---
hw/vfio/pci.h | 1 +
include/hw/vfio/vfio-device.h | 2 ++
hw/vfio/device.c | 26 +++++++++++++++++++
hw/vfio/pci.c | 47 ++++++++++++++++++++++++++++++-----
4 files changed, 70 insertions(+), 6 deletions(-)
diff --git a/hw/vfio/pci.h b/hw/vfio/pci.h
index 61fa385ddb..43c2d72b84 100644
--- a/hw/vfio/pci.h
+++ b/hw/vfio/pci.h
@@ -191,6 +191,7 @@ struct VFIOPCIDevice {
bool defer_kvm_irq_routing;
bool clear_parent_atomics_on_exit;
bool skip_vsc_check;
+ bool can_mask_msix;
VFIODisplay *dpy;
Notifier irqchip_change_notifier;
};
diff --git a/include/hw/vfio/vfio-device.h b/include/hw/vfio/vfio-device.h
index 8bcb3c19f6..923f9cd116 100644
--- a/include/hw/vfio/vfio-device.h
+++ b/include/hw/vfio/vfio-device.h
@@ -133,7 +133,9 @@ struct VFIODeviceOps {
(ret < 0 ? strerror(-ret) : "short write")
void vfio_device_irq_disable(VFIODevice *vbasedev, int index);
+void vfio_device_irq_unmask_single(VFIODevice *vbasedev, int index, int irq);
void vfio_device_irq_unmask(VFIODevice *vbasedev, int index);
+void vfio_device_irq_mask_single(VFIODevice *vbasedev, int index, int irq);
void vfio_device_irq_mask(VFIODevice *vbasedev, int index);
bool vfio_device_irq_set_signaling(VFIODevice *vbasedev, int index, int
subindex,
int action, int fd, Error **errp);
diff --git a/hw/vfio/device.c b/hw/vfio/device.c
index 9fba2c7272..d0068086ae 100644
--- a/hw/vfio/device.c
+++ b/hw/vfio/device.c
@@ -85,6 +85,19 @@ void vfio_device_irq_disable(VFIODevice *vbasedev, int index)
vbasedev->io_ops->set_irqs(vbasedev, &irq_set);
}
+void vfio_device_irq_unmask_single(VFIODevice *vbasedev, int index, int irq)
+{
+ struct vfio_irq_set irq_set = {
+ .argsz = sizeof(irq_set),
+ .flags = VFIO_IRQ_SET_DATA_NONE | VFIO_IRQ_SET_ACTION_UNMASK,
+ .index = index,
+ .start = irq,
+ .count = 1,
+ };
+
+ vbasedev->io_ops->set_irqs(vbasedev, &irq_set);
+}
+
void vfio_device_irq_unmask(VFIODevice *vbasedev, int index)
{
struct vfio_irq_set irq_set = {
@@ -98,6 +111,19 @@ void vfio_device_irq_unmask(VFIODevice *vbasedev, int index)
vbasedev->io_ops->set_irqs(vbasedev, &irq_set);
}
+void vfio_device_irq_mask_single(VFIODevice *vbasedev, int index, int irq)
+{
+ struct vfio_irq_set irq_set = {
+ .argsz = sizeof(irq_set),
+ .flags = VFIO_IRQ_SET_DATA_NONE | VFIO_IRQ_SET_ACTION_MASK,
+ .index = index,
+ .start = irq,
+ .count = 1,
+ };
+
+ vbasedev->io_ops->set_irqs(vbasedev, &irq_set);
+}
+
void vfio_device_irq_mask(VFIODevice *vbasedev, int index)
{
struct vfio_irq_set irq_set = {
diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index 5159198bdb..ef38b4692a 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -535,6 +535,7 @@ static int vfio_msix_vector_do_use(PCIDevice *pdev,
unsigned int nr,
{
VFIOPCIDevice *vdev = VFIO_PCI_BASE(pdev);
VFIOMSIVector *vector;
+ bool new_vec = false;
int ret;
bool resizing = !!(vdev->nr_vectors < nr + 1);
@@ -549,6 +550,7 @@ static int vfio_msix_vector_do_use(PCIDevice *pdev, unsigned int nr,
error_report("vfio: Error: event_notifier_init failed");
}
vector->use = true;
+ new_vec = true;
msix_vector_use(pdev, nr);
}
@@ -575,6 +577,7 @@ static int vfio_msix_vector_do_use(PCIDevice *pdev, unsigned int nr,
kvm_irqchip_commit_route_changes(&vfio_route_change);
vfio_connect_kvm_msi_virq(vector);
}
+ new_vec = true;
}
}
@@ -584,6 +587,9 @@ static int vfio_msix_vector_do_use(PCIDevice *pdev, unsigned int nr,
* in use, so we shutdown and incrementally increase them as needed.
* nr_vectors represents the total number of vectors allocated.
*
+ * Otherwise, unmask the vector if the vector is already setup (and we can
+ * do so) or send the fd if not.
+ *
* When dynamic allocation is supported, let the host only allocate
* and enable a vector when it is in use in guest. nr_vectors represents
* the upper bound of vectors being enabled (but not all of the ranges
@@ -594,13 +600,20 @@ static int vfio_msix_vector_do_use(PCIDevice *pdev,
unsigned int nr,
}
if (!vdev->defer_kvm_irq_routing) {
- if (vdev->msix->noresize && resizing) {
- vfio_device_irq_disable(&vdev->vbasedev, VFIO_PCI_MSIX_IRQ_INDEX);
- ret = vfio_enable_vectors(vdev, true);
- if (ret) {
- error_report("vfio: failed to enable vectors, %s",
- strerror(-ret));
+ if (resizing) {
+ if (vdev->msix->noresize) {
+ vfio_device_irq_disable(&vdev->vbasedev,
+ VFIO_PCI_MSIX_IRQ_INDEX);
+ ret = vfio_enable_vectors(vdev, true);
+ if (ret) {
+ error_report("vfio: failed to enable vectors, %d", ret);
+ }
+ } else {
+ set_irq_signalling(&vdev->vbasedev, vector, nr);
}
+ } else if (vdev->can_mask_msix && !new_vec) {
+ vfio_device_irq_unmask_single(&vdev->vbasedev,
+ VFIO_PCI_MSIX_IRQ_INDEX, nr);
} else {
set_irq_signalling(&vdev->vbasedev, vector, nr);
}
@@ -630,6 +643,13 @@ static void vfio_msix_vector_release(PCIDevice *pdev,
unsigned int nr)
trace_vfio_msix_vector_release(vdev->vbasedev.name, nr);
+ /* just mask vector if peer supports it */
+ if (vdev->can_mask_msix) {
+ vfio_device_irq_mask_single(&vdev->vbasedev, VFIO_PCI_MSIX_IRQ_INDEX,
+ nr);
+ return;
+ }
+
/*
* There are still old guests that mask and unmask vectors on every
* interrupt. If we're using QEMU bypass with a KVM irqfd, leave all of
@@ -702,6 +722,13 @@ static void vfio_msix_enable(VFIOPCIDevice *vdev)
error_report("vfio: failed to enable vectors, %s",
strerror(-ret));
}
+ } else if (vdev->can_mask_msix) {
+ /*
+ * If we can use single irq masking, send an invalid fd on vector 0
+ * to enable MSI-X without any vectors enabled.
+ */
+ vfio_device_irq_set_signaling(&vdev->vbasedev, VFIO_PCI_MSIX_IRQ_INDEX,
+ 0, VFIO_IRQ_SET_ACTION_TRIGGER, -1,
NULL);
} else {
/*
* Some communication channels between VF & PF or PF & fw rely on the
@@ -2842,6 +2869,14 @@ bool vfio_pci_populate_device(VFIOPCIDevice *vdev, Error
**errp)
}
}
+ ret = vfio_device_get_irq_info(vbasedev, VFIO_PCI_MSIX_IRQ_INDEX,
+ &irq_info);
+ if (ret == 0 && (irq_info.flags & VFIO_IRQ_INFO_MASKABLE)) {
+ vdev->can_mask_msix = true;
+ } else {
+ vdev->can_mask_msix = false;
+ }
+
ret = vfio_device_get_irq_info(vbasedev, VFIO_PCI_ERR_IRQ_INDEX,
&irq_info);
if (ret) {
/* This can fail for an old kernel or legacy PCI dev */
