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SubjectRe: [PATCH 1/6] x86: Add VMWare Host Communication Macros
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On 12/01/15 14:18, Sinclair Yeh wrote:
> These macros will be used by multiple VMWare modules for handling
> host communication.

> + __asm__ __volatile__ ("inl %%dx" : \

This is odd at best; the standard assembly form of this instruction is:

inl (%dx),%eax

Also, we don't need the underscored forms of asm and volatile for kernel
code.

> + __asm__ __volatile__ ("movq %13, %%rbp;" \
> + "cld; rep outsb; " \
> + "movq %%rbp, %6" : \

cld shouldn't be necessary here, DF=0 is part of the normal ABI environment.

You also don't save/restore %rbp here, but you do below? Seems very odd.

It might be better do so something like:

+#define VMW_PORT_HB_OUT(in1, in2, port_num, magic, \
+ eax, ebx, ecx, edx, si, di, bp) \
+({ \
+ __asm__ __volatile__ ("xchgq %6, %%rbp;" \
+ "cld; rep outsb; " \
+ "xchgq %%rbp, %6" : \
+ "=a"(eax), \
+ "=b"(ebx), \
+ "=c"(ecx), \
+ "=d"(edx), \
+ "+S"(si), \
+ "+D"(di), \
+ "+r"(bp) : \
+ "a"(magic), \
+ "b"(in1), \
+ "c"(in2), \
+ "d"(port_num) : \
+ "memory", "cc"); \
+})





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