Normally QEMU kvm_arch_get_registers() reads registers and sets a dirty
flag which prevents further registers reading from KVM till
kvm_arch_put_registers() executes and resets the flag.
However if we run QEMU with "-S" ("suspended"), then execute "info cpus"
from the QEMU monitor, we end up with not reading registers in
rtas_start_cpu() as qmp_query_cpus() calls kvm_cpu_synchronize_state()
which leaves @kvm_vcpu_dirty=true what prevents kvm_cpu_synchronize_state()
from synchronizing registers and we loose the values.
This resets @kvm_vcpu_dirty flag as we do not have content which we really want
to
keep at this point as the CPU is halted.
Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru>
---
We could also reset @kvm_vcpu_dirty in qmp_query_cpus() but that would be
racy.
---
hw/ppc/spapr_rtas.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/hw/ppc/spapr_rtas.c b/hw/ppc/spapr_rtas.c
index 1cb276d..3dade5e 100644
--- a/hw/ppc/spapr_rtas.c
+++ b/hw/ppc/spapr_rtas.c
@@ -185,6 +185,8 @@ static void rtas_start_cpu(PowerPCCPU *cpu_,
sPAPREnvironment *spapr,
/* This will make sure qemu state is up to date with kvm, and
* mark it dirty so our changes get flushed back before the
* new cpu enters */
+
+ cs->kvm_vcpu_dirty = false;
kvm_cpu_synchronize_state(cs);
env->msr = (1ULL << MSR_SF) | (1ULL << MSR_ME);
--
1.8.4.rc4
