Commit 122333d6 authored May 05, 2023 by Nikolay Borisov Committed by Dave Hansen May 23, 2023

x86/tdx: Wrap exit reason with hcall_func()



TDX reuses VMEXIT "reasons" in its guest->host hypercall ABI.  This is
confusing because there might not be a VMEXIT involved at *all*.
These instances are supposed to document situation and reduce confusion
by wrapping VMEXIT reasons with hcall_func().

The decompression code does not follow this convention.

Unify the TDX decompression code with the other TDX use of VMEXIT reasons.
No functional changes.

Signed-off-by: Nikolay Borisov <nik.borisov@suse.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Link: https://lore.kernel.org/all/20230505120332.1429957-1-nik.borisov%40suse.com

parent 44c026a7

arch/x86/boot/compressed/tdx.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -20,7 +20,7 @@ static inline unsigned int tdx_io_in(int size, u16 port)
		{
		struct tdx_hypercall_args args = {
		.r10 = TDX_HYPERCALL_STANDARD,
		.r11 = EXIT_REASON_IO_INSTRUCTION,
		.r11 = hcall_func(EXIT_REASON_IO_INSTRUCTION),
		.r12 = size,
		.r13 = 0,
		.r14 = port,
		@@ -36,7 +36,7 @@ static inline void tdx_io_out(int size, u16 port, u32 value)
		{
		struct tdx_hypercall_args args = {
		.r10 = TDX_HYPERCALL_STANDARD,
		.r11 = EXIT_REASON_IO_INSTRUCTION,
		.r11 = hcall_func(EXIT_REASON_IO_INSTRUCTION),
		.r12 = size,
		.r13 = 1,
		.r14 = port,

arch/x86/coco/tdx/tdx.c

+0 −11

Original line number	Diff line number	Diff line
		@@ -76,17 +76,6 @@ noinstr void __tdx_hypercall_failed(void)
		panic("TDVMCALL failed. TDX module bug?");
		}

		/*
		* The TDG.VP.VMCALL-Instruction-execution sub-functions are defined
		* independently from but are currently matched 1:1 with VMX EXIT_REASONs.
		* Reusing the KVM EXIT_REASON macros makes it easier to connect the host and
		* guest sides of these calls.
		*/
		static __always_inline u64 hcall_func(u64 exit_reason)
		{
		return exit_reason;
		}

		#ifdef CONFIG_KVM_GUEST
		long tdx_kvm_hypercall(unsigned int nr, unsigned long p1, unsigned long p2,
		unsigned long p3, unsigned long p4)

arch/x86/include/asm/shared/tdx.h

+11 −0

Original line number	Diff line number	Diff line
		@@ -40,5 +40,16 @@ u64 __tdx_hypercall_ret(struct tdx_hypercall_args *args);
		/* Called from __tdx_hypercall() for unrecoverable failure */
		void __tdx_hypercall_failed(void);

		/*
		* The TDG.VP.VMCALL-Instruction-execution sub-functions are defined
		* independently from but are currently matched 1:1 with VMX EXIT_REASONs.
		* Reusing the KVM EXIT_REASON macros makes it easier to connect the host and
		* guest sides of these calls.
		*/
		static __always_inline u64 hcall_func(u64 exit_reason)
		{
		return exit_reason;
		}

		#endif /* !__ASSEMBLY__ */
		#endif /* _ASM_X86_SHARED_TDX_H */