Re: [Qemu-devel] [PATCH 5/8] libqos: Add streaming accessors for PCI MMIO

[Laurent Vivier <lvivier@redhat.com>]

On 18/10/2016 12:52, David Gibson wrote:
> Currently PCI memory (aka MMIO) space is accessed via a set of readb/writeb
> style accessors.  This is what we want for accessing discrete registers of
> a certain size.  However, there are a few cases where we instead need a
> "bag of bytes" style streaming interface to PCI MMIO space.  This can be
> either for streaming data style registers or when there's actual memory
> rather than registers in PCI space, for example frame buffers or ivshmem.
> 
> This patch adds backend callbacks, and libqos wrappers for this type of
> byte address order preserving accesses.
> 
> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

Reviewed-by: Laurent Vivier <lvivier@redhat.com>

> ---
>  tests/libqos/pci-pc.c    | 14 ++++++++++++++
>  tests/libqos/pci-spapr.c | 17 +++++++++++++++++
>  tests/libqos/pci.c       | 16 ++++++++++++++++
>  tests/libqos/pci.h       |  6 ++++++
>  4 files changed, 53 insertions(+)
> 
> diff --git a/tests/libqos/pci-pc.c b/tests/libqos/pci-pc.c
> index b087d13..0e95772 100644
> --- a/tests/libqos/pci-pc.c
> +++ b/tests/libqos/pci-pc.c
> @@ -95,6 +95,17 @@ static void qpci_pc_mmio_writel(QPCIBus *bus, uint32_t addr, uint32_t val)
>      writel(addr, val);
>  }
>  
> +static void qpci_pc_memread(QPCIBus *bus, uint32_t addr, void *buf, size_t len)
> +{
> +    memread(addr, buf, len);
> +}
> +
> +static void qpci_pc_memwrite(QPCIBus *bus, uint32_t addr,
> +                             const void *buf, size_t len)
> +{
> +    memwrite(addr, buf, len);
> +}
> +
>  static uint8_t qpci_pc_config_readb(QPCIBus *bus, int devfn, uint8_t offset)
>  {
>      outl(0xcf8, (1U << 31) | (devfn << 8) | offset);
> @@ -153,6 +164,9 @@ QPCIBus *qpci_init_pc(QGuestAllocator *alloc)
>      ret->bus.mmio_writew = qpci_pc_mmio_writew;
>      ret->bus.mmio_writel = qpci_pc_mmio_writel;
>  
> +    ret->bus.memread = qpci_pc_memread;
> +    ret->bus.memwrite = qpci_pc_memwrite;
> +
>      ret->bus.config_readb = qpci_pc_config_readb;
>      ret->bus.config_readw = qpci_pc_config_readw;
>      ret->bus.config_readl = qpci_pc_config_readl;
> diff --git a/tests/libqos/pci-spapr.c b/tests/libqos/pci-spapr.c
> index 9a18d8a..b4c4b81 100644
> --- a/tests/libqos/pci-spapr.c
> +++ b/tests/libqos/pci-spapr.c
> @@ -122,6 +122,20 @@ static void qpci_spapr_mmio32_writel(QPCIBus *bus, uint32_t addr, uint32_t val)
>      writel(s->mmio32_cpu_base + addr, bswap32(val));
>  }
>  
> +static void qpci_spapr_memread(QPCIBus *bus, uint32_t addr,
> +                               void *buf, size_t len)
> +{
> +    QPCIBusSPAPR *s = container_of(bus, QPCIBusSPAPR, bus);
> +    memread(s->mmio32_cpu_base + addr, buf, len);
> +}
> +
> +static void qpci_spapr_memwrite(QPCIBus *bus, uint32_t addr,
> +                                const void *buf, size_t len)
> +{
> +    QPCIBusSPAPR *s = container_of(bus, QPCIBusSPAPR, bus);
> +    memwrite(s->mmio32_cpu_base + addr, buf, len);
> +}
> +
>  static uint8_t qpci_spapr_config_readb(QPCIBus *bus, int devfn, uint8_t offset)
>  {
>      QPCIBusSPAPR *s = container_of(bus, QPCIBusSPAPR, bus);
> @@ -196,6 +210,9 @@ QPCIBus *qpci_init_spapr(QGuestAllocator *alloc)
>      ret->bus.mmio_writew = qpci_spapr_mmio32_writew;
>      ret->bus.mmio_writel = qpci_spapr_mmio32_writel;
>  
> +    ret->bus.memread = qpci_spapr_memread;
> +    ret->bus.memwrite = qpci_spapr_memwrite;
> +
>      ret->bus.config_readb = qpci_spapr_config_readb;
>      ret->bus.config_readw = qpci_spapr_config_readw;
>      ret->bus.config_readl = qpci_spapr_config_readl;
> diff --git a/tests/libqos/pci.c b/tests/libqos/pci.c
> index bf1c532..1e242f9 100644
> --- a/tests/libqos/pci.c
> +++ b/tests/libqos/pci.c
> @@ -289,6 +289,22 @@ void qpci_io_writel(QPCIDevice *dev, void *data, uint32_t value)
>      }
>  }
>  
> +void qpci_memread(QPCIDevice *dev, void *data, void *buf, size_t len)
> +{
> +    uintptr_t addr = (uintptr_t)data;
> +
> +    g_assert(addr >= QPCI_PIO_LIMIT);
> +    dev->bus->memread(dev->bus, addr, buf, len);
> +}
> +
> +void qpci_memwrite(QPCIDevice *dev, void *data, const void *buf, size_t len)
> +{
> +    uintptr_t addr = (uintptr_t)data;
> +
> +    g_assert(addr >= QPCI_PIO_LIMIT);
> +    dev->bus->memwrite(dev->bus, addr, buf, len);
> +}
> +
>  void *qpci_iomap(QPCIDevice *dev, int barno, uint64_t *sizeptr)
>  {
>      QPCIBus *bus = dev->bus;
> diff --git a/tests/libqos/pci.h b/tests/libqos/pci.h
> index f6f916d..2fa5b4f 100644
> --- a/tests/libqos/pci.h
> +++ b/tests/libqos/pci.h
> @@ -39,6 +39,9 @@ struct QPCIBus {
>      void (*mmio_writew)(QPCIBus *bus, uint32_t addr, uint16_t value);
>      void (*mmio_writel)(QPCIBus *bus, uint32_t addr, uint32_t value);
>  
> +    void (*memread)(QPCIBus *bus, uint32_t addr, void *buf, size_t len);
> +    void (*memwrite)(QPCIBus *bus, uint32_t addr, const void *buf, size_t len);
> +
>      uint8_t (*config_readb)(QPCIBus *bus, int devfn, uint8_t offset);
>      uint16_t (*config_readw)(QPCIBus *bus, int devfn, uint8_t offset);
>      uint32_t (*config_readl)(QPCIBus *bus, int devfn, uint8_t offset);
> @@ -92,6 +95,9 @@ void qpci_io_writeb(QPCIDevice *dev, void *data, uint8_t value);
>  void qpci_io_writew(QPCIDevice *dev, void *data, uint16_t value);
>  void qpci_io_writel(QPCIDevice *dev, void *data, uint32_t value);
>  
> +void qpci_memread(QPCIDevice *bus, void *data, void *buf, size_t len);
> +void qpci_memwrite(QPCIDevice *bus, void *data, const void *buf, size_t len);
> +
>  void *qpci_iomap(QPCIDevice *dev, int barno, uint64_t *sizeptr);
>  void qpci_iounmap(QPCIDevice *dev, void *data);
>  
>