[PATCH 6/8] KVM: assigned dev: Preparation for mask support in userspace

Sheng Yang
2010-10-20T08:25:30Z

The feature wouldn't be enabled until later patch set msix_flags_enabled. It
would be enabled along with mask support in kernel.

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
---
arch/x86/include/asm/kvm_host.h | 2 ++
include/linux/kvm.h | 6 +++++-
include/linux/kvm_host.h | 1 +
virt/kvm/assigned-dev.c | 39 +++++++++++++++++++++++++++++++++++++++
4 files changed, 47 insertions(+), 1 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index e209078..2bb69ba 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -456,6 +456,8 @@ struct kvm_arch {
/* fields used by HYPER-V emulation */
u64 hv_guest_os_id;
u64 hv_hypercall;
+
+ bool msix_flags_enabled;
};

struct kvm_vm_stat {
diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index 919ae53..a699ec9 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -787,11 +787,15 @@ struct kvm_assigned_msix_nr {
};

#define KVM_MAX_MSIX_PER_DEV 256
+
+#define KVM_MSIX_FLAG_MASK 1
+
struct kvm_assigned_msix_entry {
__u32 assigned_dev_id;
__u32 gsi;
__u16 entry; /* The index of entry in the MSI-X table */
- __u16 padding[3];
+ __u16 flags;
+ __u16 padding[2];
};

#endif /* __LINUX_KVM_H */
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 30f83cd..81a6284 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -438,6 +438,7 @@ struct kvm_irq_ack_notifier {
};

#define KVM_ASSIGNED_MSIX_PENDING 0x1
+#define KVM_ASSIGNED_MSIX_MASK 0x2
struct kvm_guest_msix_entry {
u32 vector;
u16 entry;
diff --git a/virt/kvm/assigned-dev.c b/virt/kvm/assigned-dev.c
index 7c98928..bf96ea7 100644
--- a/virt/kvm/assigned-dev.c
+++ b/virt/kvm/assigned-dev.c
@@ -666,11 +666,35 @@ msix_nr_out:
return r;
}

+static void update_msix_mask(struct kvm_assigned_dev_kernel *assigned_dev,
+ int index)
+{
+ int irq;
+ struct irq_desc *desc;
+
+ 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;
+ BUG_ON(irq == 0);
+ desc = irq_to_desc(irq);
+ BUG_ON(!desc->msi_desc);
+
+ if (assigned_dev->guest_msix_entries[index].flags &
+ KVM_ASSIGNED_MSIX_MASK) {
+ desc->chip->mask(irq);
+ flush_work(&assigned_dev->interrupt_work);
+ } else
+ desc->chip->unmask(irq);
+}
+
static int kvm_vm_ioctl_set_msix_entry(struct kvm *kvm,
struct kvm_assigned_msix_entry *entry)
{
int r = 0, i;
struct kvm_assigned_dev_kernel *adev;
+ bool entry_masked;

mutex_lock(&kvm->lock);

@@ -688,6 +712,21 @@ 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 (!kvm->arch.msix_flags_enabled)
+ break;
+ entry_masked = adev->guest_msix_entries[i].flags &
+ KVM_ASSIGNED_MSIX_MASK;
+ if ((entry->flags & KVM_MSIX_FLAG_MASK) &&
+ !entry_masked) {
+ adev->guest_msix_entries[i].flags |=
+ KVM_ASSIGNED_MSIX_MASK;
+ update_msix_mask(adev, i);
+ } else if (!(entry->flags & KVM_MSIX_FLAG_MASK) &&
+ entry_masked) {
+ adev->guest_msix_entries[i].flags &=
+ ~KVM_ASSIGNED_MSIX_MASK;
+ update_msix_mask(adev, i);
+ }
break;
}
if (i == adev->entries_nr) {
--
1.7.0.1