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From: Andi Kleen <ak@linux.intel.com>
To: Sean Christopherson <seanjc@google.com>,
	"Kuppuswamy,
	Sathyanarayanan"  <sathyanarayanan.kuppuswamy@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	x86@kernel.org, Paolo Bonzini <pbonzini@redhat.com>,
	Juergen Gross <jgross@suse.com>, Deep Shah <sdeep@vmware.com>,
	VMware Inc <pv-drivers@vmware.com>,
	Vitaly Kuznetsov <vkuznets@redhat.com>,
	Wanpeng Li <wanpengli@tencent.com>,
	Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
	Peter H Anvin <hpa@zytor.com>, Tony Luck <tony.luck@intel.com>,
	Dan Williams <dan.j.williams@intel.com>,
	Kirill Shutemov <kirill.shutemov@linux.intel.com>,
	Kuppuswamy Sathyanarayanan <knsathya@kernel.org>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v6 11/11] x86/tdx: Handle CPUID via #VE
Date: Fri, 3 Sep 2021 16:54:04 -0700	[thread overview]
Message-ID: <f0d52056-1749-9d21-8da1-041266ade437@linux.intel.com> (raw)
In-Reply-To: <YTKzFJYy0CECENRX@google.com>


On 9/3/2021 4:43 PM, Sean Christopherson wrote:
> On Fri, Sep 03, 2021, Kuppuswamy, Sathyanarayanan wrote:
>>
>> On 9/3/21 11:35 AM, Dave Hansen wrote:
>>> On 9/3/21 10:28 AM, Kuppuswamy Sathyanarayanan wrote:
>>>> From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
>>>>
>>>> TDX has three classes of CPUID leaves: some CPUID leaves are always
>>>> handled by the CPU, others are handled by the TDX module, and some
>>>> others are handled by the VMM. Since the VMM cannot directly intercept
>>>> the instruction these are reflected with a #VE exception to the guest,
>>>> which then converts it into a hypercall to the VMM, or handled
>>>> directly.
>>> Does this patch do any of the "handled directly" leaves?  If not, why
>>> mention it?
>> It was added to give more information about CPUID leaves handling. Since
>> it has nothing to do with this patch, I can remove it.
> What leaves are "always handled by the CPU"?  VTx doesn't allow disabling
> CPUID exiting, let alone conditionally exiting on a specific CPUID leaf.  I don't
> see anything in the TDX specs that suggests that's any different in SEAM non-root
> mode.

It means they are handled by the TDX module, but always have the same 
contents as a native CPU would.

As opposed to leaves that are modified by the TDX module.

-Andi


  reply	other threads:[~2021-09-03 23:54 UTC|newest]

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-03 17:28 [PATCH v6 00/11] Add TDX Guest Support (Initial support) Kuppuswamy Sathyanarayanan
2021-09-03 17:28 ` [PATCH v6 01/11] x86/paravirt: Move halt paravirt calls under CONFIG_PARAVIRT Kuppuswamy Sathyanarayanan
2021-09-03 18:22   ` Borislav Petkov
2021-09-03 19:03     ` Kuppuswamy, Sathyanarayanan
2021-09-03 20:33       ` Borislav Petkov
2021-09-03 17:28 ` [PATCH v6 02/11] x86/tdx: Introduce INTEL_TDX_GUEST config option Kuppuswamy Sathyanarayanan
2021-09-28 11:37   ` Joerg Roedel
2021-09-28 12:52     ` Kuppuswamy, Sathyanarayanan
2021-09-03 17:28 ` [PATCH v6 03/11] x86/cpufeatures: Add TDX Guest CPU feature Kuppuswamy Sathyanarayanan
2021-09-28 11:39   ` Joerg Roedel
2021-09-28 12:53     ` Kuppuswamy, Sathyanarayanan
2021-09-03 17:28 ` [PATCH v6 04/11] x86/tdx: Add protected guest support for TDX guest Kuppuswamy Sathyanarayanan
2021-09-28 11:46   ` Joerg Roedel
2021-09-28 12:56     ` Kuppuswamy, Sathyanarayanan
2021-09-28 13:04       ` Joerg Roedel
2021-09-28 13:18         ` Borislav Petkov
2021-09-03 17:28 ` [PATCH v6 05/11] x86/tdx: Add __tdx_module_call() and __tdx_hypercall() helper functions Kuppuswamy Sathyanarayanan
2021-09-03 17:28 ` [PATCH v6 06/11] x86/traps: Add #VE support for TDX guest Kuppuswamy Sathyanarayanan
2021-09-28 12:16   ` Joerg Roedel
2021-09-28 14:05     ` Dave Hansen
2021-09-28 15:22       ` Joerg Roedel
2021-09-28 15:25         ` Dave Hansen
2021-09-28 15:23   ` Dave Hansen
2021-09-28 16:59     ` Kuppuswamy, Sathyanarayanan
2021-09-03 17:28 ` [PATCH v6 07/11] x86/tdx: Add HLT " Kuppuswamy Sathyanarayanan
2021-09-03 17:28 ` [PATCH v6 08/11] x86/tdx: Wire up KVM hypercalls Kuppuswamy Sathyanarayanan
2021-09-03 17:28 ` [PATCH v6 09/11] x86/tdx: Add MSR support for TDX guest Kuppuswamy Sathyanarayanan
2021-09-03 17:28 ` [PATCH v6 10/11] x86/tdx: Don't write CSTAR MSR on Intel Kuppuswamy Sathyanarayanan
2021-09-03 17:28 ` [PATCH v6 11/11] x86/tdx: Handle CPUID via #VE Kuppuswamy Sathyanarayanan
2021-09-03 18:35   ` Dave Hansen
2021-09-03 19:14     ` Kuppuswamy, Sathyanarayanan
2021-09-03 23:43       ` Sean Christopherson
2021-09-03 23:54         ` Andi Kleen [this message]
2021-09-04  0:00           ` Dave Hansen
2021-09-04  0:05             ` Andi Kleen

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