The following commit has been merged into the x86/misc branch of tip: Commit-ID: c494eb366dbfc5095c0f159bbb5c6d4ec3ed37ec Gitweb: https://git.kernel.org/tip/c494eb366dbfc5095c0f159bbb5c6d4ec3ed37ec Author: Kirill A. Shutemov <kirill@xxxxxxxxxxxxx> AuthorDate: Tue, 30 Nov 2021 21:49:33 +03:00 Committer: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> CommitterDate: Tue, 30 Nov 2021 14:53:30 -08:00 x86/sev-es: Use insn_decode_mmio() for MMIO implementation Switch SEV implementation to insn_decode_mmio(). The helper is going to be used by TDX too. No functional changes. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> Signed-off-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Reviewed-by: Andi Kleen <ak@xxxxxxxxxxxxxxx> Reviewed-by: Tony Luck <tony.luck@xxxxxxxxx> Tested-by: Joerg Roedel <jroedel@xxxxxxx> Acked-by: Tom Lendacky <thomas.lendacky@xxxxxxx> Link: https://lkml.kernel.org/r/20211130184933.31005-5-kirill.shutemov@xxxxxxxxxxxxxxx --- arch/x86/kernel/sev.c | 172 +++++++++-------------------------------- 1 file changed, 41 insertions(+), 131 deletions(-) diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c index 74f0ec9..09c06c0 100644 --- a/arch/x86/kernel/sev.c +++ b/arch/x86/kernel/sev.c @@ -776,22 +776,6 @@ static void __init vc_early_forward_exception(struct es_em_ctxt *ctxt) do_early_exception(ctxt->regs, trapnr); } -static long *vc_insn_get_reg(struct es_em_ctxt *ctxt) -{ - long *reg_array; - int offset; - - reg_array = (long *)ctxt->regs; - offset = insn_get_modrm_reg_off(&ctxt->insn, ctxt->regs); - - if (offset < 0) - return NULL; - - offset /= sizeof(long); - - return reg_array + offset; -} - static long *vc_insn_get_rm(struct es_em_ctxt *ctxt) { long *reg_array; @@ -839,76 +823,6 @@ static enum es_result vc_do_mmio(struct ghcb *ghcb, struct es_em_ctxt *ctxt, return sev_es_ghcb_hv_call(ghcb, true, ctxt, exit_code, exit_info_1, exit_info_2); } -static enum es_result vc_handle_mmio_twobyte_ops(struct ghcb *ghcb, - struct es_em_ctxt *ctxt) -{ - struct insn *insn = &ctxt->insn; - unsigned int bytes = 0; - enum es_result ret; - int sign_byte; - long *reg_data; - - switch (insn->opcode.bytes[1]) { - /* MMIO Read w/ zero-extension */ - case 0xb6: - bytes = 1; - fallthrough; - case 0xb7: - if (!bytes) - bytes = 2; - - ret = vc_do_mmio(ghcb, ctxt, bytes, true); - if (ret) - break; - - /* Zero extend based on operand size */ - reg_data = vc_insn_get_reg(ctxt); - if (!reg_data) - return ES_DECODE_FAILED; - - memset(reg_data, 0, insn->opnd_bytes); - - memcpy(reg_data, ghcb->shared_buffer, bytes); - break; - - /* MMIO Read w/ sign-extension */ - case 0xbe: - bytes = 1; - fallthrough; - case 0xbf: - if (!bytes) - bytes = 2; - - ret = vc_do_mmio(ghcb, ctxt, bytes, true); - if (ret) - break; - - /* Sign extend based on operand size */ - reg_data = vc_insn_get_reg(ctxt); - if (!reg_data) - return ES_DECODE_FAILED; - - if (bytes == 1) { - u8 *val = (u8 *)ghcb->shared_buffer; - - sign_byte = (*val & 0x80) ? 0xff : 0x00; - } else { - u16 *val = (u16 *)ghcb->shared_buffer; - - sign_byte = (*val & 0x8000) ? 0xff : 0x00; - } - memset(reg_data, sign_byte, insn->opnd_bytes); - - memcpy(reg_data, ghcb->shared_buffer, bytes); - break; - - default: - ret = ES_UNSUPPORTED; - } - - return ret; -} - /* * The MOVS instruction has two memory operands, which raises the * problem that it is not known whether the access to the source or the @@ -976,83 +890,79 @@ static enum es_result vc_handle_mmio_movs(struct es_em_ctxt *ctxt, return ES_RETRY; } -static enum es_result vc_handle_mmio(struct ghcb *ghcb, - struct es_em_ctxt *ctxt) +static enum es_result vc_handle_mmio(struct ghcb *ghcb, struct es_em_ctxt *ctxt) { struct insn *insn = &ctxt->insn; unsigned int bytes = 0; + enum mmio_type mmio; enum es_result ret; + u8 sign_byte; long *reg_data; - switch (insn->opcode.bytes[0]) { - /* MMIO Write */ - case 0x88: - bytes = 1; - fallthrough; - case 0x89: - if (!bytes) - bytes = insn->opnd_bytes; + mmio = insn_decode_mmio(insn, &bytes); + if (mmio == MMIO_DECODE_FAILED) + return ES_DECODE_FAILED; - reg_data = vc_insn_get_reg(ctxt); + if (mmio != MMIO_WRITE_IMM && mmio != MMIO_MOVS) { + reg_data = insn_get_modrm_reg_ptr(insn, ctxt->regs); if (!reg_data) return ES_DECODE_FAILED; + } + switch (mmio) { + case MMIO_WRITE: memcpy(ghcb->shared_buffer, reg_data, bytes); - ret = vc_do_mmio(ghcb, ctxt, bytes, false); break; - - case 0xc6: - bytes = 1; - fallthrough; - case 0xc7: - if (!bytes) - bytes = insn->opnd_bytes; - + case MMIO_WRITE_IMM: memcpy(ghcb->shared_buffer, insn->immediate1.bytes, bytes); - ret = vc_do_mmio(ghcb, ctxt, bytes, false); break; - - /* MMIO Read */ - case 0x8a: - bytes = 1; - fallthrough; - case 0x8b: - if (!bytes) - bytes = insn->opnd_bytes; - + case MMIO_READ: ret = vc_do_mmio(ghcb, ctxt, bytes, true); if (ret) break; - reg_data = vc_insn_get_reg(ctxt); - if (!reg_data) - return ES_DECODE_FAILED; - /* Zero-extend for 32-bit operation */ if (bytes == 4) *reg_data = 0; memcpy(reg_data, ghcb->shared_buffer, bytes); break; + case MMIO_READ_ZERO_EXTEND: + ret = vc_do_mmio(ghcb, ctxt, bytes, true); + if (ret) + break; + + /* Zero extend based on operand size */ + memset(reg_data, 0, insn->opnd_bytes); + memcpy(reg_data, ghcb->shared_buffer, bytes); + break; + case MMIO_READ_SIGN_EXTEND: + ret = vc_do_mmio(ghcb, ctxt, bytes, true); + if (ret) + break; - /* MOVS instruction */ - case 0xa4: - bytes = 1; - fallthrough; - case 0xa5: - if (!bytes) - bytes = insn->opnd_bytes; + if (bytes == 1) { + u8 *val = (u8 *)ghcb->shared_buffer; - ret = vc_handle_mmio_movs(ctxt, bytes); + sign_byte = (*val & 0x80) ? 0xff : 0x00; + } else { + u16 *val = (u16 *)ghcb->shared_buffer; + + sign_byte = (*val & 0x8000) ? 0xff : 0x00; + } + + /* Sign extend based on operand size */ + memset(reg_data, sign_byte, insn->opnd_bytes); + memcpy(reg_data, ghcb->shared_buffer, bytes); break; - /* Two-Byte Opcodes */ - case 0x0f: - ret = vc_handle_mmio_twobyte_ops(ghcb, ctxt); + case MMIO_MOVS: + ret = vc_handle_mmio_movs(ctxt, bytes); break; default: ret = ES_UNSUPPORTED; + break; } return ret;
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