[PATCH 04/15] xen/trace: add multicall tracing

Jeremy Fitzhardinge
2011-06-20T22:18:35Z

arch/x86/include/asm/xen/hypercall.h | 22 ++++++
arch/x86/include/asm/xen/trace_types.h | 18 +++++
arch/x86/xen/multicalls.c | 31 ++++++--
arch/x86/xen/multicalls.h | 3 +
arch/x86/xen/trace.c | 57 +++++++++++++++
include/trace/events/xen.h | 118 ++++++++++++++++++++++++++++++++
6 files changed, 241 insertions(+), 8 deletions(-)
create mode 100644 arch/x86/include/asm/xen/trace_types.h

diff --git a/arch/x86/include/asm/xen/hypercall.h b/arch/x86/include/asm/xen/hypercall.h
index d240ea9..417777d 100644
--- a/arch/x86/include/asm/xen/hypercall.h
+++ b/arch/x86/include/asm/xen/hypercall.h
@@ -39,6 +39,8 @@
#include <linux/string.h>
#include <linux/types.h>

+#include <trace/events/xen.h>
+
#include <asm/page.h>
#include <asm/pgtable.h>

@@ -459,6 +461,8 @@ MULTI_fpu_taskswitch(struct multicall_entry *mcl, int set)
{
mcl->op = __HYPERVISOR_fpu_taskswitch;
mcl->args[0] = set;
+
+ trace_xen_mc_entry(mcl, 1);
}

static inline void
@@ -475,6 +479,8 @@ MULTI_update_va_mapping(struct multicall_entry *mcl, unsigned long va,
mcl->args[2] = new_val.pte >> 32;
mcl->args[3] = flags;
}
+
+ trace_xen_mc_entry(mcl, sizeof(new_val) == sizeof(long) ? 3 : 4);
}

static inline void
@@ -485,6 +491,8 @@ MULTI_grant_table_op(struct multicall_entry *mcl, unsigned int cmd,
mcl->args[0] = cmd;
mcl->args[1] = (unsigned long)uop;
mcl->args[2] = count;
+
+ trace_xen_mc_entry(mcl, 3);
}

static inline void
@@ -504,6 +512,8 @@ MULTI_update_va_mapping_otherdomain(struct multicall_entry *mcl, unsigned long v
mcl->args[3] = flags;
mcl->args[4] = domid;
}
+
+ trace_xen_mc_entry(mcl, sizeof(new_val) == sizeof(long) ? 4 : 5);
}

static inline void
@@ -520,6 +530,8 @@ MULTI_update_descriptor(struct multicall_entry *mcl, u64 maddr,
mcl->args[2] = desc.a;
mcl->args[3] = desc.b;
}
+
+ trace_xen_mc_entry(mcl, sizeof(maddr) == sizeof(long) ? 2 : 4);
}

static inline void
@@ -528,6 +540,8 @@ MULTI_memory_op(struct multicall_entry *mcl, unsigned int cmd, void *arg)
mcl->op = __HYPERVISOR_memory_op;
mcl->args[0] = cmd;
mcl->args[1] = (unsigned long)arg;
+
+ trace_xen_mc_entry(mcl, 2);
}

static inline void
@@ -539,6 +553,8 @@ MULTI_mmu_update(struct multicall_entry *mcl, struct mmu_update *req,
mcl->args[1] = count;
mcl->args[2] = (unsigned long)success_count;
mcl->args[3] = domid;
+
+ trace_xen_mc_entry(mcl, 4);
}

static inline void
@@ -550,6 +566,8 @@ MULTI_mmuext_op(struct multicall_entry *mcl, struct mmuext_op *op, int count,
mcl->args[1] = count;
mcl->args[2] = (unsigned long)success_count;
mcl->args[3] = domid;
+
+ trace_xen_mc_entry(mcl, 4);
}

static inline void
@@ -558,6 +576,8 @@ MULTI_set_gdt(struct multicall_entry *mcl, unsigned long *frames, int entries)
mcl->op = __HYPERVISOR_set_gdt;
mcl->args[0] = (unsigned long)frames;
mcl->args[1] = entries;
+
+ trace_xen_mc_entry(mcl, 2);
}

static inline void
@@ -567,6 +587,8 @@ MULTI_stack_switch(struct multicall_entry *mcl,
mcl->op = __HYPERVISOR_stack_switch;
mcl->args[0] = ss;
mcl->args[1] = esp;
+
+ trace_xen_mc_entry(mcl, 2);
}

#endif /* _ASM_X86_XEN_HYPERCALL_H */
diff --git a/arch/x86/include/asm/xen/trace_types.h b/arch/x86/include/asm/xen/trace_types.h
new file mode 100644
index 0000000..21e1874
--- /dev/null
+++ b/arch/x86/include/asm/xen/trace_types.h
@@ -0,0 +1,18 @@
+#ifndef _ASM_XEN_TRACE_TYPES_H
+#define _ASM_XEN_TRACE_TYPES_H
+
+enum xen_mc_flush_reason {
+ XEN_MC_FL_NONE, /* explicit flush */
+ XEN_MC_FL_BATCH, /* out of hypercall space */
+ XEN_MC_FL_ARGS, /* out of argument space */
+ XEN_MC_FL_CALLBACK, /* out of callback space */
+};
+
+enum xen_mc_extend_args {
+ XEN_MC_XE_OK,
+ XEN_MC_XE_BAD_OP,
+ XEN_MC_XE_NO_SPACE
+};
+typedef void (*xen_mc_callback_fn_t)(void *);
+
+#endif /* _ASM_XEN_TRACE_TYPES_H */
diff --git a/arch/x86/xen/multicalls.c b/arch/x86/xen/multicalls.c
index d4be3fd..ac3641d 100644
--- a/arch/x86/xen/multicalls.c
+++ b/arch/x86/xen/multicalls.c
@@ -65,6 +65,8 @@ void xen_mc_flush(void)
something in the middle */
local_irq_save(flags);

+ trace_xen_mc_flush(b->mcidx, b->argidx, b->cbidx);
+
if (b->mcidx) {
#if MC_DEBUG
memcpy(b->debug, b->entries,
@@ -116,11 +118,15 @@ struct multicall_space __xen_mc_entry(size_t args)
struct multicall_space ret;
unsigned argidx = roundup(b->argidx, sizeof(u64));

+ trace_xen_mc_entry_alloc(args);
+
BUG_ON(preemptible());
BUG_ON(b->argidx > MC_ARGS);

if (b->mcidx == MC_BATCH ||
(argidx + args) > MC_ARGS) {
+ trace_xen_mc_flush_reason((b->mcidx == MC_BATCH) ?
+ XEN_MC_FL_BATCH : XEN_MC_FL_ARGS);
xen_mc_flush();
argidx = roundup(b->argidx, sizeof(u64));
}
@@ -145,20 +151,25 @@ struct multicall_space xen_mc_extend_args(unsigned long op, size_t size)
BUG_ON(preemptible());
BUG_ON(b->argidx > MC_ARGS);

- if (b->mcidx == 0)
- return ret;
-
- if (b->entries[b->mcidx - 1].op != op)
- return ret;
+ if (unlikely(b->mcidx == 0 ||
+ b->entries[b->mcidx - 1].op != op)) {
+ trace_xen_mc_extend_args(op, size, XEN_MC_XE_BAD_OP);
+ goto out;
+ }

- if ((b->argidx + size) > MC_ARGS)
- return ret;
+ if (unlikely((b->argidx + size) > MC_ARGS)) {
+ trace_xen_mc_extend_args(op, size, XEN_MC_XE_NO_SPACE);
+ goto out;
+ }

ret.mc = &b->entries[b->mcidx - 1];
ret.args = &b->args[b->argidx];
b->argidx += size;

BUG_ON(b->argidx > MC_ARGS);
+
+ trace_xen_mc_extend_args(op, size, XEN_MC_XE_OK);
+out:
return ret;
}

@@ -167,8 +178,12 @@ void xen_mc_callback(void (*fn)(void *), void *data)
struct mc_buffer *b = &__get_cpu_var(mc_buffer);
struct callback *cb;

- if (b->cbidx == MC_BATCH)
+ if (b->cbidx == MC_BATCH) {
+ trace_xen_mc_flush_reason(XEN_MC_FL_CALLBACK);
xen_mc_flush();
+ }
+
+ trace_xen_mc_callback(fn, data);

cb = &b->callbacks[b->cbidx++];
cb->fn = fn;
diff --git a/arch/x86/xen/multicalls.h b/arch/x86/xen/multicalls.h
index fa7b8af..dee79b7 100644
--- a/arch/x86/xen/multicalls.h
+++ b/arch/x86/xen/multicalls.h
@@ -25,6 +25,7 @@ static inline void xen_mc_batch(void)

/* need to disable interrupts until this entry is complete */
local_irq_save(flags);
+ trace_xen_mc_batch(paravirt_get_lazy_mode());
__this_cpu_write(xen_mc_irq_flags, flags);
}

@@ -40,6 +41,8 @@ void xen_mc_flush(void);
/* Issue a multicall if we're not in a lazy mode */
static inline void xen_mc_issue(unsigned mode)
{
+ trace_xen_mc_issue(mode);
+
if ((paravirt_get_lazy_mode() & mode) == 0)
xen_mc_flush();

diff --git a/arch/x86/xen/trace.c b/arch/x86/xen/trace.c
index 8cca616..734beba 100644
--- a/arch/x86/xen/trace.c
+++ b/arch/x86/xen/trace.c
@@ -1,4 +1,61 @@
#include <linux/ftrace.h>

+#define N(x) [__HYPERVISOR_##x] = "("#x")"
+static const char *xen_hypercall_names[] = {
+ N(set_trap_table),
+ N(mmu_update),
+ N(set_gdt),
+ N(stack_switch),
+ N(set_callbacks),
+ N(fpu_taskswitch),
+ N(sched_op_compat),
+ N(dom0_op),
+ N(set_debugreg),
+ N(get_debugreg),
+ N(update_descriptor),
+ N(memory_op),
+ N(multicall),
+ N(update_va_mapping),
+ N(set_timer_op),
+ N(event_channel_op_compat),
+ N(xen_version),
+ N(console_io),
+ N(physdev_op_compat),
+ N(grant_table_op),
+ N(vm_assist),
+ N(update_va_mapping_otherdomain),
+ N(iret),
+ N(vcpu_op),
+ N(set_segment_base),
+ N(mmuext_op),
+ N(acm_op),
+ N(nmi_op),
+ N(sched_op),
+ N(callback_op),
+ N(xenoprof_op),
+ N(event_channel_op),
+ N(physdev_op),
+ N(hvm_op),
+
+/* Architecture-specific hypercall definitions. */
+ N(arch_0),
+ N(arch_1),
+ N(arch_2),
+ N(arch_3),
+ N(arch_4),
+ N(arch_5),
+ N(arch_6),
+ N(arch_7),
+};
+#undef N
+
+static const char *xen_hypercall_name(unsigned op)
+{
+ if (op < ARRAY_SIZE(xen_hypercall_names) && xen_hypercall_names[op] != NULL)
+ return xen_hypercall_names[op];
+
+ return "";
+}
+
#define CREATE_TRACE_POINTS
#include <trace/events/xen.h>
diff --git a/include/trace/events/xen.h b/include/trace/events/xen.h
index 46c170c..54600a7 100644
--- a/include/trace/events/xen.h
+++ b/include/trace/events/xen.h
@@ -6,7 +6,125 @@

#include <linux/tracepoint.h>
#include <asm/paravirt_types.h>
+#include <asm/xen/trace_types.h>

+/* Multicalls */
+
+TRACE_EVENT(xen_mc_batch,
+ TP_PROTO(enum paravirt_lazy_mode mode),
+ TP_ARGS(mode),
+ TP_STRUCT__entry(
+ __field(enum paravirt_lazy_mode, mode)
+ ),
+ TP_fast_assign(__entry->mode = mode),
+ TP_printk("start batch LAZY_%s",
+ (__entry->mode == PARAVIRT_LAZY_MMU) ? "MMU" :
+ (__entry->mode == PARAVIRT_LAZY_CPU) ? "CPU" : "NONE")
+ );
+
+TRACE_EVENT(xen_mc_issue,
+ TP_PROTO(enum paravirt_lazy_mode mode),
+ TP_ARGS(mode),
+ TP_STRUCT__entry(
+ __field(enum paravirt_lazy_mode, mode)
+ ),
+ TP_fast_assign(__entry->mode = mode),
+ TP_printk("issue mode LAZY_%s",
+ (__entry->mode == PARAVIRT_LAZY_MMU) ? "MMU" :
+ (__entry->mode == PARAVIRT_LAZY_CPU) ? "CPU" : "NONE")
+ );
+
+TRACE_EVENT(xen_mc_entry,
+ TP_PROTO(struct multicall_entry *mc, unsigned nargs),
+ TP_ARGS(mc, nargs),
+ TP_STRUCT__entry(
+ __field(unsigned short, op)
+ __field(unsigned short, nargs)
+ __array(unsigned long, args, 6)
+ ),
+ TP_fast_assign(__entry->op = mc->op;
+ __entry->nargs = nargs;
+ memcpy(__entry->args, mc->args, sizeof(unsigned long) * nargs);
+ memset(__entry->args + nargs, 0, sizeof(unsigned long) * (6 - nargs));
+ ),
+ TP_printk("op %u%s args [%lx, %lx, %lx, %lx, %lx, %lx]",
+ __entry->op, xen_hypercall_name(__entry->op),
+ __entry->args[0], __entry->args[1], __entry->args[2],
+ __entry->args[3], __entry->args[4], __entry->args[5])
+ );
+
+TRACE_EVENT(xen_mc_entry_alloc,
+ TP_PROTO(size_t args),
+ TP_ARGS(args),
+ TP_STRUCT__entry(
+ __field(size_t, args)
+ ),
+ TP_fast_assign(__entry->args = args),
+ TP_printk("alloc entry %zu arg bytes", __entry->args)
+ );
+
+TRACE_EVENT(xen_mc_callback,
+ TP_PROTO(xen_mc_callback_fn_t fn, void *data),
+ TP_ARGS(fn, data),
+ TP_STRUCT__entry(
+ __field(xen_mc_callback_fn_t, fn)
+ __field(void *, data)
+ ),
+ TP_fast_assign(
+ __entry->fn = fn;
+ __entry->data = data;
+ ),
+ TP_printk("callback %pf, data %p",
+ __entry->fn, __entry->data)
+ );
+
+TRACE_EVENT(xen_mc_flush_reason,
+ TP_PROTO(enum xen_mc_flush_reason reason),
+ TP_ARGS(reason),
+ TP_STRUCT__entry(
+ __field(enum xen_mc_flush_reason, reason)
+ ),
+ TP_fast_assign(__entry->reason = reason),
+ TP_printk("flush reason %s",
+ (__entry->reason == XEN_MC_FL_NONE) ? "NONE" :
+ (__entry->reason == XEN_MC_FL_BATCH) ? "BATCH" :
+ (__entry->reason == XEN_MC_FL_ARGS) ? "ARGS" :
+ (__entry->reason == XEN_MC_FL_CALLBACK) ? "CALLBACK" : "??")
+ );
+
+TRACE_EVENT(xen_mc_flush,
+ TP_PROTO(unsigned mcidx, unsigned argidx, unsigned cbidx),
+ TP_ARGS(mcidx, argidx, cbidx),
+ TP_STRUCT__entry(
+ __field(unsigned, mcidx)
+ __field(unsigned, argidx)
+ __field(unsigned, cbidx)
+ ),
+ TP_fast_assign(__entry->mcidx = mcidx;
+ __entry->argidx = argidx;
+ __entry->cbidx = cbidx),
+ TP_printk("flushing %u hypercalls, %u arg bytes, %u callbacks",
+ __entry->mcidx, __entry->argidx, __entry->cbidx)
+ );
+
+TRACE_EVENT(xen_mc_extend_args,
+ TP_PROTO(unsigned long op, size_t args, enum xen_mc_extend_args res),
+ TP_ARGS(op, args, res),
+ TP_STRUCT__entry(
+ __field(unsigned long, op)
+ __field(size_t, args)
+ __field(enum xen_mc_extend_args, res)
+ ),
+ TP_fast_assign(__entry->op = op;
+ __entry->args = args;
+ __entry->res = res),
+ TP_printk("extending op %lu%s by %zu bytes res %s",
+ __entry->op, xen_hypercall_name(__entry->op),
+ __entry->args,
+ __entry->res == XEN_MC_XE_OK ? "OK" :
+ __entry->res == XEN_MC_XE_BAD_OP ? "BAD_OP" :
+ __entry->res == XEN_MC_XE_NO_SPACE ? "NO_SPACE" : "???")
+ );
#endif /* _TRACE_XEN_H */

/* This part must be outside protection */
--
1.7.5.4