This patch adds the intercept checks for instruction accessing the debug registers.
Signed-off-by: Joerg Roedel <[email protected]> --- arch/x86/include/asm/kvm_emulate.h | 2 + arch/x86/kvm/emulate.c | 63 +++++++++++++++++++++++++++-------- arch/x86/kvm/svm.c | 6 +++ 3 files changed, 56 insertions(+), 15 deletions(-) diff --git a/arch/x86/include/asm/kvm_emulate.h b/arch/x86/include/asm/kvm_emulate.h index 6922200..9b11edd 100644 --- a/arch/x86/include/asm/kvm_emulate.h +++ b/arch/x86/include/asm/kvm_emulate.h @@ -303,6 +303,8 @@ enum x86_intercept { x86_intercept_clts, x86_intercept_lmsw, x86_intercept_smsw, + x86_intercept_dr_read, + x86_intercept_dr_write, x86_intercept_lidt, x86_intercept_sidt, x86_intercept_lgdt, diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index e37630b..1f9b2e2 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -499,6 +499,11 @@ static int emulate_exception(struct x86_emulate_ctxt *ctxt, int vec, return X86EMUL_PROPAGATE_FAULT; } +static int emulate_db(struct x86_emulate_ctxt *ctxt) +{ + return emulate_exception(ctxt, DB_VECTOR, 0, false); +} + static int emulate_gp(struct x86_emulate_ctxt *ctxt, int err) { return emulate_exception(ctxt, GP_VECTOR, err, true); @@ -2437,6 +2442,47 @@ static int em_check_perm_cr_write(struct x86_emulate_ctxt *ctxt) return X86EMUL_CONTINUE; } +static int check_dr7_gd(struct x86_emulate_ctxt *ctxt) +{ + unsigned long dr7; + + ctxt->ops->get_dr(7, &dr7, ctxt->vcpu); + + /* Check if DR7.Global_Enable is set */ + return dr7 & (1 << 13); +} + +static int em_check_perm_dr_read(struct x86_emulate_ctxt *ctxt) +{ + struct decode_cache *c = &ctxt->decode; + int dr = c->modrm_reg; + u64 cr4; + + if (dr > 7) + return emulate_ud(ctxt); + + cr4 = ctxt->ops->get_cr(4, ctxt->vcpu); + if ((cr4 & X86_CR4_DE) && (dr == 4 || dr == 5)) + return emulate_ud(ctxt); + + if (check_dr7_gd(ctxt)) + return emulate_db(ctxt); + + return X86EMUL_CONTINUE; +} + +static int em_check_perm_dr_write(struct x86_emulate_ctxt *ctxt) +{ + struct decode_cache *c = &ctxt->decode; + u64 new_val = c->src.val64; + int dr = c->modrm_reg; + + if ((dr == 6 || dr == 7) && (new_val & 0xffffffff00000000ULL)) + return emulate_gp(ctxt, 0); + + return em_check_perm_dr_read(ctxt); +} + #define D(_y) { .flags = (_y) } #define DI(_y, _i) { .flags = (_y), .intercept = x86_intercept_##_i } #define DIP(_y, _i) { .flags = (_y), .intercept = x86_intercept_##_i, \ @@ -2628,9 +2674,9 @@ static struct opcode twobyte_table[256] = { N, N, N, N, N, N, N, N, D(ImplicitOps | ModRM), N, N, N, N, N, N, N, /* 0x20 - 0x2F */ DIP(ModRM | DstMem | Priv | Op3264, cr_read), - D(ModRM | DstMem | Priv | Op3264), + DIP(ModRM | DstMem | Priv | Op3264, dr_read), DIP(ModRM | SrcMem | Priv | Op3264, cr_write), - D(ModRM | SrcMem | Priv | Op3264), + DIP(ModRM | SrcMem | Priv | Op3264, dr_write), N, N, N, N, N, N, N, N, N, N, N, N, /* 0x30 - 0x3F */ @@ -3683,12 +3729,6 @@ twobyte_insn: c->dst.val = ops->get_cr(c->modrm_reg, ctxt->vcpu); break; case 0x21: /* mov from dr to reg */ - if ((ops->get_cr(4, ctxt->vcpu) & X86_CR4_DE) && - (c->modrm_reg == 4 || c->modrm_reg == 5)) { - emulate_ud(ctxt); - rc = X86EMUL_PROPAGATE_FAULT; - goto done; - } ops->get_dr(c->modrm_reg, &c->dst.val, ctxt->vcpu); break; case 0x22: /* mov reg, cr */ @@ -3700,13 +3740,6 @@ twobyte_insn: c->dst.type = OP_NONE; break; case 0x23: /* mov from reg to dr */ - if ((ops->get_cr(4, ctxt->vcpu) & X86_CR4_DE) && - (c->modrm_reg == 4 || c->modrm_reg == 5)) { - emulate_ud(ctxt); - rc = X86EMUL_PROPAGATE_FAULT; - goto done; - } - if (ops->set_dr(c->modrm_reg, c->src.val & ((ctxt->mode == X86EMUL_MODE_PROT64) ? ~0ULL : ~0U), ctxt->vcpu) < 0) { diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index ff4ed36..381b038 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -3882,6 +3882,8 @@ static struct __x86_intercept { [x86_intercept_clts] = POST_EX(SVM_EXIT_WRITE_CR0), [x86_intercept_lmsw] = POST_EX(SVM_EXIT_WRITE_CR0), [x86_intercept_smsw] = POST_EX(SVM_EXIT_READ_CR0), + [x86_intercept_dr_read] = POST_EX(SVM_EXIT_READ_DR0), + [x86_intercept_dr_write] = POST_EX(SVM_EXIT_WRITE_DR0), }; #undef POST_EX @@ -3939,6 +3941,10 @@ static int svm_check_intercept(struct kvm_vcpu *vcpu, break; } + case SVM_EXIT_READ_DR0: + case SVM_EXIT_WRITE_DR0: + icpt_info.exit_code += info->modrm_reg; + break; default: break; } -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
