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author | Jan Kiszka <jan.kiszka@siemens.com> | 2010-03-01 19:10:30 +0100 |
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committer | Marcelo Tosatti <mtosatti@redhat.com> | 2010-03-04 00:29:28 -0300 |
commit | ea375f9ab8c76686dca0af8cb4f87a4eb569cad3 (patch) | |
tree | 51e0476453c95a64bd34bc148082ac277a458203 /hw | |
parent | b0b1d69079fcb9453f45aade9e9f6b71422147b0 (diff) | |
download | hqemu-ea375f9ab8c76686dca0af8cb4f87a4eb569cad3.zip hqemu-ea375f9ab8c76686dca0af8cb4f87a4eb569cad3.tar.gz |
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 'hw')
-rw-r--r-- | hw/apic.c | 2 | ||||
-rw-r--r-- | hw/ppc_newworld.c | 3 | ||||
-rw-r--r-- | hw/ppc_oldworld.c | 3 | ||||
-rw-r--r-- | hw/s390-virtio.c | 1 |
4 files changed, 0 insertions, 9 deletions
@@ -938,8 +938,6 @@ static void apic_reset(void *opaque) APICState *s = opaque; int bsp; - cpu_synchronize_state(s->cpu_env); - bsp = cpu_is_bsp(s->cpu_env); s->apicbase = 0xfee00000 | (bsp ? MSR_IA32_APICBASE_BSP : 0) | MSR_IA32_APICBASE_ENABLE; diff --git a/hw/ppc_newworld.c b/hw/ppc_newworld.c index bc86c85..d4f9013 100644 --- a/hw/ppc_newworld.c +++ b/hw/ppc_newworld.c @@ -167,9 +167,6 @@ static void ppc_core99_init (ram_addr_t ram_size, envs[i] = env; } - /* Make sure all register sets take effect */ - cpu_synchronize_state(env); - /* allocate RAM */ ram_offset = qemu_ram_alloc(ram_size); cpu_register_physical_memory(0, ram_size, ram_offset); diff --git a/hw/ppc_oldworld.c b/hw/ppc_oldworld.c index 04a7835..93c95ba 100644 --- a/hw/ppc_oldworld.c +++ b/hw/ppc_oldworld.c @@ -165,9 +165,6 @@ static void ppc_heathrow_init (ram_addr_t ram_size, envs[i] = env; } - /* Make sure all register sets take effect */ - cpu_synchronize_state(env); - /* allocate RAM */ if (ram_size > (2047 << 20)) { fprintf(stderr, diff --git a/hw/s390-virtio.c b/hw/s390-virtio.c index 3582728..ad3386f 100644 --- a/hw/s390-virtio.c +++ b/hw/s390-virtio.c @@ -185,7 +185,6 @@ static void s390_init(ram_addr_t ram_size, exit(1); } - cpu_synchronize_state(env); env->psw.addr = KERN_IMAGE_START; env->psw.mask = 0x0000000180000000ULL; } |