RE: [PATCH char-misc 1/2] Drivers: hv: vmbus: Remove x86 MSR refs in arch independent code

[Michael Kelley (EOSG)]

> > -#define hv_init_timer(timer, tick) wrmsrl(timer, tick)
> > -#define hv_init_timer_config(config, val) wrmsrl(config, val)
> > +#define hv_init_timer(timer, tick) \
> > +	wrmsrl(HV_X64_MSR_STIMER0_COUNT + (2*timer), tick)
> > +#define hv_init_timer_config(timer, val) \
> > +	wrmsrl(HV_X64_MSR_STIMER0_CONFIG + (2*timer), val)
>
> Why are we stepping in units of 2?
> 
> K. Y

The register addresses for  the *_CONFIG and *_COUNT registers
are interleaved.  From hyperv-tlfs.h:

#define HV_X64_MSR_STIMER0_CONFIG               0x400000B0
#define HV_X64_MSR_STIMER0_COUNT                0x400000B1
#define HV_X64_MSR_STIMER1_CONFIG               0x400000B2
#define HV_X64_MSR_STIMER1_COUNT                0x400000B3
#define HV_X64_MSR_STIMER2_CONFIG               0x400000B4
#define HV_X64_MSR_STIMER2_COUNT                0x400000B5
#define HV_X64_MSR_STIMER3_CONFIG               0x400000B6
#define HV_X64_MSR_STIMER3_COUNT                0x400000B7

Michael