1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (C) 2021-2022 Intel Corporation */
16 #include <asm/insn-eval.h>
82  * tdx_mcall_get_report0() - Wrapper to get TDREPORT0 (a.k.a. TDREPORT
84  * @reportdata: Address of the input buffer which contains user-defined
86  * @tdreport: Address of the output buffer to store TDREPORT.
92  * Return 0 on success, -EINVAL for invalid operands, or -EIO on
107 			return -EINVAL;  in tdx_mcall_get_report0()
108 		return -EIO;  in tdx_mcall_get_report0()
116  * tdx_hcall_get_quote() - Wrapper to request TD Quote using GetQuote
118  * @buf: Address of the directly mapped shared kernel buffer which
121  * @size: size of the tdquote buffer (4KB-aligned).
179 	 * information like GPA width, number of available vcpus, debug mode  in tdx_parse_tdinfo()
181 	 * Guest-Host-Communication Interface (GHCI), section 2.4.2 TDCALL  in tdx_parse_tdinfo()
187 	 * The highest bit of a guest physical address is the "sharing" bit.  in tdx_parse_tdinfo()
190 	 * The GPA width that comes out of this call is critical. TDX guests  in tdx_parse_tdinfo()
194 	*cc_mask = BIT_ULL(gpa_width - 1);  in tdx_parse_tdinfo()
199 	 * TD-private memory.  Only VMM-shared memory (MMIO) will #VE.  in tdx_parse_tdinfo()
214  * The TDX module spec states that #VE may be injected for a limited set of
217  *  - Emulation of the architectural #VE injection on EPT violation;
219  *  - As a result of guest TD execution of a disallowed instruction,
222  *  - A notification to the guest TD about anomalous behavior;
224  * The last one is opt-in and is not used by the kernel.
236 	switch (ve->exit_reason) {  in ve_instr_len()
242 		/* It is safe to use ve->instr_len for #VE due instructions */  in ve_instr_len()
243 		return ve->instr_len;  in ve_instr_len()
246 		 * For EPT violations, ve->insn_len is not defined. For those,  in ve_instr_len()
250 		WARN_ONCE(1, "ve->instr_len is not defined for EPT violations");  in ve_instr_len()
253 		WARN_ONCE(1, "Unexpected #VE-type: %lld\n", ve->exit_reason);  in ve_instr_len()
254 		return ve->instr_len;  in ve_instr_len()
268 	 * can be found in TDX Guest-Host-Communication Interface  in __halt()
272 	 * enabled status (RFLAGS.IF) of the TD guest and to determine  in __halt()
286 		return -EIO;  in handle_halt()
307 		.r12 = regs->cx,  in read_msr()
312 	 * can be found in TDX Guest-Host-Communication Interface  in read_msr()
316 		return -EIO;  in read_msr()
318 	regs->ax = lower_32_bits(args.r11);  in read_msr()
319 	regs->dx = upper_32_bits(args.r11);  in read_msr()
328 		.r12 = regs->cx,  in write_msr()
329 		.r13 = (u64)regs->dx << 32 | regs->ax,  in write_msr()
334 	 * can be found in TDX Guest-Host-Communication Interface  in write_msr()
338 		return -EIO;  in write_msr()
348 		.r12 = regs->ax,  in handle_cpuid()
349 		.r13 = regs->cx,  in handle_cpuid()
356 	 * Return all-zeros for any CPUID outside the range. It matches CPU  in handle_cpuid()
357 	 * behaviour for non-supported leaf.  in handle_cpuid()
359 	if (regs->ax < 0x40000000 || regs->ax > 0x4FFFFFFF) {  in handle_cpuid()
360 		regs->ax = regs->bx = regs->cx = regs->dx = 0;  in handle_cpuid()
366 	 * ABI can be found in TDX Guest-Host-Communication Interface  in handle_cpuid()
370 		return -EIO;  in handle_cpuid()
373 	 * As per TDX GHCI CPUID ABI, r12-r15 registers contain contents of  in handle_cpuid()
377 	regs->ax = args.r12;  in handle_cpuid()
378 	regs->bx = args.r13;  in handle_cpuid()
379 	regs->cx = args.r14;  in handle_cpuid()
380 	regs->dx = args.r15;  in handle_cpuid()
417 	/* Only in-kernel MMIO is supported */  in handle_mmio()
419 		return -EFAULT;  in handle_mmio()
421 	if (copy_from_kernel_nofault(buffer, (void *)regs->ip, MAX_INSN_SIZE))  in handle_mmio()
422 		return -EFAULT;  in handle_mmio()
425 		return -EINVAL;  in handle_mmio()
429 		return -EINVAL;  in handle_mmio()
434 			return -EINVAL;  in handle_mmio()
437 	if (!fault_in_kernel_space(ve->gla)) {  in handle_mmio()
439 		return -EINVAL;  in handle_mmio()
452 	if (vaddr / PAGE_SIZE != (vaddr + size - 1) / PAGE_SIZE)  in handle_mmio()
453 		return -EFAULT;  in handle_mmio()
459 		if (!mmio_write(size, ve->gpa, val))  in handle_mmio()
460 			return -EIO;  in handle_mmio()
464 		if (!mmio_write(size, ve->gpa, val))  in handle_mmio()
465 			return -EIO;  in handle_mmio()
479 		return -EINVAL;  in handle_mmio()
482 		return -EINVAL;  in handle_mmio()
486 	if (!mmio_read(size, ve->gpa, &val))  in handle_mmio()
487 		return -EIO;  in handle_mmio()
491 		/* Zero-extend for 32-bit operation */  in handle_mmio()
509 		return -EINVAL;  in handle_mmio()
532 	 * in TDX Guest-Host-Communication Interface (GHCI) section titled  in handle_in()
537 	/* Update part of the register affected by the emulated instruction */  in handle_in()
538 	regs->ax &= ~mask;  in handle_in()
540 		regs->ax |= args.r11 & mask;  in handle_in()
551 	 * in TDX Guest-Host-Communication Interface (GHCI) section titled  in handle_out()
555 			       PORT_WRITE, port, regs->ax & mask);  in handle_out()
568 	u32 exit_qual = ve->exit_qual;  in handle_io()
573 		return -EIO;  in handle_io()
585 		return -EIO;  in handle_io()
591  * Early #VE exception handler. Only handles a subset of port I/O.
608 	regs->ip += insn_len;  in tdx_early_handle_ve()
634 	ve->exit_reason = args.rcx;  in tdx_get_ve_info()
635 	ve->exit_qual   = args.rdx;  in tdx_get_ve_info()
636 	ve->gla         = args.r8;  in tdx_get_ve_info()
637 	ve->gpa         = args.r9;  in tdx_get_ve_info()
638 	ve->instr_len   = lower_32_bits(args.r10);  in tdx_get_ve_info()
639 	ve->instr_info  = upper_32_bits(args.r10);  in tdx_get_ve_info()
645  * On success, returns the number of bytes RIP should be incremented (>=0)
646  * or -errno on error.
650 	switch (ve->exit_reason) {  in virt_exception_user()
654 		pr_warn("Unexpected #VE: %lld\n", ve->exit_reason);  in virt_exception_user()
655 		return -EIO;  in virt_exception_user()
667  * On success, returns the number of bytes RIP should be incremented (>=0)
668  * or -errno on error.
672 	switch (ve->exit_reason) {  in virt_exception_kernel()
682 		if (is_private_gpa(ve->gpa))  in virt_exception_kernel()
683 			panic("Unexpected EPT-violation on private memory.");  in virt_exception_kernel()
688 		pr_warn("Unexpected #VE: %lld\n", ve->exit_reason);  in virt_exception_kernel()
689 		return -EIO;  in virt_exception_kernel()
705 	regs->ip += insn_len;  in tdx_handle_virt_exception()
713 	 * TDX guest is responsible for flushing TLB on private->shared  in tdx_tlb_flush_required()
714 	 * transition. VMM is responsible for flushing on shared->private.  in tdx_tlb_flush_required()
722 	 * flush to avoid integrity failures in the face of a buggy or  in tdx_tlb_flush_required()
740  * Notify the VMM about page mapping conversion. More info about ABI
741  * can be found in TDX Guest-Host-Communication Interface (GHCI),
744 static bool tdx_map_gpa(phys_addr_t start, phys_addr_t end, bool enc)  in tdx_map_gpa()  argument
753 		end   |= cc_mkdec(0);  in tdx_map_gpa()
761 			.r13 = end - start };  in tdx_map_gpa()
774 		if (map_fail_paddr < start || map_fail_paddr >= end)  in tdx_map_gpa()
791  * Inform the VMM of the guest's intent for this physical page: shared with
793  * of the page in response.
798 	phys_addr_t end   = __pa(vaddr + numpages * PAGE_SIZE);  in tdx_enc_status_changed()  local
800 	if (!tdx_map_gpa(start, end, enc))  in tdx_enc_status_changed()
803 	/* shared->private conversion requires memory to be accepted before use */  in tdx_enc_status_changed()
805 		return tdx_accept_memory(start, end);  in tdx_enc_status_changed()
814 	 * Only handle shared->private conversion here.  in tdx_enc_status_change_prepare()
818 		return -EIO;  in tdx_enc_status_change_prepare()
827 	 * Only handle private->shared conversion here.  in tdx_enc_status_change_finish()
831 		return -EIO;  in tdx_enc_status_change_finish()
841 /* Stop new private<->shared conversions */
854 		pr_warn("Failed to stop shared<->private conversions\n");  in tdx_kexec_begin()
860 	unsigned long addr, end;  in tdx_kexec_finish()  local
869 	end  = PAGE_OFFSET + get_max_mapped();  in tdx_kexec_finish()
871 	while (addr < end) {  in tdx_kexec_finish()
884 			 * conversion to shared.  in tdx_kexec_finish()
901 			 * a pre-reserved memory range that is always private.  in tdx_kexec_finish()
911 				pr_err("Failed to unshare range %#lx-%#lx\n",  in tdx_kexec_finish()
934 		.r9 = -1ULL,  in tdx_early_init()
958 	 * as flag, not as part of physical address.  in tdx_early_init()
962 	physical_mask &= cc_mask - 1;  in tdx_early_init()
970 	 *   - Private mapping => Shared Page  == Guest shutdown  in tdx_early_init()
971          *   - Shared mapping  => Private Page == Recoverable #VE  in tdx_early_init()
997 	 * Intel-TDX has a secure RDMSR hypercall, but that needs to be  in tdx_early_init()