Re: [Qemu-devel] [PATCH qemu v2] hmp: Print if memory section is registered with an accelerator

[Alexey Kardashevskiy]

On 04/01/2019 04:37, Dr. David Alan Gilbert wrote:
> * Alexey Kardashevskiy (address@hidden) wrote:
>>
>>
>> On 17/12/2018 23:47, Philippe Mathieu-Daudé wrote:
>>> On 12/17/18 2:27 AM, Alexey Kardashevskiy wrote:
>>>> On 14/12/2018 22:07, Philippe Mathieu-Daudé wrote:
>>>>> Hi Alexey,
>>>>>
>>>>> On 12/14/18 3:58 AM, Alexey Kardashevskiy wrote:
>>>>>> This adds an accelerator name to the "into mtree -f" to tell the user if
>>>>>> a particular memory section is registered with the accelerator;
>>>>>> the primary user for this is KVM and such information is useful
>>>>>> for debugging purposes.
>>>>>>
>>>>>> This adds a has_memory() callback to the accelerator class allowing any
>>>>>> accelerator to have a label in that memory tree dump.
>>>>>>
>>>>>> Since memory sections are passed to memory listeners and get registered
>>>>>> in accelerators (rather than memory regions), this only prints new labels
>>>>>> for flatviews attached to the system address space.
>>>>>>
>>>>>> An example:
>>>>>>  Root memory region: system
>>>>>>   0000000000000000-0000002fffffffff (prio 0, ram): /objects/mem0 kvm
>>>>>>   0000003000000000-0000005fffffffff (prio 0, ram): /objects/mem1 kvm
>>>>>>   0000200000000020-000020000000003f (prio 1, i/o): virtio-pci
>>>>>>   0000200080000000-000020008000003f (prio 0, i/o): capabilities
>>>>>>
>>>>>> Signed-off-by: Alexey Kardashevskiy <address@hidden>
>>>>>> ---
>>>>>>
>>>>>> This supercedes "[PATCH qemu] hmp: Print if memory section is registered 
>>>>>> in KVM"
>>>>>>
>>>>>> ---
>>>>>> Changes:
>>>>>> v2:
>>>>>> * added an accelerator callback instead of hardcoding it to kvm only
>>>>>> ---
>>>>>>  include/sysemu/accel.h |  2 ++
>>>>>>  accel/kvm/kvm-all.c    | 10 ++++++++++
>>>>>>  memory.c               | 22 ++++++++++++++++++++++
>>>>>>  3 files changed, 34 insertions(+)
>>>>>>
>>>>>> diff --git a/include/sysemu/accel.h b/include/sysemu/accel.h
>>>>>> index 637358f..30b456d 100644
>>>>>> --- a/include/sysemu/accel.h
>>>>>> +++ b/include/sysemu/accel.h
>>>>>> @@ -25,6 +25,7 @@
>>>>>>  
>>>>>>  #include "qom/object.h"
>>>>>>  #include "hw/qdev-properties.h"
>>>>>> +#include "exec/hwaddr.h"
>>>>>>  
>>>>>>  typedef struct AccelState {
>>>>>>      /*< private >*/
>>>>>> @@ -41,6 +42,7 @@ typedef struct AccelClass {
>>>>>>      int (*available)(void);
>>>>>>      int (*init_machine)(MachineState *ms);
>>>>>>      void (*setup_post)(MachineState *ms, AccelState *accel);
>>>>>> +    bool (*has_memory)(MachineState *ms, hwaddr start_addr, hwaddr 
>>>>>> size);
>>>>>>      bool *allowed;
>>>>>>      /*
>>>>>>       * Array of global properties that would be applied when specific
>>>>>> diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
>>>>>> index 4880a05..634f386 100644
>>>>>> --- a/accel/kvm/kvm-all.c
>>>>>> +++ b/accel/kvm/kvm-all.c
>>>>>> @@ -2589,11 +2589,21 @@ int kvm_get_one_reg(CPUState *cs, uint64_t id, 
>>>>>> void *target)
>>>>>>      return r;
>>>>>>  }
>>>>>>  
>>>>>> +static bool kvm_accel_has_memory(MachineState *ms, hwaddr start_addr,
>>>>>> +                                 hwaddr size)
>>>>>> +{
>>>>>> +    KVMState *kvm = KVM_STATE(ms->accelerator);
>>>>>> +    KVMMemoryListener *kml = &kvm->memory_listener;
>>>>>> +
>>>>>> +    return NULL != kvm_lookup_matching_slot(kml, start_addr, size);
>>>>>> +}
>>>>>> +
>>>>>>  static void kvm_accel_class_init(ObjectClass *oc, void *data)
>>>>>>  {
>>>>>>      AccelClass *ac = ACCEL_CLASS(oc);
>>>>>>      ac->name = "KVM";
>>>>>>      ac->init_machine = kvm_init;
>>>>>> +    ac->has_memory = kvm_accel_has_memory;
>>>>>>      ac->allowed = &kvm_allowed;
>>>>>>  }
>>>>>>  
>>>>>> diff --git a/memory.c b/memory.c
>>>>>> index d14c6de..61e758a 100644
>>>>>> --- a/memory.c
>>>>>> +++ b/memory.c
>>>>>> @@ -29,7 +29,9 @@
>>>>>>  #include "exec/ram_addr.h"
>>>>>>  #include "sysemu/kvm.h"
>>>>>>  #include "sysemu/sysemu.h"
>>>>>> +#include "sysemu/accel.h"
>>>>>>  #include "hw/qdev-properties.h"
>>>>>> +#include "hw/boards.h"
>>>>>>  #include "migration/vmstate.h"
>>>>>>  
>>>>>>  //#define DEBUG_UNASSIGNED
>>>>>> @@ -2924,6 +2926,8 @@ struct FlatViewInfo {
>>>>>>      int counter;
>>>>>>      bool dispatch_tree;
>>>>>>      bool owner;
>>>>>> +    AccelClass *ac;
>>>>>> +    const char *ac_name;
>>>>>>  };
>>>>>>  
>>>>>>  static void mtree_print_flatview(gpointer key, gpointer value,
>>>>>> @@ -2939,6 +2943,7 @@ static void mtree_print_flatview(gpointer key, 
>>>>>> gpointer value,
>>>>>>      int n = view->nr;
>>>>>>      int i;
>>>>>>      AddressSpace *as;
>>>>>> +    bool system_as = false;
>>>>>>  
>>>>>>      p(f, "FlatView #%d\n", fvi->counter);
>>>>>>      ++fvi->counter;
>>>>>> @@ -2950,6 +2955,9 @@ static void mtree_print_flatview(gpointer key, 
>>>>>> gpointer value,
>>>>>>              p(f, ", alias %s", memory_region_name(as->root->alias));
>>>>>>          }
>>>>>>          p(f, "\n");
>>>>>> +        if (as == &address_space_memory) {
>>>>>> +            system_as = true;
>>>>>> +        }
>>>>>>      }
>>>>>>  
>>>>>>      p(f, " Root memory region: %s\n",
>>>>>> @@ -2985,6 +2993,13 @@ static void mtree_print_flatview(gpointer key, 
>>>>>> gpointer value,
>>>>>>          if (fvi->owner) {
>>>>>>              mtree_print_mr_owner(p, f, mr);
>>>>>>          }
>>>>>> +
>>>>>> +        if (system_as && fvi->ac &&
>>>>>> +            fvi->ac->has_memory(current_machine,
>>>>>> +                                int128_get64(range->addr.start),
>>>>>> +                                MR_SIZE(range->addr.size) + 1)) {
>>>>>> +            p(f, " %s", fvi->ac_name);
>>>>>
>>>>> Why not simply display fvi->ac->name?
>>>>> You could avoid to add the ac_name field.
>>>>
>>>>
>>>> Well, I thought I better print whatever the user passed via the command
>>>> line (which is current_machine->accel and equals to "kvm" in my case)
>>>> rather than robotic, dry and excessive "kvm-accel".
>>>
>>> I have no hit for 'kvm-accel':
>>>
>>> $ git grep kvm-accel
>>> $
>>>
>>> Names looks human friendly:
>>
>>
>> Ah, I confused with object_class_get_name(). Anyway, I'd still show the
>> user provided accelerator name than some internal name.
> 
> Aren't they exactly the same?

Nope. "kvm" vs. "kvm-accel".

> I think the accel= thing from the user is
> parsed by comparing it with the ACCEL_CLASS_NAME declarations:
> 
> ./target/i386/whpx-all.c:    .name = ACCEL_CLASS_NAME("whpx"),
> ./target/i386/hax-all.c:    .name = ACCEL_CLASS_NAME("hax"),
> ./hw/xen/xen-common.c:#define TYPE_XEN_ACCEL ACCEL_CLASS_NAME("xen")
> ./qtest.c:#define TYPE_QTEST_ACCEL ACCEL_CLASS_NAME("qtest")
> ./accel/tcg/tcg-all.c:#define TYPE_TCG_ACCEL ACCEL_CLASS_NAME("tcg")
> ./include/sysemu/hvf.h:#define TYPE_HVF_ACCEL ACCEL_CLASS_NAME("hvf")
> ./include/sysemu/kvm_int.h:#define TYPE_KVM_ACCEL ACCEL_CLASS_NAME("kvm")
> 
> and the code in accel/accel.c accel_find


https://git.qemu.org/?p=qemu.git;a=blob;f=include/sysemu/accel.h;h=5565e00a96136bc5024c17c401116ef6a497138a;hb=HEAD#l58

  55 #define TYPE_ACCEL "accel"
  56
  57 #define ACCEL_CLASS_SUFFIX  "-" TYPE_ACCEL
  58 #define ACCEL_CLASS_NAME(a) (a ACCEL_CLASS_SUFFIX)



> 
> Dave
> 
>>
>>>
>>> $ git grep 'ac->name ='
>>> accel/kvm/kvm-all.c:2595:    ac->name = "KVM";
>>> accel/tcg/tcg-all.c:74:    ac->name = "tcg";
>>> hw/xen/xen-common.c:184:    ac->name = "Xen";
>>> target/i386/hax-all.c:1088:    ac->name = "HAX";
>>> target/i386/hvf/hvf.c:959:    ac->name = "HVF";
>>> target/i386/whpx-all.c:1477:    ac->name = "WHPX";
>>> qtest.c:755:    ac->name = "QTest";
>>>
>>>>>
>>>>>> +        }
>>>>>>          p(f, "\n");
>>>>>>          range++;
>>>>>>      }
>>>>>> @@ -3028,6 +3043,13 @@ void mtree_info(fprintf_function mon_printf, void 
>>>>>> *f, bool flatview,
>>>>>>          };
>>>>>>          GArray *fv_address_spaces;
>>>>>>          GHashTable *views = g_hash_table_new(g_direct_hash, 
>>>>>> g_direct_equal);
>>>>>> +        AccelClass *ac = ACCEL_GET_CLASS(current_machine->accelerator);
>>>>>> +
>>>>>> +        if (ac->has_memory) {
>>>>>> +            fvi.ac = ac;
>>>>>> +            fvi.ac_name = current_machine->accel ? 
>>>>>> current_machine->accel :
>>>>>> +                object_class_get_name(OBJECT_CLASS(ac));
>>>>>> +        }
>>>>>>  
>>>>>>          /* Gather all FVs in one table */
>>>>>>          QTAILQ_FOREACH(as, &address_spaces, address_spaces_link) {
>>>>>>
>>
>> -- 
>> Alexey
> --
> Dr. David Alan Gilbert / address@hidden / Manchester, UK
> 

-- 
Alexey