[Qemu-devel] [PATCH 02/39] dma: keep a device alive while it has SGLists

[Paolo Bonzini <pbonzini@redhat.com>]

A QEMUSGList has a reference to a device's address space.  Keep
the device alive while the QEMUSGList exists.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 dma-helpers.c         |  6 +++++-
 hw/ide/ahci.c         |  3 ++-
 hw/ide/macio.c        |  4 ++--
 hw/scsi/megasas.c     |  4 ++--
 hw/scsi/virtio-scsi.c | 10 ++++++----
 hw/usb/hcd-ehci.c     |  4 ++--
 include/hw/pci/pci.h  |  2 +-
 include/sysemu/dma.h  |  4 +++-
 8 files changed, 23 insertions(+), 14 deletions(-)

diff --git a/dma-helpers.c b/dma-helpers.c
index 5afba47..499550f 100644
--- a/dma-helpers.c
+++ b/dma-helpers.c
@@ -34,13 +34,16 @@ int dma_memory_set(AddressSpace *as, dma_addr_t addr, uint8_t c, dma_addr_t len)
     return error;
 }
 
-void qemu_sglist_init(QEMUSGList *qsg, int alloc_hint, AddressSpace *as)
+void qemu_sglist_init(QEMUSGList *qsg, DeviceState *dev, int alloc_hint,
+                      AddressSpace *as)
 {
     qsg->sg = g_malloc(alloc_hint * sizeof(ScatterGatherEntry));
     qsg->nsg = 0;
     qsg->nalloc = alloc_hint;
     qsg->size = 0;
     qsg->as = as;
+    qsg->dev = dev;
+    object_ref(OBJECT(dev));
 }
 
 void qemu_sglist_add(QEMUSGList *qsg, dma_addr_t base, dma_addr_t len)
@@ -57,6 +60,7 @@ void qemu_sglist_add(QEMUSGList *qsg, dma_addr_t base, dma_addr_t len)
 
 void qemu_sglist_destroy(QEMUSGList *qsg)
 {
+    object_unref(OBJECT(qsg->dev));
     g_free(qsg->sg);
     memset(qsg, 0, sizeof(*qsg));
 }
diff --git a/hw/ide/ahci.c b/hw/ide/ahci.c
index 1adfa0b..6b87549 100644
--- a/hw/ide/ahci.c
+++ b/hw/ide/ahci.c
@@ -691,7 +691,8 @@ static int ahci_populate_sglist(AHCIDevice *ad, QEMUSGList *sglist, int offset)
             goto out;
         }
 
-        qemu_sglist_init(sglist, (sglist_alloc_hint - off_idx), ad->hba->as);
+        qemu_sglist_init(sglist, DEVICE(ad->hba), (sglist_alloc_hint - off_idx),
+                         ad->hba->as);
         qemu_sglist_add(sglist, le64_to_cpu(tbl[off_idx].addr + off_pos),
                         le32_to_cpu(tbl[off_idx].flags_size) + 1 - off_pos);
 
diff --git a/hw/ide/macio.c b/hw/ide/macio.c
index a1952b0..84288ae 100644
--- a/hw/ide/macio.c
+++ b/hw/ide/macio.c
@@ -70,7 +70,7 @@ static void pmac_ide_atapi_transfer_cb(void *opaque, int ret)
 
     s->io_buffer_size = io->len;
 
-    qemu_sglist_init(&s->sg, io->len / MACIO_PAGE_SIZE + 1,
+    qemu_sglist_init(&s->sg, DEVICE(m), io->len / MACIO_PAGE_SIZE + 1,
                      &address_space_memory);
     qemu_sglist_add(&s->sg, io->addr, io->len);
     io->addr += io->len;
@@ -127,7 +127,7 @@ static void pmac_ide_transfer_cb(void *opaque, int ret)
     s->io_buffer_index = 0;
     s->io_buffer_size = io->len;
 
-    qemu_sglist_init(&s->sg, io->len / MACIO_PAGE_SIZE + 1,
+    qemu_sglist_init(&s->sg, DEVICE(m), io->len / MACIO_PAGE_SIZE + 1,
                      &address_space_memory);
     qemu_sglist_add(&s->sg, io->addr, io->len);
     io->addr += io->len;
diff --git a/hw/scsi/megasas.c b/hw/scsi/megasas.c
index 7ee7d97..65ccb09 100644
--- a/hw/scsi/megasas.c
+++ b/hw/scsi/megasas.c
@@ -232,7 +232,7 @@ static int megasas_map_sgl(MegasasState *s, MegasasCmd *cmd, union mfi_sgl *sgl)
                                          MEGASAS_MAX_SGE);
         return iov_count;
     }
-    qemu_sglist_init(&cmd->qsg, iov_count, pci_get_address_space(&s->dev));
+    pci_dma_sglist_init(&cmd->qsg, &s->dev, iov_count);
     for (i = 0; i < iov_count; i++) {
         dma_addr_t iov_pa, iov_size_p;
 
@@ -628,7 +628,7 @@ static int megasas_map_dcmd(MegasasState *s, MegasasCmd *cmd)
     }
     iov_pa = megasas_sgl_get_addr(cmd, &cmd->frame->dcmd.sgl);
     iov_size = megasas_sgl_get_len(cmd, &cmd->frame->dcmd.sgl);
-    qemu_sglist_init(&cmd->qsg, 1, pci_get_address_space(&s->dev));
+    pci_dma_sglist_init(&cmd->qsg, &s->dev, 1);
     qemu_sglist_add(&cmd->qsg, iov_pa, iov_size);
     cmd->iov_size = iov_size;
     return cmd->iov_size;
diff --git a/hw/scsi/virtio-scsi.c b/hw/scsi/virtio-scsi.c
index b8a0abf..712f0ad 100644
--- a/hw/scsi/virtio-scsi.c
+++ b/hw/scsi/virtio-scsi.c
@@ -77,10 +77,12 @@ static void virtio_scsi_bad_req(void)
     exit(1);
 }
 
-static void qemu_sgl_init_external(QEMUSGList *qsgl, struct iovec *sg,
+static void qemu_sgl_init_external(VirtIOSCSIReq *req, struct iovec *sg,
                                    hwaddr *addr, int num)
 {
-    qemu_sglist_init(qsgl, num, &address_space_memory);
+    QEMUSGList *qsgl = &req->qsgl;
+
+    qemu_sglist_init(qsgl, DEVICE(req->dev), num, &address_space_memory);
     while (num--) {
         qemu_sglist_add(qsgl, *(addr++), (sg++)->iov_len);
     }
@@ -99,11 +101,11 @@ static void virtio_scsi_parse_req(VirtIOSCSI *s, VirtQueue *vq,
     req->resp.buf = req->elem.in_sg[0].iov_base;
 
     if (req->elem.out_num > 1) {
-        qemu_sgl_init_external(&req->qsgl, &req->elem.out_sg[1],
+        qemu_sgl_init_external(req, &req->elem.out_sg[1],
                                &req->elem.out_addr[1],
                                req->elem.out_num - 1);
     } else {
-        qemu_sgl_init_external(&req->qsgl, &req->elem.in_sg[1],
+        qemu_sgl_init_external(req, &req->elem.in_sg[1],
                                &req->elem.in_addr[1],
                                req->elem.in_num - 1);
     }
diff --git a/hw/usb/hcd-ehci.c b/hw/usb/hcd-ehci.c
index 1ad2159..79caa63 100644
--- a/hw/usb/hcd-ehci.c
+++ b/hw/usb/hcd-ehci.c
@@ -1245,7 +1245,7 @@ static int ehci_init_transfer(EHCIPacket *p)
     cpage  = get_field(p->qtd.token, QTD_TOKEN_CPAGE);
     bytes  = get_field(p->qtd.token, QTD_TOKEN_TBYTES);
     offset = p->qtd.bufptr[0] & ~QTD_BUFPTR_MASK;
-    qemu_sglist_init(&p->sgl, 5, p->queue->ehci->as);
+    qemu_sglist_init(&p->sgl, DEVICE(p->queue->ehci), 5, p->queue->ehci->as);
 
     while (bytes > 0) {
         if (cpage > 4) {
@@ -1484,7 +1484,7 @@ static int ehci_process_itd(EHCIState *ehci,
                 return -1;
             }
 
-            qemu_sglist_init(&ehci->isgl, 2, ehci->as);
+            qemu_sglist_init(&ehci->isgl, DEVICE(ehci), 2, ehci->as);
             if (off + len > 4096) {
                 /* transfer crosses page border */
                 uint32_t len2 = off + len - 4096;
diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
index 6ef1f97..de406d6 100644
--- a/include/hw/pci/pci.h
+++ b/include/hw/pci/pci.h
@@ -702,7 +702,7 @@ static inline void pci_dma_unmap(PCIDevice *dev, void *buffer, dma_addr_t len,
 static inline void pci_dma_sglist_init(QEMUSGList *qsg, PCIDevice *dev,
                                        int alloc_hint)
 {
-    qemu_sglist_init(qsg, alloc_hint, pci_get_address_space(dev));
+    qemu_sglist_init(qsg, DEVICE(dev), alloc_hint, pci_get_address_space(dev));
 }
 
 extern const VMStateDescription vmstate_pci_device;
diff --git a/include/sysemu/dma.h b/include/sysemu/dma.h
index 031d1f5..00f21f3 100644
--- a/include/sysemu/dma.h
+++ b/include/sysemu/dma.h
@@ -29,6 +29,7 @@ struct QEMUSGList {
     int nsg;
     int nalloc;
     size_t size;
+    DeviceState *dev;
     AddressSpace *as;
 };
 
@@ -189,7 +190,8 @@ struct ScatterGatherEntry {
     dma_addr_t len;
 };
 
-void qemu_sglist_init(QEMUSGList *qsg, int alloc_hint, AddressSpace *as);
+void qemu_sglist_init(QEMUSGList *qsg, DeviceState *dev, int alloc_hint,
+                      AddressSpace *as);
 void qemu_sglist_add(QEMUSGList *qsg, dma_addr_t base, dma_addr_t len);
 void qemu_sglist_destroy(QEMUSGList *qsg);
 #endif
-- 
1.8.1.4