Author: kib Date: Fri Oct 12 15:30:15 2018 New Revision: 339331 URL: https://svnweb.freebsd.org/changeset/base/339331
Log: bhyve: emulate CLFLUSH and CLFLUSHOPT. Apparently CLFLUSH on mmio can cause VM exit, as reported in the PR. I do not see that anything useful can be done except emulating page faults on invalid addresses. Due to the instruction encoding pecularity, also emulate SFENCE. PR: 232081 Reported by: phk Reviewed by: araujo, avg, jhb (all: previous version) Sponsored by: The FreeBSD Foundation Approved by: re (gjb) MFC after: 1 week Differential revision: https://reviews.freebsd.org/D17482 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 Oct 12 15:19:41 2018 (r339330) +++ head/sys/amd64/vmm/vmm_instruction_emul.c Fri Oct 12 15:30:15 2018 (r339331) @@ -76,6 +76,7 @@ enum { VIE_OP_TYPE_GROUP1, VIE_OP_TYPE_STOS, VIE_OP_TYPE_BITTEST, + VIE_OP_TYPE_TWOB_GRP15, VIE_OP_TYPE_LAST }; @@ -87,6 +88,10 @@ enum { #define VIE_OP_F_NO_GLA_VERIFICATION (1 << 4) static const struct vie_op two_byte_opcodes[256] = { + [0xAE] = { + .op_byte = 0xAE, + .op_type = VIE_OP_TYPE_TWOB_GRP15, + }, [0xB6] = { .op_byte = 0xB6, .op_type = VIE_OP_TYPE_MOVZX, @@ -1443,6 +1448,37 @@ emulate_bittest(void *vm, int vcpuid, uint64_t gpa, st return (0); } +static int +emulate_twob_group15(void *vm, int vcpuid, uint64_t gpa, struct vie *vie, + mem_region_read_t memread, mem_region_write_t memwrite, void *memarg) +{ + int error; + uint64_t buf; + + switch (vie->reg & 7) { + case 0x7: /* CLFLUSH, CLFLUSHOPT, and SFENCE */ + if (vie->mod == 0x3) { + /* + * SFENCE. Ignore it, VM exit provides enough + * barriers on its own. + */ + error = 0; + } else { + /* + * CLFLUSH, CLFLUSHOPT. Only check for access + * rights. + */ + error = memread(vm, vcpuid, gpa, &buf, 1, memarg); + } + break; + default: + error = EINVAL; + break; + } + + return (error); +} + int vmm_emulate_instruction(void *vm, int vcpuid, uint64_t gpa, struct vie *vie, struct vm_guest_paging *paging, mem_region_read_t memread, @@ -1501,6 +1537,10 @@ vmm_emulate_instruction(void *vm, int vcpuid, uint64_t break; case VIE_OP_TYPE_BITTEST: error = emulate_bittest(vm, vcpuid, gpa, vie, + memread, memwrite, memarg); + break; + case VIE_OP_TYPE_TWOB_GRP15: + error = emulate_twob_group15(vm, vcpuid, gpa, vie, memread, memwrite, memarg); break; default: _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
