Re: [Qemu-devel] [PATCH] qtest: add read/write accessors with a specific endianness

[David Gibson]

On Tue, Oct 04, 2016 at 02:17:28PM +0200, Cédric Le Goater wrote:
> Some test scenarios require to access memory regions using a specific
> endianness, such as a device region, but the current qtest memory
> accessors are done in native endian, which means that the values are
> byteswapped in qtest if the endianness of the guest and the host are
> different.
> 
> To maintain the endianness of a value, we need a new set of memory
> accessor. This can be done in two ways:
> 
> - first, convert the value to the required endianness in libqtest and
>   then use the memread/write routines so that qtest accesses the guest
>   memory without doing any supplementary byteswapping
> 
> - an alternative method would be to handle the byte swapping on the
>   qtest side. For that, we would need to extend the read/write
>   protocol with an ending word : "native|le|be" and modify the tswap
>   calls accordingly under the qtest_process_command() routine.
> 
> The result is the same and the first method is simpler.
> 
> Signed-off-by: Cédric Le Goater <address@hidden>
> ---
> 
>  tests/libqtest.c |   91 
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  tests/libqtest.h |   71 ++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 162 insertions(+)
> 
> Index: qemu-aspeed.git/tests/libqtest.h
> ===================================================================
> --- qemu-aspeed.git.orig/tests/libqtest.h
> +++ qemu-aspeed.git/tests/libqtest.h
> @@ -887,4 +887,75 @@ void qmp_fd_send(int fd, const char *fmt
>  QDict *qmp_fdv(int fd, const char *fmt, va_list ap);
>  QDict *qmp_fd(int fd, const char *fmt, ...);
>  
> +/*
> + * BE/LE read/write accessors
> + */
> +uint16_t qtest_readw_be(QTestState *s, uint64_t addr);
> +uint32_t qtest_readl_be(QTestState *s, uint64_t addr);
> +uint64_t qtest_readq_be(QTestState *s, uint64_t addr);
> +
> +static inline uint16_t readw_be(uint64_t addr)
> +{
> +    return qtest_readw_be(global_qtest, addr);
> +}
> +static inline uint32_t readl_be(uint64_t addr)
> +{
> +    return qtest_readl_be(global_qtest, addr);
> +}
> +static inline uint64_t readq_be(uint64_t addr)
> +{
> +    return qtest_readq_be(global_qtest, addr);
> +}
> +
> +void qtest_writew_be(QTestState *s, uint64_t addr, uint16_t value);
> +void qtest_writel_be(QTestState *s, uint64_t addr, uint32_t value);
> +void qtest_writeq_be(QTestState *s, uint64_t addr, uint64_t value);
> +
> +static inline void writew_be(uint64_t addr, uint16_t value)
> +{
> +    qtest_writew_be(global_qtest, addr, value);
> +}
> +static inline void writel_be(uint64_t addr, uint32_t value)
> +{
> +    qtest_writel_be(global_qtest, addr, value);
> +}
> +static inline void writeq_be(uint64_t addr, uint64_t value)
> +{
> +    qtest_writeq_be(global_qtest, addr, value);
> +}
> +
> +uint16_t qtest_readw_le(QTestState *s, uint64_t addr);
> +uint32_t qtest_readl_le(QTestState *s, uint64_t addr);
> +uint64_t qtest_readq_le(QTestState *s, uint64_t addr);
> +
> +static inline uint16_t readw_le(uint64_t addr)
> +{
> +    return qtest_readw_le(global_qtest, addr);
> +}
> +static inline uint32_t readl_le(uint64_t addr)
> +{
> +    return qtest_readl_le(global_qtest, addr);
> +}
> +static inline uint64_t readq_le(uint64_t addr)
> +{
> +    return qtest_readq_le(global_qtest, addr);
> +}
> +
> +void qtest_writew_le(QTestState *s, uint64_t addr, uint16_t value);
> +void qtest_writel_le(QTestState *s, uint64_t addr, uint32_t value);
> +void qtest_writeq_le(QTestState *s, uint64_t addr, uint64_t value);
> +
> +static inline void writew_le(uint64_t addr, uint16_t value)
> +{
> +    qtest_writew_le(global_qtest, addr, value);
> +}
> +static inline void writel_le(uint64_t addr, uint32_t value)
> +{
> +    qtest_writel_le(global_qtest, addr, value);
> +}
> +static inline void writeq_le(uint64_t addr, uint64_t value)
> +{
> +    qtest_writeq_le(global_qtest, addr, value);
> +}
> +
>  #endif
> Index: qemu-aspeed.git/tests/libqtest.c
> ===================================================================
> --- qemu-aspeed.git.orig/tests/libqtest.c
> +++ qemu-aspeed.git/tests/libqtest.c
> @@ -15,6 +15,7 @@
>   *
>   */
>  #include "qemu/osdep.h"
> +#include "qemu/bswap.h"
>  #include "libqtest.h"
>  
>  #include <sys/socket.h>
> @@ -688,6 +689,42 @@ void qtest_writeq(QTestState *s, uint64_
>      qtest_write(s, "writeq", addr, value);
>  }
>  
> +void qtest_writew_be(QTestState *s, uint64_t addr, uint16_t value)
> +{
> +    value = cpu_to_be16(value);
> +    qtest_memread(s, addr, &value, sizeof(value));

Uh.. this surely needs to be qtest_memwrite().

> +}
> +
> +void qtest_writel_be(QTestState *s, uint64_t addr, uint32_t value)
> +{
> +    value = cpu_to_be32(value);
> +    qtest_memread(s, addr, &value, sizeof(value));

and here,

> +}
> +
> +void qtest_writeq_be(QTestState *s, uint64_t addr, uint64_t value)
> +{
> +    value = cpu_to_be64(value);
> +    qtest_memread(s, addr, &value, sizeof(value));

here

> +}
> +
> +void qtest_writew_le(QTestState *s, uint64_t addr, uint16_t value)
> +{
> +    value = cpu_to_le16(value);
> +    qtest_memread(s, addr, &value, sizeof(value));

here

> +}
> +
> +void qtest_writel_le(QTestState *s, uint64_t addr, uint32_t value)
> +{
> +    value = cpu_to_le32(value);
> +    qtest_memread(s, addr, &value, sizeof(value));

here

> +}
> +
> +void qtest_writeq_le(QTestState *s, uint64_t addr, uint64_t value)
> +{
> +    value = cpu_to_le64(value);
> +    qtest_memread(s, addr, &value, sizeof(value));

and here

> +}
> +
>  static uint64_t qtest_read(QTestState *s, const char *cmd, uint64_t addr)
>  {
>      gchar **args;
> @@ -721,6 +758,60 @@ uint64_t qtest_readq(QTestState *s, uint
>      return qtest_read(s, "readq", addr);
>  }
>  
> +uint16_t qtest_readw_be(QTestState *s, uint64_t addr)
> +{
> +    uint16_t value;
> +
> +    qtest_memread(s, addr, &value, sizeof(value));
> +
> +    return be16_to_cpu(value);
> +}
> +
> +uint32_t qtest_readl_be(QTestState *s, uint64_t addr)
> +{
> +    uint32_t value;
> +
> +    qtest_memread(s, addr, &value, sizeof(value));
> +
> +    return be32_to_cpu(value);
> +}
> +
> +uint64_t qtest_readq_be(QTestState *s, uint64_t addr)
> +{
> +    uint64_t value;
> +
> +    qtest_memread(s, addr, &value, sizeof(value));
> +
> +    return be64_to_cpu(value);
> +}
> +
> +uint16_t qtest_readw_le(QTestState *s, uint64_t addr)
> +{
> +    uint16_t value;
> +
> +    qtest_memread(s, addr, &value, sizeof(value));
> +
> +    return le16_to_cpu(value);
> +}
> +
> +uint32_t qtest_readl_le(QTestState *s, uint64_t addr)
> +{
> +    uint32_t value;
> +
> +    qtest_memread(s, addr, &value, sizeof(value));
> +
> +    return le32_to_cpu(value);
> +}
> +
> +uint64_t qtest_readq_le(QTestState *s, uint64_t addr)
> +{
> +    uint64_t value;
> +
> +    qtest_memread(s, addr, &value, sizeof(value));
> +
> +    return le64_to_cpu(value);
> +}
> +
>  static int hex2nib(char ch)
>  {
>      if (ch >= '0' && ch <= '9') {
> 

-- 
David Gibson                    | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au  | minimalist, thank you.  NOT _the_ _other_
                                | _way_ _around_!
http://www.ozlabs.org/~dgibson

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