[PATCH 14/26] hypervisor: support bypassing cache for managed save

[Daniel P. Berrangé <berrange@xxxxxxxxxx>]

Bypassing cache can make save performance more predictable and avoids
trashing the OS cache with data that will not be read again.

Signed-off-by: Daniel P. Berrangé <berrange@xxxxxxxxxx>
---
 src/hypervisor/domain_driver.c | 7 +++++--
 src/hypervisor/domain_driver.h | 1 +
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/hypervisor/domain_driver.c b/src/hypervisor/domain_driver.c
index 4fecaf7e5c..867ee1ae2a 100644
--- a/src/hypervisor/domain_driver.c
+++ b/src/hypervisor/domain_driver.c
@@ -725,9 +725,9 @@ virDomainDriverAutoShutdown(virDomainDriverAutoShutdownConfig *cfg)
     g_autofree bool *transient = NULL;
 
     VIR_DEBUG("Run autoshutdown uri=%s trySave=%d tryShutdown=%d poweroff=%d"
-              "waitShutdownSecs=%d",
+              "waitShutdownSecs=%d saveBypassCache=%d",
               cfg->uri, cfg->trySave, cfg->tryShutdown, cfg->poweroff,
-              cfg->waitShutdownSecs);
+              cfg->waitShutdownSecs, cfg->saveBypassCache);
 
     /*
      * Ideally guests will shutdown in a few seconds, but it would
@@ -784,6 +784,9 @@ virDomainDriverAutoShutdown(virDomainDriverAutoShutdownConfig *cfg)
                 if (state == VIR_DOMAIN_PAUSED)
                     flags[i] = VIR_DOMAIN_SAVE_PAUSED;
             }
+            if (cfg->saveBypassCache)
+                flags[i] |= VIR_DOMAIN_SAVE_BYPASS_CACHE;
+
             virDomainSuspend(domains[i]);
         }
 
diff --git a/src/hypervisor/domain_driver.h b/src/hypervisor/domain_driver.h
index acb7a41b5d..16832f2449 100644
--- a/src/hypervisor/domain_driver.h
+++ b/src/hypervisor/domain_driver.h
@@ -108,6 +108,7 @@ typedef struct _virDomainDriverAutoShutdownConfig {
     virDomainDriverAutoShutdownScope tryShutdown;
     virDomainDriverAutoShutdownScope poweroff;
     int waitShutdownSecs;
+    bool saveBypassCache;
 } virDomainDriverAutoShutdownConfig;
 
 void virDomainDriverAutoShutdown(virDomainDriverAutoShutdownConfig *cfg);
-- 
2.47.1