[Qemu-devel] [RFC PATCH 04/13] ide: use the DMA memory access interface for PCI IDE controllers

[Eduard - Gabriel Munteanu]

Emulated PCI IDE controllers now use the memory access interface. This
also allows an emulated IOMMU to translate and check accesses.

Map invalidation results in cancelling DMA transfers. Since the guest OS
can't properly recover the DMA results in case the mapping is changed,
this is a fairly good approximation.

Note this doesn't handle AHCI emulation yet!

Signed-off-by: Eduard - Gabriel Munteanu <address@hidden>
---
 dma-helpers.c     |   23 ++++++++++++++++++-----
 dma.h             |    4 +++-
 hw/ide/ahci.c     |    3 ++-
 hw/ide/internal.h |    1 +
 hw/ide/macio.c    |    4 ++--
 hw/ide/pci.c      |   18 +++++++++++-------
 6 files changed, 37 insertions(+), 16 deletions(-)

diff --git a/dma-helpers.c b/dma-helpers.c
index 712ed89..29a74a4 100644
--- a/dma-helpers.c
+++ b/dma-helpers.c
@@ -10,12 +10,13 @@
 #include "dma.h"
 #include "block_int.h"
 
-void qemu_sglist_init(QEMUSGList *qsg, int alloc_hint)
+void qemu_sglist_init(QEMUSGList *qsg, int alloc_hint, DMADevice *dma)
 {
     qsg->sg = qemu_malloc(alloc_hint * sizeof(ScatterGatherEntry));
     qsg->nsg = 0;
     qsg->nalloc = alloc_hint;
     qsg->size = 0;
+    qsg->dma = dma;
 }
 
 void qemu_sglist_add(QEMUSGList *qsg, target_phys_addr_t base,
@@ -73,12 +74,23 @@ static void dma_bdrv_unmap(DMAAIOCB *dbs)
     int i;
 
     for (i = 0; i < dbs->iov.niov; ++i) {
-        cpu_physical_memory_unmap(dbs->iov.iov[i].iov_base,
-                                  dbs->iov.iov[i].iov_len, !dbs->is_write,
-                                  dbs->iov.iov[i].iov_len);
+        dma_memory_unmap(dbs->sg->dma,
+                         dbs->iov.iov[i].iov_base,
+                         dbs->iov.iov[i].iov_len, !dbs->is_write,
+                         dbs->iov.iov[i].iov_len);
     }
 }
 
+static void dma_bdrv_cancel(void *opaque)
+{
+    DMAAIOCB *dbs = opaque;
+
+    bdrv_aio_cancel(dbs->acb);
+    dma_bdrv_unmap(dbs);
+    qemu_iovec_destroy(&dbs->iov);
+    qemu_aio_release(dbs);
+}
+
 static void dma_bdrv_cb(void *opaque, int ret)
 {
     DMAAIOCB *dbs = (DMAAIOCB *)opaque;
@@ -100,7 +112,8 @@ static void dma_bdrv_cb(void *opaque, int ret)
     while (dbs->sg_cur_index < dbs->sg->nsg) {
         cur_addr = dbs->sg->sg[dbs->sg_cur_index].base + dbs->sg_cur_byte;
         cur_len = dbs->sg->sg[dbs->sg_cur_index].len - dbs->sg_cur_byte;
-        mem = cpu_physical_memory_map(cur_addr, &cur_len, !dbs->is_write);
+        mem = dma_memory_map(dbs->sg->dma, dma_bdrv_cancel, dbs,
+                             cur_addr, &cur_len, !dbs->is_write);
         if (!mem)
             break;
         qemu_iovec_add(&dbs->iov, mem, cur_len);
diff --git a/dma.h b/dma.h
index f3bb275..2417b32 100644
--- a/dma.h
+++ b/dma.h
@@ -14,6 +14,7 @@
 //#include "cpu.h"
 #include "hw/hw.h"
 #include "block.h"
+#include "hw/dma_rw.h"
 
 typedef struct {
     target_phys_addr_t base;
@@ -25,9 +26,10 @@ typedef struct {
     int nsg;
     int nalloc;
     target_phys_addr_t size;
+    DMADevice *dma;
 } QEMUSGList;
 
-void qemu_sglist_init(QEMUSGList *qsg, int alloc_hint);
+void qemu_sglist_init(QEMUSGList *qsg, int alloc_hint, DMADevice *dma);
 void qemu_sglist_add(QEMUSGList *qsg, target_phys_addr_t base,
                      target_phys_addr_t len);
 void qemu_sglist_destroy(QEMUSGList *qsg);
diff --git a/hw/ide/ahci.c b/hw/ide/ahci.c
index c6e0c77..68b87d2 100644
--- a/hw/ide/ahci.c
+++ b/hw/ide/ahci.c
@@ -680,7 +680,8 @@ static int ahci_populate_sglist(AHCIDevice *ad, QEMUSGList 
*sglist)
     if (sglist_alloc_hint > 0) {
         AHCI_SG *tbl = (AHCI_SG *)prdt;
 
-        qemu_sglist_init(sglist, sglist_alloc_hint);
+        /* FIXME: pass a proper DMADevice. */
+        qemu_sglist_init(sglist, sglist_alloc_hint, NULL);
         for (i = 0; i < sglist_alloc_hint; i++) {
             /* flags_size is zero-based */
             qemu_sglist_add(sglist, le64_to_cpu(tbl[i].addr),
diff --git a/hw/ide/internal.h b/hw/ide/internal.h
index aa198b6..b830d67 100644
--- a/hw/ide/internal.h
+++ b/hw/ide/internal.h
@@ -474,6 +474,7 @@ struct IDEDMA {
     struct iovec iov;
     QEMUIOVector qiov;
     BlockDriverAIOCB *aiocb;
+    DMADevice *dev;
 };
 
 struct IDEBus {
diff --git a/hw/ide/macio.c b/hw/ide/macio.c
index 7107f6b..a111481 100644
--- a/hw/ide/macio.c
+++ b/hw/ide/macio.c
@@ -78,7 +78,7 @@ 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, io->len / MACIO_PAGE_SIZE + 1, NULL);
     qemu_sglist_add(&s->sg, io->addr, io->len);
     io->addr += io->len;
     io->len = 0;
@@ -140,7 +140,7 @@ 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, io->len / MACIO_PAGE_SIZE + 1, NULL);
     qemu_sglist_add(&s->sg, io->addr, io->len);
     io->addr += io->len;
     io->len = 0;
diff --git a/hw/ide/pci.c b/hw/ide/pci.c
index 65cb56c..a14f2ae 100644
--- a/hw/ide/pci.c
+++ b/hw/ide/pci.c
@@ -63,7 +63,8 @@ static int bmdma_prepare_buf(IDEDMA *dma, int is_write)
     } prd;
     int l, len;
 
-    qemu_sglist_init(&s->sg, s->nsector / (BMDMA_PAGE_SIZE / 512) + 1);
+    qemu_sglist_init(&s->sg,
+                     s->nsector / (BMDMA_PAGE_SIZE / 512) + 1, dma->dev);
     s->io_buffer_size = 0;
     for(;;) {
         if (bm->cur_prd_len == 0) {
@@ -71,7 +72,7 @@ static int bmdma_prepare_buf(IDEDMA *dma, int is_write)
             if (bm->cur_prd_last ||
                 (bm->cur_addr - bm->addr) >= BMDMA_PAGE_SIZE)
                 return s->io_buffer_size != 0;
-            cpu_physical_memory_read(bm->cur_addr, (uint8_t *)&prd, 8);
+            dma_memory_read(dma->dev, bm->cur_addr, (uint8_t *)&prd, 8);
             bm->cur_addr += 8;
             prd.addr = le32_to_cpu(prd.addr);
             prd.size = le32_to_cpu(prd.size);
@@ -113,7 +114,7 @@ static int bmdma_rw_buf(IDEDMA *dma, int is_write)
             if (bm->cur_prd_last ||
                 (bm->cur_addr - bm->addr) >= BMDMA_PAGE_SIZE)
                 return 0;
-            cpu_physical_memory_read(bm->cur_addr, (uint8_t *)&prd, 8);
+            dma_memory_read(dma->dev, bm->cur_addr, (uint8_t *)&prd, 8);
             bm->cur_addr += 8;
             prd.addr = le32_to_cpu(prd.addr);
             prd.size = le32_to_cpu(prd.size);
@@ -128,11 +129,11 @@ static int bmdma_rw_buf(IDEDMA *dma, int is_write)
             l = bm->cur_prd_len;
         if (l > 0) {
             if (is_write) {
-                cpu_physical_memory_write(bm->cur_prd_addr,
-                                          s->io_buffer + s->io_buffer_index, 
l);
+                dma_memory_write(dma->dev, bm->cur_prd_addr,
+                                 s->io_buffer + s->io_buffer_index, l);
             } else {
-                cpu_physical_memory_read(bm->cur_prd_addr,
-                                          s->io_buffer + s->io_buffer_index, 
l);
+                dma_memory_read(dma->dev, bm->cur_prd_addr,
+                                s->io_buffer + s->io_buffer_index, l);
             }
             bm->cur_prd_addr += l;
             bm->cur_prd_len -= l;
@@ -436,6 +437,9 @@ void pci_ide_create_devs(PCIDevice *dev, DriveInfo 
**hd_table)
             continue;
         ide_create_drive(d->bus+bus[i], unit[i], hd_table[i]);
     }
+
+    d->bmdma[0].dma.dev = &dev->dma;
+    d->bmdma[1].dma.dev = &dev->dma;
 }
 
 static const struct IDEDMAOps bmdma_ops = {
-- 
1.7.3.4