RE: [PATCH v4 1/2] KVM: VMX: Cleanup VMX basic information defines and usages

From: Li, Xin3
Date: Mon Jan 15 2024 - 23:14:10 EST


> > Define VMX basic information fields with BIT_ULL()/GENMASK_ULL(), and
> > replace hardcoded VMX basic numbers with these field macros.
> >
> > Per Sean's ask, save the full/raw value of MSR_IA32_VMX_BASIC in the
> > global vmcs_config as type u64 to get rid of the hi/lo crud, and then
> > use VMX_BASIC helpers to extract info as needed.
>
> For the sake of wanting a single 'u64 vmx_basic', feel free to add:
>
> Acked-by: Kai Huang <kai.huang@xxxxxxxxx>
>
> Although I still don't like splitting ...
>
> [...]
>
>
> > --- a/arch/x86/include/asm/vmx.h
> > +++ b/arch/x86/include/asm/vmx.h
> > @@ -120,6 +120,14 @@
> >
> ...
>
> > +/* VMX_BASIC bits and bitmasks */
> > +#define VMX_BASIC_32BIT_PHYS_ADDR_ONLY BIT_ULL(48)
> > +#define VMX_BASIC_INOUT BIT_ULL(54)
> > +
> >
> ...
>
> > --- a/arch/x86/kvm/vmx/nested.c
> > +++ b/arch/x86/kvm/vmx/nested.c
> > @@ -1226,23 +1226,32 @@ static bool is_bitwise_subset(u64 superset, u64
> subset, u64 mask)
> > return (superset | subset) == superset; }
> >
> > +#define VMX_BASIC_DUAL_MONITOR_TREATMENT BIT_ULL(49)
> > +#define VMX_BASIC_TRUE_CTLS BIT_ULL(55)
>
> ... these VMX_BASIC bit definitions across multiple files.

IIUC, Sean prefers to define a macro just above the function in which
it is only used:
https://lore.kernel.org/kvm/ZTBJO75Zu1JBsqvw@xxxxxxxxxx/

>
> [...]
>
>
> > +#define VMX_BASIC_MEM_TYPE_WB (MEM_TYPE_WB << 50);
>
> Also, please fix this one.

Bah!