Re: [PATCH V2 2/4] vDPA/ifcvf: implement device MSIX vector allocator
From: "Michael S. Tsirkin" <mst@redhat.com>
Date: 2022-01-25 19:37:36
Also in:
virtualization
On Tue, Jan 25, 2022 at 05:17:42PM +0800, Zhu Lingshan wrote:
quoted hunk ↗ jump to hunk
This commit implements a MSIX vector allocation helper for vqs and config interrupts. Signed-off-by: Zhu Lingshan <redacted> --- drivers/vdpa/ifcvf/ifcvf_main.c | 30 ++++++++++++++++++++++++++++-- 1 file changed, 28 insertions(+), 2 deletions(-)diff --git a/drivers/vdpa/ifcvf/ifcvf_main.c b/drivers/vdpa/ifcvf/ifcvf_main.c index d1a6b5ab543c..7e2af2d2aaf5 100644 --- a/drivers/vdpa/ifcvf/ifcvf_main.c +++ b/drivers/vdpa/ifcvf/ifcvf_main.c@@ -58,14 +58,40 @@ static void ifcvf_free_irq(struct ifcvf_adapter *adapter, int queues) ifcvf_free_irq_vectors(pdev); } +static int ifcvf_alloc_vectors(struct ifcvf_adapter *adapter)
So the helper returns an int...
+{
+ struct pci_dev *pdev = adapter->pdev;
+ struct ifcvf_hw *vf = &adapter->vf;
+ u16 max_intr, ret;
+
+ /* all queues and config interrupt */
+ max_intr = vf->nr_vring + 1;
+ ret = pci_alloc_irq_vectors(pdev, 1, max_intr, PCI_IRQ_MSIX | PCI_IRQ_AFFINITY);
+
+ if (ret < 0) {
+ IFCVF_ERR(pdev, "Failed to alloc IRQ vectors\n");
+ return ret;which is negative on error...
+ }
+
+ if (ret < max_intr)
+ IFCVF_INFO(pdev,
+ "Requested %u vectors, however only %u allocated, lower performance\n",
+ max_intr, ret);
+
+ return ret;
+}
+
static int ifcvf_request_irq(struct ifcvf_adapter *adapter)
{
struct pci_dev *pdev = adapter->pdev;
struct ifcvf_hw *vf = &adapter->vf;
int vector, i, ret, irq;
- u16 max_intr;
+ u16 nvectors, max_intr;
+
+ nvectors = ifcvf_alloc_vectors(adapter);which you proceed to stash into an unsigned int ...
+ if (!(nvectors > 0))
and then compare to zero ...
+ return nvectors;
correct error handling is unlikely as a result.
- /* all queues and config interrupt */ max_intr = vf->nr_vring + 1; ret = pci_alloc_irq_vectors(pdev, max_intr,
As long as you are introducing a helper, document it's return type and behaviour and then use correctly.
-- 2.27.0