Re: [Qemu-devel] [RFC v1 20/22] dma: make dma access its own address space

[Anthony Liguori]

Avi Kivity <address@hidden> writes:

> Instead of accessing the cpu address space, use an address space
> configured by the caller.
>
> Eventually all dma functionality will be folded into AddressSpace,
> but we have to start from something.
>
> Signed-off-by: Avi Kivity <address@hidden>

Reviewed-by: Anthony Liguori <address@hidden>

Regards,

Anthony Liguori

> ---
>  dma-helpers.c    | 25 ++++++++++++-------------
>  dma.h            | 17 ++++++++---------
>  hw/Makefile.objs |  5 +++--
>  hw/spapr_iommu.c |  3 ++-
>  4 files changed, 25 insertions(+), 25 deletions(-)
>
> diff --git a/dma-helpers.c b/dma-helpers.c
> index 433d8b2..3f09dcb 100644
> --- a/dma-helpers.c
> +++ b/dma-helpers.c
> @@ -14,7 +14,8 @@
>  
>  /* #define DEBUG_IOMMU */
>  
> -static void do_dma_memory_set(dma_addr_t addr, uint8_t c, dma_addr_t len)
> +static void do_dma_memory_set(AddressSpace *as,
> +                              dma_addr_t addr, uint8_t c, dma_addr_t len)
>  {
>  #define FILLBUF_SIZE 512
>      uint8_t fillbuf[FILLBUF_SIZE];
> @@ -23,7 +24,7 @@ static void do_dma_memory_set(dma_addr_t addr, uint8_t c, 
> dma_addr_t len)
>      memset(fillbuf, c, FILLBUF_SIZE);
>      while (len > 0) {
>          l = len < FILLBUF_SIZE ? len : FILLBUF_SIZE;
> -        cpu_physical_memory_rw(addr, fillbuf, l, true);
> +        address_space_rw(as, addr, fillbuf, l, true);
>          len -= l;
>          addr += l;
>      }
> @@ -36,7 +37,7 @@ int dma_memory_set(DMAContext *dma, dma_addr_t addr, 
> uint8_t c, dma_addr_t len)
>      if (dma_has_iommu(dma)) {
>          return iommu_dma_memory_set(dma, addr, c, len);
>      }
> -    do_dma_memory_set(addr, c, len);
> +    do_dma_memory_set(dma->as, addr, c, len);
>  
>      return 0;
>  }
> @@ -332,8 +333,7 @@ int iommu_dma_memory_rw(DMAContext *dma, dma_addr_t addr,
>              plen = len;
>          }
>  
> -        cpu_physical_memory_rw(paddr, buf, plen,
> -                               dir == DMA_DIRECTION_FROM_DEVICE);
> +        address_space_rw(dma->as, paddr, buf, plen, dir == 
> DMA_DIRECTION_FROM_DEVICE);
>  
>          len -= plen;
>          addr += plen;
> @@ -366,7 +366,7 @@ int iommu_dma_memory_set(DMAContext *dma, dma_addr_t 
> addr, uint8_t c,
>              plen = len;
>          }
>  
> -        do_dma_memory_set(paddr, c, plen);
> +        do_dma_memory_set(dma->as, paddr, c, plen);
>  
>          len -= plen;
>          addr += plen;
> @@ -375,13 +375,14 @@ int iommu_dma_memory_set(DMAContext *dma, dma_addr_t 
> addr, uint8_t c,
>      return 0;
>  }
>  
> -void dma_context_init(DMAContext *dma, DMATranslateFunc translate,
> +void dma_context_init(DMAContext *dma, AddressSpace *as, DMATranslateFunc 
> translate,
>                        DMAMapFunc map, DMAUnmapFunc unmap)
>  {
>  #ifdef DEBUG_IOMMU
>      fprintf(stderr, "dma_context_init(%p, %p, %p, %p)\n",
>              dma, translate, map, unmap);
>  #endif
> +    dma->as = as;
>      dma->translate = translate;
>      dma->map = map;
>      dma->unmap = unmap;
> @@ -407,14 +408,13 @@ void *iommu_dma_memory_map(DMAContext *dma, dma_addr_t 
> addr, dma_addr_t *len,
>      /*
>       * If this is true, the virtual region is contiguous,
>       * but the translated physical region isn't. We just
> -     * clamp *len, much like cpu_physical_memory_map() does.
> +     * clamp *len, much like address_space_map() does.
>       */
>      if (plen < *len) {
>          *len = plen;
>      }
>  
> -    buf = cpu_physical_memory_map(paddr, &plen,
> -                                  dir == DMA_DIRECTION_FROM_DEVICE);
> +    buf = address_space_map(dma->as, paddr, &plen, dir == 
> DMA_DIRECTION_FROM_DEVICE);
>      *len = plen;
>  
>      return buf;
> @@ -428,8 +428,7 @@ void iommu_dma_memory_unmap(DMAContext *dma, void 
> *buffer, dma_addr_t len,
>          return;
>      }
>  
> -    cpu_physical_memory_unmap(buffer, len,
> -                              dir == DMA_DIRECTION_FROM_DEVICE,
> -                              access_len);
> +    address_space_unmap(dma->as, buffer, len, dir == 
> DMA_DIRECTION_FROM_DEVICE,
> +                        access_len);
>  
>  }
> diff --git a/dma.h b/dma.h
> index f35c4b6..94cf806 100644
> --- a/dma.h
> +++ b/dma.h
> @@ -11,6 +11,7 @@
>  #define DMA_H
>  
>  #include <stdio.h>
> +#include "memory.h"
>  #include "hw/hw.h"
>  #include "block.h"
>  #include "kvm.h"
> @@ -61,6 +62,7 @@ typedef void DMAUnmapFunc(DMAContext *dma,
>                            dma_addr_t access_len);
>  
>  struct DMAContext {
> +    AddressSpace *as;
>      DMATranslateFunc *translate;
>      DMAMapFunc *map;
>      DMAUnmapFunc *unmap;
> @@ -93,7 +95,7 @@ static inline void dma_barrier(DMAContext *dma, 
> DMADirection dir)
>  
>  static inline bool dma_has_iommu(DMAContext *dma)
>  {
> -    return !!dma;
> +    return dma && dma->translate;
>  }
>  
>  /* Checks that the given range of addresses is valid for DMA.  This is
> @@ -120,8 +122,7 @@ static inline int dma_memory_rw_relaxed(DMAContext *dma, 
> dma_addr_t addr,
>  {
>      if (!dma_has_iommu(dma)) {
>          /* Fast-path for no IOMMU */
> -        cpu_physical_memory_rw(addr, buf, len,
> -                               dir == DMA_DIRECTION_FROM_DEVICE);
> +        address_space_rw(dma->as, addr, buf, len, dir == 
> DMA_DIRECTION_FROM_DEVICE);
>          return 0;
>      } else {
>          return iommu_dma_memory_rw(dma, addr, buf, len, dir);
> @@ -179,8 +180,7 @@ static inline void *dma_memory_map(DMAContext *dma,
>          target_phys_addr_t xlen = *len;
>          void *p;
>  
> -        p = cpu_physical_memory_map(addr, &xlen,
> -                                    dir == DMA_DIRECTION_FROM_DEVICE);
> +        p = address_space_map(dma->as, addr, &xlen, dir == 
> DMA_DIRECTION_FROM_DEVICE);
>          *len = xlen;
>          return p;
>      } else {
> @@ -196,9 +196,8 @@ static inline void dma_memory_unmap(DMAContext *dma,
>                                      DMADirection dir, dma_addr_t access_len)
>  {
>      if (!dma_has_iommu(dma)) {
> -        cpu_physical_memory_unmap(buffer, (target_phys_addr_t)len,
> -                                  dir == DMA_DIRECTION_FROM_DEVICE,
> -                                  access_len);
> +        address_space_unmap(dma->as, buffer, (target_phys_addr_t)len,
> +                            dir == DMA_DIRECTION_FROM_DEVICE, access_len);
>      } else {
>          iommu_dma_memory_unmap(dma, buffer, len, dir, access_len);
>      }
> @@ -242,7 +241,7 @@ DEFINE_LDST_DMA(q, q, 64, be);
>  
>  #undef DEFINE_LDST_DMA
>  
> -void dma_context_init(DMAContext *dma, DMATranslateFunc translate,
> +void dma_context_init(DMAContext *dma, AddressSpace *as, DMATranslateFunc 
> translate,
>                        DMAMapFunc map, DMAUnmapFunc unmap);
>  
>  struct ScatterGatherEntry {
> diff --git a/hw/Makefile.objs b/hw/Makefile.objs
> index ecdbe44..9e4ec6e 100644
> --- a/hw/Makefile.objs
> +++ b/hw/Makefile.objs
> @@ -169,8 +169,9 @@ common-obj-$(CONFIG_MAX111X) += max111x.o
>  common-obj-$(CONFIG_DS1338) += ds1338.o
>  common-obj-y += i2c.o smbus.o smbus_eeprom.o
>  common-obj-y += eeprom93xx.o
> -common-obj-y += scsi-disk.o cdrom.o hd-geometry.o block-common.o
> -common-obj-y += scsi-generic.o scsi-bus.o
> +common-obj-y += cdrom.o hd-geometry.o block-common.o
> +common-obj-y += scsi-generic.o
> +hw-obj-y += scsi-disk.o scsi-bus.o
>  common-obj-y += hid.o
>  common-obj-$(CONFIG_SSI) += ssi.o
>  common-obj-$(CONFIG_SSI_SD) += ssi-sd.o
> diff --git a/hw/spapr_iommu.c b/hw/spapr_iommu.c
> index 53b7317..54798a3 100644
> --- a/hw/spapr_iommu.c
> +++ b/hw/spapr_iommu.c
> @@ -21,6 +21,7 @@
>  #include "qdev.h"
>  #include "kvm_ppc.h"
>  #include "dma.h"
> +#include "exec-memory.h"
>  
>  #include "hw/spapr.h"
>  
> @@ -117,7 +118,7 @@ DMAContext *spapr_tce_new_dma_context(uint32_t liobn, 
> size_t window_size)
>      }
>  
>      tcet = g_malloc0(sizeof(*tcet));
> -    dma_context_init(&tcet->dma, spapr_tce_translate, NULL, NULL);
> +    dma_context_init(&tcet->dma, &address_space_memory, spapr_tce_translate, 
> NULL, NULL);
>  
>      tcet->liobn = liobn;
>      tcet->window_size = window_size;
> -- 
> 1.7.12