| Message ID | 20190916132347.30676-2-imammedo@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | s390: stop abusing memory_region_allocate_system_memory() | expand |
* Igor Mammedov (imammedo@redhat.com) wrote: > Max memslot size supported by kvm on s390 is 8Tb, > move logic of splitting RAM in chunks upto 8T to KVM code. > > This way it will hide KVM specific restrictions in KVM code > and won't affect board level design decisions. Which would allow > us to avoid misusing memory_region_allocate_system_memory() API > and eventually use a single hostmem backend for guest RAM. > > Signed-off-by: Igor Mammedov <imammedo@redhat.com> > --- > Since there is quite a bit of migration related code churn in the patch > CCing migration maintainer > > CC: dgilbert@redhat.com CC'ing in peterx who knows this code better than me. But if I'm reading it right, then the rest of the migration code can be blissfully ignorant of these changes. Dave > > v6: > * KVM's migration code was assuming 1:1 relation between > memslot and MemorySection, which becomes not true fo s390x > with this patch. As result migration was broken and > dirty logging wasn't even started with when a MemorySection > was split on several memslots. Amend related KVM dirty > log tracking code to account for split MemorySection. > v5: > * move computation 'size -= slot_size' inside of loop body > (David Hildenbrand <david@redhat.com>) > v4: > * fix compilation issue > (Christian Borntraeger <borntraeger@de.ibm.com>) > * advance HVA along with GPA in kvm_set_phys_mem() > (Christian Borntraeger <borntraeger@de.ibm.com>) > > patch prepares only KVM side for switching to single RAM memory region > another patch will take care of dropping manual RAM partitioning in > s390 code. > > > include/sysemu/kvm_int.h | 1 + > accel/kvm/kvm-all.c | 239 ++++++++++++++++++++++--------------- > hw/s390x/s390-virtio-ccw.c | 9 -- > target/s390x/kvm.c | 12 ++ > 4 files changed, 159 insertions(+), 102 deletions(-) > > diff --git a/include/sysemu/kvm_int.h b/include/sysemu/kvm_int.h > index 72b2d1b3ae..ac2d1f8b56 100644 > --- a/include/sysemu/kvm_int.h > +++ b/include/sysemu/kvm_int.h > @@ -41,4 +41,5 @@ typedef struct KVMMemoryListener { > void kvm_memory_listener_register(KVMState *s, KVMMemoryListener *kml, > AddressSpace *as, int as_id); > > +void kvm_set_max_memslot_size(hwaddr max_slot_size); > #endif > diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c > index b09bad0804..0635903408 100644 > --- a/accel/kvm/kvm-all.c > +++ b/accel/kvm/kvm-all.c > @@ -140,6 +140,7 @@ bool kvm_direct_msi_allowed; > bool kvm_ioeventfd_any_length_allowed; > bool kvm_msi_use_devid; > static bool kvm_immediate_exit; > +static hwaddr kvm_max_slot_size = ~0; > > static const KVMCapabilityInfo kvm_required_capabilites[] = { > KVM_CAP_INFO(USER_MEMORY), > @@ -437,7 +438,7 @@ static int kvm_slot_update_flags(KVMMemoryListener *kml, KVMSlot *mem, > static int kvm_section_update_flags(KVMMemoryListener *kml, > MemoryRegionSection *section) > { > - hwaddr start_addr, size; > + hwaddr start_addr, size, slot_size; > KVMSlot *mem; > int ret = 0; > > @@ -448,13 +449,18 @@ static int kvm_section_update_flags(KVMMemoryListener *kml, > > kvm_slots_lock(kml); > > - mem = kvm_lookup_matching_slot(kml, start_addr, size); > - if (!mem) { > - /* We don't have a slot if we want to trap every access. */ > - goto out; > - } > + while (size && !ret) { > + slot_size = kvm_max_slot_size < size ? kvm_max_slot_size : size; > + mem = kvm_lookup_matching_slot(kml, start_addr, slot_size); > + if (!mem) { > + /* We don't have a slot if we want to trap every access. */ > + goto out; > + } > > - ret = kvm_slot_update_flags(kml, mem, section->mr); > + ret = kvm_slot_update_flags(kml, mem, section->mr); > + start_addr += slot_size; > + size -= slot_size; > + } > > out: > kvm_slots_unlock(kml); > @@ -497,11 +503,14 @@ static void kvm_log_stop(MemoryListener *listener, > > /* get kvm's dirty pages bitmap and update qemu's */ > static int kvm_get_dirty_pages_log_range(MemoryRegionSection *section, > + hwaddr offset_in_section, > + hwaddr range_size, > unsigned long *bitmap) > { > ram_addr_t start = section->offset_within_region + > + offset_in_section + > memory_region_get_ram_addr(section->mr); > - ram_addr_t pages = int128_get64(section->size) / getpagesize(); > + ram_addr_t pages = range_size / getpagesize(); > > cpu_physical_memory_set_dirty_lebitmap(bitmap, start, pages); > return 0; > @@ -527,11 +536,13 @@ static int kvm_physical_sync_dirty_bitmap(KVMMemoryListener *kml, > struct kvm_dirty_log d = {}; > KVMSlot *mem; > hwaddr start_addr, size; > + hwaddr slot_size, slot_offset = 0; > int ret = 0; > > size = kvm_align_section(section, &start_addr); > - if (size) { > - mem = kvm_lookup_matching_slot(kml, start_addr, size); > + while (size) { > + slot_size = kvm_max_slot_size < size ? kvm_max_slot_size : size; > + mem = kvm_lookup_matching_slot(kml, start_addr, slot_size); > if (!mem) { > /* We don't have a slot if we want to trap every access. */ > goto out; > @@ -549,11 +560,11 @@ static int kvm_physical_sync_dirty_bitmap(KVMMemoryListener *kml, > * So for now, let's align to 64 instead of HOST_LONG_BITS here, in > * a hope that sizeof(long) won't become >8 any time soon. > */ > - size = ALIGN(((mem->memory_size) >> TARGET_PAGE_BITS), > - /*HOST_LONG_BITS*/ 64) / 8; > if (!mem->dirty_bmap) { > + hwaddr bitmap_size = ALIGN(((mem->memory_size) >> TARGET_PAGE_BITS), > + /*HOST_LONG_BITS*/ 64) / 8; > /* Allocate on the first log_sync, once and for all */ > - mem->dirty_bmap = g_malloc0(size); > + mem->dirty_bmap = g_malloc0(bitmap_size); > } > > d.dirty_bitmap = mem->dirty_bmap; > @@ -564,7 +575,12 @@ static int kvm_physical_sync_dirty_bitmap(KVMMemoryListener *kml, > goto out; > } > > - kvm_get_dirty_pages_log_range(section, d.dirty_bitmap); > + kvm_get_dirty_pages_log_range(section, slot_offset, slot_size, > + d.dirty_bitmap); > + > + slot_offset += slot_size; > + start_addr += slot_size; > + size -= slot_size; > } > out: > return ret; > @@ -575,55 +591,14 @@ out: > #define KVM_CLEAR_LOG_ALIGN (qemu_real_host_page_size << KVM_CLEAR_LOG_SHIFT) > #define KVM_CLEAR_LOG_MASK (-KVM_CLEAR_LOG_ALIGN) > > -/** > - * kvm_physical_log_clear - Clear the kernel's dirty bitmap for range > - * > - * NOTE: this will be a no-op if we haven't enabled manual dirty log > - * protection in the host kernel because in that case this operation > - * will be done within log_sync(). > - * > - * @kml: the kvm memory listener > - * @section: the memory range to clear dirty bitmap > - */ > -static int kvm_physical_log_clear(KVMMemoryListener *kml, > - MemoryRegionSection *section) > +static int kvm_physical_log_slot_clear(uint64_t start, uint64_t size, > + KVMSlot *mem, int as_id) > { > KVMState *s = kvm_state; > - struct kvm_clear_dirty_log d; > - uint64_t start, end, bmap_start, start_delta, bmap_npages, size; > unsigned long *bmap_clear = NULL, psize = qemu_real_host_page_size; > - KVMSlot *mem = NULL; > - int ret, i; > - > - if (!s->manual_dirty_log_protect) { > - /* No need to do explicit clear */ > - return 0; > - } > - > - start = section->offset_within_address_space; > - size = int128_get64(section->size); > - > - if (!size) { > - /* Nothing more we can do... */ > - return 0; > - } > - > - kvm_slots_lock(kml); > - > - /* Find any possible slot that covers the section */ > - for (i = 0; i < s->nr_slots; i++) { > - mem = &kml->slots[i]; > - if (mem->start_addr <= start && > - start + size <= mem->start_addr + mem->memory_size) { > - break; > - } > - } > - > - /* > - * We should always find one memslot until this point, otherwise > - * there could be something wrong from the upper layer > - */ > - assert(mem && i != s->nr_slots); > + uint64_t end, bmap_start, start_delta, bmap_npages; > + struct kvm_clear_dirty_log d; > + int ret; > > /* > * We need to extend either the start or the size or both to > @@ -694,7 +669,7 @@ static int kvm_physical_log_clear(KVMMemoryListener *kml, > /* It should never overflow. If it happens, say something */ > assert(bmap_npages <= UINT32_MAX); > d.num_pages = bmap_npages; > - d.slot = mem->slot | (kml->as_id << 16); > + d.slot = mem->slot | (as_id << 16); > > if (kvm_vm_ioctl(s, KVM_CLEAR_DIRTY_LOG, &d) == -1) { > ret = -errno; > @@ -718,8 +693,66 @@ static int kvm_physical_log_clear(KVMMemoryListener *kml, > /* This handles the NULL case well */ > g_free(bmap_clear); > > - kvm_slots_unlock(kml); > + return ret; > +} > + > +/** > + * kvm_physical_log_clear - Clear the kernel's dirty bitmap for range > + * > + * NOTE: this will be a no-op if we haven't enabled manual dirty log > + * protection in the host kernel because in that case this operation > + * will be done within log_sync(). > + * > + * @kml: the kvm memory listener > + * @section: the memory range to clear dirty bitmap > + */ > +static int kvm_physical_log_clear(KVMMemoryListener *kml, > + MemoryRegionSection *section) > +{ > + KVMState *s = kvm_state; > + uint64_t start, size, slot_size; > + KVMSlot *mem = NULL; > + int i, ret = 0; > + > + if (!s->manual_dirty_log_protect) { > + /* No need to do explicit clear */ > + return 0; > + } > + > + start = section->offset_within_address_space; > + size = int128_get64(section->size); > + > + if (!size) { > + /* Nothing more we can do... */ > + return 0; > + } > + > + kvm_slots_lock(kml); > + > + while (size) { > + slot_size = kvm_max_slot_size < size ? kvm_max_slot_size : size; > + /* Iterate over slots that cover the section */ > + for (i = 0; i < s->nr_slots; i++) { > + mem = &kml->slots[i]; > + if (mem->start_addr <= start && > + start + slot_size <= mem->start_addr + mem->memory_size) { > + break; > + } > + } > > + /* > + * We should always find one memslot until this point, otherwise > + * there could be something wrong from the upper layer > + */ > + assert(mem && i != s->nr_slots); > + > + kvm_physical_log_slot_clear(start, slot_size, mem, kml->as_id); > + > + size -= slot_size; > + start += slot_size; > + } > + > + kvm_slots_unlock(kml); > return ret; > } > > @@ -953,6 +986,14 @@ kvm_check_extension_list(KVMState *s, const KVMCapabilityInfo *list) > return NULL; > } > > +void kvm_set_max_memslot_size(hwaddr max_slot_size) > +{ > + g_assert( > + ROUND_UP(max_slot_size, qemu_real_host_page_size) == max_slot_size > + ); > + kvm_max_slot_size = max_slot_size; > +} > + > static void kvm_set_phys_mem(KVMMemoryListener *kml, > MemoryRegionSection *section, bool add) > { > @@ -960,7 +1001,7 @@ static void kvm_set_phys_mem(KVMMemoryListener *kml, > int err; > MemoryRegion *mr = section->mr; > bool writeable = !mr->readonly && !mr->rom_device; > - hwaddr start_addr, size; > + hwaddr start_addr, size, slot_size; > void *ram; > > if (!memory_region_is_ram(mr)) { > @@ -985,41 +1026,52 @@ static void kvm_set_phys_mem(KVMMemoryListener *kml, > kvm_slots_lock(kml); > > if (!add) { > - mem = kvm_lookup_matching_slot(kml, start_addr, size); > - if (!mem) { > - goto out; > - } > - if (mem->flags & KVM_MEM_LOG_DIRTY_PAGES) { > - kvm_physical_sync_dirty_bitmap(kml, section); > - } > + do { > + slot_size = kvm_max_slot_size < size ? kvm_max_slot_size : size; > + mem = kvm_lookup_matching_slot(kml, start_addr, slot_size); > + if (!mem) { > + goto out; > + } > + if (mem->flags & KVM_MEM_LOG_DIRTY_PAGES) { > + kvm_physical_sync_dirty_bitmap(kml, section); > + } > > - /* unregister the slot */ > - g_free(mem->dirty_bmap); > - mem->dirty_bmap = NULL; > - mem->memory_size = 0; > - mem->flags = 0; > - err = kvm_set_user_memory_region(kml, mem, false); > - if (err) { > - fprintf(stderr, "%s: error unregistering slot: %s\n", > - __func__, strerror(-err)); > - abort(); > - } > + /* unregister the slot */ > + g_free(mem->dirty_bmap); > + mem->dirty_bmap = NULL; > + mem->memory_size = 0; > + mem->flags = 0; > + err = kvm_set_user_memory_region(kml, mem, false); > + if (err) { > + fprintf(stderr, "%s: error unregistering slot: %s\n", > + __func__, strerror(-err)); > + abort(); > + } > + start_addr += slot_size; > + size -= slot_size; > + } while (size); > goto out; > } > > /* register the new slot */ > - mem = kvm_alloc_slot(kml); > - mem->memory_size = size; > - mem->start_addr = start_addr; > - mem->ram = ram; > - mem->flags = kvm_mem_flags(mr); > - > - err = kvm_set_user_memory_region(kml, mem, true); > - if (err) { > - fprintf(stderr, "%s: error registering slot: %s\n", __func__, > - strerror(-err)); > - abort(); > - } > + do { > + slot_size = kvm_max_slot_size < size ? kvm_max_slot_size : size; > + mem = kvm_alloc_slot(kml); > + mem->memory_size = slot_size; > + mem->start_addr = start_addr; > + mem->ram = ram; > + mem->flags = kvm_mem_flags(mr); > + > + err = kvm_set_user_memory_region(kml, mem, true); > + if (err) { > + fprintf(stderr, "%s: error registering slot: %s\n", __func__, > + strerror(-err)); > + abort(); > + } > + start_addr += slot_size; > + ram += slot_size; > + size -= slot_size; > + } while (size); > > out: > kvm_slots_unlock(kml); > @@ -2859,6 +2911,7 @@ static bool kvm_accel_has_memory(MachineState *ms, AddressSpace *as, > > for (i = 0; i < kvm->nr_as; ++i) { > if (kvm->as[i].as == as && kvm->as[i].ml) { > + size = kvm_max_slot_size < size ? kvm_max_slot_size : size; > return NULL != kvm_lookup_matching_slot(kvm->as[i].ml, > start_addr, size); > } > diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c > index 8bfb6684cb..baa95aad38 100644 > --- a/hw/s390x/s390-virtio-ccw.c > +++ b/hw/s390x/s390-virtio-ccw.c > @@ -154,15 +154,6 @@ static void virtio_ccw_register_hcalls(void) > virtio_ccw_hcall_early_printk); > } > > -/* > - * KVM does only support memory slots up to KVM_MEM_MAX_NR_PAGES pages > - * as the dirty bitmap must be managed by bitops that take an int as > - * position indicator. If we have a guest beyond that we will split off > - * new subregions. The split must happen on a segment boundary (1MB). > - */ > -#define KVM_MEM_MAX_NR_PAGES ((1ULL << 31) - 1) > -#define SEG_MSK (~0xfffffULL) > -#define KVM_SLOT_MAX_BYTES ((KVM_MEM_MAX_NR_PAGES * TARGET_PAGE_SIZE) & SEG_MSK) > static void s390_memory_init(ram_addr_t mem_size) > { > MemoryRegion *sysmem = get_system_memory(); > diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c > index cea71ac7c3..838d23cb17 100644 > --- a/target/s390x/kvm.c > +++ b/target/s390x/kvm.c > @@ -28,6 +28,7 @@ > #include "cpu.h" > #include "internal.h" > #include "kvm_s390x.h" > +#include "sysemu/kvm_int.h" > #include "qapi/error.h" > #include "qemu/error-report.h" > #include "qemu/timer.h" > @@ -123,6 +124,16 @@ > #define VCPU_IRQ_BUF_SIZE(max_cpus) (sizeof(struct kvm_s390_irq) * \ > (max_cpus + NR_LOCAL_IRQS)) > > +/* > + * KVM does only support memory slots up to KVM_MEM_MAX_NR_PAGES pages > + * as the dirty bitmap must be managed by bitops that take an int as > + * position indicator. If we have a guest beyond that we will split off > + * new subregions. The split must happen on a segment boundary (1MB). > + */ > +#define KVM_MEM_MAX_NR_PAGES ((1ULL << 31) - 1) > +#define SEG_MSK (~0xfffffULL) > +#define KVM_SLOT_MAX_BYTES ((KVM_MEM_MAX_NR_PAGES * TARGET_PAGE_SIZE) & SEG_MSK) > + > static CPUWatchpoint hw_watchpoint; > /* > * We don't use a list because this structure is also used to transmit the > @@ -348,6 +359,7 @@ int kvm_arch_init(MachineState *ms, KVMState *s) > */ > /* kvm_vm_enable_cap(s, KVM_CAP_S390_AIS, 0); */ > > + kvm_set_max_memslot_size(KVM_SLOT_MAX_BYTES); > return 0; > } > > -- > 2.18.1 > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
On Mon, Sep 16, 2019 at 09:23:46AM -0400, Igor Mammedov wrote: > Max memslot size supported by kvm on s390 is 8Tb, > move logic of splitting RAM in chunks upto 8T to KVM code. > > This way it will hide KVM specific restrictions in KVM code > and won't affect board level design decisions. Which would allow > us to avoid misusing memory_region_allocate_system_memory() API > and eventually use a single hostmem backend for guest RAM. > > Signed-off-by: Igor Mammedov <imammedo@redhat.com> > --- > Since there is quite a bit of migration related code churn in the patch > CCing migration maintainer > > CC: dgilbert@redhat.com > > v6: > * KVM's migration code was assuming 1:1 relation between > memslot and MemorySection, which becomes not true fo s390x > with this patch. As result migration was broken and > dirty logging wasn't even started with when a MemorySection > was split on several memslots. Amend related KVM dirty > log tracking code to account for split MemorySection. > v5: > * move computation 'size -= slot_size' inside of loop body > (David Hildenbrand <david@redhat.com>) > v4: > * fix compilation issue > (Christian Borntraeger <borntraeger@de.ibm.com>) > * advance HVA along with GPA in kvm_set_phys_mem() > (Christian Borntraeger <borntraeger@de.ibm.com>) > > patch prepares only KVM side for switching to single RAM memory region > another patch will take care of dropping manual RAM partitioning in > s390 code. > > > include/sysemu/kvm_int.h | 1 + > accel/kvm/kvm-all.c | 239 ++++++++++++++++++++++--------------- > hw/s390x/s390-virtio-ccw.c | 9 -- > target/s390x/kvm.c | 12 ++ > 4 files changed, 159 insertions(+), 102 deletions(-) > > diff --git a/include/sysemu/kvm_int.h b/include/sysemu/kvm_int.h > index 72b2d1b3ae..ac2d1f8b56 100644 > --- a/include/sysemu/kvm_int.h > +++ b/include/sysemu/kvm_int.h > @@ -41,4 +41,5 @@ typedef struct KVMMemoryListener { > void kvm_memory_listener_register(KVMState *s, KVMMemoryListener *kml, > AddressSpace *as, int as_id); > > +void kvm_set_max_memslot_size(hwaddr max_slot_size); > #endif > diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c > index b09bad0804..0635903408 100644 > --- a/accel/kvm/kvm-all.c > +++ b/accel/kvm/kvm-all.c > @@ -140,6 +140,7 @@ bool kvm_direct_msi_allowed; > bool kvm_ioeventfd_any_length_allowed; > bool kvm_msi_use_devid; > static bool kvm_immediate_exit; > +static hwaddr kvm_max_slot_size = ~0; > > static const KVMCapabilityInfo kvm_required_capabilites[] = { > KVM_CAP_INFO(USER_MEMORY), > @@ -437,7 +438,7 @@ static int kvm_slot_update_flags(KVMMemoryListener *kml, KVMSlot *mem, > static int kvm_section_update_flags(KVMMemoryListener *kml, > MemoryRegionSection *section) > { > - hwaddr start_addr, size; > + hwaddr start_addr, size, slot_size; > KVMSlot *mem; > int ret = 0; > > @@ -448,13 +449,18 @@ static int kvm_section_update_flags(KVMMemoryListener *kml, > > kvm_slots_lock(kml); > > - mem = kvm_lookup_matching_slot(kml, start_addr, size); > - if (!mem) { > - /* We don't have a slot if we want to trap every access. */ > - goto out; > - } > + while (size && !ret) { > + slot_size = kvm_max_slot_size < size ? kvm_max_slot_size : size; Nit: use MIN()? > + mem = kvm_lookup_matching_slot(kml, start_addr, slot_size); > + if (!mem) { > + /* We don't have a slot if we want to trap every access. */ > + goto out; I don't really understand the rational behind e377e87ca6a3d by simply reading the commit message... Just want to make sure: this won't be triggered when memslot split happened for this memory region section, right? > + } > > - ret = kvm_slot_update_flags(kml, mem, section->mr); > + ret = kvm_slot_update_flags(kml, mem, section->mr); > + start_addr += slot_size; > + size -= slot_size; > + } > > out: > kvm_slots_unlock(kml); > @@ -497,11 +503,14 @@ static void kvm_log_stop(MemoryListener *listener, > > /* get kvm's dirty pages bitmap and update qemu's */ > static int kvm_get_dirty_pages_log_range(MemoryRegionSection *section, > + hwaddr offset_in_section, > + hwaddr range_size, > unsigned long *bitmap) > { > ram_addr_t start = section->offset_within_region + > + offset_in_section + > memory_region_get_ram_addr(section->mr); > - ram_addr_t pages = int128_get64(section->size) / getpagesize(); > + ram_addr_t pages = range_size / getpagesize(); I feel like we can avoid touching kvm_get_dirty_pages_log_range() by passing in a correct MemoryRegionSection* to it (please see [1] below). > > cpu_physical_memory_set_dirty_lebitmap(bitmap, start, pages); > return 0; > @@ -527,11 +536,13 @@ static int kvm_physical_sync_dirty_bitmap(KVMMemoryListener *kml, > struct kvm_dirty_log d = {}; > KVMSlot *mem; > hwaddr start_addr, size; > + hwaddr slot_size, slot_offset = 0; > int ret = 0; > > size = kvm_align_section(section, &start_addr); > - if (size) { > - mem = kvm_lookup_matching_slot(kml, start_addr, size); > + while (size) { > + slot_size = kvm_max_slot_size < size ? kvm_max_slot_size : size; (use MIN?) > + mem = kvm_lookup_matching_slot(kml, start_addr, slot_size); > if (!mem) { > /* We don't have a slot if we want to trap every access. */ > goto out; > @@ -549,11 +560,11 @@ static int kvm_physical_sync_dirty_bitmap(KVMMemoryListener *kml, > * So for now, let's align to 64 instead of HOST_LONG_BITS here, in > * a hope that sizeof(long) won't become >8 any time soon. > */ > - size = ALIGN(((mem->memory_size) >> TARGET_PAGE_BITS), > - /*HOST_LONG_BITS*/ 64) / 8; > if (!mem->dirty_bmap) { > + hwaddr bitmap_size = ALIGN(((mem->memory_size) >> TARGET_PAGE_BITS), > + /*HOST_LONG_BITS*/ 64) / 8; > /* Allocate on the first log_sync, once and for all */ > - mem->dirty_bmap = g_malloc0(size); > + mem->dirty_bmap = g_malloc0(bitmap_size); > } > > d.dirty_bitmap = mem->dirty_bmap; > @@ -564,7 +575,12 @@ static int kvm_physical_sync_dirty_bitmap(KVMMemoryListener *kml, > goto out; > } > > - kvm_get_dirty_pages_log_range(section, d.dirty_bitmap); > + kvm_get_dirty_pages_log_range(section, slot_offset, slot_size, > + d.dirty_bitmap); [1] Here can we hand-made a MemoryRegionSection which covers the slot_offset/slot_size region and pass it to kvm_get_dirty_pages_log_range()? > + > + slot_offset += slot_size; > + start_addr += slot_size; > + size -= slot_size; > } > out: > return ret; > @@ -575,55 +591,14 @@ out: > #define KVM_CLEAR_LOG_ALIGN (qemu_real_host_page_size << KVM_CLEAR_LOG_SHIFT) > #define KVM_CLEAR_LOG_MASK (-KVM_CLEAR_LOG_ALIGN) > > -/** > - * kvm_physical_log_clear - Clear the kernel's dirty bitmap for range > - * > - * NOTE: this will be a no-op if we haven't enabled manual dirty log > - * protection in the host kernel because in that case this operation > - * will be done within log_sync(). > - * > - * @kml: the kvm memory listener > - * @section: the memory range to clear dirty bitmap > - */ > -static int kvm_physical_log_clear(KVMMemoryListener *kml, > - MemoryRegionSection *section) > +static int kvm_physical_log_slot_clear(uint64_t start, uint64_t size, > + KVMSlot *mem, int as_id) > { > KVMState *s = kvm_state; > - struct kvm_clear_dirty_log d; > - uint64_t start, end, bmap_start, start_delta, bmap_npages, size; > unsigned long *bmap_clear = NULL, psize = qemu_real_host_page_size; > - KVMSlot *mem = NULL; > - int ret, i; > - > - if (!s->manual_dirty_log_protect) { > - /* No need to do explicit clear */ > - return 0; > - } > - > - start = section->offset_within_address_space; > - size = int128_get64(section->size); > - > - if (!size) { > - /* Nothing more we can do... */ > - return 0; > - } > - > - kvm_slots_lock(kml); > - > - /* Find any possible slot that covers the section */ > - for (i = 0; i < s->nr_slots; i++) { > - mem = &kml->slots[i]; > - if (mem->start_addr <= start && > - start + size <= mem->start_addr + mem->memory_size) { > - break; > - } > - } > - > - /* > - * We should always find one memslot until this point, otherwise > - * there could be something wrong from the upper layer > - */ > - assert(mem && i != s->nr_slots); > + uint64_t end, bmap_start, start_delta, bmap_npages; > + struct kvm_clear_dirty_log d; > + int ret; > > /* > * We need to extend either the start or the size or both to > @@ -694,7 +669,7 @@ static int kvm_physical_log_clear(KVMMemoryListener *kml, > /* It should never overflow. If it happens, say something */ > assert(bmap_npages <= UINT32_MAX); > d.num_pages = bmap_npages; > - d.slot = mem->slot | (kml->as_id << 16); > + d.slot = mem->slot | (as_id << 16); > > if (kvm_vm_ioctl(s, KVM_CLEAR_DIRTY_LOG, &d) == -1) { > ret = -errno; > @@ -718,8 +693,66 @@ static int kvm_physical_log_clear(KVMMemoryListener *kml, > /* This handles the NULL case well */ > g_free(bmap_clear); > > - kvm_slots_unlock(kml); > + return ret; > +} > + > +/** > + * kvm_physical_log_clear - Clear the kernel's dirty bitmap for range > + * > + * NOTE: this will be a no-op if we haven't enabled manual dirty log > + * protection in the host kernel because in that case this operation > + * will be done within log_sync(). > + * > + * @kml: the kvm memory listener > + * @section: the memory range to clear dirty bitmap > + */ > +static int kvm_physical_log_clear(KVMMemoryListener *kml, > + MemoryRegionSection *section) > +{ > + KVMState *s = kvm_state; > + uint64_t start, size, slot_size; > + KVMSlot *mem = NULL; > + int i, ret = 0; > + > + if (!s->manual_dirty_log_protect) { > + /* No need to do explicit clear */ > + return 0; > + } > + > + start = section->offset_within_address_space; > + size = int128_get64(section->size); > + > + if (!size) { > + /* Nothing more we can do... */ > + return 0; > + } > + > + kvm_slots_lock(kml); > + > + while (size) { > + slot_size = kvm_max_slot_size < size ? kvm_max_slot_size : size; MIN? Also, the naming of slot_size might be a bit misleading here because log_clear() is different in that it could happen with very small memory region section passed in, hence slot_size could very probably not be the size of slot. Maybe range_size or anything else? > + /* Iterate over slots that cover the section */ > + for (i = 0; i < s->nr_slots; i++) { > + mem = &kml->slots[i]; > + if (mem->start_addr <= start && > + start + slot_size <= mem->start_addr + mem->memory_size) { > + break; > + } > + } > > + /* > + * We should always find one memslot until this point, otherwise > + * there could be something wrong from the upper layer > + */ > + assert(mem && i != s->nr_slots); > + > + kvm_physical_log_slot_clear(start, slot_size, mem, kml->as_id); Use ret to capture errors? > + > + size -= slot_size; > + start += slot_size; > + } > + > + kvm_slots_unlock(kml); > return ret; > } > > @@ -953,6 +986,14 @@ kvm_check_extension_list(KVMState *s, const KVMCapabilityInfo *list) > return NULL; > } > > +void kvm_set_max_memslot_size(hwaddr max_slot_size) > +{ > + g_assert( > + ROUND_UP(max_slot_size, qemu_real_host_page_size) == max_slot_size > + ); > + kvm_max_slot_size = max_slot_size; > +} > + > static void kvm_set_phys_mem(KVMMemoryListener *kml, > MemoryRegionSection *section, bool add) > { > @@ -960,7 +1001,7 @@ static void kvm_set_phys_mem(KVMMemoryListener *kml, > int err; > MemoryRegion *mr = section->mr; > bool writeable = !mr->readonly && !mr->rom_device; > - hwaddr start_addr, size; > + hwaddr start_addr, size, slot_size; > void *ram; > > if (!memory_region_is_ram(mr)) { > @@ -985,41 +1026,52 @@ static void kvm_set_phys_mem(KVMMemoryListener *kml, > kvm_slots_lock(kml); > > if (!add) { > - mem = kvm_lookup_matching_slot(kml, start_addr, size); > - if (!mem) { > - goto out; > - } > - if (mem->flags & KVM_MEM_LOG_DIRTY_PAGES) { > - kvm_physical_sync_dirty_bitmap(kml, section); > - } > + do { > + slot_size = kvm_max_slot_size < size ? kvm_max_slot_size : size; Same > + mem = kvm_lookup_matching_slot(kml, start_addr, slot_size); > + if (!mem) { > + goto out; > + } > + if (mem->flags & KVM_MEM_LOG_DIRTY_PAGES) { > + kvm_physical_sync_dirty_bitmap(kml, section); > + } > > - /* unregister the slot */ > - g_free(mem->dirty_bmap); > - mem->dirty_bmap = NULL; > - mem->memory_size = 0; > - mem->flags = 0; > - err = kvm_set_user_memory_region(kml, mem, false); > - if (err) { > - fprintf(stderr, "%s: error unregistering slot: %s\n", > - __func__, strerror(-err)); > - abort(); > - } > + /* unregister the slot */ > + g_free(mem->dirty_bmap); > + mem->dirty_bmap = NULL; > + mem->memory_size = 0; > + mem->flags = 0; > + err = kvm_set_user_memory_region(kml, mem, false); > + if (err) { > + fprintf(stderr, "%s: error unregistering slot: %s\n", > + __func__, strerror(-err)); > + abort(); > + } > + start_addr += slot_size; > + size -= slot_size; > + } while (size); > goto out; > } > > /* register the new slot */ > - mem = kvm_alloc_slot(kml); > - mem->memory_size = size; > - mem->start_addr = start_addr; > - mem->ram = ram; > - mem->flags = kvm_mem_flags(mr); > - > - err = kvm_set_user_memory_region(kml, mem, true); > - if (err) { > - fprintf(stderr, "%s: error registering slot: %s\n", __func__, > - strerror(-err)); > - abort(); > - } > + do { > + slot_size = kvm_max_slot_size < size ? kvm_max_slot_size : size; Same. > + mem = kvm_alloc_slot(kml); > + mem->memory_size = slot_size; > + mem->start_addr = start_addr; > + mem->ram = ram; > + mem->flags = kvm_mem_flags(mr); > + > + err = kvm_set_user_memory_region(kml, mem, true); > + if (err) { > + fprintf(stderr, "%s: error registering slot: %s\n", __func__, > + strerror(-err)); > + abort(); > + } > + start_addr += slot_size; > + ram += slot_size; > + size -= slot_size; > + } while (size); > > out: > kvm_slots_unlock(kml); > @@ -2859,6 +2911,7 @@ static bool kvm_accel_has_memory(MachineState *ms, AddressSpace *as, > > for (i = 0; i < kvm->nr_as; ++i) { > if (kvm->as[i].as == as && kvm->as[i].ml) { > + size = kvm_max_slot_size < size ? kvm_max_slot_size : size; > return NULL != kvm_lookup_matching_slot(kvm->as[i].ml, > start_addr, size); > } > diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c > index 8bfb6684cb..baa95aad38 100644 > --- a/hw/s390x/s390-virtio-ccw.c > +++ b/hw/s390x/s390-virtio-ccw.c > @@ -154,15 +154,6 @@ static void virtio_ccw_register_hcalls(void) > virtio_ccw_hcall_early_printk); > } > > -/* > - * KVM does only support memory slots up to KVM_MEM_MAX_NR_PAGES pages > - * as the dirty bitmap must be managed by bitops that take an int as > - * position indicator. If we have a guest beyond that we will split off > - * new subregions. The split must happen on a segment boundary (1MB). > - */ > -#define KVM_MEM_MAX_NR_PAGES ((1ULL << 31) - 1) > -#define SEG_MSK (~0xfffffULL) > -#define KVM_SLOT_MAX_BYTES ((KVM_MEM_MAX_NR_PAGES * TARGET_PAGE_SIZE) & SEG_MSK) (Nit: IMHO it'll be cleaner to keep these and in the next patch to simply revert bb223055b9b327e) > static void s390_memory_init(ram_addr_t mem_size) > { > MemoryRegion *sysmem = get_system_memory(); > diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c > index cea71ac7c3..838d23cb17 100644 > --- a/target/s390x/kvm.c > +++ b/target/s390x/kvm.c > @@ -28,6 +28,7 @@ > #include "cpu.h" > #include "internal.h" > #include "kvm_s390x.h" > +#include "sysemu/kvm_int.h" > #include "qapi/error.h" > #include "qemu/error-report.h" > #include "qemu/timer.h" > @@ -123,6 +124,16 @@ > #define VCPU_IRQ_BUF_SIZE(max_cpus) (sizeof(struct kvm_s390_irq) * \ > (max_cpus + NR_LOCAL_IRQS)) > > +/* > + * KVM does only support memory slots up to KVM_MEM_MAX_NR_PAGES pages > + * as the dirty bitmap must be managed by bitops that take an int as > + * position indicator. If we have a guest beyond that we will split off > + * new subregions. The split must happen on a segment boundary (1MB). > + */ > +#define KVM_MEM_MAX_NR_PAGES ((1ULL << 31) - 1) Not related to this series, but... should kvm export this to uapi headers? > +#define SEG_MSK (~0xfffffULL) > +#define KVM_SLOT_MAX_BYTES ((KVM_MEM_MAX_NR_PAGES * TARGET_PAGE_SIZE) & SEG_MSK) > + > static CPUWatchpoint hw_watchpoint; > /* > * We don't use a list because this structure is also used to transmit the > @@ -348,6 +359,7 @@ int kvm_arch_init(MachineState *ms, KVMState *s) > */ > /* kvm_vm_enable_cap(s, KVM_CAP_S390_AIS, 0); */ > > + kvm_set_max_memslot_size(KVM_SLOT_MAX_BYTES); > return 0; > } > > -- > 2.18.1 > > Regards,
diff --git a/include/sysemu/kvm_int.h b/include/sysemu/kvm_int.h index 72b2d1b3ae..ac2d1f8b56 100644 --- a/include/sysemu/kvm_int.h +++ b/include/sysemu/kvm_int.h @@ -41,4 +41,5 @@ typedef struct KVMMemoryListener { void kvm_memory_listener_register(KVMState *s, KVMMemoryListener *kml, AddressSpace *as, int as_id); +void kvm_set_max_memslot_size(hwaddr max_slot_size); #endif diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c index b09bad0804..0635903408 100644 --- a/accel/kvm/kvm-all.c +++ b/accel/kvm/kvm-all.c @@ -140,6 +140,7 @@ bool kvm_direct_msi_allowed; bool kvm_ioeventfd_any_length_allowed; bool kvm_msi_use_devid; static bool kvm_immediate_exit; +static hwaddr kvm_max_slot_size = ~0; static const KVMCapabilityInfo kvm_required_capabilites[] = { KVM_CAP_INFO(USER_MEMORY), @@ -437,7 +438,7 @@ static int kvm_slot_update_flags(KVMMemoryListener *kml, KVMSlot *mem, static int kvm_section_update_flags(KVMMemoryListener *kml, MemoryRegionSection *section) { - hwaddr start_addr, size; + hwaddr start_addr, size, slot_size; KVMSlot *mem; int ret = 0; @@ -448,13 +449,18 @@ static int kvm_section_update_flags(KVMMemoryListener *kml, kvm_slots_lock(kml); - mem = kvm_lookup_matching_slot(kml, start_addr, size); - if (!mem) { - /* We don't have a slot if we want to trap every access. */ - goto out; - } + while (size && !ret) { + slot_size = kvm_max_slot_size < size ? kvm_max_slot_size : size; + mem = kvm_lookup_matching_slot(kml, start_addr, slot_size); + if (!mem) { + /* We don't have a slot if we want to trap every access. */ + goto out; + } - ret = kvm_slot_update_flags(kml, mem, section->mr); + ret = kvm_slot_update_flags(kml, mem, section->mr); + start_addr += slot_size; + size -= slot_size; + } out: kvm_slots_unlock(kml); @@ -497,11 +503,14 @@ static void kvm_log_stop(MemoryListener *listener, /* get kvm's dirty pages bitmap and update qemu's */ static int kvm_get_dirty_pages_log_range(MemoryRegionSection *section, + hwaddr offset_in_section, + hwaddr range_size, unsigned long *bitmap) { ram_addr_t start = section->offset_within_region + + offset_in_section + memory_region_get_ram_addr(section->mr); - ram_addr_t pages = int128_get64(section->size) / getpagesize(); + ram_addr_t pages = range_size / getpagesize(); cpu_physical_memory_set_dirty_lebitmap(bitmap, start, pages); return 0; @@ -527,11 +536,13 @@ static int kvm_physical_sync_dirty_bitmap(KVMMemoryListener *kml, struct kvm_dirty_log d = {}; KVMSlot *mem; hwaddr start_addr, size; + hwaddr slot_size, slot_offset = 0; int ret = 0; size = kvm_align_section(section, &start_addr); - if (size) { - mem = kvm_lookup_matching_slot(kml, start_addr, size); + while (size) { + slot_size = kvm_max_slot_size < size ? kvm_max_slot_size : size; + mem = kvm_lookup_matching_slot(kml, start_addr, slot_size); if (!mem) { /* We don't have a slot if we want to trap every access. */ goto out; @@ -549,11 +560,11 @@ static int kvm_physical_sync_dirty_bitmap(KVMMemoryListener *kml, * So for now, let's align to 64 instead of HOST_LONG_BITS here, in * a hope that sizeof(long) won't become >8 any time soon. */ - size = ALIGN(((mem->memory_size) >> TARGET_PAGE_BITS), - /*HOST_LONG_BITS*/ 64) / 8; if (!mem->dirty_bmap) { + hwaddr bitmap_size = ALIGN(((mem->memory_size) >> TARGET_PAGE_BITS), + /*HOST_LONG_BITS*/ 64) / 8; /* Allocate on the first log_sync, once and for all */ - mem->dirty_bmap = g_malloc0(size); + mem->dirty_bmap = g_malloc0(bitmap_size); } d.dirty_bitmap = mem->dirty_bmap; @@ -564,7 +575,12 @@ static int kvm_physical_sync_dirty_bitmap(KVMMemoryListener *kml, goto out; } - kvm_get_dirty_pages_log_range(section, d.dirty_bitmap); + kvm_get_dirty_pages_log_range(section, slot_offset, slot_size, + d.dirty_bitmap); + + slot_offset += slot_size; + start_addr += slot_size; + size -= slot_size; } out: return ret; @@ -575,55 +591,14 @@ out: #define KVM_CLEAR_LOG_ALIGN (qemu_real_host_page_size << KVM_CLEAR_LOG_SHIFT) #define KVM_CLEAR_LOG_MASK (-KVM_CLEAR_LOG_ALIGN) -/** - * kvm_physical_log_clear - Clear the kernel's dirty bitmap for range - * - * NOTE: this will be a no-op if we haven't enabled manual dirty log - * protection in the host kernel because in that case this operation - * will be done within log_sync(). - * - * @kml: the kvm memory listener - * @section: the memory range to clear dirty bitmap - */ -static int kvm_physical_log_clear(KVMMemoryListener *kml, - MemoryRegionSection *section) +static int kvm_physical_log_slot_clear(uint64_t start, uint64_t size, + KVMSlot *mem, int as_id) { KVMState *s = kvm_state; - struct kvm_clear_dirty_log d; - uint64_t start, end, bmap_start, start_delta, bmap_npages, size; unsigned long *bmap_clear = NULL, psize = qemu_real_host_page_size; - KVMSlot *mem = NULL; - int ret, i; - - if (!s->manual_dirty_log_protect) { - /* No need to do explicit clear */ - return 0; - } - - start = section->offset_within_address_space; - size = int128_get64(section->size); - - if (!size) { - /* Nothing more we can do... */ - return 0; - } - - kvm_slots_lock(kml); - - /* Find any possible slot that covers the section */ - for (i = 0; i < s->nr_slots; i++) { - mem = &kml->slots[i]; - if (mem->start_addr <= start && - start + size <= mem->start_addr + mem->memory_size) { - break; - } - } - - /* - * We should always find one memslot until this point, otherwise - * there could be something wrong from the upper layer - */ - assert(mem && i != s->nr_slots); + uint64_t end, bmap_start, start_delta, bmap_npages; + struct kvm_clear_dirty_log d; + int ret; /* * We need to extend either the start or the size or both to @@ -694,7 +669,7 @@ static int kvm_physical_log_clear(KVMMemoryListener *kml, /* It should never overflow. If it happens, say something */ assert(bmap_npages <= UINT32_MAX); d.num_pages = bmap_npages; - d.slot = mem->slot | (kml->as_id << 16); + d.slot = mem->slot | (as_id << 16); if (kvm_vm_ioctl(s, KVM_CLEAR_DIRTY_LOG, &d) == -1) { ret = -errno; @@ -718,8 +693,66 @@ static int kvm_physical_log_clear(KVMMemoryListener *kml, /* This handles the NULL case well */ g_free(bmap_clear); - kvm_slots_unlock(kml); + return ret; +} + +/** + * kvm_physical_log_clear - Clear the kernel's dirty bitmap for range + * + * NOTE: this will be a no-op if we haven't enabled manual dirty log + * protection in the host kernel because in that case this operation + * will be done within log_sync(). + * + * @kml: the kvm memory listener + * @section: the memory range to clear dirty bitmap + */ +static int kvm_physical_log_clear(KVMMemoryListener *kml, + MemoryRegionSection *section) +{ + KVMState *s = kvm_state; + uint64_t start, size, slot_size; + KVMSlot *mem = NULL; + int i, ret = 0; + + if (!s->manual_dirty_log_protect) { + /* No need to do explicit clear */ + return 0; + } + + start = section->offset_within_address_space; + size = int128_get64(section->size); + + if (!size) { + /* Nothing more we can do... */ + return 0; + } + + kvm_slots_lock(kml); + + while (size) { + slot_size = kvm_max_slot_size < size ? kvm_max_slot_size : size; + /* Iterate over slots that cover the section */ + for (i = 0; i < s->nr_slots; i++) { + mem = &kml->slots[i]; + if (mem->start_addr <= start && + start + slot_size <= mem->start_addr + mem->memory_size) { + break; + } + } + /* + * We should always find one memslot until this point, otherwise + * there could be something wrong from the upper layer + */ + assert(mem && i != s->nr_slots); + + kvm_physical_log_slot_clear(start, slot_size, mem, kml->as_id); + + size -= slot_size; + start += slot_size; + } + + kvm_slots_unlock(kml); return ret; } @@ -953,6 +986,14 @@ kvm_check_extension_list(KVMState *s, const KVMCapabilityInfo *list) return NULL; } +void kvm_set_max_memslot_size(hwaddr max_slot_size) +{ + g_assert( + ROUND_UP(max_slot_size, qemu_real_host_page_size) == max_slot_size + ); + kvm_max_slot_size = max_slot_size; +} + static void kvm_set_phys_mem(KVMMemoryListener *kml, MemoryRegionSection *section, bool add) { @@ -960,7 +1001,7 @@ static void kvm_set_phys_mem(KVMMemoryListener *kml, int err; MemoryRegion *mr = section->mr; bool writeable = !mr->readonly && !mr->rom_device; - hwaddr start_addr, size; + hwaddr start_addr, size, slot_size; void *ram; if (!memory_region_is_ram(mr)) { @@ -985,41 +1026,52 @@ static void kvm_set_phys_mem(KVMMemoryListener *kml, kvm_slots_lock(kml); if (!add) { - mem = kvm_lookup_matching_slot(kml, start_addr, size); - if (!mem) { - goto out; - } - if (mem->flags & KVM_MEM_LOG_DIRTY_PAGES) { - kvm_physical_sync_dirty_bitmap(kml, section); - } + do { + slot_size = kvm_max_slot_size < size ? kvm_max_slot_size : size; + mem = kvm_lookup_matching_slot(kml, start_addr, slot_size); + if (!mem) { + goto out; + } + if (mem->flags & KVM_MEM_LOG_DIRTY_PAGES) { + kvm_physical_sync_dirty_bitmap(kml, section); + } - /* unregister the slot */ - g_free(mem->dirty_bmap); - mem->dirty_bmap = NULL; - mem->memory_size = 0; - mem->flags = 0; - err = kvm_set_user_memory_region(kml, mem, false); - if (err) { - fprintf(stderr, "%s: error unregistering slot: %s\n", - __func__, strerror(-err)); - abort(); - } + /* unregister the slot */ + g_free(mem->dirty_bmap); + mem->dirty_bmap = NULL; + mem->memory_size = 0; + mem->flags = 0; + err = kvm_set_user_memory_region(kml, mem, false); + if (err) { + fprintf(stderr, "%s: error unregistering slot: %s\n", + __func__, strerror(-err)); + abort(); + } + start_addr += slot_size; + size -= slot_size; + } while (size); goto out; } /* register the new slot */ - mem = kvm_alloc_slot(kml); - mem->memory_size = size; - mem->start_addr = start_addr; - mem->ram = ram; - mem->flags = kvm_mem_flags(mr); - - err = kvm_set_user_memory_region(kml, mem, true); - if (err) { - fprintf(stderr, "%s: error registering slot: %s\n", __func__, - strerror(-err)); - abort(); - } + do { + slot_size = kvm_max_slot_size < size ? kvm_max_slot_size : size; + mem = kvm_alloc_slot(kml); + mem->memory_size = slot_size; + mem->start_addr = start_addr; + mem->ram = ram; + mem->flags = kvm_mem_flags(mr); + + err = kvm_set_user_memory_region(kml, mem, true); + if (err) { + fprintf(stderr, "%s: error registering slot: %s\n", __func__, + strerror(-err)); + abort(); + } + start_addr += slot_size; + ram += slot_size; + size -= slot_size; + } while (size); out: kvm_slots_unlock(kml); @@ -2859,6 +2911,7 @@ static bool kvm_accel_has_memory(MachineState *ms, AddressSpace *as, for (i = 0; i < kvm->nr_as; ++i) { if (kvm->as[i].as == as && kvm->as[i].ml) { + size = kvm_max_slot_size < size ? kvm_max_slot_size : size; return NULL != kvm_lookup_matching_slot(kvm->as[i].ml, start_addr, size); } diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c index 8bfb6684cb..baa95aad38 100644 --- a/hw/s390x/s390-virtio-ccw.c +++ b/hw/s390x/s390-virtio-ccw.c @@ -154,15 +154,6 @@ static void virtio_ccw_register_hcalls(void) virtio_ccw_hcall_early_printk); } -/* - * KVM does only support memory slots up to KVM_MEM_MAX_NR_PAGES pages - * as the dirty bitmap must be managed by bitops that take an int as - * position indicator. If we have a guest beyond that we will split off - * new subregions. The split must happen on a segment boundary (1MB). - */ -#define KVM_MEM_MAX_NR_PAGES ((1ULL << 31) - 1) -#define SEG_MSK (~0xfffffULL) -#define KVM_SLOT_MAX_BYTES ((KVM_MEM_MAX_NR_PAGES * TARGET_PAGE_SIZE) & SEG_MSK) static void s390_memory_init(ram_addr_t mem_size) { MemoryRegion *sysmem = get_system_memory(); diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c index cea71ac7c3..838d23cb17 100644 --- a/target/s390x/kvm.c +++ b/target/s390x/kvm.c @@ -28,6 +28,7 @@ #include "cpu.h" #include "internal.h" #include "kvm_s390x.h" +#include "sysemu/kvm_int.h" #include "qapi/error.h" #include "qemu/error-report.h" #include "qemu/timer.h" @@ -123,6 +124,16 @@ #define VCPU_IRQ_BUF_SIZE(max_cpus) (sizeof(struct kvm_s390_irq) * \ (max_cpus + NR_LOCAL_IRQS)) +/* + * KVM does only support memory slots up to KVM_MEM_MAX_NR_PAGES pages + * as the dirty bitmap must be managed by bitops that take an int as + * position indicator. If we have a guest beyond that we will split off + * new subregions. The split must happen on a segment boundary (1MB). + */ +#define KVM_MEM_MAX_NR_PAGES ((1ULL << 31) - 1) +#define SEG_MSK (~0xfffffULL) +#define KVM_SLOT_MAX_BYTES ((KVM_MEM_MAX_NR_PAGES * TARGET_PAGE_SIZE) & SEG_MSK) + static CPUWatchpoint hw_watchpoint; /* * We don't use a list because this structure is also used to transmit the @@ -348,6 +359,7 @@ int kvm_arch_init(MachineState *ms, KVMState *s) */ /* kvm_vm_enable_cap(s, KVM_CAP_S390_AIS, 0); */ + kvm_set_max_memslot_size(KVM_SLOT_MAX_BYTES); return 0; }
Max memslot size supported by kvm on s390 is 8Tb, move logic of splitting RAM in chunks upto 8T to KVM code. This way it will hide KVM specific restrictions in KVM code and won't affect board level design decisions. Which would allow us to avoid misusing memory_region_allocate_system_memory() API and eventually use a single hostmem backend for guest RAM. Signed-off-by: Igor Mammedov <imammedo@redhat.com> --- Since there is quite a bit of migration related code churn in the patch CCing migration maintainer CC: dgilbert@redhat.com v6: * KVM's migration code was assuming 1:1 relation between memslot and MemorySection, which becomes not true fo s390x with this patch. As result migration was broken and dirty logging wasn't even started with when a MemorySection was split on several memslots. Amend related KVM dirty log tracking code to account for split MemorySection. v5: * move computation 'size -= slot_size' inside of loop body (David Hildenbrand <david@redhat.com>) v4: * fix compilation issue (Christian Borntraeger <borntraeger@de.ibm.com>) * advance HVA along with GPA in kvm_set_phys_mem() (Christian Borntraeger <borntraeger@de.ibm.com>) patch prepares only KVM side for switching to single RAM memory region another patch will take care of dropping manual RAM partitioning in s390 code. include/sysemu/kvm_int.h | 1 + accel/kvm/kvm-all.c | 239 ++++++++++++++++++++++--------------- hw/s390x/s390-virtio-ccw.c | 9 -- target/s390x/kvm.c | 12 ++ 4 files changed, 159 insertions(+), 102 deletions(-)