Author: jhb Date: Fri May 3 21:48:42 2019 New Revision: 347065 URL: https://svnweb.freebsd.org/changeset/base/347065
Log: Emulate the "ADD reg, r/m" instruction (opcode 03H). OVMF's flash variable storage is using add instructions when indexing the variable store bootrom location. Submitted by: D Scott Phillips <d.scott.phill...@intel.com> Reviewed by: rgrimes MFC after: 1 week Sponsored by: Intel Corporation Differential Revision: https://reviews.freebsd.org/D19975 Modified: head/sys/amd64/vmm/vmm_instruction_emul.c Modified: head/sys/amd64/vmm/vmm_instruction_emul.c ============================================================================== --- head/sys/amd64/vmm/vmm_instruction_emul.c Fri May 3 21:46:25 2019 (r347064) +++ head/sys/amd64/vmm/vmm_instruction_emul.c Fri May 3 21:48:42 2019 (r347065) @@ -77,6 +77,7 @@ enum { VIE_OP_TYPE_STOS, VIE_OP_TYPE_BITTEST, VIE_OP_TYPE_TWOB_GRP15, + VIE_OP_TYPE_ADD, VIE_OP_TYPE_LAST }; @@ -112,6 +113,10 @@ static const struct vie_op two_byte_opcodes[256] = { }; static const struct vie_op one_byte_opcodes[256] = { + [0x03] = { + .op_byte = 0x03, + .op_type = VIE_OP_TYPE_ADD, + }, [0x0F] = { .op_byte = 0x0F, .op_type = VIE_OP_TYPE_TWO_BYTE @@ -410,6 +415,41 @@ getcc(int opsize, uint64_t x, uint64_t y) return (getcc64(x, y)); } +/* + * Macro creation of functions getaddflags{8,16,32,64} + */ +#define GETADDFLAGS(sz) \ +static u_long \ +getaddflags##sz(uint##sz##_t x, uint##sz##_t y) \ +{ \ + u_long rflags; \ + \ + __asm __volatile("add %2,%1; pushfq; popq %0" : \ + "=r" (rflags), "+r" (x) : "m" (y)); \ + return (rflags); \ +} struct __hack + +GETADDFLAGS(8); +GETADDFLAGS(16); +GETADDFLAGS(32); +GETADDFLAGS(64); + +static u_long +getaddflags(int opsize, uint64_t x, uint64_t y) +{ + KASSERT(opsize == 1 || opsize == 2 || opsize == 4 || opsize == 8, + ("getaddflags: invalid operand size %d", opsize)); + + if (opsize == 1) + return (getaddflags8(x, y)); + else if (opsize == 2) + return (getaddflags16(x, y)); + else if (opsize == 4) + return (getaddflags32(x, y)); + else + return (getaddflags64(x, y)); +} + static int emulate_mov(void *vm, int vcpuid, uint64_t gpa, struct vie *vie, mem_region_read_t memread, mem_region_write_t memwrite, void *arg) @@ -1179,6 +1219,62 @@ emulate_cmp(void *vm, int vcpuid, uint64_t gpa, struct } static int +emulate_add(void *vm, int vcpuid, uint64_t gpa, struct vie *vie, + mem_region_read_t memread, mem_region_write_t memwrite, void *arg) +{ + int error, size; + uint64_t nval, rflags, rflags2, val1, val2; + enum vm_reg_name reg; + + size = vie->opsize; + error = EINVAL; + + switch (vie->op.op_byte) { + case 0x03: + /* + * ADD r/m to r and store the result in r + * + * 03/r ADD r16, r/m16 + * 03/r ADD r32, r/m32 + * REX.W + 03/r ADD r64, r/m64 + */ + + /* get the first operand */ + reg = gpr_map[vie->reg]; + error = vie_read_register(vm, vcpuid, reg, &val1); + if (error) + break; + + /* get the second operand */ + error = memread(vm, vcpuid, gpa, &val2, size, arg); + if (error) + break; + + /* perform the operation and write the result */ + nval = val1 + val2; + error = vie_update_register(vm, vcpuid, reg, nval, size); + break; + default: + break; + } + + if (!error) { + rflags2 = getaddflags(size, val1, val2); + error = vie_read_register(vm, vcpuid, VM_REG_GUEST_RFLAGS, + &rflags); + if (error) + return (error); + + rflags &= ~RFLAGS_STATUS_BITS; + rflags |= rflags2 & RFLAGS_STATUS_BITS; + error = vie_update_register(vm, vcpuid, VM_REG_GUEST_RFLAGS, + rflags, 8); + } + + return (error); +} + +static int emulate_sub(void *vm, int vcpuid, uint64_t gpa, struct vie *vie, mem_region_read_t memread, mem_region_write_t memwrite, void *arg) { @@ -1542,6 +1638,10 @@ vmm_emulate_instruction(void *vm, int vcpuid, uint64_t case VIE_OP_TYPE_TWOB_GRP15: error = emulate_twob_group15(vm, vcpuid, gpa, vie, memread, memwrite, memarg); + break; + case VIE_OP_TYPE_ADD: + error = emulate_add(vm, vcpuid, gpa, vie, memread, + memwrite, memarg); break; default: error = EINVAL; _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
