Merge remote-tracking branch 'remotes/mst/tags/for_upstream' into staging

pc, pci, virtio: patches queued before 2.10

A bunch of stuff that was posted before the 2.10 timeframe,
mostly fixes/cleanups.  New PCI bridges.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

# gpg: Signature made Fri 08 Sep 2017 14:15:34 BST
# gpg:                using RSA key 0x281F0DB8D28D5469
# gpg: Good signature from "Michael S. Tsirkin <mst@kernel.org>"
# gpg:                 aka "Michael S. Tsirkin <mst@redhat.com>"
# Primary key fingerprint: 0270 606B 6F3C DF3D 0B17  0970 C350 3912 AFBE 8E67
#      Subkey fingerprint: 5D09 FD08 71C8 F85B 94CA  8A0D 281F 0DB8 D28D 5469

* remotes/mst/tags/for_upstream:
  fw_cfg: rename read callback
  pci: add reserved slot check to do_pci_register_device()
  pci: move check for existing devfn into new pci_bus_devfn_available() helper
  vmgenid: replace x-write-pointer-available hack
  vhost-user-bridge: fix resume regression (since 2.9)
  libvhost-user: support resuming vq->last_avail_idx based on used_idx
  acpi/vmgenid: change device category to misc
  intel_iommu: fix missing BQL in pt fast path
  docs: update documentation considering PCIE-PCI bridge
  hw/pci: add QEMU-specific PCI capability to the Generic PCI Express Root Port
  hw/pci: introduce bridge-only vendor-specific capability to provide some hints to firmware
  hw/pci: introduce pcie-pci-bridge device
  Revert "ACPI: don't call acpi_pcihp_device_plug_cb on xen"
  hw/acpi: Move acpi_set_pci_info to pcihp
  hw/acpi: Limit hotplug to root bus on legacy mode
  pc: add 2.11 machine types
  vhost: Release memory references on cleanup

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 15 insertions, 0 deletions

diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
index a7bf87a19e..3a5bb0bc2e 100644
--- a/hw/i386/intel_iommu.c
+++ b/hw/i386/intel_iommu.c
@@ -957,6 +957,8 @@ static bool vtd_dev_pt_enabled(VTDAddressSpace *as)
 static bool vtd_switch_address_space(VTDAddressSpace *as)
 {
     bool use_iommu;
+    /* Whether we need to take the BQL on our own */
+    bool take_bql = !qemu_mutex_iothread_locked();
 
     assert(as);
 
@@ -967,6 +969,15 @@ static bool vtd_switch_address_space(VTDAddressSpace *as)
                                    VTD_PCI_FUNC(as->devfn),
                                    use_iommu);
 
+    /*
+     * It's possible that we reach here without BQL, e.g., when called
+     * from vtd_pt_enable_fast_path(). However the memory APIs need
+     * it. We'd better make sure we have had it already, or, take it.
+     */
+    if (take_bql) {
+        qemu_mutex_lock_iothread();
+    }
+
     /* Turn off first then on the other */
     if (use_iommu) {
         memory_region_set_enabled(&as->sys_alias, false);
@@ -976,6 +987,10 @@ static bool vtd_switch_address_space(VTDAddressSpace *as)
         memory_region_set_enabled(&as->sys_alias, true);
     }
 
+    if (take_bql) {
+        qemu_mutex_unlock_iothread();
+    }
+
     return use_iommu;
 }