Re: [PATCH v2 04/16] kvm: Return number of free memslots
On 06.09.23 16:14, David Hildenbrand wrote: On 29.08.23 00:26, Philippe Mathieu-Daudé wrote: On 25/8/23 15:21, David Hildenbrand wrote: Let's return the number of free slots instead of only checking if there is a free slot. While at it, check all address spaces, which will also consider SMM under x86 correctly. Make the stub return UINT_MAX, such that we can call the function unconditionally. This is a preparation for memory devices that consume multiple memslots. Signed-off-by: David Hildenbrand --- accel/kvm/kvm-all.c | 33 - accel/stubs/kvm-stub.c | 4 ++-- hw/mem/memory-device.c | 2 +- include/sysemu/kvm.h | 2 +- include/sysemu/kvm_int.h | 1 + 5 files changed, 25 insertions(+), 17 deletions(-) diff --git a/accel/stubs/kvm-stub.c b/accel/stubs/kvm-stub.c index 235dc661bc..f39997d86e 100644 --- a/accel/stubs/kvm-stub.c +++ b/accel/stubs/kvm-stub.c @@ -109,9 +109,9 @@ int kvm_irqchip_remove_irqfd_notifier_gsi(KVMState *s, EventNotifier *n, return -ENOSYS; } -bool kvm_has_free_slot(MachineState *ms) +unsigned int kvm_get_free_memslots(void) { -return false; +return UINT_MAX; Isn't it clearer returning 0 here and keeping kvm_enabled() below? I tried doing it similarly to vhost_has_free_slot(). I'll leave the kvm_enabled() check in place, looks cleaner. -- Cheers, David / dhildenb
Re: [PATCH v2 04/16] kvm: Return number of free memslots
On 29.08.23 00:26, Philippe Mathieu-Daudé wrote: On 25/8/23 15:21, David Hildenbrand wrote: Let's return the number of free slots instead of only checking if there is a free slot. While at it, check all address spaces, which will also consider SMM under x86 correctly. Make the stub return UINT_MAX, such that we can call the function unconditionally. This is a preparation for memory devices that consume multiple memslots. Signed-off-by: David Hildenbrand --- accel/kvm/kvm-all.c | 33 - accel/stubs/kvm-stub.c | 4 ++-- hw/mem/memory-device.c | 2 +- include/sysemu/kvm.h | 2 +- include/sysemu/kvm_int.h | 1 + 5 files changed, 25 insertions(+), 17 deletions(-) diff --git a/accel/stubs/kvm-stub.c b/accel/stubs/kvm-stub.c index 235dc661bc..f39997d86e 100644 --- a/accel/stubs/kvm-stub.c +++ b/accel/stubs/kvm-stub.c @@ -109,9 +109,9 @@ int kvm_irqchip_remove_irqfd_notifier_gsi(KVMState *s, EventNotifier *n, return -ENOSYS; } -bool kvm_has_free_slot(MachineState *ms) +unsigned int kvm_get_free_memslots(void) { -return false; +return UINT_MAX; Isn't it clearer returning 0 here and keeping kvm_enabled() below? I tried doing it similarly to vhost_has_free_slot(). Also simplifies patch #12 :) No strong opinion, though. diff --git a/include/sysemu/kvm_int.h b/include/sysemu/kvm_int.h index 511b42bde5..8b09e78b12 100644 --- a/include/sysemu/kvm_int.h +++ b/include/sysemu/kvm_int.h @@ -40,6 +40,7 @@ typedef struct KVMMemoryUpdate { typedef struct KVMMemoryListener { MemoryListener listener; KVMSlot *slots; +int nr_used_slots; Preferably using 'unsigned' here: Sure, that should work. Reviewed-by: Philippe Mathieu-Daudé Thanks! -- Cheers, David / dhildenb
Re: [PATCH v2 04/16] kvm: Return number of free memslots
On 25/8/23 15:21, David Hildenbrand wrote: Let's return the number of free slots instead of only checking if there is a free slot. While at it, check all address spaces, which will also consider SMM under x86 correctly. Make the stub return UINT_MAX, such that we can call the function unconditionally. This is a preparation for memory devices that consume multiple memslots. Signed-off-by: David Hildenbrand --- accel/kvm/kvm-all.c | 33 - accel/stubs/kvm-stub.c | 4 ++-- hw/mem/memory-device.c | 2 +- include/sysemu/kvm.h | 2 +- include/sysemu/kvm_int.h | 1 + 5 files changed, 25 insertions(+), 17 deletions(-) diff --git a/accel/stubs/kvm-stub.c b/accel/stubs/kvm-stub.c index 235dc661bc..f39997d86e 100644 --- a/accel/stubs/kvm-stub.c +++ b/accel/stubs/kvm-stub.c @@ -109,9 +109,9 @@ int kvm_irqchip_remove_irqfd_notifier_gsi(KVMState *s, EventNotifier *n, return -ENOSYS; } -bool kvm_has_free_slot(MachineState *ms) +unsigned int kvm_get_free_memslots(void) { -return false; +return UINT_MAX; Isn't it clearer returning 0 here and keeping kvm_enabled() below? } void kvm_init_cpu_signals(CPUState *cpu) diff --git a/hw/mem/memory-device.c b/hw/mem/memory-device.c index 667d56bd29..7c24685796 100644 --- a/hw/mem/memory-device.c +++ b/hw/mem/memory-device.c @@ -59,7 +59,7 @@ static void memory_device_check_addable(MachineState *ms, MemoryRegion *mr, const uint64_t size = memory_region_size(mr); /* we will need a new memory slot for kvm and vhost */ -if (kvm_enabled() && !kvm_has_free_slot(ms)) { +if (!kvm_get_free_memslots()) { (here) error_setg(errp, "hypervisor has no free memory slots left"); return; } diff --git a/include/sysemu/kvm_int.h b/include/sysemu/kvm_int.h index 511b42bde5..8b09e78b12 100644 --- a/include/sysemu/kvm_int.h +++ b/include/sysemu/kvm_int.h @@ -40,6 +40,7 @@ typedef struct KVMMemoryUpdate { typedef struct KVMMemoryListener { MemoryListener listener; KVMSlot *slots; +int nr_used_slots; Preferably using 'unsigned' here: Reviewed-by: Philippe Mathieu-Daudé
[PATCH v2 04/16] kvm: Return number of free memslots
Let's return the number of free slots instead of only checking if there is a free slot. While at it, check all address spaces, which will also consider SMM under x86 correctly. Make the stub return UINT_MAX, such that we can call the function unconditionally. This is a preparation for memory devices that consume multiple memslots. Signed-off-by: David Hildenbrand --- accel/kvm/kvm-all.c | 33 - accel/stubs/kvm-stub.c | 4 ++-- hw/mem/memory-device.c | 2 +- include/sysemu/kvm.h | 2 +- include/sysemu/kvm_int.h | 1 + 5 files changed, 25 insertions(+), 17 deletions(-) diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c index d07f1ecbd3..0fcea923a1 100644 --- a/accel/kvm/kvm-all.c +++ b/accel/kvm/kvm-all.c @@ -181,6 +181,24 @@ int kvm_get_max_memslots(void) return s->nr_slots; } +unsigned int kvm_get_free_memslots(void) +{ +unsigned int used_slots = 0; +KVMState *s = kvm_state; +int i; + +kvm_slots_lock(); +for (i = 0; i < s->nr_as; i++) { +if (!s->as[i].ml) { +continue; +} +used_slots = MAX(used_slots, s->as[i].ml->nr_used_slots); +} +kvm_slots_unlock(); + +return s->nr_slots - used_slots; +} + /* Called with KVMMemoryListener.slots_lock held */ static KVMSlot *kvm_get_free_slot(KVMMemoryListener *kml) { @@ -196,19 +214,6 @@ static KVMSlot *kvm_get_free_slot(KVMMemoryListener *kml) return NULL; } -bool kvm_has_free_slot(MachineState *ms) -{ -KVMState *s = KVM_STATE(ms->accelerator); -bool result; -KVMMemoryListener *kml = >memory_listener; - -kvm_slots_lock(); -result = !!kvm_get_free_slot(kml); -kvm_slots_unlock(); - -return result; -} - /* Called with KVMMemoryListener.slots_lock held */ static KVMSlot *kvm_alloc_slot(KVMMemoryListener *kml) { @@ -1387,6 +1392,7 @@ static void kvm_set_phys_mem(KVMMemoryListener *kml, } start_addr += slot_size; size -= slot_size; +kml->nr_used_slots--; } while (size); return; } @@ -1412,6 +1418,7 @@ static void kvm_set_phys_mem(KVMMemoryListener *kml, ram_start_offset += slot_size; ram += slot_size; size -= slot_size; +kml->nr_used_slots++; } while (size); } diff --git a/accel/stubs/kvm-stub.c b/accel/stubs/kvm-stub.c index 235dc661bc..f39997d86e 100644 --- a/accel/stubs/kvm-stub.c +++ b/accel/stubs/kvm-stub.c @@ -109,9 +109,9 @@ int kvm_irqchip_remove_irqfd_notifier_gsi(KVMState *s, EventNotifier *n, return -ENOSYS; } -bool kvm_has_free_slot(MachineState *ms) +unsigned int kvm_get_free_memslots(void) { -return false; +return UINT_MAX; } void kvm_init_cpu_signals(CPUState *cpu) diff --git a/hw/mem/memory-device.c b/hw/mem/memory-device.c index 667d56bd29..7c24685796 100644 --- a/hw/mem/memory-device.c +++ b/hw/mem/memory-device.c @@ -59,7 +59,7 @@ static void memory_device_check_addable(MachineState *ms, MemoryRegion *mr, const uint64_t size = memory_region_size(mr); /* we will need a new memory slot for kvm and vhost */ -if (kvm_enabled() && !kvm_has_free_slot(ms)) { +if (!kvm_get_free_memslots()) { error_setg(errp, "hypervisor has no free memory slots left"); return; } diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h index ccaf55caf7..321427a543 100644 --- a/include/sysemu/kvm.h +++ b/include/sysemu/kvm.h @@ -216,7 +216,7 @@ typedef struct KVMRouteChange { /* external API */ -bool kvm_has_free_slot(MachineState *ms); +unsigned int kvm_get_free_memslots(void); bool kvm_has_sync_mmu(void); int kvm_has_vcpu_events(void); int kvm_has_robust_singlestep(void); diff --git a/include/sysemu/kvm_int.h b/include/sysemu/kvm_int.h index 511b42bde5..8b09e78b12 100644 --- a/include/sysemu/kvm_int.h +++ b/include/sysemu/kvm_int.h @@ -40,6 +40,7 @@ typedef struct KVMMemoryUpdate { typedef struct KVMMemoryListener { MemoryListener listener; KVMSlot *slots; +int nr_used_slots; int as_id; QSIMPLEQ_HEAD(, KVMMemoryUpdate) transaction_add; QSIMPLEQ_HEAD(, KVMMemoryUpdate) transaction_del; -- 2.41.0