linux-kernel - Re: [PATCH v6 7/7] KVM: TDX: Explicitly do WBINVD when no more TDX SEAMCALLs

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Message-ID: <404b8048111697a49c9ca18a77ed36730a32ef18.camel@intel.com>
Date: Thu, 14 Aug 2025 22:25:50 +0000
From: "Huang, Kai" <kai.huang@...el.com>
To: "seanjc@...gle.com" <seanjc@...gle.com>
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Subject: Re: [PATCH v6 7/7] KVM: TDX: Explicitly do WBINVD when no more TDX
 SEAMCALLs

On Thu, 2025-08-14 at 06:54 -0700, Sean Christopherson wrote:
> > diff --git a/arch/x86/include/asm/tdx.h b/arch/x86/include/asm/tdx.h
> > index 0922265c6bdc..e9a213582f03 100644
> > --- a/arch/x86/include/asm/tdx.h
> > +++ b/arch/x86/include/asm/tdx.h
> > @@ -217,6 +217,7 @@ u64 tdh_mem_page_remove(struct tdx_td *td, u64 gpa, u64 level, u64 *ext_err1, u6
> >   u64 tdh_phymem_cache_wb(bool resume);
> >   u64 tdh_phymem_page_wbinvd_tdr(struct tdx_td *td);
> >   u64 tdh_phymem_page_wbinvd_hkid(u64 hkid, struct page *page);
> > +void tdx_cpu_flush_cache(void);
> >   #else
> >   static inline void tdx_init(void) { }
> >   static inline int tdx_cpu_enable(void) { return -ENODEV; }
> > @@ -224,6 +225,7 @@ static inline int tdx_enable(void)  { return -ENODEV; }
> >   static inline u32 tdx_get_nr_guest_keyids(void) { return 0; }
> >   static inline const char *tdx_dump_mce_info(struct mce *m) { return NULL; }
> >   static inline const struct tdx_sys_info *tdx_get_sysinfo(void) { return NULL; }
> > +static inline void tdx_cpu_flush_cache(void) { }
> 
> Stub is unnecessary.  tdx.c is built iff KVM_INTEL_TDX=y, and that depends on
> INTEL_TDX_HOST.
> 
> At a glance, some of the existing stubs are useless as well.

OK I will remove it.  Thanks.