[Qemu-devel] [PATCH] hw/block: Fix pin-based interrupt behaviour of NVMe

[Hikaru Nishida <hikarupsp@gmail.com>]

Pin-based interrupt of NVMe controller did not work properly
because using an obsolated function pci_irq_pulse().
To fix this, change to use pci_irq_assert() / pci_irq_deassert()
instead of pci_irq_pulse().

Signed-off-by: Hikaru Nishida <hikarupsp@gmail.com>
---
 hw/block/nvme.c | 39 ++++++++++++++++++++++++++++++++++-----
 hw/block/nvme.h |  1 +
 2 files changed, 35 insertions(+), 5 deletions(-)

diff --git a/hw/block/nvme.c b/hw/block/nvme.c
index 441e21e..2d164fc 100644
--- a/hw/block/nvme.c
+++ b/hw/block/nvme.c
@@ -82,13 +82,40 @@ static uint8_t nvme_sq_empty(NvmeSQueue *sq)
     return sq->head == sq->tail;
 }
 
-static void nvme_isr_notify(NvmeCtrl *n, NvmeCQueue *cq)
+static void nvme_irq_check(NvmeCtrl *n)
+{
+    if (msix_enabled(&(n->parent_obj))) {
+        return;
+    }
+    if (~n->bar.intms & n->irq_status) {
+        pci_irq_assert(&n->parent_obj);
+    } else {
+        pci_irq_deassert(&n->parent_obj);
+    }
+}
+
+static void nvme_irq_assert(NvmeCtrl *n, NvmeCQueue *cq)
 {
     if (cq->irq_enabled) {
         if (msix_enabled(&(n->parent_obj))) {
             msix_notify(&(n->parent_obj), cq->vector);
         } else {
-            pci_irq_pulse(&n->parent_obj);
+            assert(cq->cqid < 64);
+            n->irq_status |= 1 << cq->cqid;
+            nvme_irq_check(n);
+        }
+    }
+}
+
+static void nvme_irq_deassert(NvmeCtrl *n, NvmeCQueue *cq)
+{
+    if (cq->irq_enabled) {
+        if (msix_enabled(&(n->parent_obj))) {
+            return;
+        } else {
+            assert(cq->cqid < 64);
+            n->irq_status &= ~(1 << cq->cqid);
+            nvme_irq_check(n);
         }
     }
 }
@@ -220,7 +247,7 @@ static void nvme_post_cqes(void *opaque)
             sizeof(req->cqe));
         QTAILQ_INSERT_TAIL(&sq->req_list, req, entry);
     }
-    nvme_isr_notify(n, cq);
+    nvme_irq_assert(n, cq);
 }
 
 static void nvme_enqueue_req_completion(NvmeCQueue *cq, NvmeRequest *req)
@@ -753,10 +780,12 @@ static void nvme_write_bar(NvmeCtrl *n, hwaddr offset, uint64_t data,
     case 0xc:
         n->bar.intms |= data & 0xffffffff;
         n->bar.intmc = n->bar.intms;
+        nvme_irq_check(n);
         break;
     case 0x10:
         n->bar.intms &= ~(data & 0xffffffff);
         n->bar.intmc = n->bar.intms;
+        nvme_irq_check(n);
         break;
     case 0x14:
         /* Windows first sends data, then sends enable bit */
@@ -851,8 +880,8 @@ static void nvme_process_db(NvmeCtrl *n, hwaddr addr, int val)
             timer_mod(cq->timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + 500);
         }
 
-        if (cq->tail != cq->head) {
-            nvme_isr_notify(n, cq);
+        if (cq->tail == cq->head) {
+            nvme_irq_deassert(n, cq);
         }
     } else {
         uint16_t new_tail = val & 0xffff;
diff --git a/hw/block/nvme.h b/hw/block/nvme.h
index 6aab338..7b62dad 100644
--- a/hw/block/nvme.h
+++ b/hw/block/nvme.h
@@ -775,6 +775,7 @@ typedef struct NvmeCtrl {
     uint32_t    cmbsz;
     uint32_t    cmbloc;
     uint8_t     *cmbuf;
+    uint64_t    irq_status;
 
     char            *serial;
     NvmeNamespace   *namespaces;
-- 
2.7.4