Merge remote-tracking branch 'remotes/aperard/tags/pull-xen-20200227' into staging

Xen queue 2020-02-27

* fix for xen-block
* fix in exec.c for migration of xen guest
* one cleanup patch

# gpg: Signature made Thu 27 Feb 2020 11:57:12 GMT
# gpg:                using RSA key F80C006308E22CFD8A92E7980CF5572FD7FB55AF
# gpg:                issuer "anthony.perard@citrix.com"
# gpg: Good signature from "Anthony PERARD <anthony.perard@gmail.com>" [marginal]
# gpg:                 aka "Anthony PERARD <anthony.perard@citrix.com>" [marginal]
# gpg: WARNING: This key is not certified with sufficiently trusted signatures!
# gpg:          It is not certain that the signature belongs to the owner.
# Primary key fingerprint: 5379 2F71 024C 600F 778A  7161 D8D5 7199 DF83 42C8
#      Subkey fingerprint: F80C 0063 08E2 2CFD 8A92  E798 0CF5 572F D7FB 55AF

* remotes/aperard/tags/pull-xen-20200227:
  Memory: Only call ramblock_ptr when needed in qemu_ram_writeback
  xen-bus/block: explicitly assign event channels to an AioContext
  hw/xen/xen_pt_load_rom: Remove unused includes

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

3 files changed, 41 insertions, 10 deletions

diff --git a/hw/block/dataplane/xen-block.c b/hw/block/dataplane/xen-block.c
index 3b9caeb2fa..288a87a814 100644
--- a/hw/block/dataplane/xen-block.c
+++ b/hw/block/dataplane/xen-block.c
@@ -685,12 +685,24 @@ void xen_block_dataplane_stop(XenBlockDataPlane *dataplane)
         return;
     }
 
+    xendev = dataplane->xendev;
+
     aio_context_acquire(dataplane->ctx);
+    if (dataplane->event_channel) {
+        /* Only reason for failure is a NULL channel */
+        xen_device_set_event_channel_context(xendev, dataplane->event_channel,
+                                             qemu_get_aio_context(),
+                                             &error_abort);
+    }
     /* Xen doesn't have multiple users for nodes, so this can't fail */
     blk_set_aio_context(dataplane->blk, qemu_get_aio_context(), &error_abort);
     aio_context_release(dataplane->ctx);
 
-    xendev = dataplane->xendev;
+    /*
+     * Now that the context has been moved onto the main thread, cancel
+     * further processing.
+     */
+    qemu_bh_cancel(dataplane->bh);
 
     if (dataplane->event_channel) {
         Error *local_err = NULL;
@@ -807,7 +819,7 @@ void xen_block_dataplane_start(XenBlockDataPlane *dataplane,
     }
 
     dataplane->event_channel =
-        xen_device_bind_event_channel(xendev, dataplane->ctx, event_channel,
+        xen_device_bind_event_channel(xendev, event_channel,
                                       xen_block_dataplane_event, dataplane,
                                       &local_err);
     if (local_err) {
@@ -818,7 +830,11 @@ void xen_block_dataplane_start(XenBlockDataPlane *dataplane,
     aio_context_acquire(dataplane->ctx);
     /* If other users keep the BlockBackend in the iothread, that's ok */
     blk_set_aio_context(dataplane->blk, dataplane->ctx, NULL);
+    /* Only reason for failure is a NULL channel */
+    xen_device_set_event_channel_context(xendev, dataplane->event_channel,
+                                         dataplane->ctx, &error_abort);
     aio_context_release(dataplane->ctx);
+
     return;
 
 stop:
diff --git a/hw/xen/xen-bus.c b/hw/xen/xen-bus.c
index 919e66162a..18237b34ea 100644
--- a/hw/xen/xen-bus.c
+++ b/hw/xen/xen-bus.c
@@ -1089,8 +1089,26 @@ static void xen_device_event(void *opaque)
     }
 }
 
+void xen_device_set_event_channel_context(XenDevice *xendev,
+                                          XenEventChannel *channel,
+                                          AioContext *ctx,
+                                          Error **errp)
+{
+    if (!channel) {
+        error_setg(errp, "bad channel");
+        return;
+    }
+
+    if (channel->ctx)
+        aio_set_fd_handler(channel->ctx, xenevtchn_fd(channel->xeh), true,
+                           NULL, NULL, NULL, NULL);
+
+    channel->ctx = ctx;
+    aio_set_fd_handler(channel->ctx, xenevtchn_fd(channel->xeh), true,
+                       xen_device_event, NULL, xen_device_poll, channel);
+}
+
 XenEventChannel *xen_device_bind_event_channel(XenDevice *xendev,
-                                               AioContext *ctx,
                                                unsigned int port,
                                                XenEventHandler handler,
                                                void *opaque, Error **errp)
@@ -1116,9 +1134,10 @@ XenEventChannel *xen_device_bind_event_channel(XenDevice *xendev,
     channel->handler = handler;
     channel->opaque = opaque;
 
-    channel->ctx = ctx;
-    aio_set_fd_handler(channel->ctx, xenevtchn_fd(channel->xeh), true,
-                       xen_device_event, NULL, xen_device_poll, channel);
+    /* Only reason for failure is a NULL channel */
+    xen_device_set_event_channel_context(xendev, channel,
+                                         qemu_get_aio_context(),
+                                         &error_abort);
 
     QLIST_INSERT_HEAD(&xendev->event_channels, channel, list);
 
diff --git a/hw/xen/xen_pt_load_rom.c b/hw/xen/xen_pt_load_rom.c
index 307a5c93e2..a50a80837e 100644
--- a/hw/xen/xen_pt_load_rom.c
+++ b/hw/xen/xen_pt_load_rom.c
@@ -3,12 +3,8 @@
  */
 #include "qemu/osdep.h"
 #include "qapi/error.h"
-#include "hw/i386/pc.h"
 #include "qemu/error-report.h"
-#include "ui/console.h"
 #include "hw/loader.h"
-#include "monitor/monitor.h"
-#include "qemu/range.h"
 #include "hw/pci/pci.h"
 #include "xen_pt.h"