KVM: Use a big lock to replace per-kml slots_lock

Per-kml slots_lock will bring some trouble if we want to take all slots_lock of
all the KMLs, especially when we're in a context that we could have taken some
of the KML slots_lock, then we even need to figure out what we've taken and
what we need to take.

Make this simple by merging all KML slots_lock into a single slots lock.

Per-kml slots_lock isn't anything that helpful anyway - so far only x86 has two
address spaces (so, two slots_locks).  All the rest archs will be having one
address space always, which means there's actually one slots_lock so it will be
the same as before.

Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20210506160549.130416-3-peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Peter Xu 2021-05-06 12:05:41 -04:00 committed by Paolo Bonzini
parent b87eaa9b82
commit a2f77862ff
2 changed files with 18 additions and 17 deletions

View File

@ -172,8 +172,10 @@ typedef struct KVMResampleFd KVMResampleFd;
static QLIST_HEAD(, KVMResampleFd) kvm_resample_fd_list =
QLIST_HEAD_INITIALIZER(kvm_resample_fd_list);
#define kvm_slots_lock(kml) qemu_mutex_lock(&(kml)->slots_lock)
#define kvm_slots_unlock(kml) qemu_mutex_unlock(&(kml)->slots_lock)
static QemuMutex kml_slots_lock;
#define kvm_slots_lock() qemu_mutex_lock(&kml_slots_lock)
#define kvm_slots_unlock() qemu_mutex_unlock(&kml_slots_lock)
static inline void kvm_resample_fd_remove(int gsi)
{
@ -239,9 +241,9 @@ bool kvm_has_free_slot(MachineState *ms)
bool result;
KVMMemoryListener *kml = &s->memory_listener;
kvm_slots_lock(kml);
kvm_slots_lock();
result = !!kvm_get_free_slot(kml);
kvm_slots_unlock(kml);
kvm_slots_unlock();
return result;
}
@ -307,7 +309,7 @@ int kvm_physical_memory_addr_from_host(KVMState *s, void *ram,
KVMMemoryListener *kml = &s->memory_listener;
int i, ret = 0;
kvm_slots_lock(kml);
kvm_slots_lock();
for (i = 0; i < s->nr_slots; i++) {
KVMSlot *mem = &kml->slots[i];
@ -317,7 +319,7 @@ int kvm_physical_memory_addr_from_host(KVMState *s, void *ram,
break;
}
}
kvm_slots_unlock(kml);
kvm_slots_unlock();
return ret;
}
@ -513,7 +515,7 @@ static int kvm_section_update_flags(KVMMemoryListener *kml,
return 0;
}
kvm_slots_lock(kml);
kvm_slots_lock();
while (size && !ret) {
slot_size = MIN(kvm_max_slot_size, size);
@ -529,7 +531,7 @@ static int kvm_section_update_flags(KVMMemoryListener *kml,
}
out:
kvm_slots_unlock(kml);
kvm_slots_unlock();
return ret;
}
@ -810,7 +812,7 @@ static int kvm_physical_log_clear(KVMMemoryListener *kml,
return ret;
}
kvm_slots_lock(kml);
kvm_slots_lock();
for (i = 0; i < s->nr_slots; i++) {
mem = &kml->slots[i];
@ -836,7 +838,7 @@ static int kvm_physical_log_clear(KVMMemoryListener *kml,
}
}
kvm_slots_unlock(kml);
kvm_slots_unlock();
return ret;
}
@ -1141,7 +1143,7 @@ static void kvm_set_phys_mem(KVMMemoryListener *kml,
ram = memory_region_get_ram_ptr(mr) + section->offset_within_region +
(start_addr - section->offset_within_address_space);
kvm_slots_lock(kml);
kvm_slots_lock();
if (!add) {
do {
@ -1199,7 +1201,7 @@ static void kvm_set_phys_mem(KVMMemoryListener *kml,
} while (size);
out:
kvm_slots_unlock(kml);
kvm_slots_unlock();
}
static void kvm_region_add(MemoryListener *listener,
@ -1226,9 +1228,9 @@ static void kvm_log_sync(MemoryListener *listener,
KVMMemoryListener *kml = container_of(listener, KVMMemoryListener, listener);
int r;
kvm_slots_lock(kml);
kvm_slots_lock();
r = kvm_physical_sync_dirty_bitmap(kml, section);
kvm_slots_unlock(kml);
kvm_slots_unlock();
if (r < 0) {
abort();
}
@ -1328,7 +1330,6 @@ void kvm_memory_listener_register(KVMState *s, KVMMemoryListener *kml,
{
int i;
qemu_mutex_init(&kml->slots_lock);
kml->slots = g_malloc0(s->nr_slots * sizeof(KVMSlot));
kml->as_id = as_id;
@ -2001,6 +2002,8 @@ static int kvm_init(MachineState *ms)
int type = 0;
uint64_t dirty_log_manual_caps;
qemu_mutex_init(&kml_slots_lock);
s = KVM_STATE(ms->accelerator);
/*

View File

@ -27,8 +27,6 @@ typedef struct KVMSlot
typedef struct KVMMemoryListener {
MemoryListener listener;
/* Protects the slots and all inside them */
QemuMutex slots_lock;
KVMSlot *slots;
int as_id;
} KVMMemoryListener;