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: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

diff --git a/arch/arm64/kvm/debug.c b/arch/arm64/kvm/debug.c
index 4a99e54d7f3db735a939d544be49067b4da52a45..47e5f0feaee82c05ac1b56bd89f9acd0edffa82d 100644 (file)
--- a/arch/arm64/kvm/debug.c
+++ b/arch/arm64/kvm/debug.c
@@ -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]);
+               }
        }
 }

diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index 6f1b249e0587350aac0b4cb229a369c705bd2aef..48868d893870710ce3c029731ed24fcafea429be 100644 (file)
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -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;
 

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 158bae7c52cc46a0bbace8407087b6110ac67c14..b41607d270ac83ebd1413a185753bf0b9e2af7f0 100644 (file)
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -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;

diff --git a/arch/arm64/kvm/trace.h b/arch/arm64/kvm/trace.h
index 157416e963f2f2e2e2ee83a2656e27fb611f7b76..7fb0008c4fa3d487cc282225b13fbec8fb3fc215 100644 (file)
--- a/arch/arm64/kvm/trace.h
+++ b/arch/arm64/kvm/trace.h
@@ -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