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  1. 23 3月, 2016 8 次提交
  3. 18 3月, 2016 1 次提交
    • E
      qapi: Don't special-case simple union wrappers · 32bafa8f
      由 Eric Blake 提交于 
      Simple unions were carrying a special case that hid their 'data'
QMP member from the resulting C struct, via the hack method
QAPISchemaObjectTypeVariant.simple_union_type().  But by using
the work we started by unboxing flat union and alternate
branches, coupled with the ability to visit the members of an
implicit type, we can now expose the simple union's implicit
type in qapi-types.h:

| struct q_obj_ImageInfoSpecificQCow2_wrapper {
|     ImageInfoSpecificQCow2 *data;
| };
|
| struct q_obj_ImageInfoSpecificVmdk_wrapper {
|     ImageInfoSpecificVmdk *data;
| };
...
| struct ImageInfoSpecific {
|     ImageInfoSpecificKind type;
|     union { /* union tag is @type */
|         void *data;
|-        ImageInfoSpecificQCow2 *qcow2;
|-        ImageInfoSpecificVmdk *vmdk;
|+        q_obj_ImageInfoSpecificQCow2_wrapper qcow2;
|+        q_obj_ImageInfoSpecificVmdk_wrapper vmdk;
|     } u;
| };

Doing this removes asymmetry between QAPI's QMP side and its
C side (both sides now expose 'data'), and means that the
treatment of a simple union as sugar for a flat union is now
equivalent in both languages (previously the two approaches used
a different layer of dereferencing, where the simple union could
be converted to a flat union with equivalent C layout but
different {} on the wire, or to an equivalent QMP wire form
but with different C representation).  Using the implicit type
also lets us get rid of the simple_union_type() hack.

Of course, now all clients of simple unions have to adjust from
using su->u.member to using su->u.member.data; while this touches
a number of files in the tree, some earlier cleanup patches
helped minimize the change to the initialization of a temporary
variable rather than every single member access.  The generated
qapi-visit.c code is also affected by the layout change:

|@@ -7393,10 +7393,10 @@ void visit_type_ImageInfoSpecific_member
|     }
|     switch (obj->type) {
|     case IMAGE_INFO_SPECIFIC_KIND_QCOW2:
|-        visit_type_ImageInfoSpecificQCow2(v, "data", &obj->u.qcow2, &err);
|+        visit_type_q_obj_ImageInfoSpecificQCow2_wrapper_members(v, &obj->u.qcow2, &err);
|         break;
|     case IMAGE_INFO_SPECIFIC_KIND_VMDK:
|-        visit_type_ImageInfoSpecificVmdk(v, "data", &obj->u.vmdk, &err);
|+        visit_type_q_obj_ImageInfoSpecificVmdk_wrapper_members(v, &obj->u.vmdk, &err);
|         break;
|     default:
|         abort();
Signed-off-by: NEric Blake <eblake@redhat.com>
Message-Id: <1458254921-17042-13-git-send-email-eblake@redhat.com>
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
      32bafa8f
  5. 17 3月, 2016 21 次提交
  7. 16 3月, 2016 10 次提交
    • D
      vfio: Eliminate vfio_container_ioctl() · 3356128c
      由 David Gibson 提交于 
      vfio_container_ioctl() was a bad interface that bypassed abstraction
boundaries, had semantics that sat uneasily with its name, and was unsafe
in many realistic circumstances.  Now that spapr-pci-vfio-host-bridge has
been folded into spapr-pci-host-bridge, there are no more users, so remove
it.
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
Reviewed-by: NAlexey Kardashevskiy <aik@ozlabs.ru>
Acked-by: NAlex Williamson <alex.williamson@redhat.com>
      3356128c
    • D
      spapr_pci: Remove finish_realize hook · a36304fd
      由 David Gibson 提交于 
      Now that spapr-pci-vfio-host-bridge is reduced to just a stub, there is
only one implementation of the finish_realize hook in sPAPRPHBClass.  So,
we can fold that implementation into its (single) caller, and remove the
hook.  That's the last thing left in sPAPRPHBClass, so that can go away as
well.
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
Reviewed-by: NAlexey Kardashevskiy <aik@ozlabs.ru>
      a36304fd
    • D
      spapr_pci: (Mostly) remove spapr-pci-vfio-host-bridge · 72700d7e
      由 David Gibson 提交于 
      Now that the regular spapr-pci-host-bridge can handle EEH, there are only
two things that spapr-pci-vfio-host-bridge does differently:
    1. automatically sizes its DMA window to match the host IOMMU
    2. checks if the attached VFIO container is backed by the
       VFIO_SPAPR_TCE_IOMMU type on the host

(1) is not particularly useful, since the default window used by the
regular host bridge will work with the host IOMMU configuration on all
current systems anyway.

Plus, automatically changing guest visible configuration (such as the DMA
window) based on host settings is generally a bad idea.  It's not
definitively broken, since spapr-pci-vfio-host-bridge is only supposed to
support VFIO devices which can't be migrated anyway, but still.

(2) is not really useful, because if a guest tries to configure EEH on a
different host IOMMU, the first call will fail and that will be that.

It's possible there are scripts or tools out there which expect
spapr-pci-vfio-host-bridge, so we don't remove it entirely.  This patch
reduces it to just a stub for backwards compatibility.
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
Reviewed-by: NAlexey Kardashevskiy <aik@ozlabs.ru>
      72700d7e
    • D
      spapr_pci: Allow EEH on spapr-pci-host-bridge · c1fa017c
      由 David Gibson 提交于 
      Now that the EEH code is independent of the special
spapr-vfio-pci-host-bridge device, we can allow it on all spapr PCI
host bridges instead.  We do this by changing spapr_phb_eeh_available()
to be based on the vfio_eeh_as_ok() call instead of the host bridge class.

Because the value of vfio_eeh_as_ok() can change with devices being
hotplugged or unplugged, this can potentially lead to some strange edge
cases where the guest starts using EEH, then it starts failing because
of a change in status.

However, it's not really any worse than the current situation.  Cases that
would have worked previously will still work (i.e. VFIO devices from at
most one VFIO IOMMU group per vPHB), it's just that it's no longer
necessary to use spapr-vfio-pci-host-bridge with the groupid pre-specified.
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
Reviewed-by: NAlexey Kardashevskiy <aik@ozlabs.ru>
      c1fa017c
    • D
      spapr_pci: Eliminate class callbacks · fbb4e983
      由 David Gibson 提交于 
      The EEH operations in the spapr-vfio-pci-host-bridge no longer rely on the
special groupid field in sPAPRPHBVFIOState.  So we can simplify, removing
the class specific callbacks with direct calls based on a simple
spapr_phb_eeh_enabled() helper.  For now we implement that in terms of
a boolean in the class, but we'll continue to clean that up later.

On its own this is a rather strange way of doing things, but it's a useful
intermediate step to further cleanups.
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
Reviewed-by: NAlexey Kardashevskiy <aik@ozlabs.ru>
      fbb4e983
    • D
      spapr_pci: Switch to vfio_eeh_as_op() interface · 76a9e9f6
      由 David Gibson 提交于 
      This switches all EEH on VFIO operations in spapr_pci_vfio.c from the
broken vfio_container_ioctl() interface to the new vfio_as_eeh_op()
interface.
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
Reviewed-by: NAlexey Kardashevskiy <aik@ozlabs.ru>
      76a9e9f6
    • D
      vfio: Start improving VFIO/EEH interface · 3153119e
      由 David Gibson 提交于 
      At present the code handling IBM's Enhanced Error Handling (EEH) interface
on VFIO devices operates by bypassing the usual VFIO logic with
vfio_container_ioctl().  That's a poorly designed interface with unclear
semantics about exactly what can be operated on.

In particular it operates on a single vfio container internally (hence the
name), but takes an address space and group id, from which it deduces the
container in a rather roundabout way.  groupids are something that code
outside vfio shouldn't even be aware of.

This patch creates new interfaces for EEH operations.  Internally we
have vfio_eeh_container_op() which takes a VFIOContainer object
directly.  For external use we have vfio_eeh_as_ok() which determines
if an AddressSpace is usable for EEH (at present this means it has a
single container with exactly one group attached), and vfio_eeh_as_op()
which will perform an operation on an AddressSpace in the unambiguous case,
and otherwise returns an error.

This interface still isn't great, but it's enough of an improvement to
allow a number of cleanups in other places.
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
Reviewed-by: NAlexey Kardashevskiy <aik@ozlabs.ru>
Acked-by: NAlex Williamson <alex.williamson@redhat.com>
      3153119e
    • G
      spapr_rng: fix race with main loop · f1a6cf3e
      由 Greg Kurz 提交于 
      Since commit "60253ed1 rng: add request queue support to rng-random",
the use of a spapr_rng device may hang vCPU threads.

The following path is taken without holding the lock to the main loop mutex:

h_random()
  rng_backend_request_entropy()
    rng_random_request_entropy()
      qemu_set_fd_handler()

The consequence is that entropy_available() may be called before the vCPU
thread could even queue the request: depending on the scheduling, it may
happen that entropy_available() does not call random_recv()->qemu_sem_post().
The vCPU thread will then sleep forever in h_random()->qemu_sem_wait().

This could not happen before 60253ed1 because entropy_available() used
to call random_recv() unconditionally.

This patch ensures the lock is held to avoid the race.
Signed-off-by: NGreg Kurz <gkurz@linux.vnet.ibm.com>
Reviewed-by: NCédric Le Goater <clg@fr.ibm.com>
Reviewed-by: NThomas Huth <thuth@redhat.com>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
      f1a6cf3e
    • D
      target-ppc: Eliminate kvmppc_kern_htab global · c18ad9a5
      由 David Gibson 提交于 
      fa48b432 "target-ppc: Remove hack for ppc_hash64_load_hpte*() with HV KVM"
purports to remove a hack in the handling of hash page tables (HPTs)
managed by KVM instead of qemu.  However, it actually went in the wrong
direction.

That patch requires anything looking for an external HPT (that is one not
managed by the guest itself) to check both env->external_htab (for a qemu
managed HPT) and kvmppc_kern_htab (for a KVM managed HPT).  That's a
problem because kvmppc_kern_htab is local to mmu-hash64.c, but some places
which need to check for an external HPT are outside that, such as
kvm_arch_get_registers().  The latter was subtly broken by the earlier
patch such that gdbstub can no longer access memory.

Basically a KVM managed HPT is much more like a qemu managed HPT than it is
like a guest managed HPT, so the original "hack" was actually on the right
track.

This partially reverts fa48b432, so we again mark a KVM managed external HPT
by putting a special but non-NULL value in env->external_htab.  It then
goes further, using that marker to eliminate the kvmppc_kern_htab global
entirely.  The ppc_hash64_set_external_hpt() helper function is extended
to set that marker if passed a NULL value (if you're setting an external
HPT, but don't have an actual HPT to set, the assumption is that it must
be a KVM managed HPT).

This also has some flow-on changes to the HPT access helpers, required by
the above changes.
Reported-by: NGreg Kurz <gkurz@linux.vnet.ibm.com>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
Reviewed-by: NThomas Huth <thuth@redhat.com>
Reviewed-by: NGreg Kurz <gkurz@linux.vnet.ibm.com>
Tested-by: NGreg Kurz <gkurz@linux.vnet.ibm.com>
      c18ad9a5
    • D
      target-ppc: Add helpers for updating a CPU's SDR1 and external HPT · e5c0d3ce
      由 David Gibson 提交于 
      When a Power cpu with 64-bit hash MMU has it's hash page table (HPT)
pointer updated by a write to the SDR1 register we need to update some
derived variables.  Likewise, when the cpu is configured for an external
HPT (one not in the guest memory space) some derived variables need to be
updated.

Currently the logic for this is (partially) duplicated in ppc_store_sdr1()
and in spapr_cpu_reset().  In future we're going to need it in some other
places, so make some common helpers for this update.

In addition the new ppc_hash64_set_external_hpt() helper also updates
SDR1 in KVM - it's not updated by the normal runtime KVM <-> qemu CPU
synchronization.  In a sense this belongs logically in the
ppc_hash64_set_sdr1() helper, but that is called from
kvm_arch_get_registers() so can't itself call cpu_synchronize_state()
without infinite recursion.  In practice this doesn't matter because
the only other caller is TCG specific.

Currently there aren't situations where updating SDR1 at runtime in KVM
matters, but there are going to be in future.
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
Reviewed-by: NGreg Kurz <gkurz@linux.vnet.ibm.com>
Reviewed-by: NThomas Huth <thuth@redhat.com>
      e5c0d3ce