Message ID | 4192d04a830ee542c5d6c4e6dbe2f66a7f444c23.1521142210.git.joseph.salisbury@canonical.com |
---|---|
State | New |
Headers | show |
Series | KVM: PPC: Book3S HV: Fix guest time accounting with VIRT_CPU_ACCOUNTING_GEN | expand |
Acked-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Applied to bionic master-next branches.
Thanks.
Cascardo.
Applied-to: bionic/master-next
On 23.03.2018 21:03, Joseph Salisbury wrote: > From: Laurent Vivier <lvivier@redhat.com> > > BugLink: http://bugs.launchpad.net/bugs/1755979 > > 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> > (cherry picked from commit 61bd0f66ff92d5ce765ff9850fd3cbfec773c560) > Signed-off-by: Joseph Salisbury <joseph.salisbury@canonical.com> Acked-by: Stefan Bader <stefan.bader@canonical.com> > --- > arch/powerpc/kvm/book3s_hv.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c > index 6c402f6..a532743 100644 > --- a/arch/powerpc/kvm/book3s_hv.c > +++ b/arch/powerpc/kvm/book3s_hv.c > @@ -2875,7 +2875,7 @@ static noinline void kvmppc_run_core(struct kvmppc_vcore *vc) > */ > trace_hardirqs_on(); > > - guest_enter(); > + guest_enter_irqoff(); > > srcu_idx = srcu_read_lock(&vc->kvm->srcu); > > @@ -2883,8 +2883,6 @@ static noinline void kvmppc_run_core(struct kvmppc_vcore *vc) > > srcu_read_unlock(&vc->kvm->srcu, srcu_idx); > > - guest_exit(); > - > trace_hardirqs_off(); > set_irq_happened(trap); > > @@ -2927,6 +2925,7 @@ static noinline void kvmppc_run_core(struct kvmppc_vcore *vc) > 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) { >
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index 6c402f6..a532743 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -2875,7 +2875,7 @@ static noinline void kvmppc_run_core(struct kvmppc_vcore *vc) */ trace_hardirqs_on(); - guest_enter(); + guest_enter_irqoff(); srcu_idx = srcu_read_lock(&vc->kvm->srcu); @@ -2883,8 +2883,6 @@ static noinline void kvmppc_run_core(struct kvmppc_vcore *vc) srcu_read_unlock(&vc->kvm->srcu, srcu_idx); - guest_exit(); - trace_hardirqs_off(); set_irq_happened(trap); @@ -2927,6 +2925,7 @@ static noinline void kvmppc_run_core(struct kvmppc_vcore *vc) 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) {