From: Vasant Karasulli <vkarasulli@xxxxxxx> Using Linux's IOIO #VC processing logic. Signed-off-by: Varad Gautam <varad.gautam@xxxxxxxx> Signed-off-by: Vasant Karasulli <vkarasulli@xxxxxxx> Reviewed-by: Marc Orr <marcorr@xxxxxxxxxx> --- lib/x86/amd_sev_vc.c | 169 +++++++++++++++++++++++++++++++++++++++++++ lib/x86/processor.h | 7 ++ 2 files changed, 176 insertions(+) diff --git a/lib/x86/amd_sev_vc.c b/lib/x86/amd_sev_vc.c index 6238f1ec..2a553db1 100644 --- a/lib/x86/amd_sev_vc.c +++ b/lib/x86/amd_sev_vc.c @@ -177,6 +177,172 @@ static enum es_result vc_handle_msr(struct ghcb *ghcb, struct es_em_ctxt *ctxt) return ret; } +#define IOIO_TYPE_STR BIT(2) +#define IOIO_TYPE_IN 1 +#define IOIO_TYPE_INS (IOIO_TYPE_IN | IOIO_TYPE_STR) +#define IOIO_TYPE_OUT 0 +#define IOIO_TYPE_OUTS (IOIO_TYPE_OUT | IOIO_TYPE_STR) + +#define IOIO_REP BIT(3) + +#define IOIO_ADDR_64 BIT(9) +#define IOIO_ADDR_32 BIT(8) +#define IOIO_ADDR_16 BIT(7) + +#define IOIO_DATA_32 BIT(6) +#define IOIO_DATA_16 BIT(5) +#define IOIO_DATA_8 BIT(4) + +#define IOIO_SEG_ES (0 << 10) +#define IOIO_SEG_DS (3 << 10) + +/** + * insn_has_rep_prefix() - Determine if instruction has a REP prefix + * @insn: Instruction containing the prefix to inspect + * + * Returns: + * + * 1 if the instruction has a REP prefix, 0 if not. + */ +static int insn_has_rep_prefix(struct insn *insn) +{ + insn_byte_t p; + int i; + + insn_get_prefixes(insn); + + for_each_insn_prefix(insn, i, p) { + if (p == 0xf2 || p == 0xf3) + return 1; + } + + return 0; +} + +static enum es_result vc_ioio_exitinfo(struct es_em_ctxt *ctxt, u64 *exitinfo) +{ + struct insn *insn = &ctxt->insn; + *exitinfo = 0; + + switch (insn->opcode.bytes[0]) { + /* INS opcodes */ + case 0x6c: + case 0x6d: + *exitinfo |= IOIO_TYPE_INS; + *exitinfo |= IOIO_SEG_ES; + *exitinfo |= (ctxt->regs->rdx & 0xffff) << 16; + break; + + /* OUTS opcodes */ + case 0x6e: + case 0x6f: + *exitinfo |= IOIO_TYPE_OUTS; + *exitinfo |= IOIO_SEG_DS; + *exitinfo |= (ctxt->regs->rdx & 0xffff) << 16; + break; + + /* IN immediate opcodes */ + case 0xe4: + case 0xe5: + *exitinfo |= IOIO_TYPE_IN; + *exitinfo |= (u8)insn->immediate.value << 16; + break; + + /* OUT immediate opcodes */ + case 0xe6: + case 0xe7: + *exitinfo |= IOIO_TYPE_OUT; + *exitinfo |= (u8)insn->immediate.value << 16; + break; + + /* IN register opcodes */ + case 0xec: + case 0xed: + *exitinfo |= IOIO_TYPE_IN; + *exitinfo |= (ctxt->regs->rdx & 0xffff) << 16; + break; + + /* OUT register opcodes */ + case 0xee: + case 0xef: + *exitinfo |= IOIO_TYPE_OUT; + *exitinfo |= (ctxt->regs->rdx & 0xffff) << 16; + break; + + default: + return ES_DECODE_FAILED; + } + + switch (insn->opcode.bytes[0]) { + case 0x6c: + case 0x6e: + case 0xe4: + case 0xe6: + case 0xec: + case 0xee: + /* Single byte opcodes */ + *exitinfo |= IOIO_DATA_8; + break; + default: + /* Length determined by instruction parsing */ + *exitinfo |= (insn->opnd_bytes == 2) ? IOIO_DATA_16 + : IOIO_DATA_32; + } + switch (insn->addr_bytes) { + case 2: + *exitinfo |= IOIO_ADDR_16; + break; + case 4: + *exitinfo |= IOIO_ADDR_32; + break; + case 8: + *exitinfo |= IOIO_ADDR_64; + break; + } + + if (insn_has_rep_prefix(insn)) + *exitinfo |= IOIO_REP; + + return ES_OK; +} + +static enum es_result vc_handle_ioio(struct ghcb *ghcb, struct es_em_ctxt *ctxt) +{ + struct ex_regs *regs = ctxt->regs; + u64 exit_info_1; + enum es_result ret; + + ret = vc_ioio_exitinfo(ctxt, &exit_info_1); + if (ret != ES_OK) + return ret; + + if (exit_info_1 & IOIO_TYPE_STR) { + ret = ES_VMM_ERROR; + } else { + /* IN/OUT into/from rAX */ + + int bits = (exit_info_1 & 0x70) >> 1; + u64 rax = 0; + + if (!(exit_info_1 & IOIO_TYPE_IN)) + rax = lower_bits(regs->rax, bits); + + ghcb_set_rax(ghcb, rax); + + ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_IOIO, exit_info_1, 0); + if (ret != ES_OK) + return ret; + + if (exit_info_1 & IOIO_TYPE_IN) { + if (!ghcb_rax_is_valid(ghcb)) + return ES_VMM_ERROR; + regs->rax = lower_bits(ghcb->save.rax, bits); + } + } + + return ret; +} + static enum es_result vc_handle_exitcode(struct es_em_ctxt *ctxt, struct ghcb *ghcb, unsigned long exit_code) @@ -190,6 +356,9 @@ static enum es_result vc_handle_exitcode(struct es_em_ctxt *ctxt, case SVM_EXIT_MSR: result = vc_handle_msr(ghcb, ctxt); break; + case SVM_EXIT_IOIO: + result = vc_handle_ioio(ghcb, ctxt); + break; default: /* * Unexpected #VC exception diff --git a/lib/x86/processor.h b/lib/x86/processor.h index d839308f..661ded31 100644 --- a/lib/x86/processor.h +++ b/lib/x86/processor.h @@ -835,6 +835,13 @@ static inline int test_bit(int nr, const volatile unsigned long *addr) return (*word & mask) != 0; } +static inline u64 lower_bits(u64 val, unsigned int bits) +{ + u64 mask = (1ULL << bits) - 1; + + return (val & mask); +} + static inline void flush_tlb(void) { ulong cr4; -- 2.34.1