Re: [PATCH 08/23] accel/tcg: Add IntervalTreeRoot to CPUTLBDesc

[Pierrick Bouvier]

On 10/9/24 08:08, Richard Henderson wrote:

Add the data structures for tracking softmmu pages via
a balanced interval tree.  So far, only initialize and
destroy the data structure.

Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
---
  include/hw/core/cpu.h |  3 +++
  accel/tcg/cputlb.c    | 11 +++++++++++
  2 files changed, 14 insertions(+)

diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h
index d21a24c82f..b567abe3e2 100644
--- a/include/hw/core/cpu.h
+++ b/include/hw/core/cpu.h
@@ -34,6 +34,7 @@
  #include "qemu/rcu_queue.h"
  #include "qemu/queue.h"
  #include "qemu/thread.h"
+#include "qemu/interval-tree.h"
  #include "qom/object.h"

typedef int (*WriteCoreDumpFunction)(const void *buf, size_t size,

@@ -287,6 +288,8 @@ typedef struct CPUTLBDesc {
      CPUTLBEntry vtable[CPU_VTLB_SIZE];
      CPUTLBEntryFull vfulltlb[CPU_VTLB_SIZE];
      CPUTLBEntryFull *fulltlb;
+    /* All active tlb entries for this address space. */
+    IntervalTreeRoot iroot;
  } CPUTLBDesc;

/*

diff --git a/accel/tcg/cputlb.c b/accel/tcg/cputlb.c
index 8affa25db3..435c2dc132 100644
--- a/accel/tcg/cputlb.c
+++ b/accel/tcg/cputlb.c
@@ -89,6 +89,13 @@ QEMU_BUILD_BUG_ON(sizeof(vaddr) > sizeof(run_on_cpu_data));
  QEMU_BUILD_BUG_ON(NB_MMU_MODES > 16);
  #define ALL_MMUIDX_BITS ((1 << NB_MMU_MODES) - 1)

+/* Extra data required to manage CPUTLBEntryFull within an interval tree. */

+typedef struct CPUTLBEntryTree {
+    IntervalTreeNode itree;
+    CPUTLBEntry copy;
+    CPUTLBEntryFull full;
+} CPUTLBEntryTree;
+
  static inline size_t tlb_n_entries(CPUTLBDescFast *fast)
  {
      return (fast->mask >> CPU_TLB_ENTRY_BITS) + 1;
@@ -305,6 +312,7 @@ static void tlb_mmu_flush_locked(CPUTLBDesc *desc, 
CPUTLBDescFast *fast)
      desc->large_page_mask = -1;
      desc->vindex = 0;
      memset(desc->vtable, -1, sizeof(desc->vtable));
+    interval_tree_free_nodes(&desc->iroot, offsetof(CPUTLBEntryTree, itree));
  }

static void tlb_flush_one_mmuidx_locked(CPUState *cpu, int mmu_idx,

@@ -326,6 +334,7 @@ static void tlb_mmu_init(CPUTLBDesc *desc, CPUTLBDescFast 
*fast, int64_t now)
      fast->mask = (n_entries - 1) << CPU_TLB_ENTRY_BITS;
      fast->table = g_new(CPUTLBEntry, n_entries);
      desc->fulltlb = g_new(CPUTLBEntryFull, n_entries);
+    memset(&desc->iroot, 0, sizeof(desc->iroot));
      tlb_mmu_flush_locked(desc, fast);
  }

@@ -365,6 +374,8 @@ void tlb_destroy(CPUState *cpu) g_free(fast->table);

          g_free(desc->fulltlb);
+        interval_tree_free_nodes(&cpu->neg.tlb.d[i].iroot,
+                                 offsetof(CPUTLBEntryTree, itree));
      }
  }

Reviewed-by: Pierrick Bouvier <pierrick.bouv...@linaro.org>