profiling: fix the profiling tool crash by page faults

Profiling tools are broken, which cause page faults during collection.
The issue happens by enabling SMAP recently. Therefore,
we use stac() and clac() to allow access to buffers allocated by guest.

Tacked-On: #2157
Signed-off-by: Min Lim <min.yeol.lim@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>

Author: mlim19

hypervisor/debug/profiling.c

@@ -235,14 +235,14 @@ static int32_t profiling_sbuf_put_variable(struct shared_buf *sbuf,
 	 * 5. return number of bytes of data put in buffer
 	 */
 
+	stac();
 	if ((sbuf == NULL) || (data == NULL)) {
-		dev_dbg(ACRN_DBG_PROFILING, "buffer or data not initialized!");
+		clac();
 		return -EINVAL;
 	}
 
 	if (size == 0U) {
-		dev_dbg(ACRN_DBG_PROFILING,
-			"0 bytes reqeusted to be put in buffer!");
+		clac();
 		return 0;
 	}
 
@@ -257,19 +257,15 @@ static int32_t profiling_sbuf_put_variable(struct shared_buf *sbuf,
 		 * Since if the next_tail equals head, then it is assumed
 		 * that buffer is empty, not full
 		 */
-		dev_dbg(ACRN_DBG_PROFILING,
-		"Not enough space to write data! Returning without writing");
+		clac();
 		return 0;
 	}
 
 	next_tail = sbuf_next_ptr(sbuf->tail, size, sbuf->size);
-	dev_dbg(ACRN_DBG_PROFILING, "sbuf->tail: %llu, next_tail: %llu",
-		sbuf->tail, next_tail);
 
 	to = (void *)sbuf + SBUF_HEAD_SIZE + sbuf->tail;
 
 	if (next_tail < sbuf->tail) { /* wrap-around */
-		dev_dbg(ACRN_DBG_PROFILING, "wrap-around condition!");
 		offset = sbuf->size - sbuf->tail;
 		(void)memcpy_s(to, offset, data, offset);
 
@@ -281,11 +277,11 @@ static int32_t profiling_sbuf_put_variable(struct shared_buf *sbuf,
 				data + offset, size - offset);
 		}
 	} else {
-		dev_dbg(ACRN_DBG_PROFILING, "non-wrap-around!");
 		(void)memcpy_s(to, size, data, size);
 	}
 
 	sbuf->tail = next_tail;
+	clac();
 
 	return (int32_t)size;
 }
@@ -306,6 +302,8 @@ static int32_t profiling_generate_data(int32_t collector, uint32_t type)
 	struct sep_state *ss = &(get_cpu_var(profiling_info.sep_state));
 	struct sw_msr_op_info *sw_msrop
 		= &(get_cpu_var(profiling_info.sw_msr_op_info));
+	uint64_t rflags;
+	spinlock_t *sw_lock = NULL;
 
 	dev_dbg(ACRN_DBG_PROFILING, "%s: entering cpu%d",
 		__func__,  get_cpu_id());
@@ -322,12 +320,14 @@ static int32_t profiling_generate_data(int32_t collector, uint32_t type)
 		}
 
 		if (ss->pmu_state == PMU_RUNNING) {
+			stac();
 			if (sbuf->tail >= sbuf->head) {
 				remaining_space = sbuf->size
 						- (sbuf->tail - sbuf->head);
 			} else {
 				remaining_space = sbuf->head - sbuf->tail;
 			}
+			clac();
 
 			/* populate the data header */
 			pkt_header.tsc = rdtsc();
@@ -393,12 +393,16 @@ static int32_t profiling_generate_data(int32_t collector, uint32_t type)
 			return 0;
 		}
 
+		sw_lock = &(get_cpu_var(profiling_info.sw_lock));
+		spinlock_irqsave_obtain(sw_lock, &rflags);
+		stac();
 		if (sbuf->tail >= sbuf->head) {
 			remaining_space
 				= sbuf->size - (sbuf->tail - sbuf->head);
 		} else {
 			remaining_space = sbuf->head - sbuf->tail;
 		}
+		clac();
 
 		/* populate the data header */
 		pkt_header.tsc = rdtsc();
@@ -448,6 +452,7 @@ static int32_t profiling_generate_data(int32_t collector, uint32_t type)
 		(void)profiling_sbuf_put_variable((struct shared_buf *)sbuf,
 			(uint8_t *)payload, (uint32_t)payload_size);
 
+		spinlock_irqrestore_release(sw_lock, rflags);
 	} else {
 		dev_dbg(ACRN_ERR_PROFILING,
 			"%s: Unknown collector type", __func__);

hypervisor/include/debug/profiling_internal.h

@@ -291,6 +291,7 @@ struct profiling_info_wrapper {
 	struct vm_switch_trace	vm_switch_trace;
 	socwatch_state			soc_state;
 	struct sw_msr_op_info	sw_msr_op_info;
+	spinlock_t		sw_lock;
 } __aligned(8);
 
 int32_t profiling_get_version_info(struct acrn_vm *vm, uint64_t addr);