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Commit eef8c85a authored by Alex Bennée's avatar Alex Bennée Committed by Marc Zyngier
Browse files

KVM: arm64: add trace points for guest_debug debug 



This includes trace points for:
  kvm_arch_setup_guest_debug
  kvm_arch_clear_guest_debug

I've also added some generic register setting trace events and also a
trace point to dump the array of hardware registers.

Acked-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: default avatarAlex Bennée <alex.bennee@linaro.org>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
parent 834bf887

arch/arm64/kvm/debug.c

+35 −1
Original line number Diff line number Diff line
@@ -18,12 +18,15 @@ 
 */



#include <linux/kvm_host.h>

#include <linux/hw_breakpoint.h>



#include <asm/debug-monitors.h>

#include <asm/kvm_asm.h>

#include <asm/kvm_arm.h>

#include <asm/kvm_emulate.h>



#include "trace.h"



/* These are the bits of MDSCR_EL1 we may manipulate */

#define MDSCR_EL1_DEBUG_MASK	(DBG_MDSCR_SS | \

				DBG_MDSCR_KDE | \
@@ -44,11 +47,17 @@ static DEFINE_PER_CPU(u32, mdcr_el2); 
static void save_guest_debug_regs(struct kvm_vcpu *vcpu)

{

	vcpu->arch.guest_debug_preserved.mdscr_el1 = vcpu_sys_reg(vcpu, MDSCR_EL1);



	trace_kvm_arm_set_dreg32("Saved MDSCR_EL1",

				vcpu->arch.guest_debug_preserved.mdscr_el1);

}



static void restore_guest_debug_regs(struct kvm_vcpu *vcpu)

{

	vcpu_sys_reg(vcpu, MDSCR_EL1) = vcpu->arch.guest_debug_preserved.mdscr_el1;



	trace_kvm_arm_set_dreg32("Restored MDSCR_EL1",

				vcpu_sys_reg(vcpu, MDSCR_EL1));

}



/**
@@ -99,6 +108,8 @@ void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) 
{

	bool trap_debug = !(vcpu->arch.debug_flags & KVM_ARM64_DEBUG_DIRTY);



	trace_kvm_arm_setup_debug(vcpu, vcpu->guest_debug);



	vcpu->arch.mdcr_el2 = __this_cpu_read(mdcr_el2) & MDCR_EL2_HPMN_MASK;

	vcpu->arch.mdcr_el2 |= (MDCR_EL2_TPM |

				MDCR_EL2_TPMCR |
@@ -140,6 +151,8 @@ void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) 
			vcpu_sys_reg(vcpu, MDSCR_EL1) &= ~DBG_MDSCR_SS;

		}



		trace_kvm_arm_set_dreg32("SPSR_EL2", *vcpu_cpsr(vcpu));



		/*

		 * HW Breakpoints and watchpoints

		 *
@@ -156,6 +169,14 @@ void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) 
			vcpu->arch.debug_ptr = &vcpu->arch.external_debug_state;

			vcpu->arch.debug_flags |= KVM_ARM64_DEBUG_DIRTY;

			trap_debug = true;



			trace_kvm_arm_set_regset("BKPTS", get_num_brps(),

						&vcpu->arch.debug_ptr->dbg_bcr[0],

						&vcpu->arch.debug_ptr->dbg_bvr[0]);



			trace_kvm_arm_set_regset("WAPTS", get_num_wrps(),

						&vcpu->arch.debug_ptr->dbg_wcr[0],

						&vcpu->arch.debug_ptr->dbg_wvr[0]);

		}

	}
@@ -165,10 +186,15 @@ void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) 
	/* Trap debug register access */

	if (trap_debug)

		vcpu->arch.mdcr_el2 |= MDCR_EL2_TDA;



	trace_kvm_arm_set_dreg32("MDCR_EL2", vcpu->arch.mdcr_el2);

	trace_kvm_arm_set_dreg32("MDSCR_EL1", vcpu_sys_reg(vcpu, MDSCR_EL1));

}



void kvm_arm_clear_debug(struct kvm_vcpu *vcpu)

{

	trace_kvm_arm_clear_debug(vcpu->guest_debug);



	if (vcpu->guest_debug) {

		restore_guest_debug_regs(vcpu);
@@ -176,8 +202,16 @@ void kvm_arm_clear_debug(struct kvm_vcpu *vcpu) 
		 * If we were using HW debug we need to restore the

		 * debug_ptr to the guest debug state.

		 */

		if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW)

		if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW) {

			kvm_arm_reset_debug_ptr(vcpu);



			trace_kvm_arm_set_regset("BKPTS", get_num_brps(),

						&vcpu->arch.debug_ptr->dbg_bcr[0],

						&vcpu->arch.debug_ptr->dbg_bvr[0]);



			trace_kvm_arm_set_regset("WAPTS", get_num_wrps(),

						&vcpu->arch.debug_ptr->dbg_wcr[0],

						&vcpu->arch.debug_ptr->dbg_wvr[0]);

		}

	}

}

arch/arm64/kvm/guest.c

+4 −0
Original line number Diff line number Diff line
@@ -32,6 +32,8 @@ 
#include <asm/kvm_emulate.h>

#include <asm/kvm_coproc.h>



#include "trace.h"



struct kvm_stats_debugfs_item debugfs_entries[] = {

	{ NULL }

};
@@ -350,6 +352,8 @@ int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu, 
int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,

					struct kvm_guest_debug *dbg)

{

	trace_kvm_set_guest_debug(vcpu, dbg->control);



	if (dbg->control & ~KVM_GUESTDBG_VALID_MASK)

		return -EINVAL;

arch/arm64/kvm/sys_regs.c

+17 −0
Original line number Diff line number Diff line
@@ -38,6 +38,8 @@ 


#include "sys_regs.h"



#include "trace.h"



/*

 * All of this file is extremly similar to the ARM coproc.c, but the

 * types are different. My gut feeling is that it should be pretty
@@ -208,6 +210,8 @@ static bool trap_debug_regs(struct kvm_vcpu *vcpu, 
		*vcpu_reg(vcpu, p->Rt) = vcpu_sys_reg(vcpu, r->reg);

	}



	trace_trap_reg(__func__, r->reg, p->is_write, *vcpu_reg(vcpu, p->Rt));



	return true;

}
@@ -258,6 +262,8 @@ static inline bool trap_bvr(struct kvm_vcpu *vcpu, 
	else

		dbg_to_reg(vcpu, p, dbg_reg);



	trace_trap_reg(__func__, rd->reg, p->is_write, *dbg_reg);



	return true;

}
@@ -298,6 +304,8 @@ static inline bool trap_bcr(struct kvm_vcpu *vcpu, 
	else

		dbg_to_reg(vcpu, p, dbg_reg);



	trace_trap_reg(__func__, rd->reg, p->is_write, *dbg_reg);



	return true;

}
@@ -339,6 +347,9 @@ static inline bool trap_wvr(struct kvm_vcpu *vcpu, 
	else

		dbg_to_reg(vcpu, p, dbg_reg);



	trace_trap_reg(__func__, rd->reg, p->is_write,

		vcpu->arch.vcpu_debug_state.dbg_wvr[rd->reg]);



	return true;

}
@@ -379,6 +390,8 @@ static inline bool trap_wcr(struct kvm_vcpu *vcpu, 
	else

		dbg_to_reg(vcpu, p, dbg_reg);



	trace_trap_reg(__func__, rd->reg, p->is_write, *dbg_reg);



	return true;

}
@@ -742,6 +755,8 @@ static inline bool trap_xvr(struct kvm_vcpu *vcpu, 
		*vcpu_reg(vcpu, p->Rt) = *dbg_reg >> 32;

	}



	trace_trap_reg(__func__, rd->reg, p->is_write, *dbg_reg);



	return true;

}
@@ -1223,6 +1238,8 @@ int kvm_handle_sys_reg(struct kvm_vcpu *vcpu, struct kvm_run *run) 
	struct sys_reg_params params;

	unsigned long esr = kvm_vcpu_get_hsr(vcpu);



	trace_kvm_handle_sys_reg(esr);



	params.is_aarch32 = false;

	params.is_32bit = false;

	params.Op0 = (esr >> 20) & 3;

arch/arm64/kvm/trace.h

+123 −0
Original line number Diff line number Diff line
@@ -44,6 +44,129 @@ TRACE_EVENT(kvm_hvc_arm64, 
		  __entry->vcpu_pc, __entry->r0, __entry->imm)

);



TRACE_EVENT(kvm_arm_setup_debug,

	TP_PROTO(struct kvm_vcpu *vcpu, __u32 guest_debug),

	TP_ARGS(vcpu, guest_debug),



	TP_STRUCT__entry(

		__field(struct kvm_vcpu *, vcpu)

		__field(__u32, guest_debug)

	),



	TP_fast_assign(

		__entry->vcpu = vcpu;

		__entry->guest_debug = guest_debug;

	),



	TP_printk("vcpu: %p, flags: 0x%08x", __entry->vcpu, __entry->guest_debug)

);



TRACE_EVENT(kvm_arm_clear_debug,

	TP_PROTO(__u32 guest_debug),

	TP_ARGS(guest_debug),



	TP_STRUCT__entry(

		__field(__u32, guest_debug)

	),



	TP_fast_assign(

		__entry->guest_debug = guest_debug;

	),



	TP_printk("flags: 0x%08x", __entry->guest_debug)

);



TRACE_EVENT(kvm_arm_set_dreg32,

	TP_PROTO(const char *name, __u32 value),

	TP_ARGS(name, value),



	TP_STRUCT__entry(

		__field(const char *, name)

		__field(__u32, value)

	),



	TP_fast_assign(

		__entry->name = name;

		__entry->value = value;

	),



	TP_printk("%s: 0x%08x", __entry->name, __entry->value)

);



TRACE_EVENT(kvm_arm_set_regset,

	TP_PROTO(const char *type, int len, __u64 *control, __u64 *value),

	TP_ARGS(type, len, control, value),

	TP_STRUCT__entry(

		__field(const char *, name)

		__field(int, len)

		__array(u64, ctrls, 16)

		__array(u64, values, 16)

	),

	TP_fast_assign(

		__entry->name = type;

		__entry->len = len;

		memcpy(__entry->ctrls, control, len << 3);

		memcpy(__entry->values, value, len << 3);

	),

	TP_printk("%d %s CTRL:%s VALUE:%s", __entry->len, __entry->name,

		__print_array(__entry->ctrls, __entry->len, sizeof(__u64)),

		__print_array(__entry->values, __entry->len, sizeof(__u64)))

);



TRACE_EVENT(trap_reg,

	TP_PROTO(const char *fn, int reg, bool is_write, u64 write_value),

	TP_ARGS(fn, reg, is_write, write_value),



	TP_STRUCT__entry(

		__field(const char *, fn)

		__field(int, reg)

		__field(bool, is_write)

		__field(u64, write_value)

	),



	TP_fast_assign(

		__entry->fn = fn;

		__entry->reg = reg;

		__entry->is_write = is_write;

		__entry->write_value = write_value;

	),



	TP_printk("%s %s reg %d (0x%08llx)", __entry->fn,  __entry->is_write?"write to":"read from", __entry->reg, __entry->write_value)

);



TRACE_EVENT(kvm_handle_sys_reg,

	TP_PROTO(unsigned long hsr),

	TP_ARGS(hsr),



	TP_STRUCT__entry(

		__field(unsigned long,	hsr)

	),



	TP_fast_assign(

		__entry->hsr = hsr;

	),



	TP_printk("HSR 0x%08lx", __entry->hsr)

);



TRACE_EVENT(kvm_set_guest_debug,

	TP_PROTO(struct kvm_vcpu *vcpu, __u32 guest_debug),

	TP_ARGS(vcpu, guest_debug),



	TP_STRUCT__entry(

		__field(struct kvm_vcpu *, vcpu)

		__field(__u32, guest_debug)

	),



	TP_fast_assign(

		__entry->vcpu = vcpu;

		__entry->guest_debug = guest_debug;

	),



	TP_printk("vcpu: %p, flags: 0x%08x", __entry->vcpu, __entry->guest_debug)

);





#endif /* _TRACE_ARM64_KVM_H */



#undef TRACE_INCLUDE_PATH