Merge tag 'xenfv-2' of git://git.infradead.org/users/dwmw2/qemu into staging

Enable PV backends with Xen/KVM emulation

This is phase 2, following on from the basic platform support which was
already merged.

 • Add a simple single-tenant internal XenStore implementation
 • Indirect Xen gnttab/evtchn/foreignmem/xenstore through operations table
 • Provide emulated back ends for Xen operations
 • Header cleanups to allow PV back ends to build without Xen itself
 • Enable PV back ends in emulated mode
 • Documentation update

Tested-by: Paul Durrant <paul@xen.org>
... on real Xen (master branch, 4.18) with a Debian guest.

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# gpg:          There is no indication that the signature belongs to the owner.
# Primary key fingerprint: 314B 08AC D0DE 4811 33A5  F286 9BE9 80FD 0AC0 1544

* tag 'xenfv-2' of git://git.infradead.org/users/dwmw2/qemu: (27 commits)
  docs: Update Xen-on-KVM documentation for PV disk support
  MAINTAINERS: Add entry for Xen on KVM emulation
  i386/xen: Initialize Xen backends from pc_basic_device_init() for emulation
  hw/xen: Implement soft reset for emulated gnttab
  hw/xen: Map guest XENSTORE_PFN grant in emulated Xenstore
  hw/xen: Add emulated implementation of XenStore operations
  hw/xen: Add emulated implementation of grant table operations
  hw/xen: Hook up emulated implementation for event channel operations
  hw/xen: Only advertise ring-page-order for xen-block if gnttab supports it
  hw/xen: Avoid crash when backend watch fires too early
  hw/xen: Build PV backend drivers for CONFIG_XEN_BUS
  hw/xen: Rename xen_common.h to xen_native.h
  hw/xen: Use XEN_PAGE_SIZE in PV backend drivers
  hw/xen: Move xenstore_store_pv_console_info to xen_console.c
  hw/xen: Add xenstore operations to allow redirection to internal emulation
  hw/xen: Add foreignmem operations to allow redirection to internal emulation
  hw/xen: Pass grant ref to gnttab unmap operation
  hw/xen: Add gnttab operations to allow redirection to internal emulation
  hw/xen: Add evtchn operations to allow redirection to internal emulation
  hw/xen: Create initial XenStore nodes
  ...

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

4 files changed, 17 insertions, 11 deletions

diff --git a/hw/block/dataplane/meson.build b/hw/block/dataplane/meson.build
index 12c6a26..78d7ac1 100644
--- a/hw/block/dataplane/meson.build
+++ b/hw/block/dataplane/meson.build
@@ -1,2 +1,2 @@
 specific_ss.add(when: 'CONFIG_VIRTIO_BLK', if_true: files('virtio-blk.c'))
-specific_ss.add(when: 'CONFIG_XEN', if_true: files('xen-block.c'))
+specific_ss.add(when: 'CONFIG_XEN_BUS', if_true: files('xen-block.c'))
diff --git a/hw/block/dataplane/xen-block.c b/hw/block/dataplane/xen-block.c
index 2785b9e..734da42 100644
--- a/hw/block/dataplane/xen-block.c
+++ b/hw/block/dataplane/xen-block.c
@@ -23,8 +23,9 @@
 #include "qemu/main-loop.h"
 #include "qemu/memalign.h"
 #include "qapi/error.h"
-#include "hw/xen/xen_common.h"
+#include "hw/xen/xen.h"
 #include "hw/block/xen_blkif.h"
+#include "hw/xen/interface/io/ring.h"
 #include "sysemu/block-backend.h"
 #include "sysemu/iothread.h"
 #include "xen-block.h"
@@ -101,9 +102,9 @@ static XenBlockRequest *xen_block_start_request(XenBlockDataPlane *dataplane)
          * re-use requests, allocate the memory once here. It will be freed
          * xen_block_dataplane_destroy() when the request list is freed.
          */
-        request->buf = qemu_memalign(XC_PAGE_SIZE,
+        request->buf = qemu_memalign(XEN_PAGE_SIZE,
                                      BLKIF_MAX_SEGMENTS_PER_REQUEST *
-                                     XC_PAGE_SIZE);
+                                     XEN_PAGE_SIZE);
         dataplane->requests_total++;
         qemu_iovec_init(&request->v, 1);
     } else {
@@ -185,7 +186,7 @@ static int xen_block_parse_request(XenBlockRequest *request)
             goto err;
         }
         if (request->req.seg[i].last_sect * dataplane->sector_size >=
-            XC_PAGE_SIZE) {
+            XEN_PAGE_SIZE) {
             error_report("error: page crossing");
             goto err;
         }
@@ -705,6 +706,7 @@ void xen_block_dataplane_stop(XenBlockDataPlane *dataplane)
         Error *local_err = NULL;
 
         xen_device_unmap_grant_refs(xendev, dataplane->sring,
+                                    dataplane->ring_ref,
                                     dataplane->nr_ring_ref, &local_err);
         dataplane->sring = NULL;
 
@@ -739,7 +741,7 @@ void xen_block_dataplane_start(XenBlockDataPlane *dataplane,
 
     dataplane->protocol = protocol;
 
-    ring_size = XC_PAGE_SIZE * dataplane->nr_ring_ref;
+    ring_size = XEN_PAGE_SIZE * dataplane->nr_ring_ref;
     switch (dataplane->protocol) {
     case BLKIF_PROTOCOL_NATIVE:
     {
diff --git a/hw/block/meson.build b/hw/block/meson.build
index b434d56..cc2a75c 100644
--- a/hw/block/meson.build
+++ b/hw/block/meson.build
@@ -14,7 +14,7 @@ softmmu_ss.add(when: 'CONFIG_PFLASH_CFI02', if_true: files('pflash_cfi02.c'))
 softmmu_ss.add(when: 'CONFIG_SSI_M25P80', if_true: files('m25p80.c'))
 softmmu_ss.add(when: 'CONFIG_SSI_M25P80', if_true: files('m25p80_sfdp.c'))
 softmmu_ss.add(when: 'CONFIG_SWIM', if_true: files('swim.c'))
-softmmu_ss.add(when: 'CONFIG_XEN', if_true: files('xen-block.c'))
+softmmu_ss.add(when: 'CONFIG_XEN_BUS', if_true: files('xen-block.c'))
 softmmu_ss.add(when: 'CONFIG_TC58128', if_true: files('tc58128.c'))
 
 specific_ss.add(when: 'CONFIG_VIRTIO_BLK', if_true: files('virtio-blk.c', 'virtio-blk-common.c'))
diff --git a/hw/block/xen-block.c b/hw/block/xen-block.c
index 345b284..f5a7445 100644
--- a/hw/block/xen-block.c
+++ b/hw/block/xen-block.c
@@ -19,7 +19,6 @@
 #include "qapi/qmp/qdict.h"
 #include "qapi/qmp/qstring.h"
 #include "qom/object_interfaces.h"
-#include "hw/xen/xen_common.h"
 #include "hw/block/xen_blkif.h"
 #include "hw/qdev-properties.h"
 #include "hw/xen/xen-block.h"
@@ -84,7 +83,8 @@ static void xen_block_connect(XenDevice *xendev, Error **errp)
             g_free(ring_ref);
             return;
         }
-    } else if (order <= blockdev->props.max_ring_page_order) {
+    } else if (qemu_xen_gnttab_can_map_multi() &&
+               order <= blockdev->props.max_ring_page_order) {
         unsigned int i;
 
         nr_ring_ref = 1 << order;
@@ -256,8 +256,12 @@ static void xen_block_realize(XenDevice *xendev, Error **errp)
     }
 
     xen_device_backend_printf(xendev, "feature-flush-cache", "%u", 1);
-    xen_device_backend_printf(xendev, "max-ring-page-order", "%u",
-                              blockdev->props.max_ring_page_order);
+
+    if (qemu_xen_gnttab_can_map_multi()) {
+        xen_device_backend_printf(xendev, "max-ring-page-order", "%u",
+                                  blockdev->props.max_ring_page_order);
+    }
+
     xen_device_backend_printf(xendev, "info", "%u", blockdev->info);
 
     xen_device_frontend_printf(xendev, "virtual-device", "%lu",