On Jun 14 15:54, Jakub Jermář wrote:
An IRQ vector used by a completion queue cannot be deasserted without
first checking if the same vector does not need to stay asserted for
some other completion queue. To this end the controller structure is
extended by a counter of asserted completion queues.

To prevent incrementing the counter for completion queues that are
asserted repeatedly, each completion queue is extended by a flag which
tells whether the queue is currently asserted.


I wasn't clear on this on my last review, but the misunderstanding here is that the completion queue vector somehow matters for pin-based interrupts - it does not. There is only *one* interrupt vector and if the controller is not using MSI-X, then the Interrupt Vector (IV) field of the Create I/O Completion Queue command *must* be zero.

In other words, all that matters is if there are one or more CQEs posted (in any queue).

Would this (untested) patch do the trick?


diff --git i/hw/nvme/nvme.h w/hw/nvme/nvme.h
index 93a7e0e5380e..60250b579464 100644
--- i/hw/nvme/nvme.h
+++ w/hw/nvme/nvme.h
@@ -405,6 +405,7 @@ typedef struct NvmeCtrl {
     uint32_t    max_q_ents;
     uint8_t     outstanding_aers;
     uint32_t    irq_status;
+    int         cq_pending;
     uint64_t    host_timestamp;                 /* Timestamp sent by the host 
*/
     uint64_t    timestamp_set_qemu_clock_ms;    /* QEMU clock time */
     uint64_t    starttime_ms;
diff --git i/hw/nvme/ctrl.c w/hw/nvme/ctrl.c
index 7dea64b72e6a..4de4b3177463 100644
--- i/hw/nvme/ctrl.c
+++ w/hw/nvme/ctrl.c
@@ -473,6 +473,10 @@ static void nvme_irq_deassert(NvmeCtrl *n, NvmeCQueue *cq)
             return;
         } else {
             assert(cq->vector < 32);
+            if (--(n->cq_pending)) {
+                return;
+            }
+
             n->irq_status &= ~(1 << cq->vector);
             nvme_irq_check(n);
         }
@@ -1258,6 +1262,7 @@ static void nvme_post_cqes(void *opaque)
     NvmeCQueue *cq = opaque;
     NvmeCtrl *n = cq->ctrl;
     NvmeRequest *req, *next;
+    bool empty = cq->head == cq->tail;
     int ret;

     QTAILQ_FOREACH_SAFE(req, &cq->req_list, entry, next) {
@@ -1287,6 +1292,10 @@ static void nvme_post_cqes(void *opaque)
         QTAILQ_INSERT_TAIL(&sq->req_list, req, entry);
     }
     if (cq->tail != cq->head) {
+        if (empty) {
+            n->cq_pending++;
+        }
+
         nvme_irq_assert(n, cq);
     }
 }


Signed-off-by: Jakub Jermar <jakub.jer...@kernkonzept.com>
---
hw/nvme/ctrl.c | 22 ++++++++++++++++------
hw/nvme/nvme.h |  2 ++
2 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/hw/nvme/ctrl.c b/hw/nvme/ctrl.c
index 0bcaf7192f..97a5d768ee 100644
--- a/hw/nvme/ctrl.c
+++ b/hw/nvme/ctrl.c
@@ -451,9 +451,13 @@ static void nvme_irq_assert(NvmeCtrl *n, NvmeCQueue *cq)
            msix_notify(&(n->parent_obj), cq->vector);
        } else {
            trace_pci_nvme_irq_pin();
-            assert(cq->vector < 32);
-            n->irq_status |= 1 << cq->vector;
-            nvme_irq_check(n);
+            if (!cq->irq_asserted) {
+                cq->irq_asserted = true;
+                assert(cq->vector < 32);
+                n->irq_asserted_cnt[cq->vector]++;
+                n->irq_status |= 1 << cq->vector;
+                nvme_irq_check(n);
+            }
        }
    } else {
        trace_pci_nvme_irq_masked();
@@ -466,9 +470,15 @@ static void nvme_irq_deassert(NvmeCtrl *n, NvmeCQueue *cq)
        if (msix_enabled(&(n->parent_obj))) {
            return;
        } else {
-            assert(cq->vector < 32);
-            n->irq_status &= ~(1 << cq->vector);
-            nvme_irq_check(n);
+            if (cq->irq_asserted) {
+                cq->irq_asserted = false;
+                assert(cq->vector < 32);
+                assert(n->irq_asserted_cnt[cq->vector]);
+                if (n->irq_asserted_cnt[cq->vector]-- == 1) {
+                    n->irq_status &= ~(1 << cq->vector);
+                }
+                nvme_irq_check(n);
+            }
        }
    }
}
diff --git a/hw/nvme/nvme.h b/hw/nvme/nvme.h
index 81a35cda14..753bf7a923 100644
--- a/hw/nvme/nvme.h
+++ b/hw/nvme/nvme.h
@@ -352,6 +352,7 @@ typedef struct NvmeCQueue {
    uint32_t    head;
    uint32_t    tail;
    uint32_t    vector;
+    bool        irq_asserted;
    uint32_t    size;
    uint64_t    dma_addr;
    QEMUTimer   *timer;
@@ -404,6 +405,7 @@ typedef struct NvmeCtrl {
    uint32_t    max_q_ents;
    uint8_t     outstanding_aers;
    uint32_t    irq_status;
+    uint16_t    irq_asserted_cnt[32];
    uint64_t    host_timestamp;                 /* Timestamp sent by the host */
    uint64_t    timestamp_set_qemu_clock_ms;    /* QEMU clock time */
    uint64_t    starttime_ms;
--
2.31.1



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One of us - No more doubt, silence or taboo about mental illness.

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