi - /* Restore callee-saved GPRs as mandated by the x86_64 ABI */ pop %rbx pop %r12 @@ -221,9 +207,33 @@ SYM_FUNC_START(__tdx_hypercall) FRAME_END RET -.Lpanic: +.Lpanic\@: call __tdx_hypercall_failed /* __tdx_hypercall_failed never returns */ REACHABLE - jmp .Lpanic + jmp .Lpanic\@ +.endm + +/* + * + * __tdx_hypercall() function ABI: + * + * @args (RDI) - struct tdx_hypercall_args for input + * + * On successful completion, return the hypercall error code. + */ +SYM_FUNC_START(__tdx_hypercall) + TDX_HYPERCALL ret=0 SYM_FUNC_END(__tdx_hypercall) + +/* + * + * __tdx_hypercall_ret() function ABI: + * + * @args (RDI) - struct tdx_hypercall_args for input and output + * + * On successful completion, return the hypercall error code. + */ +SYM_FUNC_START(__tdx_hypercall_ret) + TDX_HYPERCALL ret=1 +SYM_FUNC_END(__tdx_hypercall_ret) diff --git a/arch/x86/coco/tdx/tdx.c b/arch/x86/coco/tdx/tdx.c index 055300e08fb3..e146b599260f 100644 --- a/arch/x86/coco/tdx/tdx.c +++ b/arch/x86/coco/tdx/tdx.c @@ -66,7 +66,7 @@ static inline u64 _tdx_hypercall(u64 fn, u64 r12, u64 r13, u64 r14, u64 r15) .r15 = r15, }; - return __tdx_hypercall(&args, 0); + return __tdx_hypercall(&args); } /* Called from __tdx_hypercall() for unrecoverable failure */ @@ -99,7 +99,7 @@ long tdx_kvm_hypercall(unsigned int nr, unsigned long p1, unsigned long p2, .r14 = p4, }; - return __tdx_hypercall(&args, 0); + return __tdx_hypercall(&args); } EXPORT_SYMBOL_GPL(tdx_kvm_hypercall); #endif @@ -179,7 +179,7 @@ static void __noreturn tdx_panic(const char *msg) * happens to return. */ while (1) - __tdx_hypercall(&args, 0); + __tdx_hypercall(&args); } static void tdx_parse_tdinfo(u64 *cc_mask) @@ -289,7 +289,7 @@ static u64 __cpuidle __halt(const bool irq_disabled) * can keep the vCPU in virtual HLT, even if an IRQ is * pending, without hanging/breaking the guest. */ - return __tdx_hypercall(&args, 0); + return __tdx_hypercall(&args); } static int handle_halt(struct ve_info *ve) @@ -326,7 +326,7 @@ static int read_msr(struct pt_regs *regs, struct ve_info *ve) * 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)) + if (__tdx_hypercall_ret(&args)) return -EIO; regs->ax = lower_32_bits(args.r11); @@ -348,7 +348,7 @@ static int write_msr(struct pt_regs *regs, struct ve_info *ve) * can be found in TDX Guest-Host-Communication Interface * (GHCI) section titled "TDG.VP.VMCALL<Instruction.WRMSR>". */ - if (__tdx_hypercall(&args, 0)) + if (__tdx_hypercall(&args)) return -EIO; return ve_instr_len(ve); @@ -380,7 +380,7 @@ static int handle_cpuid(struct pt_regs *regs, struct ve_info *ve) * ABI can be found in TDX Guest-Host-Communication Interface * (GHCI), section titled "VP.VMCALL<Instruction.CPUID>". */ - if (__tdx_hypercall(&args, TDX_HCALL_HAS_OUTPUT)) + if (__tdx_hypercall_ret(&args)) return -EIO; /* @@ -407,7 +407,7 @@ static bool mmio_read(int size, unsigned long addr, unsigned long *val) .r15 = *val, }; - if (__tdx_hypercall(&args, TDX_HCALL_HAS_OUTPUT)) + if (__tdx_hypercall_ret(&args)) return false; *val = args.r11; return true; @@ -541,7 +541,7 @@ static bool handle_in(struct pt_regs *regs, int size, int port) * in TDX Guest-Host-Communication Interface (GHCI) section titled * "TDG.VP.VMCALL<Instruction.IO>". */ - success = !__tdx_hypercall(&args, TDX_HCALL_HAS_OUTPUT); + success = !__tdx_hypercall_ret(&args); /* Update part of the register affected by the emulated instruction */ regs->ax &= ~mask; diff --git a/arch/x86/include/asm/shared/tdx.h b/arch/x86/include/asm/shared/tdx.h index 4a03993e0785..2631e01f6e0f 100644 --- a/arch/x86/include/asm/shared/tdx.h +++ b/arch/x86/include/asm/shared/tdx.h @@ -7,8 +7,6 @@ #define TDX_HYPERCALL_STANDARD 0 -#define TDX_HCALL_HAS_OUTPUT BIT(0) - #define TDX_CPUID_LEAF_ID 0x21 #define TDX_IDENT "IntelTDX " @@ -36,7 +34,8 @@ struct tdx_hypercall_args { }; /* Used to request services from the VMM */ -u64 __tdx_hypercall(struct tdx_hypercall_args *args, unsigned long flags); +u64 __tdx_hypercall(struct tdx_hypercall_args *args); +u64 __tdx_hypercall_ret(struct tdx_hypercall_args *args); /* Called from __tdx_hypercall() for unrecoverable failure */ void __tdx_hypercall_failed(void); |