From: Sean Christopherson <seanjc@google.com>
To: "Kuppuswamy,
Sathyanarayanan" <sathyanarayanan.kuppuswamy@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
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>,
Kuppuswamy Sathyanarayanan <knsathya@kernel.org>,
x86@kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v5 11/12] x86/tdx: Don't write CSTAR MSR on Intel
Date: Wed, 4 Aug 2021 21:44:58 +0000 [thread overview]
Message-ID: <YQsKWuiUyUWoA5kb@google.com> (raw)
In-Reply-To: <4c1ee7b9-9941-fdc4-73f5-3d2ef0530556@linux.intel.com>
On Wed, Aug 04, 2021, Kuppuswamy, Sathyanarayanan wrote:
>
> On 8/4/21 11:31 AM, Sean Christopherson wrote:
> > > On Intel CPUs writing the CSTAR MSR is not really needed. Syscalls
> > > from 32bit work using SYSENTER and 32bit SYSCALL is an illegal opcode.
> > > But the kernel did write it anyways even though it was ignored by
> > > the CPU. Inside a TDX guest this actually leads to a #GP. While the #GP
> > > is caught and recovered from, it prints an ugly message at boot.
> > > Do not write the CSTAR MSR on Intel CPUs.
> > Not that it really matters, but...
> >
> > Is #GP the actual TDX-Module behavior? If so, isn't that a contradiction with
>
> No, #GP is triggered by guest.
#GP is not triggered by the guest, it's not even reported by the guest. From
patch 7, the #VE handler escalates unhandled #VEs "similar to #GP handler", but
it still reports #VE as the actual vector.
Now, that particular behavior could change, e.g. setting tsk->thread.trap_nr to
#VE might confuse userspace, but at no point does this "trigger" a #GP.
next prev parent reply other threads:[~2021-08-04 21:45 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
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 [this message]
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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