diff mbox

[v12,2/6] migration: add postcopy blocktime ctx into MigrationIncomingState

Message ID 1509369390-8285-3-git-send-email-a.perevalov@samsung.com (mailing list archive)
State New, archived
Headers show

Commit Message

Alexey Perevalov Oct. 30, 2017, 1:16 p.m. UTC
This patch adds request to kernel space for UFFD_FEATURE_THREAD_ID,
in case when this feature is provided by kernel.

PostcopyBlocktimeContext is incapsulated inside postcopy-ram.c,
due to it's postcopy only feature.
Also it defines PostcopyBlocktimeContext's instance live time.
Information from PostcopyBlocktimeContext instance will be provided
much after postcopy migration end, instance of PostcopyBlocktimeContext
will live till QEMU exit, but part of it (vcpu_addr,
page_fault_vcpu_time) used only during calculation, will be released
when postcopy ended or failed.

To enable postcopy blocktime calculation on destination, need to request
proper capabiltiy (Patch for documentation will be at the tail of the patch
set).

As an example following command enable that capability, assume QEMU was
started with
-chardev socket,id=charmonitor,path=/var/lib/migrate-vm-monitor.sock
option to control it

[root@host]#printf "{\"execute\" : \"qmp_capabilities\"}\r\n \
{\"execute\": \"migrate-set-capabilities\" , \"arguments\":   {
\"capabilities\": [ { \"capability\": \"postcopy-blocktime\", \"state\":
true } ] } }" | nc -U /var/lib/migrate-vm-monitor.sock

Or just with HMP
(qemu) migrate_set_capability postcopy-blocktime on

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Alexey Perevalov <a.perevalov@samsung.com>
---
 migration/migration.h    |  8 +++++++
 migration/postcopy-ram.c | 59 ++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 67 insertions(+)

Comments

Juan Quintela Jan. 2, 2018, 8:51 p.m. UTC | #1
Alexey Perevalov <a.perevalov@samsung.com> wrote:
> This patch adds request to kernel space for UFFD_FEATURE_THREAD_ID,
> in case when this feature is provided by kernel.
>
> PostcopyBlocktimeContext is incapsulated inside postcopy-ram.c,
> due to it's postcopy only feature.
> Also it defines PostcopyBlocktimeContext's instance live time.
> Information from PostcopyBlocktimeContext instance will be provided
> much after postcopy migration end, instance of PostcopyBlocktimeContext
> will live till QEMU exit, but part of it (vcpu_addr,
> page_fault_vcpu_time) used only during calculation, will be released
> when postcopy ended or failed.
>
> To enable postcopy blocktime calculation on destination, need to request
> proper capabiltiy (Patch for documentation will be at the tail of the patch
> set).
>
> As an example following command enable that capability, assume QEMU was
> started with
> -chardev socket,id=charmonitor,path=/var/lib/migrate-vm-monitor.sock
> option to control it
>
> [root@host]#printf "{\"execute\" : \"qmp_capabilities\"}\r\n \
> {\"execute\": \"migrate-set-capabilities\" , \"arguments\":   {
> \"capabilities\": [ { \"capability\": \"postcopy-blocktime\", \"state\":
> true } ] } }" | nc -U /var/lib/migrate-vm-monitor.sock
>
> Or just with HMP
> (qemu) migrate_set_capability postcopy-blocktime on
>
> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> Signed-off-by: Alexey Perevalov <a.perevalov@samsung.com>

Reviewed-by: Juan Quintela <quintela@redhat.com>
Eric Blake Jan. 2, 2018, 9:22 p.m. UTC | #2
On 10/30/2017 08:16 AM, Alexey Perevalov wrote:
> This patch adds request to kernel space for UFFD_FEATURE_THREAD_ID,
> in case when this feature is provided by kernel.

Either 'in the case when this feature' or 'in case this feature'.

> 
> PostcopyBlocktimeContext is incapsulated inside postcopy-ram.c,

s/incapsulated/encapsulated/

> due to it's postcopy only feature.

s/it's postcopy only/it being a postcopy-only/

> Also it defines PostcopyBlocktimeContext's instance live time.
> Information from PostcopyBlocktimeContext instance will be provided
> much after postcopy migration end, instance of PostcopyBlocktimeContext
> will live till QEMU exit, but part of it (vcpu_addr,
> page_fault_vcpu_time) used only during calculation, will be released
> when postcopy ended or failed.
> 
> To enable postcopy blocktime calculation on destination, need to request
> proper capabiltiy (Patch for documentation will be at the tail of the patch

s/capabiltiy/capability/

> set).
> 
> As an example following command enable that capability, assume QEMU was
> started with
> -chardev socket,id=charmonitor,path=/var/lib/migrate-vm-monitor.sock
> option to control it
> 
> [root@host]#printf "{\"execute\" : \"qmp_capabilities\"}\r\n \
> {\"execute\": \"migrate-set-capabilities\" , \"arguments\":   {
> \"capabilities\": [ { \"capability\": \"postcopy-blocktime\", \"state\":
> true } ] } }" | nc -U /var/lib/migrate-vm-monitor.sock
> 
> Or just with HMP
> (qemu) migrate_set_capability postcopy-blocktime on
> 
> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> Signed-off-by: Alexey Perevalov <a.perevalov@samsung.com>
> ---
Juan Quintela Jan. 3, 2018, 8:25 a.m. UTC | #3
Eric Blake <eblake@redhat.com> wrote:
> On 10/30/2017 08:16 AM, Alexey Perevalov wrote:
>> This patch adds request to kernel space for UFFD_FEATURE_THREAD_ID,
>> in case when this feature is provided by kernel.
>
> Either 'in the case when this feature' or 'in case this feature'.
>
>> 
>> PostcopyBlocktimeContext is incapsulated inside postcopy-ram.c,
>
> s/incapsulated/encapsulated/
>
>> due to it's postcopy only feature.
>
> s/it's postcopy only/it being a postcopy-only/


>
>> Also it defines PostcopyBlocktimeContext's instance live time.
>> Information from PostcopyBlocktimeContext instance will be provided
>> much after postcopy migration end, instance of PostcopyBlocktimeContext
>> will live till QEMU exit, but part of it (vcpu_addr,
>> page_fault_vcpu_time) used only during calculation, will be released
>> when postcopy ended or failed.
>> 
>> To enable postcopy blocktime calculation on destination, need to request
>> proper capabiltiy (Patch for documentation will be at the tail of the patch
>
> s/capabiltiy/capability/

Changed for the pull request


>
>> set).
>> 
>> As an example following command enable that capability, assume QEMU was
>> started with
>> -chardev socket,id=charmonitor,path=/var/lib/migrate-vm-monitor.sock
>> option to control it
>> 
>> [root@host]#printf "{\"execute\" : \"qmp_capabilities\"}\r\n \
>> {\"execute\": \"migrate-set-capabilities\" , \"arguments\":   {
>> \"capabilities\": [ { \"capability\": \"postcopy-blocktime\", \"state\":
>> true } ] } }" | nc -U /var/lib/migrate-vm-monitor.sock
>> 
>> Or just with HMP
>> (qemu) migrate_set_capability postcopy-blocktime on
>> 
>> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
>> Signed-off-by: Alexey Perevalov <a.perevalov@samsung.com>
>> ---
diff mbox

Patch

diff --git a/migration/migration.h b/migration/migration.h
index 5f5e527..fb8d2ef 100644
--- a/migration/migration.h
+++ b/migration/migration.h
@@ -22,6 +22,8 @@ 
 #include "hw/qdev.h"
 #include "io/channel.h"
 
+struct PostcopyBlocktimeContext;
+
 /* State for the incoming migration */
 struct MigrationIncomingState {
     QEMUFile *from_src_file;
@@ -59,6 +61,12 @@  struct MigrationIncomingState {
     /* The coroutine we should enter (back) after failover */
     Coroutine *migration_incoming_co;
     QemuSemaphore colo_incoming_sem;
+
+    /*
+     * PostcopyBlocktimeContext to keep information for postcopy
+     * live migration, to calculate vCPU block time
+     * */
+    struct PostcopyBlocktimeContext *blocktime_ctx;
 };
 
 MigrationIncomingState *migration_incoming_get_current(void);
diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
index bec6c2c..c18ec5a 100644
--- a/migration/postcopy-ram.c
+++ b/migration/postcopy-ram.c
@@ -61,6 +61,52 @@  struct PostcopyDiscardState {
 #include <sys/eventfd.h>
 #include <linux/userfaultfd.h>
 
+typedef struct PostcopyBlocktimeContext {
+    /* time when page fault initiated per vCPU */
+    int64_t *page_fault_vcpu_time;
+    /* page address per vCPU */
+    uint64_t *vcpu_addr;
+    int64_t total_blocktime;
+    /* blocktime per vCPU */
+    int64_t *vcpu_blocktime;
+    /* point in time when last page fault was initiated */
+    int64_t last_begin;
+    /* number of vCPU are suspended */
+    int smp_cpus_down;
+
+    /*
+     * Handler for exit event, necessary for
+     * releasing whole blocktime_ctx
+     */
+    Notifier exit_notifier;
+} PostcopyBlocktimeContext;
+
+static void destroy_blocktime_context(struct PostcopyBlocktimeContext *ctx)
+{
+    g_free(ctx->page_fault_vcpu_time);
+    g_free(ctx->vcpu_addr);
+    g_free(ctx->vcpu_blocktime);
+    g_free(ctx);
+}
+
+static void migration_exit_cb(Notifier *n, void *data)
+{
+    PostcopyBlocktimeContext *ctx = container_of(n, PostcopyBlocktimeContext,
+                                                 exit_notifier);
+    destroy_blocktime_context(ctx);
+}
+
+static struct PostcopyBlocktimeContext *blocktime_context_new(void)
+{
+    PostcopyBlocktimeContext *ctx = g_new0(PostcopyBlocktimeContext, 1);
+    ctx->page_fault_vcpu_time = g_new0(int64_t, smp_cpus);
+    ctx->vcpu_addr = g_new0(uint64_t, smp_cpus);
+    ctx->vcpu_blocktime = g_new0(int64_t, smp_cpus);
+
+    ctx->exit_notifier.notify = migration_exit_cb;
+    qemu_add_exit_notifier(&ctx->exit_notifier);
+    return ctx;
+}
 
 /**
  * receive_ufd_features: check userfault fd features, to request only supported
@@ -153,6 +199,19 @@  static bool ufd_check_and_apply(int ufd, MigrationIncomingState *mis)
         }
     }
 
+#ifdef UFFD_FEATURE_THREAD_ID
+    if (migrate_postcopy_blocktime() && mis &&
+        UFFD_FEATURE_THREAD_ID & supported_features) {
+        /* kernel supports that feature */
+        /* don't create blocktime_context if it exists */
+        if (!mis->blocktime_ctx) {
+            mis->blocktime_ctx = blocktime_context_new();
+        }
+
+        asked_features |= UFFD_FEATURE_THREAD_ID;
+    }
+#endif
+
     /*
      * request features, even if asked_features is 0, due to
      * kernel expects UFFD_API before UFFDIO_REGISTER, per