Skip to content
Snippets Groups Projects
Select Git revision
  • feature/libtcg-rebase default protected
1 result
Search by author
  • Any Author
  • Anton Anton anjo
1 author
  1. May 08, 2018
    • Paolo Bonzini's avatar
      exec: reintroduce MemoryRegion caching · 48564041
      Paolo Bonzini authored 
      
MemoryRegionCache was reverted to "normal" address_space_* operations
for 2.9, due to lack of support for IOMMUs.  Reinstate the
optimizations, caching only the IOMMU translation at address_cache_init
but not the IOMMU lookup and target AddressSpace translation are not
cached; now that MemoryRegionCache supports IOMMUs, it becomes more widely
applicable too.

The inlined fast path is defined in memory_ldst_cached.inc.h, while the
slow path uses memory_ldst.inc.c as before.  The smaller fast path causes
a little code size reduction in MemoryRegionCache users:

    hw/virtio/virtio.o text size before: 32373
    hw/virtio/virtio.o text size after: 31941

Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      48564041
  3. Mar 06, 2018
  5. Feb 19, 2018
    • Marcel Apfelbaum's avatar
      mem: add share parameter to memory-backend-ram · 06329cce
      Marcel Apfelbaum authored 
      
Currently only file backed memory backend can
be created with a "share" flag in order to allow
sharing guest RAM with other processes in the host.

Add the "share" flag also to RAM Memory Backend
in order to allow remapping parts of the guest RAM
to different host virtual addresses. This is needed
by the RDMA devices in order to remap non-contiguous
QEMU virtual addresses to a contiguous virtual address range.

Moved the "share" flag to the Host Memory base class,
modified phys_mem_alloc to include the new parameter
and a new interface memory_region_init_ram_shared_nomigrate.

There are no functional changes if the new flag is not used.

Reviewed-by: default avatarEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: default avatarMarcel Apfelbaum <marcel@redhat.com>
      06329cce
  7. Feb 13, 2018
  9. Feb 07, 2018
    • Peter Xu's avatar
      memory: do explicit cleanup when remove listeners · d25836ca
      Peter Xu authored 
      When unregister memory listeners, we should call, e.g.,
region_del() (and possibly other undo operations) on every existing
memory region sections there, otherwise we may leak resources that are
held during the region_add(). This patch undo the stuff for the
listeners, which emulates the case when the address space is set from
current to an empty state.

I found this problem when debugging a refcount leak issue that leads to
a device unplug event lost (please see the "Bug:" line below).  In that
case, the leakage of resource is the PCI BAR memory region refcount.
And since memory regions are not keeping their own refcount but onto
their owners, so the vfio-pci device's (who is the owner of the PCI BAR
memory regions) refcount is leaked, and event missing.

We had encountered similar issues before and fixed in other
way (ee4c1128, "vhost: Release memory references on cleanup"). This
patch can be seen as a more high-level fix of similar problems that are
caused by the resource leaks from memory listeners. So now we can remove
the explicit unref of memory regions since that'll be done altogether
during unregistering of listeners now.

Bug: https://bugzilla.redhat.com/show_bug.cgi?id=1531393


Signed-off-by: default avatarPeter Xu <peterx@redhat.com>
Message-Id: <20180122060244.29368-5-peterx@redhat.com>
Reviewed-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      d25836ca
  11. Feb 06, 2018
  13. Feb 05, 2018
  15. Jan 19, 2018
    • Haozhong Zhang's avatar
      hostmem-file: add "align" option · 98376843
      Haozhong Zhang authored 
      
When mmap(2) the backend files, QEMU uses the host page size
(getpagesize(2)) by default as the alignment of mapping address.
However, some backends may require alignments different than the page
size. For example, mmap a device DAX (e.g., /dev/dax0.0) on Linux
kernel 4.13 to an address, which is 4K-aligned but not 2M-aligned,
fails with a kernel message like

[617494.969768] dax dax0.0: qemu-system-x86: dax_mmap: fail, unaligned vma (0x7fa37c579000 - 0x7fa43c579000, 0x1fffff)

Because there is no common approach to get such alignment requirement,
we add the 'align' option to 'memory-backend-file', so that users or
management utils, which have enough knowledge about the backend, can
specify a proper alignment via this option.

Signed-off-by: default avatarHaozhong Zhang <haozhong.zhang@intel.com>
Message-Id: <20171211072806.2812-2-haozhong.zhang@intel.com>
Reviewed-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Reviewed-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
[ehabkost: fixed typo, fixed error_setg() format string]
Signed-off-by: default avatarEduardo Habkost <ehabkost@redhat.com>
      98376843
  17. Dec 18, 2017
  19. Oct 18, 2017
  21. Oct 12, 2017
  23. Sep 21, 2017
  25. Sep 19, 2017
  27. Aug 01, 2017
    • Jay Zhou's avatar
      migration: optimize the downtime · 19310760
      Jay Zhou authored 
      
Qemu_savevm_state_cleanup takes about 300ms in my ram migration tests
with a 8U24G vm(20G is really occupied), the main cost comes from
KVM_SET_USER_MEMORY_REGION ioctl when mem.memory_size = 0 in
kvm_set_user_memory_region. In kmod, the main cost is
kvm_zap_obsolete_pages, which traverses the active_mmu_pages list to
zap the unsync sptes.

It can be optimized by delaying memory_global_dirty_log_stop to the next
vm_start.

Changes v2->v3:
 - NULL VMChangeStateHandler if it is deleted and protect the scenario
   of nested invocations of memory_global_dirty_log_start/stop [Paolo]

Changes v1->v2:
 - create a VMChangeStateHandler in memory.c to reduce the coupling [Paolo]

Signed-off-by: default avatarJay Zhou <jianjay.zhou@huawei.com>
Message-Id: <1501237733-2736-1-git-send-email-jianjay.zhou@huawei.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      19310760
  29. Jul 14, 2017
  31. Jun 27, 2017