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[Qemu-devel] [PULL v2 26/50] postcopy: Add vhost-user flag for postcopy
From: |
Michael S. Tsirkin |
Subject: |
[Qemu-devel] [PULL v2 26/50] postcopy: Add vhost-user flag for postcopy and check it |
Date: |
Tue, 20 Mar 2018 05:17:39 +0200 |
From: "Dr. David Alan Gilbert" <address@hidden>
Add a vhost feature flag for postcopy support, and
use the postcopy notifier to check it before allowing postcopy.
Signed-off-by: Dr. David Alan Gilbert <address@hidden>
Reviewed-by: Peter Xu <address@hidden>
Reviewed-by: Michael S. Tsirkin <address@hidden>
Signed-off-by: Michael S. Tsirkin <address@hidden>
---
docs/interop/vhost-user.txt | 10 +++++++++
contrib/libvhost-user/libvhost-user.h | 2 ++
hw/virtio/vhost-user.c | 41 ++++++++++++++++++++++++++++++++++-
3 files changed, 52 insertions(+), 1 deletion(-)
diff --git a/docs/interop/vhost-user.txt b/docs/interop/vhost-user.txt
index cb3a759..91a572d 100644
--- a/docs/interop/vhost-user.txt
+++ b/docs/interop/vhost-user.txt
@@ -290,6 +290,15 @@ Once the source has finished migration, rings will be
stopped by
the source. No further update must be done before rings are
restarted.
+In postcopy migration the slave is started before all the memory has been
+received from the source host, and care must be taken to avoid accessing pages
+that have yet to be received. The slave opens a 'userfault'-fd and registers
+the memory with it; this fd is then passed back over to the master.
+The master services requests on the userfaultfd for pages that are accessed
+and when the page is available it performs WAKE ioctl's on the userfaultfd
+to wake the stalled slave. The client indicates support for this via the
+VHOST_USER_PROTOCOL_F_PAGEFAULT feature.
+
Memory access
-------------
@@ -369,6 +378,7 @@ Protocol features
#define VHOST_USER_PROTOCOL_F_SLAVE_REQ 5
#define VHOST_USER_PROTOCOL_F_CROSS_ENDIAN 6
#define VHOST_USER_PROTOCOL_F_CRYPTO_SESSION 7
+#define VHOST_USER_PROTOCOL_F_PAGEFAULT 8
Master message types
--------------------
diff --git a/contrib/libvhost-user/libvhost-user.h
b/contrib/libvhost-user/libvhost-user.h
index 18f95f6..96db29c 100644
--- a/contrib/libvhost-user/libvhost-user.h
+++ b/contrib/libvhost-user/libvhost-user.h
@@ -48,6 +48,8 @@ enum VhostUserProtocolFeature {
VHOST_USER_PROTOCOL_F_NET_MTU = 4,
VHOST_USER_PROTOCOL_F_SLAVE_REQ = 5,
VHOST_USER_PROTOCOL_F_CROSS_ENDIAN = 6,
+ VHOST_USER_PROTOCOL_F_CRYPTO_SESSION = 7,
+ VHOST_USER_PROTOCOL_F_PAGEFAULT = 8,
VHOST_USER_PROTOCOL_F_MAX
};
diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
index 41ff5cf..aab35c4 100644
--- a/hw/virtio/vhost-user.c
+++ b/hw/virtio/vhost-user.c
@@ -18,6 +18,8 @@
#include "qemu/error-report.h"
#include "qemu/sockets.h"
#include "sysemu/cryptodev.h"
+#include "migration/migration.h"
+#include "migration/postcopy-ram.h"
#include <sys/ioctl.h>
#include <sys/socket.h>
@@ -41,7 +43,7 @@ enum VhostUserProtocolFeature {
VHOST_USER_PROTOCOL_F_SLAVE_REQ = 5,
VHOST_USER_PROTOCOL_F_CROSS_ENDIAN = 6,
VHOST_USER_PROTOCOL_F_CRYPTO_SESSION = 7,
-
+ VHOST_USER_PROTOCOL_F_PAGEFAULT = 8,
VHOST_USER_PROTOCOL_F_MAX
};
@@ -164,8 +166,10 @@ static VhostUserMsg m __attribute__ ((unused));
#define VHOST_USER_VERSION (0x1)
struct vhost_user {
+ struct vhost_dev *dev;
CharBackend *chr;
int slave_fd;
+ NotifierWithReturn postcopy_notifier;
};
static bool ioeventfd_enabled(void)
@@ -791,6 +795,33 @@ out:
return ret;
}
+static int vhost_user_postcopy_notifier(NotifierWithReturn *notifier,
+ void *opaque)
+{
+ struct PostcopyNotifyData *pnd = opaque;
+ struct vhost_user *u = container_of(notifier, struct vhost_user,
+ postcopy_notifier);
+ struct vhost_dev *dev = u->dev;
+
+ switch (pnd->reason) {
+ case POSTCOPY_NOTIFY_PROBE:
+ if (!virtio_has_feature(dev->protocol_features,
+ VHOST_USER_PROTOCOL_F_PAGEFAULT)) {
+ /* TODO: Get the device name into this error somehow */
+ error_setg(pnd->errp,
+ "vhost-user backend not capable of postcopy");
+ return -ENOENT;
+ }
+ break;
+
+ default:
+ /* We ignore notifications we don't know */
+ break;
+ }
+
+ return 0;
+}
+
static int vhost_user_init(struct vhost_dev *dev, void *opaque)
{
uint64_t features, protocol_features;
@@ -802,6 +833,7 @@ static int vhost_user_init(struct vhost_dev *dev, void
*opaque)
u = g_new0(struct vhost_user, 1);
u->chr = opaque;
u->slave_fd = -1;
+ u->dev = dev;
dev->opaque = u;
err = vhost_user_get_features(dev, &features);
@@ -858,6 +890,9 @@ static int vhost_user_init(struct vhost_dev *dev, void
*opaque)
return err;
}
+ u->postcopy_notifier.notify = vhost_user_postcopy_notifier;
+ postcopy_add_notifier(&u->postcopy_notifier);
+
return 0;
}
@@ -868,6 +903,10 @@ static int vhost_user_cleanup(struct vhost_dev *dev)
assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER);
u = dev->opaque;
+ if (u->postcopy_notifier.notify) {
+ postcopy_remove_notifier(&u->postcopy_notifier);
+ u->postcopy_notifier.notify = NULL;
+ }
if (u->slave_fd >= 0) {
qemu_set_fd_handler(u->slave_fd, NULL, NULL, NULL);
close(u->slave_fd);
--
MST
- [Qemu-devel] [PULL v2 16/50] pc-dimm: make qmp_pc_dimm_device_list() sort devices by address, (continued)
- [Qemu-devel] [PULL v2 16/50] pc-dimm: make qmp_pc_dimm_device_list() sort devices by address, Michael S. Tsirkin, 2018/03/19
- [Qemu-devel] [PULL v2 19/50] tests/bios-tables-test: add test cases for DIMM proximity, Michael S. Tsirkin, 2018/03/19
- [Qemu-devel] [PULL v2 18/50] hw/acpi-build: build SRAT memory affinity structures for DIMM devices, Michael S. Tsirkin, 2018/03/19
- [Qemu-devel] [PULL v2 17/50] qmp: distinguish PC-DIMM and NVDIMM in MemoryDeviceInfoList, Michael S. Tsirkin, 2018/03/19
- [Qemu-devel] [PULL v2 12/50] virt_arm: acpi: reuse common build_fadt(), Michael S. Tsirkin, 2018/03/19
- [Qemu-devel] [PULL v2 11/50] acpi: move build_fadt() from i386 specific to generic ACPI source, Michael S. Tsirkin, 2018/03/19
- [Qemu-devel] [PULL v2 20/50] test/acpi-test-data: add ACPI tables for dimmpxm test, Michael S. Tsirkin, 2018/03/19
- [Qemu-devel] [PULL v2 21/50] Makefile: add target to print generated files, Michael S. Tsirkin, 2018/03/19
- [Qemu-devel] [PULL v2 22/50] migrate: Update ram_block_discard_range for shared, Michael S. Tsirkin, 2018/03/19
- [Qemu-devel] [PULL v2 23/50] qemu_ram_block_host_offset, Michael S. Tsirkin, 2018/03/19
- [Qemu-devel] [PULL v2 26/50] postcopy: Add vhost-user flag for postcopy and check it,
Michael S. Tsirkin <=
- [Qemu-devel] [PULL v2 24/50] postcopy: use UFFDIO_ZEROPAGE only when available, Michael S. Tsirkin, 2018/03/19
- [Qemu-devel] [PULL v2 25/50] postcopy: Add notifier chain, Michael S. Tsirkin, 2018/03/19
- [Qemu-devel] [PULL v2 27/50] vhost-user: Add 'VHOST_USER_POSTCOPY_ADVISE' message, Michael S. Tsirkin, 2018/03/19
- [Qemu-devel] [PULL v2 28/50] libvhost-user: Support sending fds back to qemu, Michael S. Tsirkin, 2018/03/19
- [Qemu-devel] [PULL v2 29/50] libvhost-user: Open userfaultfd, Michael S. Tsirkin, 2018/03/19
- [Qemu-devel] [PULL v2 31/50] vhost+postcopy: Register shared ufd with postcopy, Michael S. Tsirkin, 2018/03/19
- [Qemu-devel] [PULL v2 32/50] vhost+postcopy: Transmit 'listen' to slave, Michael S. Tsirkin, 2018/03/19
- [Qemu-devel] [PULL v2 33/50] postcopy+vhost-user: Split set_mem_table for postcopy, Michael S. Tsirkin, 2018/03/19
- [Qemu-devel] [PULL v2 34/50] migration/ram: ramblock_recv_bitmap_test_byte_offset, Michael S. Tsirkin, 2018/03/19
- [Qemu-devel] [PULL v2 37/50] vhost+postcopy: Stash RAMBlock and offset, Michael S. Tsirkin, 2018/03/19