From 996ff5429e9898947016206ee9da387a93d63d9d Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Mon, 14 Dec 2020 07:49:54 -0500 Subject: [PATCH] KVM: x86: move kvm_inject_gp up from kvm_set_dr to callers Push the injection of #GP up to the callers, so that they can just use kvm_complete_insn_gp. __kvm_set_dr is pretty much what the callers can use together with kvm_complete_insn_gp, so rename it to kvm_set_dr and drop the old kvm_set_dr wrapper. This also allows nested VMX code, which really wanted to use __kvm_set_dr, to use the right function. While at it, remove the kvm_require_dr() check from the SVM interception. The APM states: All normal exception checks take precedence over the SVM intercepts. which includes the CR4.DE=1 #UD. Signed-off-by: Paolo Bonzini --- arch/x86/kvm/svm/svm.c | 13 +++++-------- arch/x86/kvm/vmx/vmx.c | 17 ++++++++++------- arch/x86/kvm/x86.c | 19 +++++-------------- 3 files changed, 20 insertions(+), 29 deletions(-) diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index ef2f2b0f20d3..42d4710074a6 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -2617,6 +2617,7 @@ static int dr_interception(struct vcpu_svm *svm) { int reg, dr; unsigned long val; + int err = 0; if (svm->vcpu.guest_debug == 0) { /* @@ -2634,20 +2635,16 @@ static int dr_interception(struct vcpu_svm *svm) reg = svm->vmcb->control.exit_info_1 & SVM_EXITINFO_REG_MASK; dr = svm->vmcb->control.exit_code - SVM_EXIT_READ_DR0; - - if (dr >= 16) { /* mov to DRn */ - if (!kvm_require_dr(&svm->vcpu, dr - 16)) - return 1; + if (dr >= 16) { /* mov to DRn */ + dr -= 16; val = kvm_register_read(&svm->vcpu, reg); - kvm_set_dr(&svm->vcpu, dr - 16, val); + err = kvm_set_dr(&svm->vcpu, dr, val); } else { - if (!kvm_require_dr(&svm->vcpu, dr)) - return 1; kvm_get_dr(&svm->vcpu, dr, &val); kvm_register_write(&svm->vcpu, reg, val); } - return kvm_skip_emulated_instruction(&svm->vcpu); + return kvm_complete_insn_gp(&svm->vcpu, err); } static int cr8_write_interception(struct vcpu_svm *svm) diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 049fbbd0aa1a..13898871e5b0 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -5095,6 +5095,7 @@ static int handle_dr(struct kvm_vcpu *vcpu) { unsigned long exit_qualification; int dr, dr7, reg; + int err = 1; exit_qualification = vmx_get_exit_qual(vcpu); dr = exit_qualification & DEBUG_REG_ACCESS_NUM; @@ -5103,9 +5104,9 @@ static int handle_dr(struct kvm_vcpu *vcpu) if (!kvm_require_dr(vcpu, dr)) return 1; - /* Do not handle if the CPL > 0, will trigger GP on re-entry */ - if (!kvm_require_cpl(vcpu, 0)) - return 1; + if (kvm_x86_ops.get_cpl(vcpu) > 0) + goto out; + dr7 = vmcs_readl(GUEST_DR7); if (dr7 & DR7_GD) { /* @@ -5144,11 +5145,13 @@ static int handle_dr(struct kvm_vcpu *vcpu) kvm_get_dr(vcpu, dr, &val); kvm_register_write(vcpu, reg, val); - } else - if (kvm_set_dr(vcpu, dr, kvm_register_readl(vcpu, reg))) - return 1; + err = 0; + } else { + err = kvm_set_dr(vcpu, dr, kvm_register_readl(vcpu, reg)); + } - return kvm_skip_emulated_instruction(vcpu); +out: + return kvm_complete_insn_gp(vcpu, err); } static void vmx_sync_dirty_debug_regs(struct kvm_vcpu *vcpu) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index dcb67429b75d..baa90ae76ba5 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1143,7 +1143,7 @@ static u64 kvm_dr6_fixed(struct kvm_vcpu *vcpu) return fixed; } -static int __kvm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long val) +int kvm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long val) { size_t size = ARRAY_SIZE(vcpu->arch.db); @@ -1156,13 +1156,13 @@ static int __kvm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long val) case 4: case 6: if (!kvm_dr6_valid(val)) - return -1; /* #GP */ + return 1; /* #GP */ vcpu->arch.dr6 = (val & DR6_VOLATILE) | kvm_dr6_fixed(vcpu); break; case 5: default: /* 7 */ if (!kvm_dr7_valid(val)) - return -1; /* #GP */ + return 1; /* #GP */ vcpu->arch.dr7 = (val & DR7_VOLATILE) | DR7_FIXED_1; kvm_update_dr7(vcpu); break; @@ -1170,15 +1170,6 @@ static int __kvm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long val) return 0; } - -int kvm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long val) -{ - if (__kvm_set_dr(vcpu, dr, val)) { - kvm_inject_gp(vcpu, 0); - return 1; - } - return 0; -} EXPORT_SYMBOL_GPL(kvm_set_dr); void kvm_get_dr(struct kvm_vcpu *vcpu, int dr, unsigned long *val) @@ -6619,7 +6610,7 @@ static int emulator_set_dr(struct x86_emulate_ctxt *ctxt, int dr, unsigned long value) { - return __kvm_set_dr(emul_to_vcpu(ctxt), dr, value); + return kvm_set_dr(emul_to_vcpu(ctxt), dr, value); } static u64 mk_cr_64(u64 curr_cr, u32 new_val) @@ -8664,7 +8655,7 @@ static void enter_smm(struct kvm_vcpu *vcpu) dt.address = dt.size = 0; static_call(kvm_x86_set_idt)(vcpu, &dt); - __kvm_set_dr(vcpu, 7, DR7_FIXED_1); + kvm_set_dr(vcpu, 7, DR7_FIXED_1); cs.selector = (vcpu->arch.smbase >> 4) & 0xffff; cs.base = vcpu->arch.smbase;