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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-18 17:35:05 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-18 17:39:31 +0000
commit85c675d0d09a45a135bddd15d7b385f8758c32fb (patch)
tree76267dbc9b9a130337be3640948fe397b04ac629 /arch/x86/coco/tdx/tdcall.S
parentAdding upstream version 6.6.15. (diff)
downloadlinux-85c675d0d09a45a135bddd15d7b385f8758c32fb.tar.xz
linux-85c675d0d09a45a135bddd15d7b385f8758c32fb.zip
Adding upstream version 6.7.7.upstream/6.7.7
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/x86/coco/tdx/tdcall.S')
-rw-r--r--arch/x86/coco/tdx/tdcall.S235
1 files changed, 29 insertions, 206 deletions
diff --git a/arch/x86/coco/tdx/tdcall.S b/arch/x86/coco/tdx/tdcall.S
index 2eca5f4373..52d9786da3 100644
--- a/arch/x86/coco/tdx/tdcall.S
+++ b/arch/x86/coco/tdx/tdcall.S
@@ -1,240 +1,63 @@
/* SPDX-License-Identifier: GPL-2.0 */
#include <asm/asm-offsets.h>
#include <asm/asm.h>
-#include <asm/frame.h>
-#include <asm/unwind_hints.h>
#include <linux/linkage.h>
-#include <linux/bits.h>
#include <linux/errno.h>
#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"
/*
- * __tdx_module_call() - Used by TDX guests to request services from
- * the TDX module (does not include VMM services) using TDCALL instruction.
- *
- * Transforms function call register arguments into the TDCALL register ABI.
- * After TDCALL operation, TDX module output is saved in @out (if it is
- * provided by the user).
- *
- *-------------------------------------------------------------------------
- * TDCALL ABI:
- *-------------------------------------------------------------------------
- * Input Registers:
- *
- * RAX - TDCALL Leaf number.
- * RCX,RDX,R8-R9 - TDCALL Leaf specific input registers.
- *
- * Output Registers:
+ * __tdcall() - Used by TDX guests to request services from the TDX
+ * module (does not include VMM services) using TDCALL instruction.
*
- * RAX - TDCALL instruction error code.
- * RCX,RDX,R8-R11 - TDCALL Leaf specific output registers.
+ * __tdcall() function ABI:
*
- *-------------------------------------------------------------------------
+ * @fn (RDI) - TDCALL Leaf ID, moved to RAX
+ * @args (RSI) - struct tdx_module_args for input
*
- * __tdx_module_call() function ABI:
- *
- * @fn (RDI) - TDCALL Leaf ID, moved to RAX
- * @rcx (RSI) - Input parameter 1, moved to RCX
- * @rdx (RDX) - Input parameter 2, moved to RDX
- * @r8 (RCX) - Input parameter 3, moved to R8
- * @r9 (R8) - Input parameter 4, moved to R9
- *
- * @out (R9) - struct tdx_module_output pointer
- * stored temporarily in R12 (not
- * shared with the TDX module). It
- * can be NULL.
+ * Only RCX/RDX/R8-R11 are used as input registers.
*
* Return status of TDCALL via RAX.
*/
-SYM_FUNC_START(__tdx_module_call)
- FRAME_BEGIN
+SYM_FUNC_START(__tdcall)
TDX_MODULE_CALL host=0
- FRAME_END
- RET
-SYM_FUNC_END(__tdx_module_call)
+SYM_FUNC_END(__tdcall)
/*
- * 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, if \ret is 1.
- *
- *-------------------------------------------------------------------------
- * TD VMCALL ABI:
- *-------------------------------------------------------------------------
- *
- * Input Registers:
+ * __tdcall_ret() - Used by TDX guests to request services from the TDX
+ * module (does not include VMM services) using TDCALL instruction, with
+ * saving output registers to the 'struct tdx_module_args' used as input.
*
- * 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.
+ * __tdcall_ret() function ABI:
*
- * Output Registers:
+ * @fn (RDI) - TDCALL Leaf ID, moved to RAX
+ * @args (RSI) - struct tdx_module_args for input and output
*
- * RAX - TDCALL instruction status (Not related to hypercall
- * output).
- * RBX, RDX, RDI, RSI - Hypercall sub function specific output values.
- * R8-R15 - Same as above.
+ * Only RCX/RDX/R8-R11 are used as input/output registers.
*
+ * Return status of TDCALL via RAX.
*/
-.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
+SYM_FUNC_START(__tdcall_ret)
+ TDX_MODULE_CALL host=0 ret=1
+SYM_FUNC_END(__tdcall_ret)
/*
+ * __tdcall_saved_ret() - Used by TDX guests to request services from the
+ * TDX module (including VMM services) using TDCALL instruction, with
+ * saving output registers to the 'struct tdx_module_args' used as input.
*
- * __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)
-
-/*
+ * __tdcall_saved_ret() function ABI:
*
- * __tdx_hypercall_ret() function ABI:
+ * @fn (RDI) - TDCALL leaf ID, moved to RAX
+ * @args (RSI) - struct tdx_module_args for input/output
*
- * @args (RDI) - struct tdx_hypercall_args for input and output
+ * All registers in @args are used as input/output registers.
*
* On successful completion, return the hypercall error code.
*/
-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)