Merge remote-tracking branch 'remotes/philmd/tags/memory-api-20220118' into staging

Memory API patches

- Directly dispatch MemoryRegion alias accesses
- Remove duplicated Address Space information in 'info mtree'
- Cleanups around memory_region_is_mapped()
- Fix incorrect calls of log_global_start/stop()
- Use dma_addr_t type definition when relevant
- Let dma_buf_read() / dma_buf_write() propagate MemTxResult
- Clarify MemoryRegion aliases documentation

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# gpg: Good signature from "Philippe Mathieu-Daudé (F4BUG) <f4bug@amsat.org>" [unknown]
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* remotes/philmd/tags/memory-api-20220118:
  docs/devel: add some clarifying text for aliases
  hw/dma: Let dma_buf_read() / dma_buf_write() propagate MemTxResult
  hw/dma: Use dma_addr_t type definition when relevant
  hw/dma: Move ScatterGatherEntry / QEMUSGList declarations around
  hw/dma: Fix format string issues using dma_addr_t
  hw/scsi: Rename SCSIRequest::resid as 'residual'
  hw/rdma/rdma_utils: Rename rdma_pci_dma_map 'len' argument
  hw/dma: Remove CONFIG_USER_ONLY check
  hw/pci: Document pci_dma_map()
  hw/pci: Restrict pci-bus stub to sysemu
  hw/nvram: Restrict fw_cfg QOM interface to sysemu and tools
  stubs: Restrict fw_cfg to system emulation
  memory: Fix incorrect calls of log_global_start/stop
  memory: Update description of memory_region_is_mapped()
  memory: Make memory_region_is_mapped() succeed when mapped via an alias
  machine: Use host_memory_backend_is_mapped() in machine_consume_memdev()
  memory: Have 'info mtree' remove duplicated Address Space information
  memory: Split mtree_info() as mtree_info_flatview() + mtree_info_as()
  memory: Directly dispatch alias accesses on origin memory region

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

4 files changed, 32 insertions, 19 deletions

diff --git a/include/exec/memory.h b/include/exec/memory.h
index 20f1b27377..63be794a06 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -738,6 +738,7 @@ struct MemoryRegion {
     const MemoryRegionOps *ops;
     void *opaque;
     MemoryRegion *container;
+    int mapped_via_alias; /* Mapped via an alias, container might be NULL */
     Int128 size;
     hwaddr addr;
     void (*destructor)(MemoryRegion *mr);
@@ -2296,7 +2297,8 @@ bool memory_region_present(MemoryRegion *container, hwaddr addr);
 
 /**
  * memory_region_is_mapped: returns true if #MemoryRegion is mapped
- * into any address space.
+ * into another memory region, which does not necessarily imply that it is
+ * mapped into an address space.
  *
  * @mr: a #MemoryRegion which should be checked if it's mapped
  */
diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
index 483d5c7c72..023abc0f79 100644
--- a/include/hw/pci/pci.h
+++ b/include/hw/pci/pci.h
@@ -881,6 +881,18 @@ PCI_DMA_DEFINE_LDST(q_be, q_be, 64);
 
 #undef PCI_DMA_DEFINE_LDST
 
+/**
+ * pci_dma_map: Map device PCI address space range into host virtual address
+ * @dev: #PCIDevice to be accessed
+ * @addr: address within that device's address space
+ * @plen: pointer to length of buffer; updated on return to indicate
+ *        if only a subset of the requested range has been mapped
+ * @dir: indicates the transfer direction
+ *
+ * Return: A host pointer, or %NULL if the resources needed to
+ *         perform the mapping are exhausted (in that case *@plen
+ *         is set to zero).
+ */
 static inline void *pci_dma_map(PCIDevice *dev, dma_addr_t addr,
                                 dma_addr_t *plen, DMADirection dir)
 {
diff --git a/include/hw/scsi/scsi.h b/include/hw/scsi/scsi.h
index 2ef80af6dc..1ffb367f94 100644
--- a/include/hw/scsi/scsi.h
+++ b/include/hw/scsi/scsi.h
@@ -30,7 +30,7 @@ struct SCSIRequest {
     int16_t           status;
     int16_t           host_status;
     void              *hba_private;
-    size_t            resid;
+    uint64_t          residual;
     SCSICommand       cmd;
     NotifierList      cancel_notifiers;
 
@@ -125,7 +125,7 @@ struct SCSIBusInfo {
                      void *hba_private);
     void (*transfer_data)(SCSIRequest *req, uint32_t arg);
     void (*fail)(SCSIRequest *req);
-    void (*complete)(SCSIRequest *req, size_t resid);
+    void (*complete)(SCSIRequest *req, size_t residual);
     void (*cancel)(SCSIRequest *req);
     void (*change)(SCSIBus *bus, SCSIDevice *dev, SCSISense sense);
     QEMUSGList *(*get_sg_list)(SCSIRequest *req);
diff --git a/include/sysemu/dma.h b/include/sysemu/dma.h
index b3faef41b2..a1ac5bc1b5 100644
--- a/include/sysemu/dma.h
+++ b/include/sysemu/dma.h
@@ -15,24 +15,11 @@
 #include "block/block.h"
 #include "block/accounting.h"
 
-typedef struct ScatterGatherEntry ScatterGatherEntry;
-
 typedef enum {
     DMA_DIRECTION_TO_DEVICE = 0,
     DMA_DIRECTION_FROM_DEVICE = 1,
 } DMADirection;
 
-struct QEMUSGList {
-    ScatterGatherEntry *sg;
-    int nsg;
-    int nalloc;
-    size_t size;
-    DeviceState *dev;
-    AddressSpace *as;
-};
-
-#ifndef CONFIG_USER_ONLY
-
 /*
  * When an IOMMU is present, bus addresses become distinct from
  * CPU/memory physical addresses and may be a different size.  Because
@@ -45,6 +32,17 @@ typedef uint64_t dma_addr_t;
 #define DMA_ADDR_BITS 64
 #define DMA_ADDR_FMT "%" PRIx64
 
+typedef struct ScatterGatherEntry ScatterGatherEntry;
+
+struct QEMUSGList {
+    ScatterGatherEntry *sg;
+    int nsg;
+    int nalloc;
+    dma_addr_t size;
+    DeviceState *dev;
+    AddressSpace *as;
+};
+
 static inline void dma_barrier(AddressSpace *as, DMADirection dir)
 {
     /*
@@ -288,7 +286,6 @@ 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
 
 typedef BlockAIOCB *DMAIOFunc(int64_t offset, QEMUIOVector *iov,
                               BlockCompletionFunc *cb, void *cb_opaque,
@@ -304,8 +301,10 @@ BlockAIOCB *dma_blk_read(BlockBackend *blk,
 BlockAIOCB *dma_blk_write(BlockBackend *blk,
                           QEMUSGList *sg, uint64_t offset, uint32_t align,
                           BlockCompletionFunc *cb, void *opaque);
-uint64_t dma_buf_read(void *ptr, int32_t len, QEMUSGList *sg, MemTxAttrs attrs);
-uint64_t dma_buf_write(void *ptr, int32_t len, QEMUSGList *sg, MemTxAttrs attrs);
+MemTxResult dma_buf_read(void *ptr, dma_addr_t len, dma_addr_t *residual,
+                         QEMUSGList *sg, MemTxAttrs attrs);
+MemTxResult dma_buf_write(void *ptr, dma_addr_t len, dma_addr_t *residual,
+                          QEMUSGList *sg, MemTxAttrs attrs);
 
 void dma_acct_start(BlockBackend *blk, BlockAcctCookie *cookie,
                     QEMUSGList *sg, enum BlockAcctType type);