Every guest entry, we need to keep track of host use of the debug
registers.
We only call the function upon guest entry, after preempt_disable()
and local_irq_disable(), so there is no race for it.
Signed-off-by: Zhichao Huang <zhichao.huang@xxxxxxxxxx>
---
arch/arm/include/asm/kvm_asm.h | 3 +++
arch/arm/include/asm/kvm_host.h | 4 ++++
arch/arm/kernel/asm-offsets.c | 1 +
arch/arm/kvm/arm.c | 2 ++
arch/arm/kvm/coproc.c | 8 ++++++++
arch/arm64/include/asm/kvm_host.h | 1 +
6 files changed, 19 insertions(+)
diff --git a/arch/arm/include/asm/kvm_asm.h b/arch/arm/include/asm/kvm_asm.h
index 7443a3a..5b1c3eb 100644
--- a/arch/arm/include/asm/kvm_asm.h
+++ b/arch/arm/include/asm/kvm_asm.h
@@ -64,6 +64,9 @@
#define cp14_DBGDSCRext 65 /* Debug Status and Control external */
#define NR_CP14_REGS 66 /* Number of regs (incl. invalid) */
+#define KVM_ARM_DEBUG_HOST_INUSE_SHIFT 0
+#define KVM_ARM_DEBUG_HOST_INUSE (1 << KVM_ARM_DEBUG_HOST_INUSE_SHIFT)
+
#define ARM_EXCEPTION_RESET 0
#define ARM_EXCEPTION_UNDEFINED 1
#define ARM_EXCEPTION_SOFTWARE 2
diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
index fc461ac..7338f34 100644
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -131,6 +131,9 @@ struct kvm_vcpu_arch {
/* System control coprocessor (cp14) */
u32 cp14[NR_CP14_REGS];
+ /* Debug State */
+ u32 debug_flags;
+
/*
* Anything that is not used directly from assembly code goes
* here.
@@ -237,5 +240,6 @@ static inline void kvm_arch_hardware_unsetup(void) {}
static inline void kvm_arch_sync_events(struct kvm *kvm) {}
static inline void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) {}
static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {}
+void kvm_arm_setup_debug(struct kvm_vcpu *vcpu);
#endif /* __ARM_KVM_HOST_H__ */
diff --git a/arch/arm/kernel/asm-offsets.c b/arch/arm/kernel/asm-offsets.c
index cee4254..7750597 100644
--- a/arch/arm/kernel/asm-offsets.c
+++ b/arch/arm/kernel/asm-offsets.c
@@ -178,6 +178,7 @@ int main(void)
DEFINE(VCPU_HOST_CONTEXT, offsetof(struct kvm_vcpu, arch.host_cpu_context));
DEFINE(VCPU_VFP_HOST, offsetof(struct kvm_cpu_context, vfp));
DEFINE(VCPU_CP14_HOST, offsetof(struct kvm_cpu_context, cp14));
+ DEFINE(VCPU_DEBUG_FLAGS, offsetof(struct kvm_vcpu, arch.debug_flags));
DEFINE(VCPU_REGS, offsetof(struct kvm_vcpu, arch.regs));
DEFINE(VCPU_USR_REGS, offsetof(struct kvm_vcpu, arch.regs.usr_regs));
DEFINE(VCPU_SVC_REGS, offsetof(struct kvm_vcpu, arch.regs.svc_regs));
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index bc738d2..0129346 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -550,6 +550,8 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
continue;
}
+ kvm_arm_setup_debug(vcpu);
+
/**************************************************************
* Enter the guest
*/
diff --git a/arch/arm/kvm/coproc.c b/arch/arm/kvm/coproc.c
index d15b250..b37afd6 100644
--- a/arch/arm/kvm/coproc.c
+++ b/arch/arm/kvm/coproc.c
@@ -1516,3 +1516,11 @@ void kvm_reset_coprocs(struct kvm_vcpu *vcpu)
if (vcpu->arch.cp15[num] == 0x42424242)
panic("Didn't reset vcpu->arch.cp15[%zi]", num);
}
+
+void kvm_arm_setup_debug(struct kvm_vcpu *vcpu)
+{
+ if (hw_breakpoint_enabled())
+ vcpu->arch.debug_flags |= KVM_ARM_DEBUG_HOST_INUSE;
+ else
+ vcpu->arch.debug_flags &= ~KVM_ARM_DEBUG_HOST_INUSE;
+}
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 2709db2..84fa4f0 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -226,5 +226,6 @@ static inline void kvm_arch_hardware_unsetup(void) {}
static inline void kvm_arch_sync_events(struct kvm *kvm) {}
static inline void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) {}
static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {}
+static inline void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) {}
#endif /* __ARM64_KVM_HOST_H__ */
--
1.7.12.4
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