search for: postcopy

...sched_out notifier nor in vcpu_put() after preempt_disable)). __copy_to_user in kvm_write_guest_offset_cached schedules and locks up the host. kvm->srcu (or kvm->slots_lock) is also not taken and kvm_write_guest_offset_cached needs to call kvm_memslots which requires it. This I think is why postcopy live migration locks up with current upstream, and it doesn't seem related to userfaultfd at all (initially I suspected the vmf conversion but it wasn't that) and in theory it can happen with heavy swapping or page migration too. Just the page is written so frequently it's unlikely to...

...sched_out notifier nor in vcpu_put() after preempt_disable)). __copy_to_user in kvm_write_guest_offset_cached schedules and locks up the host. kvm->srcu (or kvm->slots_lock) is also not taken and kvm_write_guest_offset_cached needs to call kvm_memslots which requires it. This I think is why postcopy live migration locks up with current upstream, and it doesn't seem related to userfaultfd at all (initially I suspected the vmf conversion but it wasn't that) and in theory it can happen with heavy swapping or page migration too. Just the page is written so frequently it's unlikely to...

...sable()/enable(), we can not call __copy_to_user I think. > kvm->srcu (or kvm->slots_lock) is also not taken and > kvm_write_guest_offset_cached needs to call kvm_memslots which > requires it. > let me check the details later. thanks for pointing it out. > This I think is why postcopy live migration locks up with current > upstream, and it doesn't seem related to userfaultfd at all (initially > I suspected the vmf conversion but it wasn't that) and in theory it > can happen with heavy swapping or page migration too. > > Just the page is written so frequent...

...libvirt and have few doubts: 1) libvirt talks to QEMU/KVM guests via QEMU API. So overall, in order to manage QEMU/KVM guests I can either use libvirt (or tools based on libvirt like virsh) or QEMU monitor. Is it so? 2) Since libvirt is Hypervisor neutral so actual migration algorithm(precopy or postcopy) is present in the hypervisor ,i.e. in case of QEMU it should be present in QEMU code base . I was going through the code starting from libvirt-domain api and not able to follow after virDomainMigrateVersion3Full(.....) . Kindly help. Thanks in advance. And sorry if that was too basic. Anubhav

Hi, when a normally running VM is migrated, libvirt sends VIR_DOMAIN_EVENT_RESUMED_MIGRATED event on the destination once the migration completes. I can see that when a paused VM is migrated, libvirt sends VIR_DOMAIN_EVENT_SUSPENDED_PAUSED instead. Since there seems to be nothing migration specific about VIR_DOMAIN_EVENT_SUSPENDED_PAUSED event, my question is: Is it safe to assume on the

...s.c:360:8: error: 'struct hvm_info_table' has no member named 'acpi_enabled' > va_hvm->acpi_enabled = f.acpi; > ^ > xenguest_stubs.c: At top level: > xenguest_stubs.c:470:3: warning: initialization from incompatible pointer type [enabled by default] > .postcopy = switch_qemu_logdirty, > ^ > xenguest_stubs.c:470:3: warning: (near initialization for 'save_callbacks.postcopy') [enabled by default] > xenguest_stubs.c: In function 'stub_xc_domain_save': > xenguest_stubs.c:490:18: warning: assignment makes pointer from integer wit...

On 09/24/2013 10:04 PM, St?phane Glondu wrote: > Le 24/09/2013 15:48, St?phane Glondu a ?crit : >> If I remove all binary packages of xen-api from testing, the following >> new packages are broken: xcp-guest-templates, nova-xcp-plugins, >> nova-compute-xen. >> >> xcp-guest-templates is built by guest-templates which seems to be a leaf >> package and could be

...ENT_RESUMED_MIGRATED is received > before)? Yes. This is the code that handles the finish phase of migration: https://libvirt.org/git/?p=libvirt.git;a=blob;f=src/qemu/qemu_migration.c;h=29d228a8d9345ec8e2853571444614008a95e914;hb=HEAD#l5105 which can be read as the following pseudo code: if (postCopy) sendEvent(VIR_DOMAIN_EVENT_RESUMED_MIGRATED); if (domain.paused) sendEvent(VIR_DOMAIN_EVENT_SUSPENDED_PAUSED); Michal

...s.c:360:8: error: 'struct hvm_info_table' has no member named 'acpi_enabled' > va_hvm->acpi_enabled = f.acpi; > ^ > xenguest_stubs.c: At top level: > xenguest_stubs.c:470:3: warning: initialization from incompatible pointer type [enabled by default] > .postcopy = switch_qemu_logdirty, > ^ > [...] On the other hand, there is a new upstream release (upstream version is 1.6 and unstable version is 1.3.2). It doesn't make sense to me to invest time in this without updating the package, which goes beyond the scope of an NMU. Fixing #713349 was al...

...map - if that can be used to detect unmapped/zero mapped pages in the guest ram, would it achieve the same result? > This RFC version doesn't take the post-copy and RDMA into > consideration, maybe both of them can benefit from this PV solution > by with some extra modifications. For postcopy to be safe, you would still need to send a message to the destination telling it that there were zero pages, otherwise the destination can't tell if it's supposed to request the page from the source or treat the page as zero. Dave > > Performance data > ================ > &g...

...t redhat.com> - ev-2.6.0-28.el7_3.10.1 - Removing RH branding from package name * Mon May 22 2017 Miroslav Rezanina <mrezanin at redhat.com> - rhev-2.6.0-28.el7_3.10 - kvm-virtio-rng-stop-virtqueue-while-the-CPU-is-stopped.patch [bz#1450375] - Resolves: bz#1450375 (Migration failed with postcopy enabled from rhel7.3.z host to rhel7.4 host "error while loading state for instance 0x0 of device 'pci) -- SANDRO BONAZZOLA ASSOCIATE MANAGER, SOFTWARE ENGINEERING, EMEA ENG VIRTUALIZATION R&D Red Hat EMEA <https://www.redhat.com/> <https://red.ht/sig> TRIED. TESTED....

...eantime. > > The NBD server is going to be (a) storing huge quantities of temporary > data which we'll mostly not use, and (b) blocking libguestfs for > arbitrary periods of time. This doesn't sound very lightweight to me. Hmm. Sounds a bit like we want to take advantage of postcopy migration smarts - where the destination receives the full stream of writes as a low-priority, but can interject and request out-of-order reads to satisfy page faults on a high-priority. All reads are guaranteed to resolve to the correct data, even if it means blocking the read until the out-of-or...

change from v6: fix typos and remove uncessary comments. change from v5: spilt x86/kvm patch into guest/host part. introduce kvm_write_guest_offset_cached. fix some typos. rebase patch onto 4.9.2 change from v4: spilt x86 kvm vcpu preempted check into two patches. add documentation patch. add x86 vcpu preempted check patch under xen add s390 vcpu preempted check patch change from v3:

change from v6: fix typos and remove uncessary comments. change from v5: spilt x86/kvm patch into guest/host part. introduce kvm_write_guest_offset_cached. fix some typos. rebase patch onto 4.9.2 change from v4: spilt x86 kvm vcpu preempted check into two patches. add documentation patch. add x86 vcpu preempted check patch under xen add s390 vcpu preempted check patch change from v3:

...N_RAM #define DPRINTF(fmt, ...) \ @@ -241,6 +242,7 @@ static struct BitmapRcu { struct rcu_head rcu; /* Main migration bitmap */ unsigned long *bmap; + unsigned long *free_pages_bmap; /* bitmap of pages that haven't been sent even once * only maintained and used in postcopy at the moment * where it's used to send the dirtymap at the start @@ -561,12 +563,7 @@ ram_addr_t migration_bitmap_find_dirty(RAMBlock *rb, unsigned long next; bitmap = atomic_rcu_read(&migration_bitmap_rcu)->bmap; - if (ram_bulk_stage && nr > base) { -...

...is not enough. Consider the situation like case 2, it can't achieve the same result. > > This RFC version doesn't take the post-copy and RDMA into > > consideration, maybe both of them can benefit from this PV solution by > > with some extra modifications. > > For postcopy to be safe, you would still need to send a message to the > destination telling it that there were zero pages, otherwise the destination > can't tell if it's supposed to request the page from the source or treat the > page as zero. > > Dave I will consider this later, thank...

...is not enough. Consider the situation like case 2, it can't achieve the same result. > > This RFC version doesn't take the post-copy and RDMA into > > consideration, maybe both of them can benefit from this PV solution by > > with some extra modifications. > > For postcopy to be safe, you would still need to send a message to the > destination telling it that there were zero pages, otherwise the destination > can't tell if it's supposed to request the page from the source or treat the > page as zero. > > Dave I will consider this later, thank...

...urce ~]# virsh qemu-monitor-command 11 '{"execute":"query-migrate"}' > > {"return":{"status":"completed","setup-time":2,"downtime":2451,"total-time":3753,"ram":{"total":2114785280,"postcopy-requests":0,"dirty-sync-count":3,"page-size":4096,"remaining":0,"mbps":898.199209,"transferred":421345514,"duplicate":414940,"dirty-pages-rate":0,"skipped":0,"normal-bytes":416796672,"normal":10...

On Fri, Mar 27, 2015 at 10:37:44AM -0600, Eric Blake wrote: > On 03/27/2015 09:35 AM, Richard W.M. Jones wrote: > > But libguestfs doesn't want to do a backup, nor get a copy of the > > whole disk, it just wants to access a scattering of blocks (maybe a > > few hundred) but at a single point in time, in as lightweight a manner > > as possible. > > If you KNOW

...situation like case 2, it can't achieve the same result. > > > > This RFC version doesn't take the post-copy and RDMA into > > > consideration, maybe both of them can benefit from this PV solution by > > > with some extra modifications. > > > > For postcopy to be safe, you would still need to send a message to the > > destination telling it that there were zero pages, otherwise the destination > > can't tell if it's supposed to request the page from the source or treat the > > page as zero. > > > > Dave > >...