From: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
Vector notifiers shall be triggered by the MSI/MSI-X core whenever a
relevant configuration change is programmed by the guest. In case of
MSI-X, changes are reported when the effective mask (global &&
per-vector) alters its state. On unmask, the current vector
configuration is included in the event report. This allows users - e.g.
virtio-pci layer - to transfer this information to external MSI-X
routing subsystems - like vhost + KVM in-kernel irqchip.
This implementation only provides MSI-X support, but extension to MSI is
feasible and will be provided later on when adding support for KVM PCI
device assignment.
Signed-off-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
Signed-off-by: Avi Kivity <avi@xxxxxxxxxx>
---
hw/msix.c | 93 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
hw/msix.h | 4 +++
hw/pci.h | 8 ++++++
3 files changed, 105 insertions(+)
diff --git a/hw/msix.c b/hw/msix.c
index e1a7d92..1622e16 100644
--- a/hw/msix.c
+++ b/hw/msix.c
@@ -139,13 +139,34 @@ static bool msix_is_masked(PCIDevice *dev, int vector)
return msix_vector_masked(dev, vector, dev->msix_function_masked);
}
+static void msix_fire_vector_notifier(PCIDevice *dev,
+ unsigned int vector, bool is_masked)
+{
+ MSIMessage msg;
+ int ret;
+
+ if (!dev->msix_vector_use_notifier) {
+ return;
+ }
+ if (is_masked) {
+ dev->msix_vector_release_notifier(dev, vector);
+ } else {
+ msg = msix_get_message(dev, vector);
+ ret = dev->msix_vector_use_notifier(dev, vector, msg);
+ assert(ret >= 0);
+ }
+}
+
static void msix_handle_mask_update(PCIDevice *dev, int vector, bool was_masked)
{
bool is_masked = msix_is_masked(dev, vector);
+
if (is_masked == was_masked) {
return;
}
+ msix_fire_vector_notifier(dev, vector, is_masked);
+
if (!is_masked && msix_is_pending(dev, vector)) {
msix_clr_pending(dev, vector);
msix_notify(dev, vector);
@@ -330,6 +351,7 @@ void msix_save(PCIDevice *dev, QEMUFile *f)
void msix_load(PCIDevice *dev, QEMUFile *f)
{
unsigned n = dev->msix_entries_nr;
+ unsigned int vector;
if (!(dev->cap_present & QEMU_PCI_CAP_MSIX)) {
return;
@@ -339,6 +361,10 @@ void msix_load(PCIDevice *dev, QEMUFile *f)
qemu_get_buffer(f, dev->msix_table_page, n * PCI_MSIX_ENTRY_SIZE);
qemu_get_buffer(f, dev->msix_table_page + MSIX_PAGE_PENDING, (n + 7) / 8);
msix_update_function_masked(dev);
+
+ for (vector = 0; vector < n; vector++) {
+ msix_handle_mask_update(dev, vector, true);
+ }
}
/* Does device support MSI-X? */
@@ -425,3 +451,70 @@ void msix_unuse_all_vectors(PCIDevice *dev)
return;
msix_free_irq_entries(dev);
}
+
+static int msix_set_notifier_for_vector(PCIDevice *dev, unsigned int vector)
+{
+ MSIMessage msg;
+
+ if (msix_is_masked(dev, vector)) {
+ return 0;
+ }
+ msg = msix_get_message(dev, vector);
+ return dev->msix_vector_use_notifier(dev, vector, msg);
+}
+
+static void msix_unset_notifier_for_vector(PCIDevice *dev, unsigned int vector)
+{
+ if (msix_is_masked(dev, vector)) {
+ return;
+ }
+ dev->msix_vector_release_notifier(dev, vector);
+}
+
+int msix_set_vector_notifiers(PCIDevice *dev,
+ MSIVectorUseNotifier use_notifier,
+ MSIVectorReleaseNotifier release_notifier)
+{
+ int vector, ret;
+
+ assert(use_notifier && release_notifier);
+
+ dev->msix_vector_use_notifier = use_notifier;
+ dev->msix_vector_release_notifier = release_notifier;
+
+ if ((dev->config[dev->msix_cap + MSIX_CONTROL_OFFSET] &
+ (MSIX_ENABLE_MASK | MSIX_MASKALL_MASK)) == MSIX_ENABLE_MASK) {
+ for (vector = 0; vector < dev->msix_entries_nr; vector++) {
+ ret = msix_set_notifier_for_vector(dev, vector);
+ if (ret < 0) {
+ goto undo;
+ }
+ }
+ }
+ return 0;
+
+undo:
+ while (--vector >= 0) {
+ msix_unset_notifier_for_vector(dev, vector);
+ }
+ dev->msix_vector_use_notifier = NULL;
+ dev->msix_vector_release_notifier = NULL;
+ return ret;
+}
+
+void msix_unset_vector_notifiers(PCIDevice *dev)
+{
+ int vector;
+
+ assert(dev->msix_vector_use_notifier &&
+ dev->msix_vector_release_notifier);
+
+ if ((dev->config[dev->msix_cap + MSIX_CONTROL_OFFSET] &
+ (MSIX_ENABLE_MASK | MSIX_MASKALL_MASK)) == MSIX_ENABLE_MASK) {
+ for (vector = 0; vector < dev->msix_entries_nr; vector++) {
+ msix_unset_notifier_for_vector(dev, vector);
+ }
+ }
+ dev->msix_vector_use_notifier = NULL;
+ dev->msix_vector_release_notifier = NULL;
+}
diff --git a/hw/msix.h b/hw/msix.h
index 5aba22b..f33f18b 100644
--- a/hw/msix.h
+++ b/hw/msix.h
@@ -29,4 +29,8 @@ void msix_notify(PCIDevice *dev, unsigned vector);
void msix_reset(PCIDevice *dev);
+int msix_set_vector_notifiers(PCIDevice *dev,
+ MSIVectorUseNotifier use_notifier,
+ MSIVectorReleaseNotifier release_notifier);
+void msix_unset_vector_notifiers(PCIDevice *dev);
#endif
diff --git a/hw/pci.h b/hw/pci.h
index 8d0aa49..c3cacce 100644
--- a/hw/pci.h
+++ b/hw/pci.h
@@ -173,6 +173,10 @@ typedef struct PCIDeviceClass {
const char *romfile;
} PCIDeviceClass;
+typedef int (*MSIVectorUseNotifier)(PCIDevice *dev, unsigned int vector,
+ MSIMessage msg);
+typedef void (*MSIVectorReleaseNotifier)(PCIDevice *dev, unsigned int vector);
+
struct PCIDevice {
DeviceState qdev;
/* PCI config space */
@@ -243,6 +247,10 @@ struct PCIDevice {
bool has_rom;
MemoryRegion rom;
uint32_t rom_bar;
+
+ /* MSI-X notifiers */
+ MSIVectorUseNotifier msix_vector_use_notifier;
+ MSIVectorReleaseNotifier msix_vector_release_notifier;
};
void pci_register_bar(PCIDevice *pci_dev, int region_num,
--
1.7.10.1
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