| Message ID | 1246808892-2179-1-git-send-email-gleb@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 07/05/2009 06:48 PM, Gleb Natapov wrote: > The check for an edge is broken in current ioapic code. ioapic->irr is > cleared on each edge interrupt by ioapic_service() and this makes > old_irr != ioapic->irr condition in kvm_ioapic_set_irq() to be always > true. The patch fixes the code to properly recognise edge. > > Some HW emulation calls set_irq() without level change. If each such > call is propagated to an OS it may confuse a device driver. This is the > case with keyboard device emulation and WindowsXP installer on SMP VM. > Each button stroke produce two interrupts (down/up) one interrupt is > submitted to CPU0 and another to CPU1. This confuses Windows somehow > and it ignores button strokes. > > Signed-off-by: Gleb Natapov<gleb@redhat.com> > --- > > Same patch as before but split in two. First one fixes bug, second > make cosmetic changes. > > Applied both, thanks.
diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c index 124ecf7..8a9c6cc 100644 --- a/virt/kvm/ioapic.c +++ b/virt/kvm/ioapic.c @@ -95,8 +95,6 @@ static int ioapic_service(struct kvm_ioapic *ioapic, unsigned int idx) if (injected && pent->fields.trig_mode == IOAPIC_LEVEL_TRIG) pent->fields.remote_irr = 1; } - if (!pent->fields.trig_mode) - ioapic->irr &= ~(1 << idx); return injected; } @@ -136,7 +134,8 @@ static void ioapic_write_indirect(struct kvm_ioapic *ioapic, u32 val) mask_after = ioapic->redirtbl[index].fields.mask; if (mask_before != mask_after) kvm_fire_mask_notifiers(ioapic->kvm, index, mask_after); - if (ioapic->irr & (1 << index)) + if (ioapic->redirtbl[index].fields.trig_mode == IOAPIC_LEVEL_TRIG + && ioapic->irr & (1 << index)) ioapic_service(ioapic, index); break; } @@ -186,9 +185,10 @@ int kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int level) if (!level) ioapic->irr &= ~mask; else { + int edge = (entry.fields.trig_mode == IOAPIC_EDGE_TRIG); ioapic->irr |= mask; - if ((!entry.fields.trig_mode && old_irr != ioapic->irr) - || !entry.fields.remote_irr) + if ((edge && old_irr != ioapic->irr) || + (!edge && !entry.fields.remote_irr)) ret = ioapic_service(ioapic, irq); } }
The check for an edge is broken in current ioapic code. ioapic->irr is cleared on each edge interrupt by ioapic_service() and this makes old_irr != ioapic->irr condition in kvm_ioapic_set_irq() to be always true. The patch fixes the code to properly recognise edge. Some HW emulation calls set_irq() without level change. If each such call is propagated to an OS it may confuse a device driver. This is the case with keyboard device emulation and WindowsXP installer on SMP VM. Each button stroke produce two interrupts (down/up) one interrupt is submitted to CPU0 and another to CPU1. This confuses Windows somehow and it ignores button strokes. Signed-off-by: Gleb Natapov <gleb@redhat.com> --- Same patch as before but split in two. First one fixes bug, second make cosmetic changes. virt/kvm/ioapic.c | 10 +++++----- 1 files changed, 5 insertions(+), 5 deletions(-)