Re: [Qemu-devel] [PATCH qemu v3] hmp: Print if memory section is registered with an accelerator

[Paolo Bonzini]

On 18/07/19 09:21, Alexey Kardashevskiy wrote:
> Paolo, ping? :)

Queued, thanks.  I'll sneak it into 4.1, I have a couple other patches
to send.

Paolo

> 
> On 14/06/2019 11:52, 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>
>> ---
>> Changes:
>> v3:
>> * added support for multiple ASes per accelerator (KVM can do 2 at least)
>> as Paolo suggested
>>
>> v2:
>> * added an accelerator callback instead of hardcoding it to kvm only
>> ---
>>   include/sysemu/accel.h |  3 +++
>>   accel/kvm/kvm-all.c    | 38 ++++++++++++++++++++++++++++++++++++++
>>   memory.c               | 22 ++++++++++++++++++++++
>>   3 files changed, 63 insertions(+)
>>
>> diff --git a/include/sysemu/accel.h b/include/sysemu/accel.h
>> index 81293cdb08f9..89ce57e404ca 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 >*/
>> @@ -39,6 +40,8 @@ typedef struct AccelClass {
>>       const char *name;
>>       int (*init_machine)(MachineState *ms);
>>       void (*setup_post)(MachineState *ms, AccelState *accel);
>> +    bool (*has_memory)(MachineState *ms, AddressSpace *as,
>> +                       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 b0c4bed6e367..948b7e53df47 100644
>> --- a/accel/kvm/kvm-all.c
>> +++ b/accel/kvm/kvm-all.c
>> @@ -109,6 +109,13 @@ struct KVMState
>>       /* memory encryption */
>>       void *memcrypt_handle;
>>       int (*memcrypt_encrypt_data)(void *handle, uint8_t *ptr,
>> uint64_t len);
>> +
>> +    /* For "info mtree -f" to tell if an MR is registered in KVM */
>> +    int nr_as;
>> +    struct KVMAs {
>> +        KVMMemoryListener *ml;
>> +        AddressSpace *as;
>> +    } *as;
>>   };
>>     KVMState *kvm_state;
>> @@ -940,6 +947,14 @@ void kvm_memory_listener_register(KVMState *s,
>> KVMMemoryListener *kml,
>>       kml->listener.priority = 10;
>>         memory_listener_register(&kml->listener, as);
>> +
>> +    for (i = 0; i < s->nr_as; ++i) {
>> +        if (!s->as[i].as) {
>> +            s->as[i].as = as;
>> +            s->as[i].ml = kml;
>> +            break;
>> +        }
>> +    }
>>   }
>>     static MemoryListener kvm_io_listener = {
>> @@ -1590,6 +1605,12 @@ static int kvm_init(MachineState *ms)
>>           s->nr_slots = 32;
>>       }
>>   +    s->nr_as = kvm_check_extension(s, KVM_CAP_MULTI_ADDRESS_SPACE);
>> +    if (s->nr_as <= 1) {
>> +        s->nr_as = 1;
>> +    }
>> +    s->as = g_new0(struct KVMAs, s->nr_as);
>> +
>>       kvm_type = qemu_opt_get(qemu_get_machine_opts(), "kvm-type");
>>       if (mc->kvm_type) {
>>           type = mc->kvm_type(ms, kvm_type);
>> @@ -2591,11 +2612,28 @@ int kvm_get_one_reg(CPUState *cs, uint64_t id,
>> void *target)
>>       return r;
>>   }
>>   +static bool kvm_accel_has_memory(MachineState *ms, AddressSpace *as,
>> +                                 hwaddr start_addr, hwaddr size)
>> +{
>> +    KVMState *kvm = KVM_STATE(ms->accelerator);
>> +    int i;
>> +
>> +    for (i = 0; i < kvm->nr_as; ++i) {
>> +        if (kvm->as[i].as == as && kvm->as[i].ml) {
>> +            return NULL != kvm_lookup_matching_slot(kvm->as[i].ml,
>> +                                                    start_addr, size);
>> +        }
>> +    }
>> +
>> +    return false;
>> +}
>> +
>>   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 0a089a73ae1a..61524156a1ce 100644
>> --- a/memory.c
>> +++ b/memory.c
>> @@ -30,7 +30,9 @@
>>   #include "sysemu/kvm.h"
>>   #include "sysemu/sysemu.h"
>>   #include "sysemu/tcg.h"
>> +#include "sysemu/accel.h"
>>   #include "hw/qdev-properties.h"
>> +#include "hw/boards.h"
>>   #include "migration/vmstate.h"
>>     //#define DEBUG_UNASSIGNED
>> @@ -2939,6 +2941,8 @@ struct FlatViewInfo {
>>       int counter;
>>       bool dispatch_tree;
>>       bool owner;
>> +    AccelClass *ac;
>> +    const char *ac_name;
>>   };
>>     static void mtree_print_flatview(gpointer key, gpointer value,
>> @@ -3001,6 +3005,17 @@ static void mtree_print_flatview(gpointer key,
>> gpointer value,
>>           if (fvi->owner) {
>>               mtree_print_mr_owner(mr);
>>           }
>> +
>> +        if (fvi->ac) {
>> +            for (i = 0; i < fv_address_spaces->len; ++i) {
>> +                as = g_array_index(fv_address_spaces, AddressSpace*, i);
>> +                if (fvi->ac->has_memory(current_machine, as,
>> +                                        int128_get64(range->addr.start),
>> +                                        MR_SIZE(range->addr.size) +
>> 1)) {
>> +                    qemu_printf(" %s", fvi->ac_name);
>> +                }
>> +            }
>> +        }
>>           qemu_printf("\n");
>>           range++;
>>       }
>> @@ -3041,6 +3056,13 @@ void mtree_info(bool flatview, bool
>> dispatch_tree, bool owner)
>>           };
>>           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) {
>>
>