Re: [PATCH repost] kvm: drop parameter validation

From: Gleb Natapov
Date: Mon Aug 13 2012 - 10:30:49 EST


On Mon, Aug 13, 2012 at 01:43:58PM +0300, Michael S. Tsirkin wrote:
> We validate irq pin number when routing is setup, so
> code handling illegal irq # in pic and ioapic on each injection
> is never called.
> Drop it.
>
I would leave BUG_ON there for a while.

> Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
> ---
>
> Reposting, applies without changes to kvm/next.
>
> arch/x86/kvm/i8259.c | 16 +++++++---------
> virt/kvm/ioapic.c | 35 +++++++++++++++++------------------
> 2 files changed, 24 insertions(+), 27 deletions(-)
>
> diff --git a/arch/x86/kvm/i8259.c b/arch/x86/kvm/i8259.c
> index 1df8fb9..277ec0d 100644
> --- a/arch/x86/kvm/i8259.c
> +++ b/arch/x86/kvm/i8259.c
> @@ -190,17 +190,15 @@ void kvm_pic_update_irq(struct kvm_pic *s)
>
> int kvm_pic_set_irq(struct kvm_pic *s, int irq, int irq_source_id, int level)
> {
> - int ret = -1;
> + int ret, irq_level;
>
> pic_lock(s);
> - if (irq >= 0 && irq < PIC_NUM_PINS) {
> - int irq_level = __kvm_irq_line_state(&s->irq_states[irq],
> - irq_source_id, level);
> - ret = pic_set_irq1(&s->pics[irq >> 3], irq & 7, irq_level);
> - pic_update_irq(s);
> - trace_kvm_pic_set_irq(irq >> 3, irq & 7, s->pics[irq >> 3].elcr,
> - s->pics[irq >> 3].imr, ret == 0);
> - }
> + irq_level = __kvm_irq_line_state(&s->irq_states[irq],
> + irq_source_id, level);
> + ret = pic_set_irq1(&s->pics[irq >> 3], irq & 7, irq_level);
> + pic_update_irq(s);
> + trace_kvm_pic_set_irq(irq >> 3, irq & 7, s->pics[irq >> 3].elcr,
> + s->pics[irq >> 3].imr, ret == 0);
> pic_unlock(s);
>
> return ret;
> diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c
> index ef61d52..4d824c7 100644
> --- a/virt/kvm/ioapic.c
> +++ b/virt/kvm/ioapic.c
> @@ -197,28 +197,27 @@ int kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int irq_source_id,
> u32 old_irr;
> u32 mask = 1 << irq;
> union kvm_ioapic_redirect_entry entry;
> - int ret = 1;
> + int ret, irq_level;
>
> spin_lock(&ioapic->lock);
> old_irr = ioapic->irr;
> - if (irq >= 0 && irq < IOAPIC_NUM_PINS) {
> - int irq_level = __kvm_irq_line_state(&ioapic->irq_states[irq],
> - irq_source_id, level);
> - entry = ioapic->redirtbl[irq];
> - irq_level ^= entry.fields.polarity;
> - if (!irq_level)
> - ioapic->irr &= ~mask;
> - else {
> - int edge = (entry.fields.trig_mode == IOAPIC_EDGE_TRIG);
> - ioapic->irr |= mask;
> - if ((edge && old_irr != ioapic->irr) ||
> - (!edge && !entry.fields.remote_irr))
> - ret = ioapic_service(ioapic, irq);
> - else
> - ret = 0; /* report coalesced interrupt */
> - }
> - trace_kvm_ioapic_set_irq(entry.bits, irq, ret == 0);
> + irq_level = __kvm_irq_line_state(&ioapic->irq_states[irq],
> + irq_source_id, level);
> + entry = ioapic->redirtbl[irq];
> + irq_level ^= entry.fields.polarity;
> + if (!irq_level) {
> + ioapic->irr &= ~mask;
> + ret = 1;
> + } else {
> + int edge = (entry.fields.trig_mode == IOAPIC_EDGE_TRIG);
> + ioapic->irr |= mask;
> + if ((edge && old_irr != ioapic->irr) ||
> + (!edge && !entry.fields.remote_irr))
> + ret = ioapic_service(ioapic, irq);
> + else
> + ret = 0; /* report coalesced interrupt */
> }
> + trace_kvm_ioapic_set_irq(entry.bits, irq, ret == 0);
> spin_unlock(&ioapic->lock);
>
> return ret;
> --
> MST

--
Gleb.
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