aboutsummaryrefslogtreecommitdiff
path: root/savevm.c
diff options
context:
space:
mode:
authorJan Kiszka <jan.kiszka@siemens.com>2010-03-01 19:10:30 +0100
committerMarcelo Tosatti <mtosatti@redhat.com>2010-03-04 00:29:28 -0300
commitea375f9ab8c76686dca0af8cb4f87a4eb569cad3 (patch)
tree51e0476453c95a64bd34bc148082ac277a458203 /savevm.c
parentb0b1d69079fcb9453f45aade9e9f6b71422147b0 (diff)
downloadqemu-ea375f9ab8c76686dca0af8cb4f87a4eb569cad3.zip
qemu-ea375f9ab8c76686dca0af8cb4f87a4eb569cad3.tar.gz
qemu-ea375f9ab8c76686dca0af8cb4f87a4eb569cad3.tar.bz2
KVM: Rework VCPU state writeback API
This grand cleanup drops all reset and vmsave/load related synchronization points in favor of four(!) generic hooks: - cpu_synchronize_all_states in qemu_savevm_state_complete (initial sync from kernel before vmsave) - cpu_synchronize_all_post_init in qemu_loadvm_state (writeback after vmload) - cpu_synchronize_all_post_init in main after machine init - cpu_synchronize_all_post_reset in qemu_system_reset (writeback after system reset) These writeback points + the existing one of VCPU exec after cpu_synchronize_state map on three levels of writeback: - KVM_PUT_RUNTIME_STATE (during runtime, other VCPUs continue to run) - KVM_PUT_RESET_STATE (on synchronous system reset, all VCPUs stopped) - KVM_PUT_FULL_STATE (on init or vmload, all VCPUs stopped as well) This level is passed to the arch-specific VCPU state writing function that will decide which concrete substates need to be written. That way, no writer of load, save or reset functions that interact with in-kernel KVM states will ever have to worry about synchronization again. That also means that a lot of reasons for races, segfaults and deadlocks are eliminated. cpu_synchronize_state remains untouched, just as Anthony suggested. We continue to need it before reading or writing of VCPU states that are also tracked by in-kernel KVM subsystems. Consequently, this patch removes many cpu_synchronize_state calls that are now redundant, just like remaining explicit register syncs. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Diffstat (limited to 'savevm.c')
-rw-r--r--savevm.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/savevm.c b/savevm.c
index 4b58663..a6e774b 100644
--- a/savevm.c
+++ b/savevm.c
@@ -1345,6 +1345,8 @@ int qemu_savevm_state_complete(Monitor *mon, QEMUFile *f)
{
SaveStateEntry *se;
+ cpu_synchronize_all_states();
+
QTAILQ_FOREACH(se, &savevm_handlers, entry) {
if (se->save_live_state == NULL)
continue;
@@ -1545,6 +1547,8 @@ int qemu_loadvm_state(QEMUFile *f)
}
}
+ cpu_synchronize_all_post_init();
+
ret = 0;
out: