1. 18 7月, 2007 2 次提交
    • J
      xen: SMP guest support · f87e4cac
      Jeremy Fitzhardinge 提交于
      This is a fairly straightforward Xen implementation of smp_ops.
      
      Xen has its own IPI mechanisms, and has no dependency on any
      APIC-based IPI.  The smp_ops hooks and the flush_tlb_others pv_op
      allow a Xen guest to avoid all APIC code in arch/i386 (the only apic
      operation is a single apic_read for the apic version number).
      
      One subtle point which needs to be addressed is unpinning pagetables
      when another cpu may have a lazy tlb reference to the pagetable. Xen
      will not allow an in-use pagetable to be unpinned, so we must find any
      other cpus with a reference to the pagetable and get them to shoot
      down their references.
      Signed-off-by: NJeremy Fitzhardinge <jeremy@xensource.com>
      Signed-off-by: NChris Wright <chrisw@sous-sol.org>
      Cc: Benjamin LaHaise <bcrl@kvack.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Andi Kleen <ak@suse.de>
      f87e4cac
    • J
      xen: event channels · e46cdb66
      Jeremy Fitzhardinge 提交于
      Xen implements interrupts in terms of event channels.  Each guest
      domain gets 1024 event channels which can be used for a variety of
      purposes, such as Xen timer events, inter-domain events,
      inter-processor events (IPI) or for real hardware IRQs.
      
      Within the kernel, we map the event channels to IRQs, and implement
      the whole interrupt handling using a Xen irq_chip.
      
      Rather than setting NR_IRQ to 1024 under PARAVIRT in order to
      accomodate Xen, we create a dynamic mapping between event channels and
      IRQs.  Ideally, Linux will eventually move towards dynamically
      allocating per-irq structures, and we can use a 1:1 mapping between
      event channels and irqs.
      Signed-off-by: NJeremy Fitzhardinge <jeremy@xensource.com>
      Signed-off-by: NChris Wright <chrisw@sous-sol.org>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Eric W. Biederman <ebiederm@xmission.com>
      e46cdb66