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

pc, pci, virtio: fixes, features

A bunch of fixes all over the place.
A new vmcore device - the user interface around it is still somewhat
controversial, but I feel most of the code is fine, suggestions can be
addressed by adding patches on top.

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

# gpg: Signature made Sun 15 Oct 2017 04:02:23 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: (26 commits)
  tests/pxe: Test more NICs when running in SPEED=slow mode
  pc: remove useless hot_add_cpu initialisation
  isapc: Remove unnecessary migration compatibility code
  virtio-pci: Replace modern_as with direct access to modern_bar
  virtio: fix descriptor counting in virtqueue_pop
  hw/gen_pcie_root_port: make IO RO 0 on IO disabled
  pci: Validate interfaces on base_class_init
  xen/pt: Mark TYPE_XEN_PT_DEVICE as hybrid
  pci: Add INTERFACE_CONVENTIONAL_PCI_DEVICE to Conventional PCI devices
  pci: Add INTERFACE_PCIE_DEVICE to all PCIe devices
  pci: Add interface names to hybrid PCI devices
  pci: conventional-pci-device and pci-express-device interfaces
  PCI: PCIe access should always be little endian
  virtio/pci/migration: Convert to VMState
  hw/pci-bridge/pcie_pci_bridge: properly handle MSI unavailability case
  pci: allow 32-bit PCI IO accesses to pass through the PCI bridge
  virtio/vhost: reset dev->log after syncing
  MAINTAINERS: add Dump maintainers
  scripts/dump-guest-memory.py: add vmcoreinfo
  kdump: set vmcoreinfo location
  ...

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

docs/specs/vmcoreinfo.txt

@@ -0,0 +1,49 @@
+=================
+VMCoreInfo device
+=================
+
+The `-device vmcoreinfo` will create a fw_cfg entry for a guest to
+store dump details.
+
+etc/vmcoreinfo
+**************
+
+A guest may use this fw_cfg entry to add information details to qemu
+dumps.
+
+The entry of 16 bytes has the following layout, in little-endian::
+
+#define VMCOREINFO_FORMAT_NONE 0x0
+#define VMCOREINFO_FORMAT_ELF 0x1
+
+    struct FWCfgVMCoreInfo {
+        uint16_t host_format;  /* formats host supports */
+        uint16_t guest_format; /* format guest supplies */
+        uint32_t size;         /* size of vmcoreinfo region */
+        uint64_t paddr;        /* physical address of vmcoreinfo region */
+    };
+
+Only full write (of 16 bytes) are considered valid for further
+processing of entry values.
+
+A write of 0 in guest_format will disable further processing of
+vmcoreinfo entry values & content.
+
+Format & content
+****************
+
+As of qemu 2.11, only VMCOREINFO_FORMAT_ELF is supported.
+
+The entry gives location and size of an ELF note that is appended in
+qemu dumps.
+
+The note format/class must be of the target bitness and the size must
+be less than 1Mb.
+
+If the ELF note name is "VMCOREINFO", it is expected to be the Linux
+vmcoreinfo note (see Documentation/ABI/testing/sysfs-kernel-vmcoreinfo
+in Linux source). In this case, qemu dump code will read the content
+as a key=value text file, looking for "NUMBER(phys_base)" key
+value. The value is expected to be more accurate than architecture
+guess of the value. This is useful for KASLR-enabled guest with
+ancient tools not handling the VMCOREINFO note.