Snapshot for ECRTS'25 artifact evaluation

1 files changed, 76 insertions, 3 deletions

diff --git a/device_info_procfs.c b/device_info_procfs.c
index 4e4ab03..105e731 100644
--- a/device_info_procfs.c
+++ b/device_info_procfs.c
@@ -18,7 +18,7 @@ static ssize_t nvdebug_reg32_read(struct file *f, char __user *buf, size_t size,
                 return 0;
 
         if ((read = nvdebug_readl(g, (uintptr_t)pde_data(file_inode(f)))) == -1)
-                return -EOPNOTSUPP;
+                return -EIO;
         // 32 bit register will always take less than 16 characters to print
         chars_written = scnprintf(out, 16, "%#0x\n", read);
         if (copy_to_user(buf, out, chars_written))
@@ -32,12 +32,85 @@ struct file_operations nvdebug_read_reg32_file_ops = {
         .llseek = default_llseek,
 };
 
+typedef union {
+        struct {
+                uint8_t partitioning_select:2;
+                uint8_t table_select:2;
+                 uint32_t pad_1:12;
+                uint8_t veid_offset:6;
+                 uint32_t pad_2:2;
+                uint8_t table_offset:6;
+                 uint32_t pad_3:2;
+        };
+        uint32_t raw;
+} partition_ctl_t;
+
+static ssize_t nvdebug_read_part(struct file *f, char __user *buf, size_t size, loff_t *off) {
+        char out[12*64+2];
+        int i, chars_written = 0;
+        partition_ctl_t part_ctl;
+        struct nvdebug_state *g = &g_nvdebug_state[file2parentgpuidx(f)];
+        if (size < 16 || *off != 0)
+                return 0;
+        // 32 bit register will always take less than 16 characters to print
+        part_ctl.raw = nvdebug_readl(g, 0x00405b2c);
+        //part_ctl.partitioning_select = 0; // XXX XXX XXX Temp; 06/18/2024
+        //part_ctl.table_select = 3; // 3 == ???
+        //part_ctl.table_select = 2; // 2 == TBL_SEL_PARTITIONING_LMEM_BLK
+        part_ctl.table_select = 1; // 1 == TBL_SEL_PARTITIONING_ENABLE
+        //part_ctl.table_select = 0; // 0 == TBL_SEL_NONE
+        part_ctl.veid_offset = (uintptr_t)pde_data(file_inode(f)); // Range of [0, 0x3f], aka [0, 63]
+        for (i = 0; i < 64; i++) {
+                // Increment to next table offset in PARTITION_CTL
+                part_ctl.table_offset = i;
+                nvdebug_writel(g, 0x00405b2c, part_ctl.raw);
+                // Verify write applied to PARTITION_CTL
+                part_ctl.raw = nvdebug_readl(g, 0x00405b2c);
+                if (part_ctl.table_offset != i)
+                        return -ENOTRECOVERABLE;
+                // Read PARTITION_DATA and print
+                // ---
+                // I get back 0x000000ff on Volta and 0x00000003 on Turing from
+                // PARTITION_DATA for all possible VEID_OFFSET, TBL_OFFSET, and TBL_SEL
+                // combinations.
+                // ---
+                // There's a 48-byte (12-word) gap after the address for PARTITION_DATA.
+                // Exploring this on Turing for TBL_SEL_PARTITIONING_ENABLE, VEID 1, 62, and
+                // 63, with CUDA_MPS_ACTIVE_THREAD_PERCENTAGE=5 for constant_cycles_kernel
+                // running under MPS:
+                // +0x0: 0x3
+                // +0x4: 0
+                // +0x8: 0x100
+                // +0xC: 0
+                // +0x10: 0xffffffff
+                // +0x14: 0
+                // +0x18: 0
+                // +0x1C: 0xffffffff
+                // +0x20: 0
+                // +0x24: 0xffffffff
+                // +0x28: 0xffffffff
+                // +0x2C: 0xffffffff
+                chars_written += scnprintf(out + chars_written, 12, "%#010x ", nvdebug_readl(g, 0x00405b30));
+        }
+        chars_written += scnprintf(out + chars_written, 2, "\n");
+        if (copy_to_user(buf, out, chars_written))
+                printk(KERN_WARNING "Unable to copy all data for %s\n", file_dentry(f)->d_name.name);
+        *off += chars_written;
+        return chars_written;
+}
+
+struct file_operations nvdebug_read_part_file_ops = {
+        .read = nvdebug_read_part,
+        .llseek = default_llseek,
+};
+
 static ssize_t nvdebug_reg_range_read(struct file *f, char __user *buf, size_t size, loff_t *off) {
         char out[12];
         int chars_written;
         uint32_t read, mask;
         struct nvdebug_state *g = &g_nvdebug_state[file2parentgpuidx(f)];
-        // See comment in nvdebug_entry.c to understand `union reg_range`
+        // `start_bit` is included, `stop_bit` is not, so to print lower eight bits
+        // from a register, use `start_bit = 0` and `stop_bit = 8`.
         union reg_range range;
         range.raw = (uintptr_t)pde_data(file_inode(f));
 
@@ -47,7 +120,7 @@ static ssize_t nvdebug_reg_range_read(struct file *f, char __user *buf, size_t s
 
         // Print bits `start_bit` to `stop_bit` from 32 bits at address `offset`
         if ((read = nvdebug_readl(g, range.offset)) == -1)
-                return -EOPNOTSUPP;
+                return -EIO;
         // Setup `mask` used to throw out unused upper bits
         mask = -1u >> (32 - range.stop_bit + range.start_bit);
         // Throw out unused lower bits via a shift, apply the mask, and print