Now TDX_HYPERCALL macro shares very similar code pattern with the TDX_MODULE_CALL macro, except that TDX_HYPERCALL handles below additional things: 1) Sets RAX to 0 (TDG.VP.VMCALL leaf) internally; 2) Sets RCX to the (fixed) bitmap of shared registers; 3) Panics internally if the TDCALL return code is not zero; 4) After TDCALL, moves R10 to RAX for returning the return code of the TDVMCALL itself, regardless the "\ret" parameter; 5) Clears shared registers to prevent speculative use of VMM's values. Using the TDX_MODULE_CALL macro, 1) - 3) can be moved out to the C code. 4) can be done by always turning on the TDX_MODULE_CALL macro's "\ret" parameter, and moving it to the C function. 5) is already covered by the TDH.VP.ENTER in the TDX_MODULE_CALL. In other words, the TDX_HYPERCALL macro is redundant now and should be removed to use TDX_MODULE_CALL macro instead. TDVMCALL always uses the extra "callee-saved" registers. Replace the existing __tdx_hypercall{_ret}() assembly functions with a new __tdcall_saved_ret(), as mentioned above TDVMCALL relies on saving R10 to the register structure so that the caller (C function) can use it as the return code of the TDVMCALL itself. As a result, reimplement the existing __tdx_hypercall() using the __tdcall_saved_ret() function. __tdx_hypercall_ret() isn't necessary anymore because __tdx_hypercall() always turns on the "\ret" parameter. Also remove the 'struct tdx_hypercall_args', which has the exact members as the 'struct tdx_module_args' (except the RCX which isn't used as shared register). It's not worth to keep the structure just for one member. With this change, the __tdx_hypercall() variants are not implemented in tdcall.S anymore thus not available to the compressed code. Implement the __tdx_hypercall() variants in the compressed code directly using the __tdcall_saved_ret(). Opportunistically fix a checkpatch error complaining using space around parenthesis '(' and ')' while moving the bitmap of shared registers to <asm/shared/tdx.h>. Cc: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Suggested-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Signed-off-by: Kai Huang <kai.huang@xxxxxxxxx> --- arch/x86/boot/compressed/tdx.c | 26 +++- arch/x86/coco/tdx/tdcall.S | 194 ++++-------------------------- arch/x86/coco/tdx/tdx.c | 62 ++++++---- arch/x86/include/asm/shared/tdx.h | 48 ++++++-- arch/x86/include/asm/tdx.h | 25 ---- arch/x86/kernel/asm-offsets.c | 14 --- arch/x86/virt/vmx/tdx/tdxcall.S | 10 +- 7 files changed, 127 insertions(+), 252 deletions(-) diff --git a/arch/x86/boot/compressed/tdx.c b/arch/x86/boot/compressed/tdx.c index 8841b945a1e2..4df2259f9f7f 100644 --- a/arch/x86/boot/compressed/tdx.c +++ b/arch/x86/boot/compressed/tdx.c @@ -11,14 +11,32 @@ #include <asm/shared/tdx.h> /* Called from __tdx_hypercall() for unrecoverable failure */ -void __tdx_hypercall_failed(void) +static inline void __tdx_hypercall_failed(void) { error("TDVMCALL failed. TDX module bug?"); } +static inline u64 __tdx_hypercall(struct tdx_module_args *args) +{ + u64 ret; + + args->rcx = TDVMCALL_EXPOSE_REGS_MASK; + ret = __tdcall_saved_ret(TDG_VP_VMCALL, args); + + /* + * RAX!=0 indicates a failure of the TDVMCALL mechanism itself and that + * something has gone horribly wrong with the TDX module. + */ + if (ret) + __tdx_hypercall_failed(); + + /* The return status of the hypercall itself is in R10. */ + return args->r10; +} + static inline unsigned int tdx_io_in(int size, u16 port) { - struct tdx_hypercall_args args = { + struct tdx_module_args args = { .r10 = TDX_HYPERCALL_STANDARD, .r11 = hcall_func(EXIT_REASON_IO_INSTRUCTION), .r12 = size, @@ -26,7 +44,7 @@ static inline unsigned int tdx_io_in(int size, u16 port) .r14 = port, }; - if (__tdx_hypercall_ret(&args)) + if (__tdx_hypercall(&args)) return UINT_MAX; return args.r11; @@ -34,7 +52,7 @@ static inline unsigned int tdx_io_in(int size, u16 port) static inline void tdx_io_out(int size, u16 port, u32 value) { - struct tdx_hypercall_args args = { + struct tdx_module_args args = { .r10 = TDX_HYPERCALL_STANDARD, .r11 = hcall_func(EXIT_REASON_IO_INSTRUCTION), .r12 = size, diff --git a/arch/x86/coco/tdx/tdcall.S b/arch/x86/coco/tdx/tdcall.S index d5693330ee9b..6f3c9028577b 100644 --- a/arch/x86/coco/tdx/tdcall.S +++ b/arch/x86/coco/tdx/tdcall.S @@ -10,38 +10,11 @@ #include "../../virt/vmx/tdx/tdxcall.S" -/* - * Bitmasks of exposed registers (with VMM). - */ -#define TDX_RDX BIT(2) -#define TDX_RBX BIT(3) -#define TDX_RSI BIT(6) -#define TDX_RDI BIT(7) -#define TDX_R8 BIT(8) -#define TDX_R9 BIT(9) -#define TDX_R10 BIT(10) -#define TDX_R11 BIT(11) -#define TDX_R12 BIT(12) -#define TDX_R13 BIT(13) -#define TDX_R14 BIT(14) -#define TDX_R15 BIT(15) - -/* - * These registers are clobbered to hold arguments for each - * TDVMCALL. They are safe to expose to the VMM. - * Each bit in this mask represents a register ID. Bit field - * details can be found in TDX GHCI specification, section - * titled "TDCALL [TDG.VP.VMCALL] leaf". - */ -#define TDVMCALL_EXPOSE_REGS_MASK \ - ( TDX_RDX | TDX_RBX | TDX_RSI | TDX_RDI | TDX_R8 | TDX_R9 | \ - TDX_R10 | TDX_R11 | TDX_R12 | TDX_R13 | TDX_R14 | TDX_R15 ) - .section .noinstr.text, "ax" /* * __tdcall() - Used by TDX guests to request services from the TDX - * module (does not include VMM services) using TDCALL instruction. + * module using TDCALL instruction. * * __tdcall() function ABI: * @@ -56,7 +29,7 @@ SYM_FUNC_END(__tdcall) /* * __tdcall_ret() - Used by TDX guests to request services from the TDX - * module (does not include VMM services) using TDCALL instruction. + * module using TDCALL instruction. * * __tdcall_ret() function ABI: * @@ -70,156 +43,33 @@ SYM_FUNC_START(__tdcall_ret) SYM_FUNC_END(__tdcall_ret) /* - * TDX_HYPERCALL - Make hypercalls to a TDX VMM using TDVMCALL leaf of TDCALL - * instruction + * __tdcall_saved() - Used by the TDX guests to request services from the + * TDX module using TDCALL instruction with additional callee-saved + * registers as input. * - * 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, if \ret is 1. + * __tdcall_saved() function ABI: * - *------------------------------------------------------------------------- - * TD VMCALL ABI: - *------------------------------------------------------------------------- + * @fn (RDI) - TDCALL leaf ID, moved to RAX + * @args (RSI) - struct 'struct tdx_module_args' for input * - * Input Registers: - * - * RAX - TDCALL instruction leaf number (0 - TDG.VP.VMCALL) - * RCX - BITMAP which controls which part of TD Guest GPR - * is passed as-is to the VMM and back. - * R10 - Set 0 to indicate TDCALL follows standard TDX ABI - * specification. Non zero value indicates vendor - * specific ABI. - * R11 - VMCALL sub function number - * 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). - * RBX, RDX, RDI, RSI - Hypercall sub function specific output values. - * R8-R15 - Same as above. - * - */ -.macro TDX_HYPERCALL ret:req - FRAME_BEGIN - - /* Save callee-saved GPRs as mandated by the x86_64 ABI */ - push %r15 - push %r14 - push %r13 - push %r12 - push %rbx - - /* Free RDI to be used as TDVMCALL arguments */ - movq %rdi, %rax - - /* Copy hypercall registers from arg struct: */ - movq TDX_HYPERCALL_r8(%rax), %r8 - movq TDX_HYPERCALL_r9(%rax), %r9 - movq TDX_HYPERCALL_r10(%rax), %r10 - movq TDX_HYPERCALL_r11(%rax), %r11 - movq TDX_HYPERCALL_r12(%rax), %r12 - movq TDX_HYPERCALL_r13(%rax), %r13 - movq TDX_HYPERCALL_r14(%rax), %r14 - movq TDX_HYPERCALL_r15(%rax), %r15 - movq TDX_HYPERCALL_rdi(%rax), %rdi - movq TDX_HYPERCALL_rsi(%rax), %rsi - movq TDX_HYPERCALL_rbx(%rax), %rbx - movq TDX_HYPERCALL_rdx(%rax), %rdx - - push %rax - - /* Mangle function call ABI into TDCALL ABI: */ - /* Set TDCALL leaf ID (TDVMCALL (0)) in RAX */ - xor %eax, %eax - - movl $TDVMCALL_EXPOSE_REGS_MASK, %ecx - - tdcall - - /* - * RAX!=0 indicates a failure of the TDVMCALL mechanism itself and that - * something has gone horribly wrong with the TDX module. - * - * The return status of the hypercall operation is in a separate - * register (in R10). Hypercall errors are a part of normal operation - * and are handled by callers. - */ - testq %rax, %rax - jne .Lpanic\@ - - pop %rax - - .if \ret - movq %r8, TDX_HYPERCALL_r8(%rax) - movq %r9, TDX_HYPERCALL_r9(%rax) - movq %r10, TDX_HYPERCALL_r10(%rax) - movq %r11, TDX_HYPERCALL_r11(%rax) - movq %r12, TDX_HYPERCALL_r12(%rax) - movq %r13, TDX_HYPERCALL_r13(%rax) - movq %r14, TDX_HYPERCALL_r14(%rax) - movq %r15, TDX_HYPERCALL_r15(%rax) - movq %rdi, TDX_HYPERCALL_rdi(%rax) - movq %rsi, TDX_HYPERCALL_rsi(%rax) - movq %rbx, TDX_HYPERCALL_rbx(%rax) - movq %rdx, TDX_HYPERCALL_rdx(%rax) - .endif - - /* TDVMCALL leaf return code is in R10 */ - movq %r10, %rax - - /* - * Zero out registers exposed to the VMM to avoid speculative execution - * with VMM-controlled values. This needs to include all registers - * present in TDVMCALL_EXPOSE_REGS_MASK, except RBX, and R12-R15 which - * will be restored. - */ - xor %r8d, %r8d - xor %r9d, %r9d - xor %r10d, %r10d - xor %r11d, %r11d - xor %rdi, %rdi - xor %rsi, %rsi - xor %rdx, %rdx - - /* Restore callee-saved GPRs as mandated by the x86_64 ABI */ - pop %rbx - pop %r12 - pop %r13 - pop %r14 - pop %r15 - - FRAME_END - - RET -.Lpanic\@: - call __tdx_hypercall_failed - /* __tdx_hypercall_failed never returns */ - REACHABLE - jmp .Lpanic\@ -.endm - -/* - * - * __tdx_hypercall() function ABI: - * - * @args (RDI) - struct tdx_hypercall_args for input - * - * On successful completion, return the hypercall error code. + * Return the TDCALL return code (RAX) */ -SYM_FUNC_START(__tdx_hypercall) - TDX_HYPERCALL ret=0 -SYM_FUNC_END(__tdx_hypercall) +SYM_FUNC_START(__tdcall_saved) + TDX_MODULE_CALL host=0 ret=0 saved=1 +SYM_FUNC_END(__tdcall_saved) /* + * __tdcall_saved_ret() - Used by the TDX guests to request services from the + * TDX module using TDCALL instruction with additional callee-saved registers + * as input/output. * - * __tdx_hypercall_ret() function ABI: + * __tdcall_saved_ret() function ABI: * - * @args (RDI) - struct tdx_hypercall_args for input and output + * @fn (RDI) - TDCALL leaf ID, moved to RAX + * @args (RDI) - struct 'struct tdx_module_args' for input and output * - * On successful completion, return the hypercall error code. + * Return the TDCALL return code (RAX) */ -SYM_FUNC_START(__tdx_hypercall_ret) - TDX_HYPERCALL ret=1 -SYM_FUNC_END(__tdx_hypercall_ret) +SYM_FUNC_START(__tdcall_saved_ret) + TDX_MODULE_CALL host=0 ret=1 saved=1 +SYM_FUNC_END(__tdcall_saved_ret) diff --git a/arch/x86/coco/tdx/tdx.c b/arch/x86/coco/tdx/tdx.c index 0f16ba52ae62..a5e77893b2c0 100644 --- a/arch/x86/coco/tdx/tdx.c +++ b/arch/x86/coco/tdx/tdx.c @@ -51,13 +51,38 @@ #define TDREPORT_SUBTYPE_0 0 +/* Called from __tdx_hypercall() for unrecoverable failure */ +static noinstr void __tdx_hypercall_failed(void) +{ + instrumentation_begin(); + panic("TDVMCALL failed. TDX module bug?"); +} + +static inline u64 __tdx_hypercall(struct tdx_module_args *args) +{ + u64 ret; + + args->rcx = TDVMCALL_EXPOSE_REGS_MASK; + ret = __tdcall_saved_ret(TDG_VP_VMCALL, args); + + /* + * RAX!=0 indicates a failure of the TDVMCALL mechanism itself and that + * something has gone horribly wrong with the TDX module. + */ + if (ret) + __tdx_hypercall_failed(); + + /* The return status of the hypercall itself is in R10. */ + return args->r10; +} + /* - * Wrapper for standard use of __tdx_hypercall with no output aside from - * return code. + * Wrapper for standard use of __tdx_hypercall() w/o needing any output + * register except the return code. */ static inline u64 _tdx_hypercall(u64 fn, u64 r12, u64 r13, u64 r14, u64 r15) { - struct tdx_hypercall_args args = { + struct tdx_module_args args = { .r10 = TDX_HYPERCALL_STANDARD, .r11 = fn, .r12 = r12, @@ -69,18 +94,11 @@ static inline u64 _tdx_hypercall(u64 fn, u64 r12, u64 r13, u64 r14, u64 r15) return __tdx_hypercall(&args); } -/* Called from __tdx_hypercall() for unrecoverable failure */ -noinstr void __tdx_hypercall_failed(void) -{ - instrumentation_begin(); - panic("TDVMCALL failed. TDX module bug?"); -} - #ifdef CONFIG_KVM_GUEST long tdx_kvm_hypercall(unsigned int nr, unsigned long p1, unsigned long p2, unsigned long p3, unsigned long p4) { - struct tdx_hypercall_args args = { + struct tdx_module_args args = { .r10 = nr, .r11 = p1, .r12 = p2, @@ -140,7 +158,7 @@ EXPORT_SYMBOL_GPL(tdx_mcall_get_report0); static void __noreturn tdx_panic(const char *msg) { - struct tdx_hypercall_args args = { + struct tdx_module_args args = { .r10 = TDX_HYPERCALL_STANDARD, .r11 = TDVMCALL_REPORT_FATAL_ERROR, .r12 = 0, /* Error code: 0 is Panic */ @@ -262,7 +280,7 @@ static int ve_instr_len(struct ve_info *ve) static u64 __cpuidle __halt(const bool irq_disabled) { - struct tdx_hypercall_args args = { + struct tdx_module_args args = { .r10 = TDX_HYPERCALL_STANDARD, .r11 = hcall_func(EXIT_REASON_HLT), .r12 = irq_disabled, @@ -306,7 +324,7 @@ void __cpuidle tdx_safe_halt(void) static int read_msr(struct pt_regs *regs, struct ve_info *ve) { - struct tdx_hypercall_args args = { + struct tdx_module_args args = { .r10 = TDX_HYPERCALL_STANDARD, .r11 = hcall_func(EXIT_REASON_MSR_READ), .r12 = regs->cx, @@ -317,7 +335,7 @@ 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_ret(&args)) + if (__tdx_hypercall(&args)) return -EIO; regs->ax = lower_32_bits(args.r11); @@ -327,7 +345,7 @@ static int read_msr(struct pt_regs *regs, struct ve_info *ve) static int write_msr(struct pt_regs *regs, struct ve_info *ve) { - struct tdx_hypercall_args args = { + struct tdx_module_args args = { .r10 = TDX_HYPERCALL_STANDARD, .r11 = hcall_func(EXIT_REASON_MSR_WRITE), .r12 = regs->cx, @@ -347,7 +365,7 @@ static int write_msr(struct pt_regs *regs, struct ve_info *ve) static int handle_cpuid(struct pt_regs *regs, struct ve_info *ve) { - struct tdx_hypercall_args args = { + struct tdx_module_args args = { .r10 = TDX_HYPERCALL_STANDARD, .r11 = hcall_func(EXIT_REASON_CPUID), .r12 = regs->ax, @@ -371,7 +389,7 @@ 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_ret(&args)) + if (__tdx_hypercall(&args)) return -EIO; /* @@ -389,7 +407,7 @@ static int handle_cpuid(struct pt_regs *regs, struct ve_info *ve) static bool mmio_read(int size, unsigned long addr, unsigned long *val) { - struct tdx_hypercall_args args = { + struct tdx_module_args args = { .r10 = TDX_HYPERCALL_STANDARD, .r11 = hcall_func(EXIT_REASON_EPT_VIOLATION), .r12 = size, @@ -398,7 +416,7 @@ static bool mmio_read(int size, unsigned long addr, unsigned long *val) .r15 = *val, }; - if (__tdx_hypercall_ret(&args)) + if (__tdx_hypercall(&args)) return false; *val = args.r11; return true; @@ -517,7 +535,7 @@ static int handle_mmio(struct pt_regs *regs, struct ve_info *ve) static bool handle_in(struct pt_regs *regs, int size, int port) { - struct tdx_hypercall_args args = { + struct tdx_module_args args = { .r10 = TDX_HYPERCALL_STANDARD, .r11 = hcall_func(EXIT_REASON_IO_INSTRUCTION), .r12 = size, @@ -532,7 +550,7 @@ 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_ret(&args); + success = !__tdx_hypercall(&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 b415a24f0d48..f2a6e76dd773 100644 --- a/arch/x86/include/asm/shared/tdx.h +++ b/arch/x86/include/asm/shared/tdx.h @@ -13,32 +13,60 @@ #ifndef __ASSEMBLY__ /* - * Used in __tdx_hypercall() to pass down and get back registers' values of - * the TDCALL instruction when requesting services from the VMM. + * Used to gather input/output registers of the TDCALL and SEAMCALL + * instructions when requesting services from the TDX module. * * This is a software only structure and not part of the TDX module/VMM ABI. */ -struct tdx_hypercall_args { +struct tdx_module_args { + /* callee-clobbered */ + u64 rcx; + u64 rdx; u64 r8; u64 r9; + /* extra callee-clobbered */ u64 r10; u64 r11; + /* callee-saved + rdi/rsi */ u64 r12; u64 r13; u64 r14; u64 r15; + u64 rbx; u64 rdi; u64 rsi; - u64 rbx; - u64 rdx; }; -/* Used to request services from the VMM */ -u64 __tdx_hypercall(struct tdx_hypercall_args *args); -u64 __tdx_hypercall_ret(struct tdx_hypercall_args *args); +#define TDG_VP_VMCALL 0 -/* Called from __tdx_hypercall() for unrecoverable failure */ -void __tdx_hypercall_failed(void); +/* + * Bitmasks of exposed registers (with VMM). + */ +#define TDX_RDX BIT(2) +#define TDX_RBX BIT(3) +#define TDX_RSI BIT(6) +#define TDX_RDI BIT(7) +#define TDX_R8 BIT(8) +#define TDX_R9 BIT(9) +#define TDX_R10 BIT(10) +#define TDX_R11 BIT(11) +#define TDX_R12 BIT(12) +#define TDX_R13 BIT(13) +#define TDX_R14 BIT(14) +#define TDX_R15 BIT(15) + +/* + * These registers are clobbered to hold arguments for each + * TDVMCALL. They are safe to expose to the VMM. + * Each bit in this mask represents a register ID. Bit field + * details can be found in TDX GHCI specification, section + * titled "TDCALL [TDG.VP.VMCALL] leaf". + */ +#define TDVMCALL_EXPOSE_REGS_MASK \ + (TDX_RDX | TDX_RBX | TDX_RSI | TDX_RDI | TDX_R8 | TDX_R9 | \ + TDX_R10 | TDX_R11 | TDX_R12 | TDX_R13 | TDX_R14 | TDX_R15) + +u64 __tdcall_saved_ret(u64 fn, struct tdx_module_args *args); /* * The TDG.VP.VMCALL-Instruction-execution sub-functions are defined diff --git a/arch/x86/include/asm/tdx.h b/arch/x86/include/asm/tdx.h index a549bcc77f4f..9b0ad0176e58 100644 --- a/arch/x86/include/asm/tdx.h +++ b/arch/x86/include/asm/tdx.h @@ -20,31 +20,6 @@ #ifndef __ASSEMBLY__ -/* - * Used to gather input/output registers of the TDCALL and SEAMCALL - * instructions when requesting services from the TDX module. - * - * This is a software only structure and not part of the TDX module/VMM ABI. - */ -struct tdx_module_args { - /* callee-clobbered */ - u64 rcx; - u64 rdx; - u64 r8; - u64 r9; - /* extra callee-clobbered */ - u64 r10; - u64 r11; - /* callee-saved + rdi/rsi */ - u64 r12; - u64 r13; - u64 r14; - u64 r15; - u64 rbx; - u64 rdi; - u64 rsi; -}; - /* * Used by the #VE exception handler to gather the #VE exception * info from the TDX module. This is a software only structure diff --git a/arch/x86/kernel/asm-offsets.c b/arch/x86/kernel/asm-offsets.c index 1581564a67b7..6913b372ccf7 100644 --- a/arch/x86/kernel/asm-offsets.c +++ b/arch/x86/kernel/asm-offsets.c @@ -82,20 +82,6 @@ static void __used common(void) OFFSET(TDX_MODULE_rdi, tdx_module_args, rdi); OFFSET(TDX_MODULE_rsi, tdx_module_args, rsi); - BLANK(); - OFFSET(TDX_HYPERCALL_r8, tdx_hypercall_args, r8); - OFFSET(TDX_HYPERCALL_r9, tdx_hypercall_args, r9); - OFFSET(TDX_HYPERCALL_r10, tdx_hypercall_args, r10); - OFFSET(TDX_HYPERCALL_r11, tdx_hypercall_args, r11); - OFFSET(TDX_HYPERCALL_r12, tdx_hypercall_args, r12); - OFFSET(TDX_HYPERCALL_r13, tdx_hypercall_args, r13); - OFFSET(TDX_HYPERCALL_r14, tdx_hypercall_args, r14); - OFFSET(TDX_HYPERCALL_r15, tdx_hypercall_args, r15); - OFFSET(TDX_HYPERCALL_rdi, tdx_hypercall_args, rdi); - OFFSET(TDX_HYPERCALL_rsi, tdx_hypercall_args, rsi); - OFFSET(TDX_HYPERCALL_rbx, tdx_hypercall_args, rbx); - OFFSET(TDX_HYPERCALL_rdx, tdx_hypercall_args, rdx); - BLANK(); OFFSET(BP_scratch, boot_params, scratch); OFFSET(BP_secure_boot, boot_params, secure_boot); diff --git a/arch/x86/virt/vmx/tdx/tdxcall.S b/arch/x86/virt/vmx/tdx/tdxcall.S index 389f4ec5eee8..e4e90ebf5dad 100644 --- a/arch/x86/virt/vmx/tdx/tdxcall.S +++ b/arch/x86/virt/vmx/tdx/tdxcall.S @@ -145,11 +145,11 @@ .endif /* \ret */ .if \saved - .if \ret && \host + .if \ret /* - * Clear registers shared by guest for VP.ENTER to prevent - * speculative use of guest's values, including those are - * restored from the stack. + * Clear registers shared by guest for VP.ENTER and VP.VMCALL to + * prevent speculative use of values from guest/VMM, including + * those are restored from the stack. * * See arch/x86/kvm/vmx/vmenter.S: * @@ -173,7 +173,7 @@ xorq %r15, %r15 xorq %rbx, %rbx xorq %rdi, %rdi - .endif /* \ret && \host */ + .endif /* \ret */ /* Restore callee-saved GPRs as mandated by the x86_64 ABI */ popq %r15 -- 2.41.0