| Message ID | 20220701094955.1927867-1-nborisov@suse.com |
|---|---|
| State | Accepted |
| Headers | show |
| Series | riscv: kvm: move preempt_disable() call in kvm_arch_vcpu_ioctl_run | expand |
On Fri, Jul 1, 2022 at 3:19 PM Nikolay Borisov <nborisov@suse.com> wrote: > > local_irq_disable provides stronger guarantees than preempt_disable so > calling the latter is redundant when interrupts are disabled. Instead, > explicitly disable preemption right before interrupts are > enabled/disabled to ensure that the time accounted in guest_timing_exit_irqoff > includes time taken by the guest or interrupts. > > Signed-off-by: Nikolay Borisov <nborisov@suse.com> Looks good to me. I have queued it for 5.20 Thanks, Anup > --- > arch/riscv/kvm/vcpu.c | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > > diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c > index 7f4ad5e4373a..0c527b2c3c63 100644 > --- a/arch/riscv/kvm/vcpu.c > +++ b/arch/riscv/kvm/vcpu.c > @@ -888,8 +888,6 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu) > > kvm_riscv_check_vcpu_requests(vcpu); > > - preempt_disable(); > - > local_irq_disable(); > > /* > @@ -926,7 +924,6 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu) > kvm_request_pending(vcpu)) { > vcpu->mode = OUTSIDE_GUEST_MODE; > local_irq_enable(); > - preempt_enable(); > kvm_vcpu_srcu_read_lock(vcpu); > continue; > } > @@ -960,6 +957,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu) > /* Syncup interrupts state with HW */ > kvm_riscv_vcpu_sync_interrupts(vcpu); > > + preempt_disable(); > /* > * We must ensure that any pending interrupts are taken before > * we exit guest timing so that timer ticks are accounted as > -- > 2.25.1 >
diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c index 7f4ad5e4373a..0c527b2c3c63 100644 --- a/arch/riscv/kvm/vcpu.c +++ b/arch/riscv/kvm/vcpu.c @@ -888,8 +888,6 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu) kvm_riscv_check_vcpu_requests(vcpu); - preempt_disable(); - local_irq_disable(); /* @@ -926,7 +924,6 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu) kvm_request_pending(vcpu)) { vcpu->mode = OUTSIDE_GUEST_MODE; local_irq_enable(); - preempt_enable(); kvm_vcpu_srcu_read_lock(vcpu); continue; } @@ -960,6 +957,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu) /* Syncup interrupts state with HW */ kvm_riscv_vcpu_sync_interrupts(vcpu); + preempt_disable(); /* * We must ensure that any pending interrupts are taken before * we exit guest timing so that timer ticks are accounted as
local_irq_disable provides stronger guarantees than preempt_disable so calling the latter is redundant when interrupts are disabled. Instead, explicitly disable preemption right before interrupts are enabled/disabled to ensure that the time accounted in guest_timing_exit_irqoff includes time taken by the guest or interrupts. Signed-off-by: Nikolay Borisov <nborisov@suse.com> --- arch/riscv/kvm/vcpu.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-)