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

[Alexey Kardashevskiy <aik@ozlabs.ru>]

On 29/01/2019 13:30, Alexey Kardashevskiy wrote:
> 
> 
> On 14/01/2019 12:43, Alexey Kardashevskiy wrote:
>>
>>
>> On 04/01/2019 04:37, Dr. David Alan Gilbert wrote:
>>> * Alexey Kardashevskiy (aik@ozlabs.ru) 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 <aik@ozlabs.ru>
>>>>>>>> ---
>>>>>>>>
>>>>>>>> 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)
> 
> 
> Ping, anybody?


Yet another friendly ping. Any comments? Thanks.


> 
> 
>>
>>
>>
>>>
>>> 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 / dgilbert@redhat.com / Manchester, UK
>>>
>>
> 

-- 
Alexey