4.14-stable review patch. If anyone has any objections, please let me know.
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From: Laurent Vivier lvivier@redhat.com
commit 61bd0f66ff92d5ce765ff9850fd3cbfec773c560 upstream.
Since commit 8b24e69fc47e ("KVM: PPC: Book3S HV: Close race with testing for signals on guest entry"), if CONFIG_VIRT_CPU_ACCOUNTING_GEN is set, the guest time is not accounted to guest time and user time, but instead to system time.
This is because guest_enter()/guest_exit() are called while interrupts are disabled and the tick counter cannot be updated between them.
To fix that, move guest_exit() after local_irq_enable(), and as guest_enter() is called with IRQ disabled, call guest_enter_irqoff() instead.
Fixes: 8b24e69fc47e ("KVM: PPC: Book3S HV: Close race with testing for signals on guest entry") Signed-off-by: Laurent Vivier lvivier@redhat.com Reviewed-by: Paolo Bonzini pbonzini@redhat.com Signed-off-by: Paul Mackerras paulus@ozlabs.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/powerpc/kvm/book3s_hv.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)
--- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -2847,7 +2847,7 @@ static noinline void kvmppc_run_core(str */ trace_hardirqs_on();
- guest_enter(); + guest_enter_irqoff();
srcu_idx = srcu_read_lock(&vc->kvm->srcu);
@@ -2855,8 +2855,6 @@ static noinline void kvmppc_run_core(str
srcu_read_unlock(&vc->kvm->srcu, srcu_idx);
- guest_exit(); - trace_hardirqs_off(); set_irq_happened(trap);
@@ -2890,6 +2888,7 @@ static noinline void kvmppc_run_core(str kvmppc_set_host_core(pcpu);
local_irq_enable(); + guest_exit();
/* Let secondaries go back to the offline loop */ for (i = 0; i < controlled_threads; ++i) {