From ea375f9ab8c76686dca0af8cb4f87a4eb569cad3 Mon Sep 17 00:00:00 2001 From: Jan Kiszka Date: Mon, 1 Mar 2010 19:10:30 +0100 Subject: 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 Signed-off-by: Marcelo Tosatti --- target-i386/machine.c | 11 ----------- 1 file changed, 11 deletions(-) (limited to 'target-i386/machine.c') diff --git a/target-i386/machine.c b/target-i386/machine.c index 87704918be..b547e2ac7a 100644 --- a/target-i386/machine.c +++ b/target-i386/machine.c @@ -321,8 +321,6 @@ static void cpu_pre_save(void *opaque) CPUState *env = opaque; int i; - cpu_synchronize_state(env); - /* FPU */ env->fpus_vmstate = (env->fpus & ~0x3800) | (env->fpstt & 0x7) << 11; env->fptag_vmstate = 0; @@ -337,14 +335,6 @@ static void cpu_pre_save(void *opaque) #endif } -static int cpu_pre_load(void *opaque) -{ - CPUState *env = opaque; - - cpu_synchronize_state(env); - return 0; -} - static int cpu_post_load(void *opaque, int version_id) { CPUState *env = opaque; @@ -373,7 +363,6 @@ static const VMStateDescription vmstate_cpu = { .minimum_version_id = 3, .minimum_version_id_old = 3, .pre_save = cpu_pre_save, - .pre_load = cpu_pre_load, .post_load = cpu_post_load, .fields = (VMStateField []) { VMSTATE_UINTTL_ARRAY(regs, CPUState, CPU_NB_REGS), -- cgit v1.2.1