KVM: x86: Refactor guest debug IOCTL handling

Much of so far vendor-specific code for setting up guest debug can
actually be handled by the generic code. This also fixes a minor deficit
in the SVM part /wrt processing KVM_GUESTDBG_ENABLE.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 295c7c4..e7f8708 100644 (file)
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -475,8 +475,8 @@ struct kvm_x86_ops {
        void (*vcpu_load)(struct kvm_vcpu *vcpu, int cpu);
        void (*vcpu_put)(struct kvm_vcpu *vcpu);
 
-       int (*set_guest_debug)(struct kvm_vcpu *vcpu,
-                              struct kvm_guest_debug *dbg);
+       void (*set_guest_debug)(struct kvm_vcpu *vcpu,
+                               struct kvm_guest_debug *dbg);
        int (*get_msr)(struct kvm_vcpu *vcpu, u32 msr_index, u64 *pdata);
        int (*set_msr)(struct kvm_vcpu *vcpu, u32 msr_index, u64 data);
        u64 (*get_segment_base)(struct kvm_vcpu *vcpu, int seg);

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 02a4269..279a2ae 100644 (file)
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1065,26 +1065,16 @@ static void update_db_intercept(struct kvm_vcpu *vcpu)
                vcpu->guest_debug = 0;
 }
 
-static int svm_guest_debug(struct kvm_vcpu *vcpu, struct kvm_guest_debug *dbg)
+static void svm_guest_debug(struct kvm_vcpu *vcpu, struct kvm_guest_debug *dbg)
 {
-       int old_debug = vcpu->guest_debug;
        struct vcpu_svm *svm = to_svm(vcpu);
 
-       vcpu->guest_debug = dbg->control;
-
-       update_db_intercept(vcpu);
-
        if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP)
                svm->vmcb->save.dr7 = dbg->arch.debugreg[7];
        else
                svm->vmcb->save.dr7 = vcpu->arch.dr7;
 
-       if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP)
-               svm->vmcb->save.rflags |= X86_EFLAGS_TF | X86_EFLAGS_RF;
-       else if (old_debug & KVM_GUESTDBG_SINGLESTEP)
-               svm->vmcb->save.rflags &= ~(X86_EFLAGS_TF | X86_EFLAGS_RF);
-
-       return 0;
+       update_db_intercept(vcpu);
 }
 
 static void load_host_msrs(struct kvm_vcpu *vcpu)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 97f4265..70020e5 100644 (file)
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -1096,30 +1096,14 @@ static void vmx_cache_reg(struct kvm_vcpu *vcpu, enum kvm_reg reg)
        }
 }
 
-static int set_guest_debug(struct kvm_vcpu *vcpu, struct kvm_guest_debug *dbg)
+static void set_guest_debug(struct kvm_vcpu *vcpu, struct kvm_guest_debug *dbg)
 {
-       int old_debug = vcpu->guest_debug;
-       unsigned long flags;
-
-       vcpu->guest_debug = dbg->control;
-       if (!(vcpu->guest_debug & KVM_GUESTDBG_ENABLE))
-               vcpu->guest_debug = 0;
-
        if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP)
                vmcs_writel(GUEST_DR7, dbg->arch.debugreg[7]);
        else
                vmcs_writel(GUEST_DR7, vcpu->arch.dr7);
 
-       flags = vmcs_readl(GUEST_RFLAGS);
-       if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP)
-               flags |= X86_EFLAGS_TF | X86_EFLAGS_RF;
-       else if (old_debug & KVM_GUESTDBG_SINGLESTEP)
-               flags &= ~(X86_EFLAGS_TF | X86_EFLAGS_RF);
-       vmcs_writel(GUEST_RFLAGS, flags);
-
        update_exception_bitmap(vcpu);
-
-       return 0;
 }
 
 static __init int cpu_has_kvm_support(void)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 5f44d56..a06f88e 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4472,12 +4472,19 @@ int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
 int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
                                        struct kvm_guest_debug *dbg)
 {
-       int i, r;
+       unsigned long rflags;
+       int old_debug;
+       int i;
 
        vcpu_load(vcpu);
 
-       if ((dbg->control & (KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_HW_BP)) ==
-           (KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_HW_BP)) {
+       old_debug = vcpu->guest_debug;
+
+       vcpu->guest_debug = dbg->control;
+       if (!(vcpu->guest_debug & KVM_GUESTDBG_ENABLE))
+               vcpu->guest_debug = 0;
+
+       if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP) {
                for (i = 0; i < KVM_NR_DB_REGS; ++i)
                        vcpu->arch.eff_db[i] = dbg->arch.debugreg[i];
                vcpu->arch.switch_db_regs =
@@ -4488,16 +4495,23 @@ int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
                vcpu->arch.switch_db_regs = (vcpu->arch.dr7 & DR7_BP_EN_MASK);
        }
 
-       r = kvm_x86_ops->set_guest_debug(vcpu, dbg);
+       rflags = kvm_x86_ops->get_rflags(vcpu);
+       if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP)
+               rflags |= X86_EFLAGS_TF | X86_EFLAGS_RF;
+       else if (old_debug & KVM_GUESTDBG_SINGLESTEP)
+               rflags &= ~(X86_EFLAGS_TF | X86_EFLAGS_RF);
+       kvm_x86_ops->set_rflags(vcpu, rflags);
 
-       if (dbg->control & KVM_GUESTDBG_INJECT_DB)
+       kvm_x86_ops->set_guest_debug(vcpu, dbg);
+
+       if (vcpu->guest_debug & KVM_GUESTDBG_INJECT_DB)
                kvm_queue_exception(vcpu, DB_VECTOR);
-       else if (dbg->control & KVM_GUESTDBG_INJECT_BP)
+       else if (vcpu->guest_debug & KVM_GUESTDBG_INJECT_BP)
                kvm_queue_exception(vcpu, BP_VECTOR);
 
        vcpu_put(vcpu);
 
-       return r;
+       return 0;
 }
 
 /*