[PATCH v6 23/42] nvme: add mapping helpers

[Klaus Jensen]

From: Klaus Jensen <address@hidden>

Add nvme_map_addr, nvme_map_addr_cmb and nvme_addr_to_cmb helpers and
use them in nvme_map_prp.

This fixes a bug where in the case of a CMB transfer, the device would
map to the buffer with a wrong length.

Fixes: b2b2b67a00574 ("nvme: Add support for Read Data and Write Data in CMBs.")
Signed-off-by: Klaus Jensen <address@hidden>
---
 hw/block/nvme.c       | 97 +++++++++++++++++++++++++++++++++++--------
 hw/block/trace-events |  1 +
 2 files changed, 81 insertions(+), 17 deletions(-)

diff --git a/hw/block/nvme.c b/hw/block/nvme.c
index 08267e847671..187c816eb6ad 100644
--- a/hw/block/nvme.c
+++ b/hw/block/nvme.c
@@ -59,6 +59,11 @@
 
 static void nvme_process_sq(void *opaque);
 
+static inline void *nvme_addr_to_cmb(NvmeCtrl *n, hwaddr addr)
+{
+    return &n->cmbuf[addr - n->ctrl_mem.addr];
+}
+
 static inline bool nvme_addr_is_cmb(NvmeCtrl *n, hwaddr addr)
 {
     hwaddr low = n->ctrl_mem.addr;
@@ -70,7 +75,7 @@ static inline bool nvme_addr_is_cmb(NvmeCtrl *n, hwaddr addr)
 static void nvme_addr_read(NvmeCtrl *n, hwaddr addr, void *buf, int size)
 {
     if (n->bar.cmbsz && nvme_addr_is_cmb(n, addr)) {
-        memcpy(buf, (void *)&n->cmbuf[addr - n->ctrl_mem.addr], size);
+        memcpy(buf, nvme_addr_to_cmb(n, addr), size);
         return;
     }
 
@@ -153,29 +158,79 @@ static void nvme_irq_deassert(NvmeCtrl *n, NvmeCQueue *cq)
     }
 }
 
+static uint16_t nvme_map_addr_cmb(NvmeCtrl *n, QEMUIOVector *iov, hwaddr addr,
+                                  size_t len)
+{
+    if (!nvme_addr_is_cmb(n, addr) || !nvme_addr_is_cmb(n, addr + len)) {
+        return NVME_DATA_TRAS_ERROR;
+    }
+
+    qemu_iovec_add(iov, nvme_addr_to_cmb(n, addr), len);
+
+    return NVME_SUCCESS;
+}
+
+static uint16_t nvme_map_addr(NvmeCtrl *n, QEMUSGList *qsg, QEMUIOVector *iov,
+                              hwaddr addr, size_t len)
+{
+    if (nvme_addr_is_cmb(n, addr)) {
+        if (qsg && qsg->sg) {
+            return NVME_INVALID_USE_OF_CMB | NVME_DNR;
+        }
+
+        assert(iov);
+
+        if (!iov->iov) {
+            qemu_iovec_init(iov, 1);
+        }
+
+        return nvme_map_addr_cmb(n, iov, addr, len);
+    }
+
+    if (iov && iov->iov) {
+        return NVME_INVALID_USE_OF_CMB | NVME_DNR;
+    }
+
+    assert(qsg);
+
+    if (!qsg->sg) {
+        pci_dma_sglist_init(qsg, &n->parent_obj, 1);
+    }
+
+    qemu_sglist_add(qsg, addr, len);
+
+    return NVME_SUCCESS;
+}
+
 static uint16_t nvme_map_prp(QEMUSGList *qsg, QEMUIOVector *iov, uint64_t prp1,
                              uint64_t prp2, uint32_t len, NvmeCtrl *n)
 {
     hwaddr trans_len = n->page_size - (prp1 % n->page_size);
     trans_len = MIN(len, trans_len);
     int num_prps = (len >> n->page_bits) + 1;
+    uint16_t status;
 
     if (unlikely(!prp1)) {
         trace_nvme_dev_err_invalid_prp();
         return NVME_INVALID_FIELD | NVME_DNR;
-    } else if (n->bar.cmbsz && prp1 >= n->ctrl_mem.addr &&
-               prp1 < n->ctrl_mem.addr + int128_get64(n->ctrl_mem.size)) {
-        qsg->nsg = 0;
+    }
+
+    if (nvme_addr_is_cmb(n, prp1)) {
         qemu_iovec_init(iov, num_prps);
-        qemu_iovec_add(iov, (void *)&n->cmbuf[prp1 - n->ctrl_mem.addr], 
trans_len);
     } else {
         pci_dma_sglist_init(qsg, &n->parent_obj, num_prps);
-        qemu_sglist_add(qsg, prp1, trans_len);
     }
+
+    status = nvme_map_addr(n, qsg, iov, prp1, trans_len);
+    if (status) {
+        goto unmap;
+    }
+
     len -= trans_len;
     if (len) {
         if (unlikely(!prp2)) {
             trace_nvme_dev_err_invalid_prp2_missing();
+            status = NVME_INVALID_FIELD | NVME_DNR;
             goto unmap;
         }
         if (len > n->page_size) {
@@ -192,6 +247,7 @@ static uint16_t nvme_map_prp(QEMUSGList *qsg, QEMUIOVector 
*iov, uint64_t prp1,
                 if (i == n->max_prp_ents - 1 && len > n->page_size) {
                     if (unlikely(!prp_ent || prp_ent & (n->page_size - 1))) {
                         trace_nvme_dev_err_invalid_prplist_ent(prp_ent);
+                        status = NVME_INVALID_FIELD | NVME_DNR;
                         goto unmap;
                     }
 
@@ -205,14 +261,14 @@ static uint16_t nvme_map_prp(QEMUSGList *qsg, 
QEMUIOVector *iov, uint64_t prp1,
 
                 if (unlikely(!prp_ent || prp_ent & (n->page_size - 1))) {
                     trace_nvme_dev_err_invalid_prplist_ent(prp_ent);
+                    status = NVME_INVALID_FIELD | NVME_DNR;
                     goto unmap;
                 }
 
                 trans_len = MIN(len, n->page_size);
-                if (qsg->nsg){
-                    qemu_sglist_add(qsg, prp_ent, trans_len);
-                } else {
-                    qemu_iovec_add(iov, (void *)&n->cmbuf[prp_ent - 
n->ctrl_mem.addr], trans_len);
+                status = nvme_map_addr(n, qsg, iov, prp_ent, trans_len);
+                if (status) {
+                    goto unmap;
                 }
                 len -= trans_len;
                 i++;
@@ -220,20 +276,27 @@ static uint16_t nvme_map_prp(QEMUSGList *qsg, 
QEMUIOVector *iov, uint64_t prp1,
         } else {
             if (unlikely(prp2 & (n->page_size - 1))) {
                 trace_nvme_dev_err_invalid_prp2_align(prp2);
+                status = NVME_INVALID_FIELD | NVME_DNR;
                 goto unmap;
             }
-            if (qsg->nsg) {
-                qemu_sglist_add(qsg, prp2, len);
-            } else {
-                qemu_iovec_add(iov, (void *)&n->cmbuf[prp2 - 
n->ctrl_mem.addr], trans_len);
+            status = nvme_map_addr(n, qsg, iov, prp2, len);
+            if (status) {
+                goto unmap;
             }
         }
     }
     return NVME_SUCCESS;
 
- unmap:
-    qemu_sglist_destroy(qsg);
-    return NVME_INVALID_FIELD | NVME_DNR;
+unmap:
+    if (iov && iov->iov) {
+        qemu_iovec_destroy(iov);
+    }
+
+    if (qsg && qsg->sg) {
+        qemu_sglist_destroy(qsg);
+    }
+
+    return status;
 }
 
 static uint16_t nvme_dma_write_prp(NvmeCtrl *n, uint8_t *ptr, uint32_t len,
diff --git a/hw/block/trace-events b/hw/block/trace-events
index 4cde0844ef64..adf11313f956 100644
--- a/hw/block/trace-events
+++ b/hw/block/trace-events
@@ -33,6 +33,7 @@ nvme_dev_irq_msix(uint32_t vector) "raising MSI-X IRQ vector 
%u"
 nvme_dev_irq_pin(void) "pulsing IRQ pin"
 nvme_dev_irq_masked(void) "IRQ is masked"
 nvme_dev_dma_read(uint64_t prp1, uint64_t prp2) "DMA read, prp1=0x%"PRIx64" 
prp2=0x%"PRIx64""
+nvme_dev_map_prp(uint16_t cid, uint8_t opc, uint64_t trans_len, uint32_t len, 
uint64_t prp1, uint64_t prp2, int num_prps) "cid %"PRIu16" opc 0x%"PRIx8" 
trans_len %"PRIu64" len %"PRIu32" prp1 0x%"PRIx64" prp2 0x%"PRIx64" num_prps %d"
 nvme_dev_rw(const char *verb, uint32_t blk_count, uint64_t byte_count, 
uint64_t lba) "%s %"PRIu32" blocks (%"PRIu64" bytes) from LBA %"PRIu64""
 nvme_dev_create_sq(uint64_t addr, uint16_t sqid, uint16_t cqid, uint16_t 
qsize, uint16_t qflags) "create submission queue, addr=0x%"PRIx64", 
sqid=%"PRIu16", cqid=%"PRIu16", qsize=%"PRIu16", qflags=%"PRIu16""
 nvme_dev_create_cq(uint64_t addr, uint16_t cqid, uint16_t vector, uint16_t 
size, uint16_t qflags, int ien) "create completion queue, addr=0x%"PRIx64", 
cqid=%"PRIu16", vector=%"PRIu16", qsize=%"PRIu16", qflags=%"PRIu16", ien=%d"
-- 
2.25.1