[PATCH 34/42] KVM: x86: Refactor guest debug IOCTL handling

Avi Kivity
2009-11-16T12:22:36Z

From: Jan Kiszka <jan.kiszka@web.de>

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>
---
arch/x86/include/asm/kvm_host.h | 4 ++--
arch/x86/kvm/svm.c | 14 ++------------
arch/x86/kvm/vmx.c | 18 +-----------------
arch/x86/kvm/x86.c | 28 +++++++++++++++++++++-------
4 files changed, 26 insertions(+), 38 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 295c7c4..e7f8708 100644
--- 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
--- 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
--- 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
--- 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;
}

/*
--
1.6.5.2