1. 10 7月, 2008 12 次提交
  2. 09 7月, 2008 14 次提交
  3. 08 7月, 2008 5 次提交
  4. 07 7月, 2008 8 次提交
  5. 06 7月, 2008 1 次提交
    • M
      KVM: IOAPIC: Fix level-triggered irq injection hang · 35baff25
      Mark McLoughlin 提交于
      The "remote_irr" variable is used to indicate an interrupt
      which has been received by the LAPIC, but not acked.
      
      In our EOI handler, we unset remote_irr and re-inject the
      interrupt if the interrupt line is still asserted.
      
      However, we do not set remote_irr here, leading to a
      situation where if kvm_ioapic_set_irq() is called, then we go
      ahead and call ioapic_service(). This means that IRR is
      re-asserted even though the interrupt is currently in service
      (i.e. LAPIC IRR is cleared and ISR/TMR set)
      
      The issue with this is that when the currently executing
      interrupt handler finishes and writes LAPIC EOI, then TMR is
      unset and EOI sent to the IOAPIC. Since IRR is now asserted,
      but TMR is not, then when the second interrupt is handled,
      no EOI is sent and if there is any pending interrupt, it is
      not re-injected.
      
      This fixes a hang only seen while running mke2fs -j on an
      8Gb virtio disk backed by a fully sparse raw file, with
      aliguori "avoid fragmented virtio-blk transfers by copying"
      changes.
      Signed-off-by: NMark McLoughlin <markmc@redhat.com>
      Acked-by: NMarcelo Tosatti <mtosatti@redhat.com>
      Signed-off-by: NAvi Kivity <avi@qumranet.com>
      35baff25