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authorPeter Maydell <peter.maydell@linaro.org>2014-08-07 11:30:38 +0100
committerPeter Maydell <peter.maydell@linaro.org>2014-08-07 11:30:38 +0100
commit9d8bb3557408adc3e5e26b7915cbf6c198dfd4ff (patch)
tree418ff5391bf6747b80f055649b697c513ee3ed0d
parent69f87f713069f1f70f86cb65883f7d43e3aa21de (diff)
parent9b3af4c0e40f14b5173ad6e2d9fcc376207ec1dd (diff)
downloadqemu-arm-9d8bb3557408adc3e5e26b7915cbf6c198dfd4ff.tar.gz
Merge remote-tracking branch 'remotes/awilliam/tags/vfio-pci-for-qemu-20140805.0' into staging
VFIO patches: Fix MSI-X vector expansion, remove MSI/X message caching # gpg: Signature made Tue 05 Aug 2014 20:25:57 BST using RSA key ID 3BB08B22 # gpg: Can't check signature: public key not found * remotes/awilliam/tags/vfio-pci-for-qemu-20140805.0: vfio: Don't cache MSIMessage vfio: Fix MSI-X vector expansion Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
-rw-r--r--hw/misc/vfio.c46
1 files changed, 31 insertions, 15 deletions
diff --git a/hw/misc/vfio.c b/hw/misc/vfio.c
index 0b9eba0c84..ba08adbd99 100644
--- a/hw/misc/vfio.c
+++ b/hw/misc/vfio.c
@@ -120,11 +120,19 @@ typedef struct VFIOINTx {
} VFIOINTx;
typedef struct VFIOMSIVector {
- EventNotifier interrupt; /* eventfd triggered on interrupt */
- EventNotifier kvm_interrupt; /* eventfd triggered for KVM irqfd bypass */
+ /*
+ * Two interrupt paths are configured per vector. The first, is only used
+ * for interrupts injected via QEMU. This is typically the non-accel path,
+ * but may also be used when we want QEMU to handle masking and pending
+ * bits. The KVM path bypasses QEMU and is therefore higher performance,
+ * but requires masking at the device. virq is used to track the MSI route
+ * through KVM, thus kvm_interrupt is only available when virq is set to a
+ * valid (>= 0) value.
+ */
+ EventNotifier interrupt;
+ EventNotifier kvm_interrupt;
struct VFIODevice *vdev; /* back pointer to device */
- MSIMessage msg; /* cache the MSI message so we know when it changes */
- int virq; /* KVM irqchip route for QEMU bypass */
+ int virq;
bool use;
} VFIOMSIVector;
@@ -681,13 +689,24 @@ static int vfio_enable_vectors(VFIODevice *vdev, bool msix)
fds = (int32_t *)&irq_set->data;
for (i = 0; i < vdev->nr_vectors; i++) {
- if (!vdev->msi_vectors[i].use) {
- fds[i] = -1;
- } else if (vdev->msi_vectors[i].virq >= 0) {
- fds[i] = event_notifier_get_fd(&vdev->msi_vectors[i].kvm_interrupt);
- } else {
- fds[i] = event_notifier_get_fd(&vdev->msi_vectors[i].interrupt);
+ int fd = -1;
+
+ /*
+ * MSI vs MSI-X - The guest has direct access to MSI mask and pending
+ * bits, therefore we always use the KVM signaling path when setup.
+ * MSI-X mask and pending bits are emulated, so we want to use the
+ * KVM signaling path only when configured and unmasked.
+ */
+ if (vdev->msi_vectors[i].use) {
+ if (vdev->msi_vectors[i].virq < 0 ||
+ (msix && msix_is_masked(&vdev->pdev, i))) {
+ fd = event_notifier_get_fd(&vdev->msi_vectors[i].interrupt);
+ } else {
+ fd = event_notifier_get_fd(&vdev->msi_vectors[i].kvm_interrupt);
+ }
}
+
+ fds[i] = fd;
}
ret = ioctl(vdev->fd, VFIO_DEVICE_SET_IRQS, irq_set);
@@ -724,7 +743,6 @@ static void vfio_add_kvm_msi_virq(VFIOMSIVector *vector, MSIMessage *msg,
return;
}
- vector->msg = *msg;
vector->virq = virq;
}
@@ -740,7 +758,6 @@ static void vfio_remove_kvm_msi_virq(VFIOMSIVector *vector)
static void vfio_update_kvm_msi_virq(VFIOMSIVector *vector, MSIMessage msg)
{
kvm_irqchip_update_msi_route(kvm_state, vector->virq, msg);
- vector->msg = msg;
}
static int vfio_msix_vector_do_use(PCIDevice *pdev, unsigned int nr,
@@ -919,6 +936,7 @@ retry:
for (i = 0; i < vdev->nr_vectors; i++) {
VFIOMSIVector *vector = &vdev->msi_vectors[i];
+ MSIMessage msg = msi_get_message(&vdev->pdev, i);
vector->vdev = vdev;
vector->virq = -1;
@@ -931,13 +949,11 @@ retry:
qemu_set_fd_handler(event_notifier_get_fd(&vector->interrupt),
vfio_msi_interrupt, NULL, vector);
- vector->msg = msi_get_message(&vdev->pdev, i);
-
/*
* Attempt to enable route through KVM irqchip,
* default to userspace handling if unavailable.
*/
- vfio_add_kvm_msi_virq(vector, &vector->msg, false);
+ vfio_add_kvm_msi_virq(vector, &msg, false);
}
/* Set interrupt type prior to possible interrupts */