1 #include <asm/tdx.h> 2 #include <asm/pgtable.h> 3 4 static unsigned long try_accept_one(phys_addr_t start, unsigned long len, 5 enum pg_level pg_level) 6 { 7 unsigned long accept_size = page_level_size(pg_level); 8 struct tdx_module_args args = {}; 9 u8 page_size; 10 11 if (!IS_ALIGNED(start, accept_size)) 12 return 0; 13 14 if (len < accept_size) 15 return 0; 16 17 /* 18 * Pass the page physical address to the TDX module to accept the 19 * pending, private page. 20 * 21 * Bits 2:0 of RCX encode page size: 0 - 4K, 1 - 2M, 2 - 1G. 22 */ 23 switch (pg_level) { 24 case PG_LEVEL_4K: 25 page_size = TDX_PS_4K; 26 break; 27 case PG_LEVEL_2M: 28 page_size = TDX_PS_2M; 29 break; 30 case PG_LEVEL_1G: 31 page_size = TDX_PS_1G; 32 break; 33 default: 34 return 0; 35 } 36 37 args.rcx = start | page_size; 38 if (__tdcall(TDG_MEM_PAGE_ACCEPT, &args)) 39 return 0; 40 41 return accept_size; 42 } 43 44 bool tdx_accept_memory(phys_addr_t start, phys_addr_t end) 45 { 46 /* 47 * For shared->private conversion, accept the page using 48 * TDG_MEM_PAGE_ACCEPT TDX module call. 49 */ 50 while (start < end) { 51 unsigned long len = end - start; 52 unsigned long accept_size; 53 54 /* 55 * Try larger accepts first. It gives chance to VMM to keep 56 * 1G/2M Secure EPT entries where possible and speeds up 57 * process by cutting number of hypercalls (if successful). 58 */ 59 60 accept_size = try_accept_one(start, len, PG_LEVEL_1G); 61 if (!accept_size) 62 accept_size = try_accept_one(start, len, PG_LEVEL_2M); 63 if (!accept_size) 64 accept_size = try_accept_one(start, len, PG_LEVEL_4K); 65 if (!accept_size) 66 return false; 67 start += accept_size; 68 } 69 70 return true; 71 } 72 73 noinstr u64 __tdx_hypercall(struct tdx_module_args *args) 74 { 75 /* 76 * For TDVMCALL explicitly set RCX to the bitmap of shared registers. 77 * The caller isn't expected to set @args->rcx anyway. 78 */ 79 args->rcx = TDVMCALL_EXPOSE_REGS_MASK; 80 81 /* 82 * Failure of __tdcall_saved_ret() indicates a failure of the TDVMCALL 83 * mechanism itself and that something has gone horribly wrong with 84 * the TDX module. __tdx_hypercall_failed() never returns. 85 */ 86 if (__tdcall_saved_ret(TDG_VP_VMCALL, args)) 87 __tdx_hypercall_failed(); 88 89 /* TDVMCALL leaf return code is in R10 */ 90 return args->r10; 91 } 92