diff mbox series

[RFC] tests/tcg: add a system test to check memory instrumentation

Message ID 20240830152507.3026275-1-alex.bennee@linaro.org
State New
Headers show
Series [RFC] tests/tcg: add a system test to check memory instrumentation | expand

Commit Message

Alex Bennée Aug. 30, 2024, 3:25 p.m. UTC
At first I thought I could compile the user-mode test for system mode
however we already have a fairly comprehensive test case for system
mode in "memory" so lets use that.

First we extend the test to report where the test_data region is. Then
we expand the pdot() function to track the total number of reads and
writes to the region. We have to add some addition pdot() calls to
take into account multiple reads/writes in the test loops.

As tracking every access will quickly build up with "print-access" we
add a new mode to track groups of reads and writes to pages. Because
the test_data is page aligned we can be sure all accesses to it are
ones we can count.

Finally we add a python script to integrate the data from the plugin
and the output of the test and validate they both agree on the total
counts.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
---
 tests/tcg/multiarch/system/memory.c           |  48 +++++---
 tests/tcg/plugins/mem.c                       |  79 ++++++++++++-
 .../multiarch/system/Makefile.softmmu-target  |   6 +
 .../system/validate-memory-counts.py          | 108 ++++++++++++++++++
 4 files changed, 224 insertions(+), 17 deletions(-)
 create mode 100755 tests/tcg/multiarch/system/validate-memory-counts.py

Comments

Pierrick Bouvier Aug. 30, 2024, 7:17 p.m. UTC | #1
On 8/30/24 08:25, Alex Bennée wrote:
> At first I thought I could compile the user-mode test for system mode
> however we already have a fairly comprehensive test case for system
> mode in "memory" so lets use that.
> 
> First we extend the test to report where the test_data region is. Then
> we expand the pdot() function to track the total number of reads and
> writes to the region. We have to add some addition pdot() calls to
> take into account multiple reads/writes in the test loops.
> 
> As tracking every access will quickly build up with "print-access" we
> add a new mode to track groups of reads and writes to pages. Because
> the test_data is page aligned we can be sure all accesses to it are
> ones we can count.
> 
> Finally we add a python script to integrate the data from the plugin
> and the output of the test and validate they both agree on the total
> counts.
> 
> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
> ---
>   tests/tcg/multiarch/system/memory.c           |  48 +++++---
>   tests/tcg/plugins/mem.c                       |  79 ++++++++++++-
>   .../multiarch/system/Makefile.softmmu-target  |   6 +
>   .../system/validate-memory-counts.py          | 108 ++++++++++++++++++
>   4 files changed, 224 insertions(+), 17 deletions(-)
>   create mode 100755 tests/tcg/multiarch/system/validate-memory-counts.py
> 
> diff --git a/tests/tcg/multiarch/system/memory.c b/tests/tcg/multiarch/system/memory.c
> index 6eb2eb16f7..335ecbd7f0 100644
> --- a/tests/tcg/multiarch/system/memory.c
> +++ b/tests/tcg/multiarch/system/memory.c
> @@ -14,12 +14,16 @@
>   
>   #include <stdint.h>
>   #include <stdbool.h>
> +#include <inttypes.h>
>   #include <minilib.h>
>   
>   #ifndef CHECK_UNALIGNED
>   # error "Target does not specify CHECK_UNALIGNED"
>   #endif
>   
> +uint32_t test_read_count;
> +uint32_t test_write_count;
> +
>   #define MEM_PAGE_SIZE 4096             /* nominal 4k "pages" */
>   #define TEST_SIZE (MEM_PAGE_SIZE * 4)  /* 4 pages */
>   
> @@ -32,8 +36,13 @@ typedef void (*init_ufn) (int offset);
>   typedef bool (*read_ufn) (int offset);
>   typedef bool (*read_sfn) (int offset, bool nf);
>   
> -static void pdot(int count)
> +static void pdot(int count, bool write)
>   {
> +    if (write) {
> +        test_write_count++;
> +    } else {
> +        test_read_count++;
> +    }
>       if (count % 128 == 0) {
>           ml_printf(".");
>       }
> @@ -66,7 +75,7 @@ static void init_test_data_u8(int unused_offset)
>       ml_printf("Filling test area with u8:");
>       for (i = 0; i < TEST_SIZE; i++) {
>           *ptr++ = BYTE_NEXT(count);
> -        pdot(i);
> +        pdot(i, true);
>       }
>       ml_printf("done\n");
>   }
> @@ -91,8 +100,9 @@ static void init_test_data_s8(bool neg_first)
>                 neg_first ? "neg first" : "pos first");
>       for (i = 0; i < TEST_SIZE / 2; i++) {
>           *ptr++ = get_byte(i, neg_first);
> +        pdot(i, true);
>           *ptr++ = get_byte(i, !neg_first);
> -        pdot(i);
> +        pdot(i, true);
>       }
>       ml_printf("done\n");
>   }
> @@ -107,6 +117,7 @@ static void reset_start_data(int offset)
>       int i;
>       for (i = 0; i < offset; i++) {
>           *ptr++ = 0;
> +        pdot(i, true);
>       }
>   }
>   
> @@ -125,7 +136,7 @@ static void init_test_data_u16(int offset)
>           uint16_t low = BYTE_NEXT(count), high = BYTE_NEXT(count);
>           word = BYTE_SHIFT(high, 1) | BYTE_SHIFT(low, 0);
>           *ptr++ = word;
> -        pdot(i);
> +        pdot(i, true);
>       }
>       ml_printf("done @ %p\n", ptr);
>   }
> @@ -147,7 +158,7 @@ static void init_test_data_u32(int offset)
>           word = BYTE_SHIFT(b1, 3) | BYTE_SHIFT(b2, 2) | BYTE_SHIFT(b3, 1) |
>                  BYTE_SHIFT(b4, 0);
>           *ptr++ = word;
> -        pdot(i);
> +        pdot(i, true);
>       }
>       ml_printf("done @ %p\n", ptr);
>   }
> @@ -172,7 +183,7 @@ static void init_test_data_u64(int offset)
>                  BYTE_SHIFT(b4, 4) | BYTE_SHIFT(b5, 3) | BYTE_SHIFT(b6, 2) |
>                  BYTE_SHIFT(b7, 1) | BYTE_SHIFT(b8, 0);
>           *ptr++ = word;
> -        pdot(i);
> +        pdot(i, true);
>       }
>       ml_printf("done @ %p\n", ptr);
>   }
> @@ -194,7 +205,7 @@ static bool read_test_data_u16(int offset)
>               ml_printf("Error %d < %d\n", high, low);
>               return false;
>           } else {
> -            pdot(i);
> +            pdot(i, false);
>           }
>   
>       }
> @@ -236,7 +247,7 @@ static bool read_test_data_u32(int offset)
>               ml_printf("Error %d, %d, %d, %d", b1, b2, b3, b4);
>               return false;
>           } else {
> -            pdot(i);
> +            pdot(i, false);
>           }
>       }
>       ml_printf("done @ %p\n", ptr);
> @@ -290,7 +301,7 @@ static bool read_test_data_u64(int offset)
>                         b1, b2, b3, b4, b5, b6, b7, b8);
>               return false;
>           } else {
> -            pdot(i);
> +            pdot(i, false);
>           }
>       }
>       ml_printf("done @ %p\n", ptr);
> @@ -357,9 +368,11 @@ static bool read_test_data_s8(int offset, bool neg_first)
>           second = *ptr++;
>   
>           if (neg_first && first < 0 && second > 0) {
> -            pdot(i);
> +            pdot(i, false);
> +            pdot(i, false);
>           } else if (!neg_first && first > 0 && second < 0) {
> -            pdot(i);
> +            pdot(i, false);
> +            pdot(i, false);
>           } else {
>               ml_printf("Error %d %c %d\n", first, neg_first ? '<' : '>', second);
>               return false;
> @@ -390,9 +403,9 @@ static bool read_test_data_s16(int offset, bool neg_first)
>           int32_t data = *ptr++;
>   
>           if (neg_first && data < 0) {
> -            pdot(i);
> +            pdot(i, false);
>           } else if (!neg_first && data > 0) {
> -            pdot(i);
> +            pdot(i, false);
>           } else {
>               ml_printf("Error %d %c 0\n", data, neg_first ? '<' : '>');
>               return false;
> @@ -423,9 +436,9 @@ static bool read_test_data_s32(int offset, bool neg_first)
>           int64_t data = *ptr++;
>   
>           if (neg_first && data < 0) {
> -            pdot(i);
> +            pdot(i, false);
>           } else if (!neg_first && data > 0) {
> -            pdot(i);
> +            pdot(i, false);
>           } else {
>               ml_printf("Error %d %c 0\n", data, neg_first ? '<' : '>');
>               return false;
> @@ -475,6 +488,9 @@ int main(void)
>       int i;
>       bool ok = true;
>   
> +    ml_printf("Test data start: 0x%"PRIxPTR"\n", &test_data[0]);
> +    ml_printf("Test data end: 0x%"PRIxPTR"\n", &test_data[TEST_SIZE]);
> +
>       /* Run through the unsigned tests first */
>       for (i = 0; i < ARRAY_SIZE(init_ufns) && ok; i++) {
>           ok = do_unsigned_test(init_ufns[i]);
> @@ -490,6 +506,8 @@ int main(void)
>           ok = do_signed_reads(true);
>       }
>   
> +    ml_printf("Test data read: %"PRId32"\n", test_read_count);
> +    ml_printf("Test data write: %"PRId32"\n", test_write_count);
>       ml_printf("Test complete: %s\n", ok ? "PASSED" : "FAILED");
>       return ok ? 0 : -1;
>   }
> diff --git a/tests/tcg/plugins/mem.c b/tests/tcg/plugins/mem.c
> index 086e6f5bdf..f9a2ab4c13 100644
> --- a/tests/tcg/plugins/mem.c
> +++ b/tests/tcg/plugins/mem.c
> @@ -26,13 +26,27 @@ typedef struct {
>       const char *sym;
>   } InsnInfo;
>   
> +typedef struct {
> +    uint64_t page_address;
> +    uint64_t reads;
> +    uint64_t read_bytes;
> +    uint64_t writes;
> +    uint64_t written_bytes;
> +} PageInfo;
> +
>   static struct qemu_plugin_scoreboard *counts;
>   static qemu_plugin_u64 mem_count;
>   static qemu_plugin_u64 io_count;
> -static bool do_inline, do_callback, do_print_accesses;
> +static bool do_inline, do_callback, do_print_accesses, do_page_summary;
>   static bool do_haddr;
>   static enum qemu_plugin_mem_rw rw = QEMU_PLUGIN_MEM_RW;
>   
> +static uint64_t page_size = 4096;
> +static uint64_t page_mask;
> +
> +static GMutex lock;
> +static GHashTable *pages;
> +
>   static void plugin_exit(qemu_plugin_id_t id, void *p)
>   {
>       g_autoptr(GString) out = g_string_new("");
> @@ -46,6 +60,31 @@ static void plugin_exit(qemu_plugin_id_t id, void *p)
>                                  qemu_plugin_u64_sum(io_count));
>       }
>       qemu_plugin_outs(out->str);
> +
> +
> +    if (do_page_summary) {
> +        GList *counts = g_hash_table_get_values(pages);
> +
> +        g_string_printf(out, "PageAddr, Reads, Read Bytes, Writes, Write Bytes\n");
> +
> +        if (counts && g_list_next(counts)) {
> +            for (/* counts */; counts->next; counts = counts->next) {
> +                PageInfo *pi = (PageInfo *) counts->data;
> +
> +                g_string_append_printf(out,
> +                                       "0x%016"PRIx64", "
> +                                       "%"PRId64", %"PRId64", "
> +                                       "%"PRId64", %"PRId64"\n",
> +                                       pi->page_address,
> +                                       pi->reads,
> +                                       pi->read_bytes,
> +                                       pi->writes,
> +                                       pi->written_bytes);
> +            }
> +        }
> +        qemu_plugin_outs(out->str);
> +    }
> +
>       qemu_plugin_scoreboard_free(counts);
>   }
>   
> @@ -63,6 +102,31 @@ static void vcpu_mem(unsigned int cpu_index, qemu_plugin_meminfo_t meminfo,
>       } else {
>           qemu_plugin_u64_add(mem_count, cpu_index, 1);
>       }
> +
> +    if (do_page_summary) {
> +        uint64_t page = vaddr & ~page_mask;
> +        PageInfo *pi;
> +        unsigned size = 8 << qemu_plugin_mem_size_shift(meminfo);
> +
> +        g_mutex_lock(&lock);
> +        pi = (PageInfo *) g_hash_table_lookup(pages, GUINT_TO_POINTER(page));
> +
> +        if (!pi) {
> +            pi = g_new0(PageInfo, 1);
> +            pi->page_address = page;
> +            g_hash_table_insert(pages, GUINT_TO_POINTER(page), (gpointer) pi);
> +        }
> +
> +        if (qemu_plugin_mem_is_store(meminfo)) {
> +            pi->writes++;
> +            pi->written_bytes += size;
> +        } else {
> +            pi->reads++;
> +            pi->read_bytes += size;
> +        }
> +
> +        g_mutex_unlock(&lock);
> +    }
>   }
>   
>   static void print_access(unsigned int cpu_index, qemu_plugin_meminfo_t meminfo,
> @@ -117,7 +181,7 @@ static void vcpu_tb_trans(qemu_plugin_id_t id, struct qemu_plugin_tb *tb)
>                   QEMU_PLUGIN_INLINE_ADD_U64,
>                   mem_count, 1);
>           }
> -        if (do_callback) {
> +        if (do_callback || do_page_summary) {
>               qemu_plugin_register_vcpu_mem_cb(insn, vcpu_mem,
>                                                QEMU_PLUGIN_CB_NO_REGS,
>                                                rw, NULL);
> @@ -176,6 +240,12 @@ QEMU_PLUGIN_EXPORT int qemu_plugin_install(qemu_plugin_id_t id,
>                   fprintf(stderr, "boolean argument parsing failed: %s\n", opt);
>                   return -1;
>               }
> +        } else if (g_strcmp0(tokens[0], "page-summary") == 0) {
> +            if (!qemu_plugin_bool_parse(tokens[0], tokens[1],
> +                                        &do_page_summary)) {
> +                fprintf(stderr, "boolean argument parsing failed: %s\n", opt);
> +                return -1;
> +            }
>           } else {
>               fprintf(stderr, "option parsing failed: %s\n", opt);
>               return -1;
> @@ -196,6 +266,11 @@ QEMU_PLUGIN_EXPORT int qemu_plugin_install(qemu_plugin_id_t id,
>           qemu_plugin_outs(out->str);
>       }
>   
> +    if (do_page_summary) {
> +        page_mask = (page_size - 1);
> +        pages = g_hash_table_new(NULL, g_direct_equal);
> +    }
> +
>       counts = qemu_plugin_scoreboard_new(sizeof(CPUCount));
>       mem_count = qemu_plugin_scoreboard_u64_in_struct(
>           counts, CPUCount, mem_count);
> diff --git a/tests/tcg/multiarch/system/Makefile.softmmu-target b/tests/tcg/multiarch/system/Makefile.softmmu-target
> index 32dc0f9830..a1b33a6973 100644
> --- a/tests/tcg/multiarch/system/Makefile.softmmu-target
> +++ b/tests/tcg/multiarch/system/Makefile.softmmu-target
> @@ -65,3 +65,9 @@ endif
>   
>   MULTIARCH_RUNS += run-gdbstub-memory run-gdbstub-interrupt \
>   	run-gdbstub-untimely-packet run-gdbstub-registers
> +
> +# Test plugin memory access instrumentation
> +run-plugin-memory-with-libmem.so: 		\
> +	PLUGIN_ARGS=$(COMMA)page-summary=true
> +run-plugin-memory-with-libmem.so: 		\
> +	CHECK_PLUGIN_OUTPUT_COMMAND=$(MULTIARCH_SYSTEM_SRC)/validate-memory-counts.py $@.out
> diff --git a/tests/tcg/multiarch/system/validate-memory-counts.py b/tests/tcg/multiarch/system/validate-memory-counts.py
> new file mode 100755
> index 0000000000..8c18bff066
> --- /dev/null
> +++ b/tests/tcg/multiarch/system/validate-memory-counts.py
> @@ -0,0 +1,108 @@
> +#!/usr/bin/env python3
> +#
> +# validate-memory-counts.py: check we instrumented memory properly
> +#
> +# This program takes two inputs:
> +#   - the mem plugin output
> +#   - the memory binary output
> +#
> +# Copyright (C) 2024 Linaro Ltd
> +#
> +# SPDX-License-Identifier: GPL-2.0-or-later
> +
> +import sys
> +
> +def extract_counts(path):
> +    """
> +    Load the output from path and extract the lines containing:
> +
> +      Test data start: 0x40214000
> +      Test data end: 0x40218001
> +      Test data read: 2522280
> +      Test data write: 262111
> +
> +    From the stream of data. Extract the values for use in the
> +    validation function.
> +    """
> +    start_address = None
> +    end_address = None
> +    read_count = 0
> +    write_count = 0
> +    with open(path, 'r') as f:
> +        for line in f:
> +            if line.startswith("Test data start:"):
> +                start_address = int(line.split(':')[1].strip(), 16)
> +            elif line.startswith("Test data end:"):
> +                end_address = int(line.split(':')[1].strip(), 16)
> +            elif line.startswith("Test data read:"):
> +                read_count = int(line.split(':')[1].strip())
> +            elif line.startswith("Test data write:"):
> +                write_count = int(line.split(':')[1].strip())
> +    return start_address, end_address, read_count, write_count
> +
> +
> +def parse_plugin_output(path, start, end):
> +    """
> +    Load the plugin output from path in the form of:
> +
> +      PageAddr, Reads, Read Bytes, Writes, Write Bytes
> +      0x0000000040214000, 630296, 15719488, 69700, 1116480
> +      0x0000000040201000, 0, 0, 2, 128
> +      0x0000000040215000, 630784, 15728640, 69632, 1114112
> +
> +    And extract the ranges that match test data start and end and
> +    return the results.
> +    """
> +    total_reads = 0
> +    total_read_bytes = 0
> +    total_writes = 0
> +    total_written_bytes = 0
> +
> +    with open(path, 'r') as f:
> +        next(f)  # Skip the header
> +        for line in f:
> +            parts = line.strip().split(', ')
> +            if len(parts) != 5:
> +                continue
> +            page_addr = int(parts[0], 16)
> +            reads = int(parts[1])
> +            read_bytes = int(parts[2])
> +            writes = int(parts[3])
> +            written_bytes = int(parts[4])
> +            if start <= page_addr < end: # Checking if within range
> +                total_reads += reads
> +                total_read_bytes += read_bytes
> +                total_writes += writes
> +                total_written_bytes += written_bytes
> +
> +    return total_reads, total_read_bytes, total_writes, total_written_bytes
> +
> +def main():
> +    if len(sys.argv) != 3:
> +        print("Usage: <script_name>.py <memory_binary_output_path> <mem_plugin_output_path>")
> +        sys.exit(1)
> +
> +    memory_binary_output_path = sys.argv[1]
> +    mem_plugin_output_path = sys.argv[2]
> +
> +    # Extract counts from memory binary
> +    start, end, expected_reads, expected_writes = extract_counts(memory_binary_output_path)
> +
> +    if start is None or end is None:
> +        print("Failed to extract start or end address from memory binary output.")
> +        sys.exit(1)
> +
> +    # Parse plugin output
> +    actual_reads, actual_read_bytes, actual_writes, actual_written_bytes = parse_plugin_output(mem_plugin_output_path, start, end)
> +
> +    # Compare and report
> +    if actual_reads == expected_reads and actual_writes == expected_writes:
> +        sys.exit(0)
> +    else:
> +        print("Fail: The memory reads and writes count does not match.")
> +        print(f"Expected Reads: {expected_reads}, Actual Reads: {actual_reads}")
> +        print(f"Expected Writes: {expected_writes}, Actual Writes: {actual_writes}")
> +        sys.exit(1)
> +
> +if __name__ == "__main__":
> +    main()

Thanks for investigating this.
Overall, it would be a good thing to have a test like this.

However, I think it misses the point attached to this series.
Indeed, the new API function qemu_plugin_mem_get_value() is never 
called, and we just count expect read/write at given addresses.

There is value into this, but I definitely thing this should be in a 
different series, after the current one is merged.

What do you think?
diff mbox series

Patch

diff --git a/tests/tcg/multiarch/system/memory.c b/tests/tcg/multiarch/system/memory.c
index 6eb2eb16f7..335ecbd7f0 100644
--- a/tests/tcg/multiarch/system/memory.c
+++ b/tests/tcg/multiarch/system/memory.c
@@ -14,12 +14,16 @@ 
 
 #include <stdint.h>
 #include <stdbool.h>
+#include <inttypes.h>
 #include <minilib.h>
 
 #ifndef CHECK_UNALIGNED
 # error "Target does not specify CHECK_UNALIGNED"
 #endif
 
+uint32_t test_read_count;
+uint32_t test_write_count;
+
 #define MEM_PAGE_SIZE 4096             /* nominal 4k "pages" */
 #define TEST_SIZE (MEM_PAGE_SIZE * 4)  /* 4 pages */
 
@@ -32,8 +36,13 @@  typedef void (*init_ufn) (int offset);
 typedef bool (*read_ufn) (int offset);
 typedef bool (*read_sfn) (int offset, bool nf);
 
-static void pdot(int count)
+static void pdot(int count, bool write)
 {
+    if (write) {
+        test_write_count++;
+    } else {
+        test_read_count++;
+    }
     if (count % 128 == 0) {
         ml_printf(".");
     }
@@ -66,7 +75,7 @@  static void init_test_data_u8(int unused_offset)
     ml_printf("Filling test area with u8:");
     for (i = 0; i < TEST_SIZE; i++) {
         *ptr++ = BYTE_NEXT(count);
-        pdot(i);
+        pdot(i, true);
     }
     ml_printf("done\n");
 }
@@ -91,8 +100,9 @@  static void init_test_data_s8(bool neg_first)
               neg_first ? "neg first" : "pos first");
     for (i = 0; i < TEST_SIZE / 2; i++) {
         *ptr++ = get_byte(i, neg_first);
+        pdot(i, true);
         *ptr++ = get_byte(i, !neg_first);
-        pdot(i);
+        pdot(i, true);
     }
     ml_printf("done\n");
 }
@@ -107,6 +117,7 @@  static void reset_start_data(int offset)
     int i;
     for (i = 0; i < offset; i++) {
         *ptr++ = 0;
+        pdot(i, true);
     }
 }
 
@@ -125,7 +136,7 @@  static void init_test_data_u16(int offset)
         uint16_t low = BYTE_NEXT(count), high = BYTE_NEXT(count);
         word = BYTE_SHIFT(high, 1) | BYTE_SHIFT(low, 0);
         *ptr++ = word;
-        pdot(i);
+        pdot(i, true);
     }
     ml_printf("done @ %p\n", ptr);
 }
@@ -147,7 +158,7 @@  static void init_test_data_u32(int offset)
         word = BYTE_SHIFT(b1, 3) | BYTE_SHIFT(b2, 2) | BYTE_SHIFT(b3, 1) |
                BYTE_SHIFT(b4, 0);
         *ptr++ = word;
-        pdot(i);
+        pdot(i, true);
     }
     ml_printf("done @ %p\n", ptr);
 }
@@ -172,7 +183,7 @@  static void init_test_data_u64(int offset)
                BYTE_SHIFT(b4, 4) | BYTE_SHIFT(b5, 3) | BYTE_SHIFT(b6, 2) |
                BYTE_SHIFT(b7, 1) | BYTE_SHIFT(b8, 0);
         *ptr++ = word;
-        pdot(i);
+        pdot(i, true);
     }
     ml_printf("done @ %p\n", ptr);
 }
@@ -194,7 +205,7 @@  static bool read_test_data_u16(int offset)
             ml_printf("Error %d < %d\n", high, low);
             return false;
         } else {
-            pdot(i);
+            pdot(i, false);
         }
 
     }
@@ -236,7 +247,7 @@  static bool read_test_data_u32(int offset)
             ml_printf("Error %d, %d, %d, %d", b1, b2, b3, b4);
             return false;
         } else {
-            pdot(i);
+            pdot(i, false);
         }
     }
     ml_printf("done @ %p\n", ptr);
@@ -290,7 +301,7 @@  static bool read_test_data_u64(int offset)
                       b1, b2, b3, b4, b5, b6, b7, b8);
             return false;
         } else {
-            pdot(i);
+            pdot(i, false);
         }
     }
     ml_printf("done @ %p\n", ptr);
@@ -357,9 +368,11 @@  static bool read_test_data_s8(int offset, bool neg_first)
         second = *ptr++;
 
         if (neg_first && first < 0 && second > 0) {
-            pdot(i);
+            pdot(i, false);
+            pdot(i, false);
         } else if (!neg_first && first > 0 && second < 0) {
-            pdot(i);
+            pdot(i, false);
+            pdot(i, false);
         } else {
             ml_printf("Error %d %c %d\n", first, neg_first ? '<' : '>', second);
             return false;
@@ -390,9 +403,9 @@  static bool read_test_data_s16(int offset, bool neg_first)
         int32_t data = *ptr++;
 
         if (neg_first && data < 0) {
-            pdot(i);
+            pdot(i, false);
         } else if (!neg_first && data > 0) {
-            pdot(i);
+            pdot(i, false);
         } else {
             ml_printf("Error %d %c 0\n", data, neg_first ? '<' : '>');
             return false;
@@ -423,9 +436,9 @@  static bool read_test_data_s32(int offset, bool neg_first)
         int64_t data = *ptr++;
 
         if (neg_first && data < 0) {
-            pdot(i);
+            pdot(i, false);
         } else if (!neg_first && data > 0) {
-            pdot(i);
+            pdot(i, false);
         } else {
             ml_printf("Error %d %c 0\n", data, neg_first ? '<' : '>');
             return false;
@@ -475,6 +488,9 @@  int main(void)
     int i;
     bool ok = true;
 
+    ml_printf("Test data start: 0x%"PRIxPTR"\n", &test_data[0]);
+    ml_printf("Test data end: 0x%"PRIxPTR"\n", &test_data[TEST_SIZE]);
+
     /* Run through the unsigned tests first */
     for (i = 0; i < ARRAY_SIZE(init_ufns) && ok; i++) {
         ok = do_unsigned_test(init_ufns[i]);
@@ -490,6 +506,8 @@  int main(void)
         ok = do_signed_reads(true);
     }
 
+    ml_printf("Test data read: %"PRId32"\n", test_read_count);
+    ml_printf("Test data write: %"PRId32"\n", test_write_count);
     ml_printf("Test complete: %s\n", ok ? "PASSED" : "FAILED");
     return ok ? 0 : -1;
 }
diff --git a/tests/tcg/plugins/mem.c b/tests/tcg/plugins/mem.c
index 086e6f5bdf..f9a2ab4c13 100644
--- a/tests/tcg/plugins/mem.c
+++ b/tests/tcg/plugins/mem.c
@@ -26,13 +26,27 @@  typedef struct {
     const char *sym;
 } InsnInfo;
 
+typedef struct {
+    uint64_t page_address;
+    uint64_t reads;
+    uint64_t read_bytes;
+    uint64_t writes;
+    uint64_t written_bytes;
+} PageInfo;
+
 static struct qemu_plugin_scoreboard *counts;
 static qemu_plugin_u64 mem_count;
 static qemu_plugin_u64 io_count;
-static bool do_inline, do_callback, do_print_accesses;
+static bool do_inline, do_callback, do_print_accesses, do_page_summary;
 static bool do_haddr;
 static enum qemu_plugin_mem_rw rw = QEMU_PLUGIN_MEM_RW;
 
+static uint64_t page_size = 4096;
+static uint64_t page_mask;
+
+static GMutex lock;
+static GHashTable *pages;
+
 static void plugin_exit(qemu_plugin_id_t id, void *p)
 {
     g_autoptr(GString) out = g_string_new("");
@@ -46,6 +60,31 @@  static void plugin_exit(qemu_plugin_id_t id, void *p)
                                qemu_plugin_u64_sum(io_count));
     }
     qemu_plugin_outs(out->str);
+
+
+    if (do_page_summary) {
+        GList *counts = g_hash_table_get_values(pages);
+
+        g_string_printf(out, "PageAddr, Reads, Read Bytes, Writes, Write Bytes\n");
+
+        if (counts && g_list_next(counts)) {
+            for (/* counts */; counts->next; counts = counts->next) {
+                PageInfo *pi = (PageInfo *) counts->data;
+
+                g_string_append_printf(out,
+                                       "0x%016"PRIx64", "
+                                       "%"PRId64", %"PRId64", "
+                                       "%"PRId64", %"PRId64"\n",
+                                       pi->page_address,
+                                       pi->reads,
+                                       pi->read_bytes,
+                                       pi->writes,
+                                       pi->written_bytes);
+            }
+        }
+        qemu_plugin_outs(out->str);
+    }
+
     qemu_plugin_scoreboard_free(counts);
 }
 
@@ -63,6 +102,31 @@  static void vcpu_mem(unsigned int cpu_index, qemu_plugin_meminfo_t meminfo,
     } else {
         qemu_plugin_u64_add(mem_count, cpu_index, 1);
     }
+
+    if (do_page_summary) {
+        uint64_t page = vaddr & ~page_mask;
+        PageInfo *pi;
+        unsigned size = 8 << qemu_plugin_mem_size_shift(meminfo);
+
+        g_mutex_lock(&lock);
+        pi = (PageInfo *) g_hash_table_lookup(pages, GUINT_TO_POINTER(page));
+
+        if (!pi) {
+            pi = g_new0(PageInfo, 1);
+            pi->page_address = page;
+            g_hash_table_insert(pages, GUINT_TO_POINTER(page), (gpointer) pi);
+        }
+
+        if (qemu_plugin_mem_is_store(meminfo)) {
+            pi->writes++;
+            pi->written_bytes += size;
+        } else {
+            pi->reads++;
+            pi->read_bytes += size;
+        }
+
+        g_mutex_unlock(&lock);
+    }
 }
 
 static void print_access(unsigned int cpu_index, qemu_plugin_meminfo_t meminfo,
@@ -117,7 +181,7 @@  static void vcpu_tb_trans(qemu_plugin_id_t id, struct qemu_plugin_tb *tb)
                 QEMU_PLUGIN_INLINE_ADD_U64,
                 mem_count, 1);
         }
-        if (do_callback) {
+        if (do_callback || do_page_summary) {
             qemu_plugin_register_vcpu_mem_cb(insn, vcpu_mem,
                                              QEMU_PLUGIN_CB_NO_REGS,
                                              rw, NULL);
@@ -176,6 +240,12 @@  QEMU_PLUGIN_EXPORT int qemu_plugin_install(qemu_plugin_id_t id,
                 fprintf(stderr, "boolean argument parsing failed: %s\n", opt);
                 return -1;
             }
+        } else if (g_strcmp0(tokens[0], "page-summary") == 0) {
+            if (!qemu_plugin_bool_parse(tokens[0], tokens[1],
+                                        &do_page_summary)) {
+                fprintf(stderr, "boolean argument parsing failed: %s\n", opt);
+                return -1;
+            }
         } else {
             fprintf(stderr, "option parsing failed: %s\n", opt);
             return -1;
@@ -196,6 +266,11 @@  QEMU_PLUGIN_EXPORT int qemu_plugin_install(qemu_plugin_id_t id,
         qemu_plugin_outs(out->str);
     }
 
+    if (do_page_summary) {
+        page_mask = (page_size - 1);
+        pages = g_hash_table_new(NULL, g_direct_equal);
+    }
+
     counts = qemu_plugin_scoreboard_new(sizeof(CPUCount));
     mem_count = qemu_plugin_scoreboard_u64_in_struct(
         counts, CPUCount, mem_count);
diff --git a/tests/tcg/multiarch/system/Makefile.softmmu-target b/tests/tcg/multiarch/system/Makefile.softmmu-target
index 32dc0f9830..a1b33a6973 100644
--- a/tests/tcg/multiarch/system/Makefile.softmmu-target
+++ b/tests/tcg/multiarch/system/Makefile.softmmu-target
@@ -65,3 +65,9 @@  endif
 
 MULTIARCH_RUNS += run-gdbstub-memory run-gdbstub-interrupt \
 	run-gdbstub-untimely-packet run-gdbstub-registers
+
+# Test plugin memory access instrumentation
+run-plugin-memory-with-libmem.so: 		\
+	PLUGIN_ARGS=$(COMMA)page-summary=true
+run-plugin-memory-with-libmem.so: 		\
+	CHECK_PLUGIN_OUTPUT_COMMAND=$(MULTIARCH_SYSTEM_SRC)/validate-memory-counts.py $@.out
diff --git a/tests/tcg/multiarch/system/validate-memory-counts.py b/tests/tcg/multiarch/system/validate-memory-counts.py
new file mode 100755
index 0000000000..8c18bff066
--- /dev/null
+++ b/tests/tcg/multiarch/system/validate-memory-counts.py
@@ -0,0 +1,108 @@ 
+#!/usr/bin/env python3
+#
+# validate-memory-counts.py: check we instrumented memory properly
+#
+# This program takes two inputs:
+#   - the mem plugin output
+#   - the memory binary output
+#
+# Copyright (C) 2024 Linaro Ltd
+#
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+import sys
+
+def extract_counts(path):
+    """
+    Load the output from path and extract the lines containing:
+
+      Test data start: 0x40214000
+      Test data end: 0x40218001
+      Test data read: 2522280
+      Test data write: 262111
+
+    From the stream of data. Extract the values for use in the
+    validation function.
+    """
+    start_address = None
+    end_address = None
+    read_count = 0
+    write_count = 0
+    with open(path, 'r') as f:
+        for line in f:
+            if line.startswith("Test data start:"):
+                start_address = int(line.split(':')[1].strip(), 16)
+            elif line.startswith("Test data end:"):
+                end_address = int(line.split(':')[1].strip(), 16)
+            elif line.startswith("Test data read:"):
+                read_count = int(line.split(':')[1].strip())
+            elif line.startswith("Test data write:"):
+                write_count = int(line.split(':')[1].strip())
+    return start_address, end_address, read_count, write_count
+
+
+def parse_plugin_output(path, start, end):
+    """
+    Load the plugin output from path in the form of:
+
+      PageAddr, Reads, Read Bytes, Writes, Write Bytes
+      0x0000000040214000, 630296, 15719488, 69700, 1116480
+      0x0000000040201000, 0, 0, 2, 128
+      0x0000000040215000, 630784, 15728640, 69632, 1114112
+
+    And extract the ranges that match test data start and end and
+    return the results.
+    """
+    total_reads = 0
+    total_read_bytes = 0
+    total_writes = 0
+    total_written_bytes = 0
+
+    with open(path, 'r') as f:
+        next(f)  # Skip the header
+        for line in f:
+            parts = line.strip().split(', ')
+            if len(parts) != 5:
+                continue
+            page_addr = int(parts[0], 16)
+            reads = int(parts[1])
+            read_bytes = int(parts[2])
+            writes = int(parts[3])
+            written_bytes = int(parts[4])
+            if start <= page_addr < end: # Checking if within range
+                total_reads += reads
+                total_read_bytes += read_bytes
+                total_writes += writes
+                total_written_bytes += written_bytes
+
+    return total_reads, total_read_bytes, total_writes, total_written_bytes
+
+def main():
+    if len(sys.argv) != 3:
+        print("Usage: <script_name>.py <memory_binary_output_path> <mem_plugin_output_path>")
+        sys.exit(1)
+
+    memory_binary_output_path = sys.argv[1]
+    mem_plugin_output_path = sys.argv[2]
+
+    # Extract counts from memory binary
+    start, end, expected_reads, expected_writes = extract_counts(memory_binary_output_path)
+
+    if start is None or end is None:
+        print("Failed to extract start or end address from memory binary output.")
+        sys.exit(1)
+
+    # Parse plugin output
+    actual_reads, actual_read_bytes, actual_writes, actual_written_bytes = parse_plugin_output(mem_plugin_output_path, start, end)
+
+    # Compare and report
+    if actual_reads == expected_reads and actual_writes == expected_writes:
+        sys.exit(0)
+    else:
+        print("Fail: The memory reads and writes count does not match.")
+        print(f"Expected Reads: {expected_reads}, Actual Reads: {actual_reads}")
+        print(f"Expected Writes: {expected_writes}, Actual Writes: {actual_writes}")
+        sys.exit(1)
+
+if __name__ == "__main__":
+    main()