Messages in this thread | | | From | "Sinclair Yeh" <> | Date | Fri, 4 Dec 2015 14:33:08 -0800 | Subject | Re: [PATCH 1/6] x86: Add VMWare Host Communication Macros |
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Thanks Peter.
On Tue, Dec 01, 2015 at 02:49:11PM -0800, H. Peter Anvin wrote: > 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
Ok, I'm not sure why this worked and compiled before. Fixed.
> > 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.
Good catch. Fixed.
> > 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"); \ > +})
This is great. Changed.
Updated patch set incoming.
Sinclair
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