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[Qemu-devel] [PATCH (repost) RFC 2/2] virtio-pci: recall and return msix
From: |
Michael S. Tsirkin |
Subject: |
[Qemu-devel] [PATCH (repost) RFC 2/2] virtio-pci: recall and return msix notifications on ISR read |
Date: |
Wed, 2 Nov 2011 22:11:28 +0200 |
User-agent: |
Mutt/1.5.21 (2010-09-15) |
MSIX spec requires that device can be operated with
all vectors masked, by polling pending bits.
Add APIs to recall an msix notification, and make polling
mode possible in virtio-pci by clearing the
pending bits and setting ISR appropriately on ISR read.
Signed-off-by: Michael S. Tsirkin <address@hidden>
---
hw/msix.c | 26 ++++++++++++++++++++++++++
hw/msix.h | 3 +++
hw/virtio-pci.c | 11 ++++++++++-
3 files changed, 39 insertions(+), 1 deletions(-)
diff --git a/hw/msix.c b/hw/msix.c
index 63b41b9..fe967c9 100644
--- a/hw/msix.c
+++ b/hw/msix.c
@@ -349,6 +349,32 @@ void msix_notify(PCIDevice *dev, unsigned vector)
stl_le_phys(address, data);
}
+/* Recall outstanding MSI-X notifications for a vector, if possible.
+ * Return true if any were outstanding. */
+bool msix_recall(PCIDevice *dev, unsigned vector)
+{
+ bool ret;
+ if (vector >= dev->msix_entries_nr)
+ return false;
+ ret = msix_is_pending(dev, vector);
+ msix_clr_pending(dev, vector);
+ return ret;
+}
+
+/* Recall outstanding MSI-X notifications for all vectors, if possible.
+ * Return true if any were outstanding. */
+bool msix_recall_all(PCIDevice *dev)
+{
+ uint8_t ret = 0;
+ uint8_t *b;
+ for (b = dev->msix_table_page + MSIX_PAGE_PENDING;
+ b <= msix_pending_byte(dev, dev->msix_entries_nr - 1); ++b) {
+ ret |= *b;
+ *b = 0;
+ }
+ return ret;
+}
+
void msix_reset(PCIDevice *dev)
{
if (!(dev->cap_present & QEMU_PCI_CAP_MSIX))
diff --git a/hw/msix.h b/hw/msix.h
index 7e04336..86a92b1 100644
--- a/hw/msix.h
+++ b/hw/msix.h
@@ -27,6 +27,9 @@ void msix_unuse_all_vectors(PCIDevice *dev);
void msix_notify(PCIDevice *dev, unsigned vector);
+bool msix_recall(PCIDevice *dev, unsigned vector);
+bool msix_recall_all(PCIDevice *dev);
+
void msix_reset(PCIDevice *dev);
extern int msix_supported;
diff --git a/hw/virtio-pci.c b/hw/virtio-pci.c
index df27c19..cab7dde 100644
--- a/hw/virtio-pci.c
+++ b/hw/virtio-pci.c
@@ -393,7 +393,16 @@ static uint32_t virtio_ioport_read(VirtIOPCIProxy *proxy,
uint32_t addr)
/* reading from the ISR also clears it. */
ret = vdev->isr;
vdev->isr = 0;
- qemu_set_irq(proxy->pci_dev.irq[0], 0);
+ if (msix_enabled(&proxy->pci_dev)) {
+ if (msix_recall(&proxy->pci_dev, vdev->config_vector)) {
+ ret |= VIRTIO_ISR_CONFIG;
+ }
+ if (msix_recall_all(&proxy->pci_dev)) {
+ ret |= VIRTIO_ISR_VQ;
+ }
+ } else {
+ qemu_set_irq(proxy->pci_dev.irq[0], 0);
+ }
break;
case VIRTIO_MSI_CONFIG_VECTOR:
ret = vdev->config_vector;
--
1.7.5.53.gc233e