From: Steve Sistare <steven.sistare@oracle.com>
To: qemu-devel@nongnu.org
Cc: "Daniel P. Berrange" <berrange@redhat.com>,
"Michael S. Tsirkin" <mst@redhat.com>,
"Jason Zeng" <jason.zeng@linux.intel.com>,
"Alex Bennée" <alex.bennee@linaro.org>,
"Juan Quintela" <quintela@redhat.com>,
"Dr. David Alan Gilbert" <dgilbert@redhat.com>,
"Eric Blake" <eblake@redhat.com>,
"Markus Armbruster" <armbru@redhat.com>,
"Alex Williamson" <alex.williamson@redhat.com>,
"Steve Sistare" <steven.sistare@oracle.com>,
"Stefan Hajnoczi" <stefanha@redhat.com>,
"Marc-André Lureau" <marcandre.lureau@redhat.com>,
"Paolo Bonzini" <pbonzini@redhat.com>,
"Philippe Mathieu-Daudé" <philmd@redhat.com>
Subject: [PATCH V5 11/25] cpr: restart mode
Date: Wed, 7 Jul 2021 10:20:20 -0700 [thread overview]
Message-ID: <1625678434-240960-12-git-send-email-steven.sistare@oracle.com> (raw)
In-Reply-To: <1625678434-240960-1-git-send-email-steven.sistare@oracle.com>
Provide the cprsave restart mode, which preserves the guest VM across a
restart of the qemu process. After cprsave, the caller passes qemu
command-line arguments to cprexec, which directly exec's the new qemu
binary. The arguments must include -S so new qemu starts in a paused state.
The caller resumes the guest by calling cprload.
To use the restart mode, qemu must be started with the memfd-alloc machine
option. The memfd's are saved to the environment and kept open across exec,
after which they are found from the environment and re-mmap'd. Hence guest
ram is preserved in place, albeit with new virtual addresses in the qemu
process.
The restart mode supports vfio devices in a subsequent patch.
Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
---
migration/cpr.c | 21 +++++++++++++++++++++
softmmu/physmem.c | 6 +++++-
2 files changed, 26 insertions(+), 1 deletion(-)
diff --git a/migration/cpr.c b/migration/cpr.c
index c5bad8a..fb57dec 100644
--- a/migration/cpr.c
+++ b/migration/cpr.c
@@ -29,6 +29,7 @@
#include "sysemu/xen.h"
#include "hw/vfio/vfio-common.h"
#include "hw/virtio/vhost.h"
+#include "qemu/env.h"
QEMUFile *qf_file_open(const char *path, int flags, int mode,
const char *name, Error **errp)
@@ -108,6 +109,26 @@ done:
return;
}
+static int preserve_fd(const char *name, const char *val, void *handle)
+{
+ qemu_clr_cloexec(atoi(val));
+ return 0;
+}
+
+void cprexec(strList *args, Error **errp)
+{
+ if (xen_enabled()) {
+ error_setg(errp, "xen does not support cprexec");
+ return;
+ }
+ if (!runstate_check(RUN_STATE_SAVE_VM)) {
+ error_setg(errp, "runstate is not save-vm");
+ return;
+ }
+ walkenv(FD_PREFIX, preserve_fd, 0);
+ qemu_system_exec_request(args);
+}
+
void cprload(const char *file, Error **errp)
{
QEMUFile *f;
diff --git a/softmmu/physmem.c b/softmmu/physmem.c
index b149250..8a65ef7 100644
--- a/softmmu/physmem.c
+++ b/softmmu/physmem.c
@@ -65,6 +65,7 @@
#include "qemu/pmem.h"
#include "qemu/memfd.h"
+#include "qemu/env.h"
#include "migration/vmstate.h"
#include "qemu/range.h"
@@ -1986,7 +1987,7 @@ static void ram_block_add(RAMBlock *new_block, Error **errp)
} else {
name = memory_region_name(new_block->mr);
if (ms->memfd_alloc) {
- int mfd = -1; /* placeholder until next patch */
+ int mfd = getenv_fd(name);
mr->align = QEMU_VMALLOC_ALIGN;
if (mfd < 0) {
mfd = qemu_memfd_create(name, maxlen + mr->align,
@@ -1994,7 +1995,9 @@ static void ram_block_add(RAMBlock *new_block, Error **errp)
if (mfd < 0) {
return;
}
+ setenv_fd(name, mfd);
}
+ qemu_clr_cloexec(mfd);
new_block->flags |= RAM_SHARED;
addr = file_ram_alloc(new_block, maxlen, mfd,
false, false, 0, errp);
@@ -2246,6 +2249,7 @@ void qemu_ram_free(RAMBlock *block)
}
qemu_mutex_lock_ramlist();
+ unsetenv_fd(memory_region_name(block->mr));
QLIST_REMOVE_RCU(block, next);
ram_list.mru_block = NULL;
/* Write list before version */
--
1.8.3.1
next prev parent reply other threads:[~2021-07-07 17:31 UTC|newest]
Thread overview: 74+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-07 17:20 [PATCH V5 00/25] Live Update Steve Sistare
2021-07-07 17:20 ` [PATCH V5 01/25] qemu_ram_volatile Steve Sistare
2021-07-08 12:01 ` Marc-André Lureau
2021-07-12 17:06 ` Steven Sistare
2021-07-07 17:20 ` [PATCH V5 02/25] cpr: reboot mode Steve Sistare
2021-07-08 12:25 ` Marc-André Lureau
2021-07-12 17:07 ` Steven Sistare
2021-08-04 15:48 ` Eric Blake
2021-07-07 17:20 ` [PATCH V5 03/25] cpr: QMP interfaces for reboot Steve Sistare
2021-07-08 13:27 ` Marc-André Lureau
2021-07-12 17:07 ` Steven Sistare
2021-08-04 15:48 ` Eric Blake
2021-08-04 20:27 ` Steven Sistare
2021-07-07 17:20 ` [PATCH V5 04/25] cpr: HMP " Steve Sistare
2021-07-28 4:55 ` Zheng Chuan
2021-07-07 17:20 ` [PATCH V5 05/25] as_flat_walk Steve Sistare
2021-07-08 13:49 ` Marc-André Lureau
2021-07-12 17:07 ` Steven Sistare
2021-07-07 17:20 ` [PATCH V5 06/25] oslib: qemu_clr_cloexec Steve Sistare
2021-07-08 13:58 ` Marc-André Lureau
2021-07-12 17:07 ` Steven Sistare
2021-07-07 17:20 ` [PATCH V5 07/25] machine: memfd-alloc option Steve Sistare
2021-07-08 14:20 ` Marc-André Lureau
2021-07-12 17:07 ` Steven Sistare
2021-07-12 17:45 ` Marc-André Lureau
2021-07-07 17:20 ` [PATCH V5 08/25] vl: add helper to request re-exec Steve Sistare
2021-07-08 14:31 ` Marc-André Lureau
2021-07-12 17:07 ` Steven Sistare
2021-07-07 17:20 ` [PATCH V5 09/25] string to strList Steve Sistare
2021-07-08 14:37 ` Marc-André Lureau
2021-07-07 17:20 ` [PATCH V5 10/25] util: env var helpers Steve Sistare
2021-07-08 15:10 ` Marc-André Lureau
2021-07-12 19:19 ` Steven Sistare
2021-07-12 19:36 ` Marc-André Lureau
2021-07-13 16:15 ` Steven Sistare
2021-07-07 17:20 ` Steve Sistare [this message]
2021-07-08 15:43 ` [PATCH V5 11/25] cpr: restart mode Marc-André Lureau
2021-07-08 15:54 ` Marc-André Lureau
2021-07-12 19:19 ` Steven Sistare
2021-07-07 17:20 ` [PATCH V5 12/25] cpr: QMP interfaces for restart Steve Sistare
2021-07-08 15:49 ` Marc-André Lureau
2021-07-12 19:19 ` Steven Sistare
2021-08-04 16:00 ` Eric Blake
2021-08-04 20:22 ` Steven Sistare
2021-07-07 17:20 ` [PATCH V5 13/25] cpr: HMP " Steve Sistare
2021-07-28 4:56 ` Zheng Chuan
2021-07-07 17:20 ` [PATCH V5 14/25] pci: export functions for cpr Steve Sistare
2021-07-07 17:20 ` [PATCH V5 15/25] vfio-pci: refactor " Steve Sistare
2021-07-07 17:20 ` [PATCH V5 16/25] vfio-pci: cpr part 1 Steve Sistare
2021-07-16 17:45 ` Alex Williamson
2021-07-19 17:43 ` Steven Sistare
2021-07-28 4:56 ` Zheng Chuan
2021-07-30 12:50 ` Steven Sistare
2021-07-07 17:20 ` [PATCH V5 17/25] vfio-pci: cpr part 2 Steve Sistare
2021-07-16 20:51 ` Alex Williamson
2021-07-19 17:44 ` Steven Sistare
2021-07-19 18:10 ` Alex Williamson
2021-07-19 18:38 ` Steven Sistare
2021-07-28 4:56 ` Zheng Chuan
2021-07-30 12:52 ` Steven Sistare
2021-07-31 6:07 ` Zheng Chuan
2021-07-07 17:20 ` [PATCH V5 18/25] vhost: reset vhost devices upon cprsave Steve Sistare
2021-07-07 17:20 ` [PATCH V5 19/25] hostmem-memfd: cpr support Steve Sistare
2021-07-07 17:20 ` [PATCH V5 20/25] chardev: cpr framework Steve Sistare
2021-07-08 16:03 ` Marc-André Lureau
2021-07-12 19:20 ` Steven Sistare
2021-07-12 19:49 ` Marc-André Lureau
2021-07-13 14:34 ` Steven Sistare
2021-07-07 17:20 ` [PATCH V5 21/25] chardev: cpr for simple devices Steve Sistare
2021-07-07 17:20 ` [PATCH V5 22/25] chardev: cpr for pty Steve Sistare
2021-07-07 17:20 ` [PATCH V5 23/25] chardev: cpr for sockets Steve Sistare
2021-07-29 4:04 ` Zheng Chuan
2021-07-07 17:20 ` [PATCH V5 24/25] cpr: only-cpr-capable option Steve Sistare
2021-07-07 17:20 ` [PATCH V5 25/25] simplify savevm Steve Sistare
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