On Friday 01 October 2010 00:18:10 Marcelo Tosatti wrote:
> On Tue, Sep 28, 2010 at 05:44:10PM +0800, Sheng Yang wrote:
> > This patch enable per-vector mask for assigned devices using MSI-X.
> >
> > Signed-off-by: Sheng Yang <[email protected]>
> > ---
> >
> > arch/x86/kvm/x86.c | 1 +
> > include/linux/kvm.h | 9 ++++++++-
> > include/linux/kvm_host.h | 1 +
> > virt/kvm/assigned-dev.c | 39
+++++++++++++++++++++++++++++++++++++++
> > 4 files changed, 49 insertions(+), 1 deletions(-)
> >
> >
> > #include <linux/slab.h>
> >
> > +#include <linux/irqnr.h>
> > +
> >
> > #include "irq.h"
> >
> > static struct kvm_assigned_dev_kernel *kvm_find_assigned_dev(struct
> > list_head *head,
> >
> > @@ -666,6 +668,30 @@ msix_nr_out:
> > return r;
> >
> > }
> >
> > +static void update_msix_mask(struct kvm_assigned_dev_kernel
> > *assigned_dev, + int index)
> > +{
> > + int irq;
> > +
> > + if (!assigned_dev->dev->msix_enabled ||
> > + !(assigned_dev->irq_requested_type & KVM_DEV_IRQ_HOST_MSIX))
> > + return;
> > +
> > + irq = assigned_dev->host_msix_entries[index].vector;
> > +
> > + ASSERT(irq != 0);
> > +
> > + if (assigned_dev->guest_msix_entries[index].flags &
> > + KVM_ASSIGNED_MSIX_MASK)
> > + disable_irq(irq);
> > + else {
> > + enable_irq(irq);
> > + if (assigned_dev->guest_msix_entries[index].flags &
> > + KVM_ASSIGNED_MSIX_PENDING)
> > + schedule_work(&assigned_dev->interrupt_work);
> > + }
> > +}
> > +
>
> Should flush the workqueue after disabling irq. As you say, the
> schedule_work should be unnecessary.
>
> Also must be careful with races.
Do we need to flush the workqueue? I think the return of writing MSI-X mask bit
doesn't have implicit meaning that we have handled all pending interrupts. So I
think leave the work later should also be fine.
--
regards
Yang, Sheng
> > static int kvm_vm_ioctl_set_msix_entry(struct kvm *kvm,
> >
> > struct kvm_assigned_msix_entry *entry)
> >
> > {
> >
> > @@ -688,6 +714,19 @@ static int kvm_vm_ioctl_set_msix_entry(struct kvm
> > *kvm,
> >
> > adev->guest_msix_entries[i].entry = entry->entry;
> > adev->guest_msix_entries[i].vector = entry->gsi;
> > adev->host_msix_entries[i].entry = entry->entry;
> >
> > + if ((entry->flags & KVM_MSIX_FLAG_MASK) &&
> > + !(adev->guest_msix_entries[i].flags &
> > + KVM_ASSIGNED_MSIX_MASK)) {
> > + adev->guest_msix_entries[i].flags |=
> > + KVM_ASSIGNED_MSIX_MASK;
> > + update_msix_mask(adev, i);
> > + } else if (!(entry->flags & KVM_MSIX_FLAG_MASK) &&
> > + (adev->guest_msix_entries[i].flags &
> > + KVM_ASSIGNED_MSIX_MASK)) {
> > + adev->guest_msix_entries[i].flags &=
> > + ~KVM_ASSIGNED_MSIX_MASK;
> > + update_msix_mask(adev, i);
> > + }
> >
> > break;
> >
> > }
> >
> > if (i == adev->entries_nr) {
--
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