[PATCH 18/21] qemu-kvm: Cleanup/fix TSC and PV clock writeback

Jan Kiszka
2010-02-02T08:19:48Z

Drop kvm_load_tsc in favor of level-dependent writeback in
kvm_arch_load_regs. KVM's PV clock MSRs fall in the same category and
should therefore only be written back on full sync.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
qemu-kvm-x86.c | 19 +++++--------------
qemu-kvm.h | 4 ----
target-i386/machine.c | 5 -----
3 files changed, 5 insertions(+), 23 deletions(-)

diff --git a/qemu-kvm-x86.c b/qemu-kvm-x86.c
index f484149..4b78570 100644
--- a/qemu-kvm-x86.c
+++ b/qemu-kvm-x86.c
@@ -962,8 +962,11 @@ void kvm_arch_load_regs(CPUState *env, int level)
set_msr_entry(&msrs[n++], MSR_LSTAR , env->lstar);
}
#endif
- set_msr_entry(&msrs[n++], MSR_KVM_SYSTEM_TIME, env->system_time_msr);
- set_msr_entry(&msrs[n++], MSR_KVM_WALL_CLOCK, env->wall_clock_msr);
+ if (level == KVM_PUT_FULL_STATE) {
+ set_msr_entry(&msrs[n++], MSR_IA32_TSC, env->tsc);
+ set_msr_entry(&msrs[n++], MSR_KVM_SYSTEM_TIME, env->system_time_msr);
+ set_msr_entry(&msrs[n++], MSR_KVM_WALL_CLOCK, env->wall_clock_msr);
+ }

rc = kvm_set_msrs(env, msrs, n);
if (rc == -1)
@@ -976,18 +979,6 @@ void kvm_arch_load_regs(CPUState *env, int level)
kvm_put_vcpu_events(env, level);
}

-void kvm_load_tsc(CPUState *env)
-{
- int rc;
- struct kvm_msr_entry msr;
-
- set_msr_entry(&msr, MSR_IA32_TSC, env->tsc);
-
- rc = kvm_set_msrs(env, &msr, 1);
- if (rc == -1)
- perror("kvm_set_tsc FAILED.\n");
-}
-
void kvm_arch_save_regs(CPUState *env)
{
struct kvm_regs regs;
diff --git a/qemu-kvm.h b/qemu-kvm.h
index aa7bcce..2af206c 100644
--- a/qemu-kvm.h
+++ b/qemu-kvm.h
@@ -958,7 +958,6 @@ int handle_tpr_access(void *opaque, CPUState *env, uint64_t rip,
#ifdef TARGET_I386
#define qemu_kvm_has_pit_state2() kvm_has_pit_state2(kvm_context)
#endif
-void kvm_load_tsc(CPUState *env);
#else
#define kvm_nested 0
#define qemu_kvm_has_gsi_routing() (0)
@@ -966,9 +965,6 @@ void kvm_load_tsc(CPUState *env);
#define qemu_kvm_has_pit_state2() (0)
#endif
#define qemu_kvm_cpu_stop(env) do {} while(0)
-static inline void kvm_load_tsc(CPUState *env)
-{
-}
#endif

void kvm_mutex_unlock(void);
diff --git a/target-i386/machine.c b/target-i386/machine.c
index bcc315b..b547e2a 100644
--- a/target-i386/machine.c
+++ b/target-i386/machine.c
@@ -354,11 +354,6 @@ static int cpu_post_load(void *opaque, int version_id)
hw_breakpoint_insert(env, i);

tlb_flush(env, 1);
-
- if (kvm_enabled()) {
- kvm_load_tsc(env);
- }
-
return 0;
}

--
1.6.0.2