Date: Wed, 26 Jun 2019 21:19:43 +0000 (UTC) From: "Rodney W. Grimes" <rgrimes@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r349441 - head/sys/amd64/vmm Message-ID: <201906262119.x5QLJhkq099460@repo.freebsd.org>
next in thread | raw e-mail | index | archive | help
Author: rgrimes Date: Wed Jun 26 21:19:43 2019 New Revision: 349441 URL: https://svnweb.freebsd.org/changeset/base/349441 Log: Emulate the "TEST r/m{16,32,64}, imm{16,32,32}" instructions (opcode F7H). This adds emulation for: test r/m16, imm16 test r/m32, imm32 test r/m64, imm32 sign-extended to 64 OpenBSD guests compiled with clang 8.0.0 use TEST directly against a Local APIC register instead of separate read via MOV followed by a TEST against the register. PR: 238794 Submitted by: jhb Reported by: Jason Tubnor jason@tubnor.net Tested by: Jason Tubnor jason@tubnor.net Reviewed by: markj, Patrick Mooney patrick.mooney@joyent.com MFC after: 3 days Differential Revision: https://reviews.freebsd.org/D20755 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 Wed Jun 26 20:25:57 2019 (r349440) +++ head/sys/amd64/vmm/vmm_instruction_emul.c Wed Jun 26 21:19:43 2019 (r349441) @@ -78,6 +78,7 @@ enum { VIE_OP_TYPE_BITTEST, VIE_OP_TYPE_TWOB_GRP15, VIE_OP_TYPE_ADD, + VIE_OP_TYPE_TEST, VIE_OP_TYPE_LAST }; @@ -221,6 +222,12 @@ static const struct vie_op one_byte_opcodes[256] = { .op_byte = 0x8F, .op_type = VIE_OP_TYPE_POP, }, + [0xF7] = { + /* XXX Group 3 extended opcode - not just TEST */ + .op_byte = 0xF7, + .op_type = VIE_OP_TYPE_TEST, + .op_flags = VIE_OP_F_IMM, + }, [0xFF] = { /* XXX Group 5 extended opcode - not just PUSH */ .op_byte = 0xFF, @@ -450,6 +457,41 @@ getaddflags(int opsize, uint64_t x, uint64_t y) return (getaddflags64(x, y)); } +/* + * Return the status flags that would result from doing (x & y). + */ +#define GETANDFLAGS(sz) \ +static u_long \ +getandflags##sz(uint##sz##_t x, uint##sz##_t y) \ +{ \ + u_long rflags; \ + \ + __asm __volatile("and %2,%1; pushfq; popq %0" : \ + "=r" (rflags), "+r" (x) : "m" (y)); \ + return (rflags); \ +} struct __hack + +GETANDFLAGS(8); +GETANDFLAGS(16); +GETANDFLAGS(32); +GETANDFLAGS(64); + +static u_long +getandflags(int opsize, uint64_t x, uint64_t y) +{ + KASSERT(opsize == 1 || opsize == 2 || opsize == 4 || opsize == 8, + ("getandflags: invalid operand size %d", opsize)); + + if (opsize == 1) + return (getandflags8(x, y)); + else if (opsize == 2) + return (getandflags16(x, y)); + else if (opsize == 4) + return (getandflags32(x, y)); + else + return (getandflags64(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) @@ -1219,6 +1261,55 @@ emulate_cmp(void *vm, int vcpuid, uint64_t gpa, struct } static int +emulate_test(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 op1, rflags, rflags2; + + size = vie->opsize; + error = EINVAL; + + switch (vie->op.op_byte) { + case 0xF7: + /* + * F7 /0 test r/m16, imm16 + * F7 /0 test r/m32, imm32 + * REX.W + F7 /0 test r/m64, imm32 sign-extended to 64 + * + * Test mem (ModRM:r/m) with immediate and set status + * flags according to the results. The comparison is + * performed by anding the immediate from the first + * operand and then setting the status flags. + */ + if ((vie->reg & 7) != 0) + return (EINVAL); + + error = memread(vm, vcpuid, gpa, &op1, size, arg); + if (error) + return (error); + + rflags2 = getandflags(size, op1, vie->immediate); + break; + default: + return (EINVAL); + } + error = vie_read_register(vm, vcpuid, VM_REG_GUEST_RFLAGS, &rflags); + if (error) + return (error); + + /* + * OF and CF are cleared; the SF, ZF and PF flags are set according + * to the result; AF is undefined. + */ + rflags &= ~RFLAGS_STATUS_BITS; + rflags |= rflags2 & (PSL_PF | PSL_Z | PSL_N); + + error = vie_update_register(vm, vcpuid, VM_REG_GUEST_RFLAGS, rflags, 8); + return (error); +} + +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) { @@ -1642,6 +1733,10 @@ vmm_emulate_instruction(void *vm, int vcpuid, uint64_t case VIE_OP_TYPE_ADD: error = emulate_add(vm, vcpuid, gpa, vie, memread, memwrite, memarg); + break; + case VIE_OP_TYPE_TEST: + error = emulate_test(vm, vcpuid, gpa, vie, + memread, memwrite, memarg); break; default: error = EINVAL;
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201906262119.x5QLJhkq099460>