diff mbox series

[01/62] accel/tcg: Introduce PageEntryExtra

Message ID 20220703082419.770989-2-richard.henderson@linaro.org
State New
Headers show
Series target/arm: Implement FEAT_HAFDBS | expand

Commit Message

Richard Henderson July 3, 2022, 8:23 a.m. UTC
Add an optional structure, controlled by TARGET_PAGE_ENTRY_EXTRA,
that allows arbitrary extra data to be saved in the TLB for a
given page.  Set it with tlb_set_page_with_extra() and fetch it
with probe_access_extra().

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 include/exec/cpu-defs.h |  5 +++
 include/exec/exec-all.h | 26 +++++++++++++--
 include/qemu/typedefs.h |  1 +
 accel/tcg/cputlb.c      | 73 ++++++++++++++++++++++++++++++-----------
 4 files changed, 84 insertions(+), 21 deletions(-)

Comments

Peter Maydell July 4, 2022, 3:28 p.m. UTC | #1
On Sun, 3 Jul 2022 at 09:25, Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> Add an optional structure, controlled by TARGET_PAGE_ENTRY_EXTRA,
> that allows arbitrary extra data to be saved in the TLB for a
> given page.  Set it with tlb_set_page_with_extra() and fetch it
> with probe_access_extra().
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---



> -/* Add a new TLB entry. At most one entry for a given virtual address
> +/*
> + * Add a new TLB entry. At most one entry for a given virtual address
>   * is permitted. Only a single TARGET_PAGE_SIZE region is mapped, the
>   * supplied size is only used by tlb_flush_page.
>   *
>   * Called from TCG-generated code, which is under an RCU read-side
>   * critical section.
> + *
> + * Returns a pointer to the iotlb entry, with env_tlb(env)->c.lock
> + * still locked, for final additions to the iotlb entry.  The caller
> + * must unlock the lock.
>   */
> -void tlb_set_page_with_attrs(CPUState *cpu, target_ulong vaddr,
> -                             hwaddr paddr, MemTxAttrs attrs, int prot,
> -                             int mmu_idx, target_ulong size)
> +void tlb_set_page_with_extra(CPUState *cpu, target_ulong vaddr, hwaddr paddr,
> +                             MemTxAttrs attrs, PageEntryExtra extra,
> +                             int prot, int mmu_idx, target_ulong size)

The comment claims it returns a pointer to the iotlb entry, but
the code says it returns void... leftover from a previous design?

>  {
>      CPUArchState *env = cpu->env_ptr;
>      CPUTLB *tlb = env_tlb(env);

-- PMM
Richard Henderson July 5, 2022, 12:35 a.m. UTC | #2
On 7/4/22 20:58, Peter Maydell wrote:
>> + * Returns a pointer to the iotlb entry, with env_tlb(env)->c.lock
>> + * still locked, for final additions to the iotlb entry.  The caller
>> + * must unlock the lock.
>>    */
>> -void tlb_set_page_with_attrs(CPUState *cpu, target_ulong vaddr,
>> -                             hwaddr paddr, MemTxAttrs attrs, int prot,
>> -                             int mmu_idx, target_ulong size)
>> +void tlb_set_page_with_extra(CPUState *cpu, target_ulong vaddr, hwaddr paddr,
>> +                             MemTxAttrs attrs, PageEntryExtra extra,
>> +                             int prot, int mmu_idx, target_ulong size)
> 
> The comment claims it returns a pointer to the iotlb entry, but
> the code says it returns void... leftover from a previous design?

Whoops, yes.  In the end I thought that was a bit too much internals exposed.


r~
diff mbox series

Patch

diff --git a/include/exec/cpu-defs.h b/include/exec/cpu-defs.h
index ba3cd32a1e..f14586e219 100644
--- a/include/exec/cpu-defs.h
+++ b/include/exec/cpu-defs.h
@@ -76,6 +76,10 @@  typedef uint64_t target_ulong;
 
 #if !defined(CONFIG_USER_ONLY) && defined(CONFIG_TCG)
 
+#ifndef TARGET_PAGE_ENTRY_EXTRA
+struct PageEntryExtra { };
+#endif
+
 /* use a fully associative victim tlb of 8 entries */
 #define CPU_VTLB_SIZE 8
 
@@ -148,6 +152,7 @@  typedef struct CPUIOTLBEntry {
      */
     hwaddr addr;
     MemTxAttrs attrs;
+    PageEntryExtra extra;
 } CPUIOTLBEntry;
 
 /*
diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h
index 311e5fb422..2c036de3d8 100644
--- a/include/exec/exec-all.h
+++ b/include/exec/exec-all.h
@@ -259,11 +259,12 @@  void tlb_flush_range_by_mmuidx_all_cpus_synced(CPUState *cpu,
                                                unsigned bits);
 
 /**
- * tlb_set_page_with_attrs:
+ * tlb_set_page_with_extra:
  * @cpu: CPU to add this TLB entry for
  * @vaddr: virtual address of page to add entry for
  * @paddr: physical address of the page
  * @attrs: memory transaction attributes
+ * @extra: cpu specific extra information
  * @prot: access permissions (PAGE_READ/PAGE_WRITE/PAGE_EXEC bits)
  * @mmu_idx: MMU index to insert TLB entry for
  * @size: size of the page in bytes
@@ -279,11 +280,25 @@  void tlb_flush_range_by_mmuidx_all_cpus_synced(CPUState *cpu,
  * At most one entry for a given virtual address is permitted. Only a
  * single TARGET_PAGE_SIZE region is mapped; the supplied @size is only
  * used by tlb_flush_page.
+ *
+ * The @extra information is target-specific, and may be retrieved
+ * by calling probe_access_extra().
+ */
+void tlb_set_page_with_extra(CPUState *cpu, target_ulong vaddr, hwaddr paddr,
+                             MemTxAttrs attrs, PageEntryExtra extra,
+                             int prot, int mmu_idx, target_ulong size);
+
+/**
+ * tlb_set_page_with_attrs:
+ *
+ * This function is equivalent to calling tlb_set_page_with_extra()
+ * with an @extra argument of all zeros.
  */
 void tlb_set_page_with_attrs(CPUState *cpu, target_ulong vaddr,
                              hwaddr paddr, MemTxAttrs attrs,
                              int prot, int mmu_idx, target_ulong size);
-/* tlb_set_page:
+/**
+ * tlb_set_page:
  *
  * This function is equivalent to calling tlb_set_page_with_attrs()
  * with an @attrs argument of MEMTXATTRS_UNSPECIFIED. It's provided
@@ -435,6 +450,13 @@  int probe_access_flags(CPUArchState *env, target_ulong addr,
                        MMUAccessType access_type, int mmu_idx,
                        bool nonfault, void **phost, uintptr_t retaddr);
 
+#ifdef CONFIG_SOFTMMU
+int probe_access_extra(CPUArchState *env, target_ulong addr,
+                       MMUAccessType access_type, int mmu_idx,
+                       bool nonfault, void **phost, MemTxAttrs *pattrs,
+                       PageEntryExtra *pextra, uintptr_t retaddr);
+#endif
+
 #define CODE_GEN_ALIGN           16 /* must be >= of the size of a icache line */
 
 /* Estimated block size for TB allocation.  */
diff --git a/include/qemu/typedefs.h b/include/qemu/typedefs.h
index 42f4ceb701..a4de3bb07c 100644
--- a/include/qemu/typedefs.h
+++ b/include/qemu/typedefs.h
@@ -82,6 +82,7 @@  typedef struct NodeInfo NodeInfo;
 typedef struct NumaNodeMem NumaNodeMem;
 typedef struct Object Object;
 typedef struct ObjectClass ObjectClass;
+typedef struct PageEntryExtra PageEntryExtra;
 typedef struct PCIBridge PCIBridge;
 typedef struct PCIBus PCIBus;
 typedef struct PCIDevice PCIDevice;
diff --git a/accel/tcg/cputlb.c b/accel/tcg/cputlb.c
index f90f4312ea..05555961c9 100644
--- a/accel/tcg/cputlb.c
+++ b/accel/tcg/cputlb.c
@@ -1095,16 +1095,21 @@  static void tlb_add_large_page(CPUArchState *env, int mmu_idx,
     env_tlb(env)->d[mmu_idx].large_page_mask = lp_mask;
 }
 
-/* Add a new TLB entry. At most one entry for a given virtual address
+/*
+ * Add a new TLB entry. At most one entry for a given virtual address
  * is permitted. Only a single TARGET_PAGE_SIZE region is mapped, the
  * supplied size is only used by tlb_flush_page.
  *
  * Called from TCG-generated code, which is under an RCU read-side
  * critical section.
+ *
+ * Returns a pointer to the iotlb entry, with env_tlb(env)->c.lock
+ * still locked, for final additions to the iotlb entry.  The caller
+ * must unlock the lock.
  */
-void tlb_set_page_with_attrs(CPUState *cpu, target_ulong vaddr,
-                             hwaddr paddr, MemTxAttrs attrs, int prot,
-                             int mmu_idx, target_ulong size)
+void tlb_set_page_with_extra(CPUState *cpu, target_ulong vaddr, hwaddr paddr,
+                             MemTxAttrs attrs, PageEntryExtra extra,
+                             int prot, int mmu_idx, target_ulong size)
 {
     CPUArchState *env = cpu->env_ptr;
     CPUTLB *tlb = env_tlb(env);
@@ -1238,6 +1243,7 @@  void tlb_set_page_with_attrs(CPUState *cpu, target_ulong vaddr,
      */
     desc->iotlb[index].addr = iotlb - vaddr_page;
     desc->iotlb[index].attrs = attrs;
+    desc->iotlb[index].extra = extra;
 
     /* Now calculate the new entry */
     tn.addend = addend - vaddr_page;
@@ -1272,7 +1278,23 @@  void tlb_set_page_with_attrs(CPUState *cpu, target_ulong vaddr,
     qemu_spin_unlock(&tlb->c.lock);
 }
 
-/* Add a new TLB entry, but without specifying the memory
+/*
+ * Add a new TLB entry, specifying the memory transaction
+ * attributes to be used.
+ */
+void tlb_set_page_with_attrs(CPUState *cpu, target_ulong vaddr,
+                             hwaddr paddr, MemTxAttrs attrs, int prot,
+                             int mmu_idx, target_ulong size)
+{
+    PageEntryExtra extra;
+
+    memset(&extra, 0, sizeof(extra));
+    tlb_set_page_with_extra(cpu, vaddr, paddr, attrs, extra,
+                            prot, mmu_idx, size);
+}
+
+/*
+ * Add a new TLB entry, but without specifying the memory
  * transaction attributes to be used.
  */
 void tlb_set_page(CPUState *cpu, target_ulong vaddr,
@@ -1633,25 +1655,38 @@  static int probe_access_internal(CPUArchState *env, target_ulong addr,
     return flags;
 }
 
+int probe_access_extra(CPUArchState *env, target_ulong addr,
+                       MMUAccessType access_type, int mmu_idx,
+                       bool nonfault, void **phost, MemTxAttrs *pattrs,
+                       PageEntryExtra *pextra, uintptr_t retaddr)
+{
+    int flags = probe_access_internal(env, addr, 0, access_type, mmu_idx,
+                                      nonfault, phost, retaddr);
+
+    if (likely(!(flags & TLB_INVALID_MASK))) {
+        uintptr_t index = tlb_index(env, mmu_idx, addr);
+        CPUIOTLBEntry *iotlbentry = &env_tlb(env)->d[mmu_idx].iotlb[index];
+
+        /* Handle clean RAM pages.  */
+        if (unlikely(flags & TLB_NOTDIRTY)) {
+            notdirty_write(env_cpu(env), addr, 1, iotlbentry, retaddr);
+            flags &= ~TLB_NOTDIRTY;
+        }
+        *pattrs = iotlbentry->attrs;
+        *pextra = iotlbentry->extra;
+    }
+    return flags;
+}
+
 int probe_access_flags(CPUArchState *env, target_ulong addr,
                        MMUAccessType access_type, int mmu_idx,
                        bool nonfault, void **phost, uintptr_t retaddr)
 {
-    int flags;
+    MemTxAttrs attrs;
+    PageEntryExtra extra;
 
-    flags = probe_access_internal(env, addr, 0, access_type, mmu_idx,
-                                  nonfault, phost, retaddr);
-
-    /* Handle clean RAM pages.  */
-    if (unlikely(flags & TLB_NOTDIRTY)) {
-        uintptr_t index = tlb_index(env, mmu_idx, addr);
-        CPUIOTLBEntry *iotlbentry = &env_tlb(env)->d[mmu_idx].iotlb[index];
-
-        notdirty_write(env_cpu(env), addr, 1, iotlbentry, retaddr);
-        flags &= ~TLB_NOTDIRTY;
-    }
-
-    return flags;
+    return probe_access_extra(env, addr, access_type, mmu_idx, nonfault,
+                              phost, &attrs, &extra, retaddr);
 }
 
 void *probe_access(CPUArchState *env, target_ulong addr, int size,