iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

KVM: PPC: Book3S HV: Fix guest time accounting with VIRT_CPU_ACCOUNTING_GEN

Browse Source 
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>
This commit is contained in:
Laurent Vivier 2018-03-02 11:51:56 +01:00 committed by Greg Kroah-Hartman
parent c51eb7379d
commit f768d0f981
1 changed files with 2 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
arch/powerpc/kvm/book3s_hv.c
View File

@ -2847,7 +2847,7 @@ 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);
@ -2855,8 +2855,6 @@ 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);
@ -2890,6 +2888,7 @@ 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) {