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From: Borislav Petkov <bp@alien8.de>
To: Kuppuswamy Sathyanarayanan  <sathyanarayanan.kuppuswamy@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Andy Lutomirski <luto@kernel.org>, Peter H Anvin <hpa@zytor.com>,
	Dave Hansen <dave.hansen@intel.com>,
	Tony Luck <tony.luck@intel.com>,
	Dan Williams <dan.j.williams@intel.com>,
	Andi Kleen <ak@linux.intel.com>,
	Kirill Shutemov <kirill.shutemov@linux.intel.com>,
	Sean Christopherson <seanjc@google.com>,
	Kuppuswamy Sathyanarayanan <knsathya@kernel.org>,
	x86@kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v5 09/12] x86/tdx: Wire up KVM hypercalls
Date: Tue, 24 Aug 2021 18:34:45 +0200	[thread overview]
Message-ID: <YSUfpQPvL6wsk6Ou@zn.tnic> (raw)
In-Reply-To: <20210804181329.2899708-10-sathyanarayanan.kuppuswamy@linux.intel.com>

On Wed, Aug 04, 2021 at 11:13:26AM -0700, Kuppuswamy Sathyanarayanan wrote:
> From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
> 
> KVM hypercalls use the "vmcall" or "vmmcall" instructions.

Write instruction mnemonics in all caps pls.

> +# This option enables KVM specific hypercalls in TDX guest.
> +config INTEL_TDX_GUEST_KVM

What is that config option really for? IOW, can't you use
CONFIG_KVM_GUEST instead?

> +	def_bool y
> +	depends on KVM_GUEST && INTEL_TDX_GUEST
> +
>  endif #HYPERVISOR_GUEST
>  
>  source "arch/x86/Kconfig.cpu"
> diff --git a/arch/x86/include/asm/asm-prototypes.h b/arch/x86/include/asm/asm-prototypes.h
> index 4cb726c71ed8..9855a9ff2924 100644
> --- a/arch/x86/include/asm/asm-prototypes.h
> +++ b/arch/x86/include/asm/asm-prototypes.h
> @@ -17,6 +17,10 @@
>  extern void cmpxchg8b_emu(void);
>  #endif
>  
> +#ifdef CONFIG_INTEL_TDX_GUEST
> +#include <asm/tdx.h>
> +#endif

What "ASM sysmbol generation issue" forced this?

...

> diff --git a/arch/x86/include/asm/tdx.h b/arch/x86/include/asm/tdx.h
> index 846fe58f0426..8fa33e2c98db 100644
> --- a/arch/x86/include/asm/tdx.h
> +++ b/arch/x86/include/asm/tdx.h
> @@ -6,8 +6,9 @@
>  #include <linux/cpufeature.h>
>  #include <linux/types.h>
>  
> -#define TDX_CPUID_LEAF_ID	0x21
> -#define TDX_HYPERCALL_STANDARD  0
> +#define TDX_CPUID_LEAF_ID			0x21
> +#define TDX_HYPERCALL_STANDARD			0
> +#define TDX_HYPERCALL_VENDOR_KVM		0x4d564b2e584454

						"TDX.KVM"

Yeah, you can put it in a comment so that people don't have to do the
CTRL-V game in vim insert mode, i.e., ":help i_CTRL-V_digit" :-)

>  /*
>   * Used in __tdx_module_call() helper function to gather the
> @@ -80,4 +81,29 @@ static inline bool tdx_prot_guest_has(unsigned long flag) { return false; }
>  
>  #endif /* CONFIG_INTEL_TDX_GUEST */
>  
> +#ifdef CONFIG_INTEL_TDX_GUEST_KVM

I don't think that even needs the ifdeffery. If it is not used, the
inline will simply get discarded so why bother?

> +
> +static inline long tdx_kvm_hypercall(unsigned int nr, unsigned long p1,
> +				     unsigned long p2, unsigned long p3,
> +				     unsigned long p4)
> +{
> +	struct tdx_hypercall_output out;
> +	u64 err;
> +
> +	err = __tdx_hypercall(TDX_HYPERCALL_VENDOR_KVM, nr, p1, p2,
> +			      p3, p4, &out);
> +
> +	BUG_ON(err);
> +
> +	return out.r10;
> +}
> +#else
> +static inline long tdx_kvm_hypercall(unsigned int nr, unsigned long p1,
> +				     unsigned long p2, unsigned long p3,
> +				     unsigned long p4)
> +{
> +	return -ENODEV;
> +}
> +#endif /* CONFIG_INTEL_TDX_GUEST_KVM */
> +
>  #endif /* _ASM_X86_TDX_H */
> diff --git a/arch/x86/kernel/tdcall.S b/arch/x86/kernel/tdcall.S
> index 9df94f87465d..1823bac4542d 100644
> --- a/arch/x86/kernel/tdcall.S
> +++ b/arch/x86/kernel/tdcall.S
> @@ -3,6 +3,7 @@
>  #include <asm/asm.h>
>  #include <asm/frame.h>
>  #include <asm/unwind_hints.h>
> +#include <asm/export.h>
>  
>  #include <linux/linkage.h>
>  #include <linux/bits.h>
> @@ -309,3 +310,4 @@ skip_sti:
>  
>         retq
>  SYM_FUNC_END(__tdx_hypercall)
> +EXPORT_SYMBOL(__tdx_hypercall);

EXPORT_SYMBOL_GPL, of course.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette

  reply	other threads:[~2021-08-24 16:34 UTC|newest]

Thread overview: 72+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-04 18:13 [PATCH v5 00/12] Add TDX Guest Support (Initial support) Kuppuswamy Sathyanarayanan
2021-08-04 18:13 ` [PATCH v5 01/12] x86/paravirt: Move halt paravirt calls under CONFIG_PARAVIRT Kuppuswamy Sathyanarayanan
2021-08-12  7:18   ` Borislav Petkov
2021-08-12 17:17     ` Kuppuswamy, Sathyanarayanan
2021-08-17 12:50     ` Juergen Gross
2021-08-17 13:16       ` Kuppuswamy, Sathyanarayanan
2021-08-17 13:28         ` Juergen Gross
2021-08-17 13:39           ` Kuppuswamy, Sathyanarayanan
2021-08-17 13:47             ` Juergen Gross
2021-08-17 13:50               ` Kuppuswamy, Sathyanarayanan
2021-08-04 18:13 ` [PATCH v5 02/12] x86/tdx: Introduce INTEL_TDX_GUEST config option Kuppuswamy Sathyanarayanan
2021-08-04 18:13 ` [PATCH v5 03/12] x86/cpufeatures: Add TDX Guest CPU feature Kuppuswamy Sathyanarayanan
2021-08-12  7:39   ` Borislav Petkov
2021-08-04 18:13 ` [PATCH v5 04/12] x86/tdx: Add protected guest support for TDX guest Kuppuswamy Sathyanarayanan
2021-08-04 21:59   ` Sean Christopherson
2021-08-04 22:03     ` Dave Hansen
2021-08-04 22:26       ` Kuppuswamy, Sathyanarayanan
2021-08-04 22:42         ` Sean Christopherson
2021-08-04 23:00           ` Kuppuswamy, Sathyanarayanan
2021-08-12  7:53             ` Borislav Petkov
2021-08-12 17:18               ` Kuppuswamy, Sathyanarayanan
2021-08-20 14:28                 ` Borislav Petkov
2021-08-20 16:42                   ` Kuppuswamy, Sathyanarayanan
2021-08-20 16:59                     ` Borislav Petkov
2021-08-20 17:11                       ` Kuppuswamy, Sathyanarayanan
2021-08-04 18:13 ` [PATCH v5 05/12] x86/tdx: Add __tdx_module_call() and __tdx_hypercall() helper functions Kuppuswamy Sathyanarayanan
2021-08-20 15:16   ` Borislav Petkov
2021-08-04 18:13 ` [PATCH v5 06/12] x86/tdx: Get TD execution environment information via TDINFO Kuppuswamy Sathyanarayanan
2021-08-04 22:38   ` Sean Christopherson
2021-08-20 17:13   ` Borislav Petkov
2021-08-20 17:31     ` Kuppuswamy, Sathyanarayanan
2021-08-20 17:35       ` Borislav Petkov
2021-08-20 18:29         ` Kuppuswamy, Sathyanarayanan
2021-08-20 18:58           ` Andi Kleen
2021-08-20 19:01             ` Kuppuswamy, Sathyanarayanan
2021-08-04 18:13 ` [PATCH v5 07/12] x86/traps: Add #VE support for TDX guest Kuppuswamy Sathyanarayanan
2021-08-24 10:17   ` Borislav Petkov
2021-08-24 17:32     ` Kuppuswamy, Sathyanarayanan
2021-08-24 17:36       ` Dave Hansen
2021-08-24 17:46       ` Borislav Petkov
2021-09-02 15:24         ` Kuppuswamy, Sathyanarayanan
2021-09-03 10:17           ` Borislav Petkov
2021-08-04 18:13 ` [PATCH v5 08/12] x86/tdx: Add HLT " Kuppuswamy Sathyanarayanan
2021-08-24 16:10   ` Borislav Petkov
2021-08-24 17:06     ` Sean Christopherson
2021-08-24 17:25       ` Andi Kleen
2021-08-24 17:27       ` Borislav Petkov
2021-08-24 17:47         ` Sean Christopherson
2021-08-24 17:50           ` Borislav Petkov
2021-08-31 20:49         ` Kuppuswamy, Sathyanarayanan
2021-09-01  7:42           ` Borislav Petkov
2021-08-24 18:18       ` Kuppuswamy, Sathyanarayanan
2021-08-24 18:28         ` Andi Kleen
2021-08-24 17:35     ` Kuppuswamy, Sathyanarayanan
2021-08-24 17:48       ` Borislav Petkov
2021-08-04 18:13 ` [PATCH v5 09/12] x86/tdx: Wire up KVM hypercalls Kuppuswamy Sathyanarayanan
2021-08-24 16:34   ` Borislav Petkov [this message]
2021-08-24 18:11     ` Kuppuswamy, Sathyanarayanan
2021-08-24 18:29       ` Borislav Petkov
2021-08-24 19:11         ` Kuppuswamy, Sathyanarayanan
2021-08-24 19:39           ` Borislav Petkov
2021-08-04 18:13 ` [PATCH v5 10/12] x86/tdx: Add MSR support for TDX guest Kuppuswamy Sathyanarayanan
2021-08-24 16:55   ` Borislav Petkov
2021-08-24 18:12     ` Kuppuswamy, Sathyanarayanan
2021-08-04 18:13 ` [PATCH v5 11/12] x86/tdx: Don't write CSTAR MSR on Intel Kuppuswamy Sathyanarayanan
2021-08-04 18:31   ` Sean Christopherson
2021-08-04 21:03     ` Kuppuswamy, Sathyanarayanan
2021-08-04 21:44       ` Sean Christopherson
2021-08-04 21:48       ` Dave Hansen
2021-08-04 22:23         ` Kuppuswamy, Sathyanarayanan
2021-08-04 18:13 ` [PATCH v5 12/12] x86/tdx: Handle CPUID via #VE Kuppuswamy Sathyanarayanan
2021-08-24 17:48   ` Borislav Petkov

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