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

[Cédric Le Goater]

On 10/05/2016 01:26 AM, David Gibson wrote:
> 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().

arg. I missed a quilt refresh before sending ...

Thanks,

C. 
> 
>> +}
>> +
>> +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') {
>>
>