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

[Alexey Kardashevskiy <aik@ozlabs.ru>]

Ping, anyone? I still enjoy seeing "kvm" next to MRs in "info mtree -f"
in my local QEMU :)



On 24/04/2019 15:32, Alexey Kardashevskiy wrote:
> Paolo, ping?
> 
> 
> On 19/03/2019 18:05, Alexey Kardashevskiy wrote:
>>
>>
>> On 11/02/2019 15:56, Alexey Kardashevskiy wrote:
>>>
>>>
>>> On 09/02/2019 04:26, Paolo Bonzini wrote:
>>>> On 07/02/19 12:49, Dr. David Alan Gilbert wrote:
>>>>>  //#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);
>>>>
>>>> I don't understand this.  This doesn't check that the memory range
>>>> actually matches the memory registered with the accelerator, only that
>>>> there is something in that range. 
>>>
>>>
>>> It is checking that a flat range (i.e. what actually works) has a
>>> corresponding KVM slot:
>>> https://git.qemu.org/?p=qemu.git;a=blob;f=accel/kvm/kvm-all.c;h=4e1de942ce554c734ac2673030031c228a752ac9;hb=HEAD#l201
>>>
>>>
>>>> Why isn't it enough to use "info
>>>> mtree" and look at the KVM address space?
>>>
>>>
>>> There is no such thing in my QEMU, did you mean "KVM-SMRAM" (which is
>>> missing on spapr)? I am not sure I understand its purpose for the task -
>>> it prints all same ranges on my x86 laptop, not just ones which we told
>>> KVM about.
>>>
>>> My task is that if let's say "0000:00:1a.0 BAR 0 mmaps[0]" is split into
>>> several sections because MSIX happens to be in a middle of that BAR and
>>> it is not system page size aligned, then it is going to be several
>>> ranges with no clear indication whether or not these were registered as
>>> KVM slots. A memory chunk can be "ram" and not a KVM slot if it is 4K on
>>> PPC with 64K system pages, for example.
>>>
>>>
>>> FlatView #0
>>>  AS "memory", root: system
>>>  AS "cpu-memory-0", root: system
>>>  AS "cpu-memory-1", root: system
>>>  AS "cpu-memory-2", root: system
>>>  AS "cpu-memory-3", root: system
>>>  AS "piix3-ide", root: bus master container
>>>  AS "virtio-net-pci", root: bus master container
>>>  AS "vfio-pci", root: bus master container
>>>  Root memory region: system
>>>   0000000000000000-00000000000bffff (prio 0, ram): pc.ram kvm
>>>   00000000000c0000-00000000000c0fff (prio 0, rom): pc.ram
>>> @00000000000c0000 kvm
>>>   00000000000c1000-00000000000c3fff (prio 0, ram): pc.ram
>>> @00000000000c1000 kvm
>>>   00000000000c4000-00000000000e7fff (prio 0, rom): pc.ram
>>> @00000000000c4000 kvm
>>>   00000000000e8000-00000000000effff (prio 0, ram): pc.ram
>>> @00000000000e8000 kvm
>>>   00000000000f0000-00000000000fffff (prio 0, rom): pc.ram
>>> @00000000000f0000 kvm
>>>   0000000000100000-00000000bfffffff (prio 0, ram): pc.ram
>>> @0000000000100000 kvm
>>>   00000000febc0000-00000000febc0fff (prio 0, ramd): 0000:00:1a.0 BAR 0
>>> mmaps[0] kvm
>>>   00000000febc1000-00000000febc102f (prio 0, i/o): msix-table
>>>   00000000febc1800-00000000febc1807 (prio 0, i/o): msix-pba
>>>   00000000febfc000-00000000febfcfff (prio 0, i/o): virtio-pci-common
>>>   00000000febfd000-00000000febfdfff (prio 0, i/o): virtio-pci-isr
>>>   00000000febfe000-00000000febfefff (prio 0, i/o): virtio-pci-device
>>>   00000000febff000-00000000febfffff (prio 0, i/o): virtio-pci-notify
>>>   00000000fec00000-00000000fec00fff (prio 0, i/o): kvm-ioapic
>>>   00000000fed00000-00000000fed003ff (prio 0, i/o): hpet
>>>   00000000fee00000-00000000feefffff (prio 4096, i/o): kvm-apic-msi
>>>   00000000fffc0000-00000000ffffffff (prio 0, rom): pc.bios kvm
>>>   0000000100000000-000000013fffffff (prio 0, ram): pc.ram
>>> @00000000c0000000 kvm
>>>
>>>
>>>
>>> FlatView #3
>>>  AS "KVM-SMRAM", root: mem-container-smram
>>>  Root memory region: mem-container-smram
>>>   0000000000000000-00000000000bffff (prio 0, ram): pc.ram
>>>   00000000000c0000-00000000000c0fff (prio 0, rom): pc.ram @00000000000c0000
>>>   00000000000c1000-00000000000c3fff (prio 0, ram): pc.ram @00000000000c1000
>>>   00000000000c4000-00000000000e7fff (prio 0, rom): pc.ram @00000000000c4000
>>>   00000000000e8000-00000000000effff (prio 0, ram): pc.ram @00000000000e8000
>>>   00000000000f0000-00000000000fffff (prio 0, rom): pc.ram @00000000000f0000
>>>   0000000000100000-00000000bfffffff (prio 0, ram): pc.ram @0000000000100000
>>>   00000000febc0000-00000000febc0fff (prio 0, ramd): 0000:00:1a.0 BAR 0
>>> mmaps[0]
>>>   00000000febc1000-00000000febc102f (prio 0, i/o): msix-table
>>>   00000000febc1800-00000000febc1807 (prio 0, i/o): msix-pba
>>>   00000000febfc000-00000000febfcfff (prio 0, i/o): virtio-pci-common
>>>   00000000febfd000-00000000febfdfff (prio 0, i/o): virtio-pci-isr
>>>   00000000febfe000-00000000febfefff (prio 0, i/o): virtio-pci-device
>>>   00000000febff000-00000000febfffff (prio 0, i/o): virtio-pci-notify
>>>   00000000fec00000-00000000fec00fff (prio 0, i/o): kvm-ioapic
>>>   00000000fed00000-00000000fed003ff (prio 0, i/o): hpet
>>>   00000000fee00000-00000000feefffff (prio 4096, i/o): kvm-apic-msi
>>>   00000000fffc0000-00000000ffffffff (prio 0, rom): pc.bios
>>>   0000000100000000-000000013fffffff (prio 0, ram): pc.ram @00000000c0000000
>>>
>>>
>>>
>>>
>>>> Perhaps you could add instead an argument to "info mtree" that prints
>>>> only the AddressSpace with a given name?
>>>
>>> Nah, this is not what it is about.
>>
>>
>>
>> Still a nack? :)
> 
> 
> 

-- 
Alexey