From: Dave Hansen <dave.hansen@intel.com>
To: Peter Zijlstra <peterz@infradead.org>, Kai Huang <kai.huang@intel.com>
Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
linux-mm@kvack.org, seanjc@google.com, pbonzini@redhat.com,
dan.j.williams@intel.com, rafael.j.wysocki@intel.com,
kirill.shutemov@linux.intel.com, ying.huang@intel.com,
reinette.chatre@intel.com, len.brown@intel.com,
tony.luck@intel.com, ak@linux.intel.com,
isaku.yamahata@intel.com, chao.gao@intel.com,
sathyanarayanan.kuppuswamy@linux.intel.com, bagasdotme@gmail.com,
sagis@google.com, imammedo@redhat.com
Subject: Re: [PATCH v7 06/20] x86/virt/tdx: Shut down TDX module in case of error
Date: Tue, 22 Nov 2022 07:14:14 -0800 [thread overview]
Message-ID: <52b2be9b-defd-63ce-4cb2-96cd624a95a6@intel.com> (raw)
In-Reply-To: <Y3ySxEr64HkUaEDq@hirez.programming.kicks-ass.net>
On 11/22/22 01:13, Peter Zijlstra wrote:
> On Mon, Nov 21, 2022 at 01:26:28PM +1300, Kai Huang wrote:
>> +/*
>> + * Call the SEAMCALL on all online CPUs concurrently. Caller to check
>> + * @sc->err to determine whether any SEAMCALL failed on any cpu.
>> + */
>> +static void seamcall_on_each_cpu(struct seamcall_ctx *sc)
>> +{
>> + on_each_cpu(seamcall_smp_call_function, sc, true);
>> +}
>
> Suppose the user has NOHZ_FULL configured, and is already running
> userspace that will terminate on interrupt (this is desired feature for
> NOHZ_FULL), guess how happy they'll be if someone, on another parition,
> manages to tickle this TDX gunk?
Yeah, they'll be none too happy.
But, what do we do?
There are technical solutions like detecting if NOHZ_FULL is in play and
refusing to initialize TDX. There are also non-technical solutions like
telling folks in the documentation that they better modprobe kvm early
if they want to do TDX, or their NOHZ_FULL apps will pay.
We could also force the TDX module to be loaded early in boot before
NOHZ_FULL is in play, but that would waste memory on TDX metadata even
if TDX is never used.
How do NOHZ_FULL folks deal with late microcode updates, for example?
Those are roughly equally disruptive to all CPUs.
next prev parent reply other threads:[~2022-11-22 15:14 UTC|newest]
Thread overview: 163+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-21 0:26 [PATCH v7 00/20] TDX host kernel support Kai Huang
2022-11-21 0:26 ` [PATCH v7 01/20] x86/tdx: Define TDX supported page sizes as macros Kai Huang
2022-11-21 2:52 ` Sathyanarayanan Kuppuswamy
2022-11-21 9:15 ` Huang, Kai
2022-11-21 17:23 ` Sathyanarayanan Kuppuswamy
2022-11-21 18:12 ` Dave Hansen
2022-11-21 23:48 ` Dave Hansen
2022-11-22 0:01 ` Huang, Kai
2022-11-21 0:26 ` [PATCH v7 02/20] x86/virt/tdx: Detect TDX during kernel boot Kai Huang
2022-11-21 3:07 ` Sathyanarayanan Kuppuswamy
2022-11-21 9:37 ` Huang, Kai
2022-11-21 23:57 ` Sathyanarayanan Kuppuswamy
2022-11-22 0:10 ` Dave Hansen
2022-11-22 11:28 ` Huang, Kai
2022-11-22 16:50 ` Dave Hansen
2022-11-22 23:21 ` Huang, Kai
2022-11-21 0:26 ` [PATCH v7 03/20] x86/virt/tdx: Disable TDX if X2APIC is not enabled Kai Huang
2022-11-21 3:51 ` Sathyanarayanan Kuppuswamy
2022-11-21 9:44 ` Huang, Kai
2022-11-21 22:00 ` Sathyanarayanan Kuppuswamy
2022-11-21 23:40 ` Huang, Kai
2022-11-21 23:46 ` Dave Hansen
2022-11-22 0:30 ` Huang, Kai
2022-11-22 0:44 ` Dave Hansen
2022-11-22 0:58 ` Huang, Kai
2022-11-21 0:26 ` [PATCH v7 04/20] x86/virt/tdx: Add skeleton to initialize TDX on demand Kai Huang
2022-11-22 9:02 ` Peter Zijlstra
2022-11-22 10:31 ` Thomas Gleixner
2022-11-22 15:35 ` Dave Hansen
2022-11-22 20:03 ` Thomas Gleixner
2022-11-22 20:11 ` Sean Christopherson
2022-11-23 0:30 ` Huang, Kai
2022-11-23 1:12 ` Huang, Kai
2022-11-23 11:05 ` Thomas Gleixner
2022-11-23 12:22 ` Huang, Kai
2022-11-22 18:05 ` Dave Hansen
2022-11-23 10:18 ` Huang, Kai
2022-11-23 16:58 ` Dave Hansen
2022-11-23 21:58 ` Huang, Kai
2022-11-21 0:26 ` [PATCH v7 05/20] x86/virt/tdx: Implement functions to make SEAMCALL Kai Huang
2022-11-22 9:06 ` Peter Zijlstra
2022-11-23 8:53 ` Huang, Kai
2022-11-22 18:20 ` Dave Hansen
2022-11-23 10:43 ` Huang, Kai
2022-11-21 0:26 ` [PATCH v7 06/20] x86/virt/tdx: Shut down TDX module in case of error Kai Huang
2022-11-22 9:10 ` Peter Zijlstra
2022-11-22 9:13 ` Peter Zijlstra
2022-11-22 15:14 ` Dave Hansen [this message]
2022-11-22 19:13 ` Peter Zijlstra
2022-11-22 19:24 ` Dave Hansen
2022-11-22 19:33 ` Peter Zijlstra
2022-11-23 1:14 ` Huang, Kai
2022-11-29 21:40 ` Dave Hansen
2022-11-30 11:09 ` Thomas Gleixner
2022-11-23 0:58 ` Huang, Kai
2022-11-23 1:04 ` Dave Hansen
2022-11-23 1:22 ` Huang, Kai
2022-11-23 16:20 ` Sean Christopherson
2022-11-23 16:41 ` Dave Hansen
2022-11-23 17:37 ` Sean Christopherson
2022-11-23 18:18 ` Dave Hansen
2022-11-23 19:03 ` Sean Christopherson
2022-11-22 9:20 ` Peter Zijlstra
2022-11-22 15:06 ` Thomas Gleixner
2022-11-22 19:06 ` Peter Zijlstra
2022-11-22 19:31 ` Sean Christopherson
2022-11-23 9:39 ` Huang, Kai
2022-11-22 15:20 ` Dave Hansen
2022-11-22 16:52 ` Thomas Gleixner
2022-11-22 18:57 ` Dave Hansen
2022-11-22 19:14 ` Peter Zijlstra
2022-11-23 1:24 ` Huang, Kai
2022-11-21 0:26 ` [PATCH v7 07/20] x86/virt/tdx: Do TDX module global initialization Kai Huang
2022-11-22 19:14 ` Dave Hansen
2022-11-23 11:45 ` Huang, Kai
2022-11-21 0:26 ` [PATCH v7 08/20] x86/virt/tdx: Do logical-cpu scope TDX module initialization Kai Huang
2022-11-21 0:26 ` [PATCH v7 09/20] x86/virt/tdx: Get information about TDX module and TDX-capable memory Kai Huang
2022-11-22 23:39 ` Dave Hansen
2022-11-23 11:40 ` Huang, Kai
2022-11-23 16:44 ` Dave Hansen
2022-11-23 22:53 ` Huang, Kai
2022-12-02 11:19 ` Huang, Kai
2022-12-02 17:25 ` Dave Hansen
2022-12-02 21:57 ` Huang, Kai
2022-12-02 11:11 ` Huang, Kai
2022-12-02 17:06 ` Dave Hansen
2022-12-02 21:56 ` Huang, Kai
2022-11-21 0:26 ` [PATCH v7 10/20] x86/virt/tdx: Use all system memory when initializing TDX module as TDX memory Kai Huang
2022-11-21 5:37 ` Huang, Ying
2022-11-21 9:09 ` Huang, Kai
2022-11-22 1:54 ` Huang, Ying
2022-11-22 9:16 ` Huang, Kai
2022-11-24 0:47 ` Huang, Ying
2022-11-22 10:10 ` Peter Zijlstra
2022-11-22 11:40 ` Huang, Kai
2022-11-23 0:21 ` Dave Hansen
2022-11-23 9:29 ` Peter Zijlstra
2022-11-24 1:04 ` Huang, Kai
2022-11-24 1:22 ` Dave Hansen
2022-11-24 2:27 ` Huang, Kai
2022-11-24 1:50 ` Dan Williams
2022-11-24 9:06 ` Huang, Kai
2022-11-25 9:28 ` David Hildenbrand
2022-11-28 8:38 ` Huang, Kai
2022-11-28 8:43 ` David Hildenbrand
2022-11-28 9:21 ` Huang, Kai
2022-11-28 9:26 ` David Hildenbrand
2022-11-28 9:50 ` Huang, Kai
2022-11-24 9:26 ` Peter Zijlstra
2022-11-24 10:02 ` Huang, Kai
2022-11-30 22:26 ` Dave Hansen
2022-11-21 0:26 ` [PATCH v7 11/20] x86/virt/tdx: Add placeholder to construct TDMRs to cover all TDX memory regions Kai Huang
2022-11-23 22:17 ` Dave Hansen
2022-11-24 9:51 ` Huang, Kai
2022-11-24 12:02 ` Huang, Kai
2022-11-28 15:59 ` Dave Hansen
2022-11-28 22:13 ` Huang, Kai
2022-11-28 22:19 ` Dave Hansen
2022-11-28 22:50 ` Huang, Kai
2022-12-07 11:47 ` Huang, Kai
2022-12-08 12:56 ` Huang, Kai
2022-12-08 14:58 ` Dave Hansen
2022-12-08 23:29 ` Huang, Kai
2022-11-21 0:26 ` [PATCH v7 12/20] x86/virt/tdx: Create " Kai Huang
2022-11-23 22:41 ` Dave Hansen
2022-11-24 11:29 ` Huang, Kai
2022-11-21 0:26 ` [PATCH v7 13/20] x86/virt/tdx: Allocate and set up PAMTs for TDMRs Kai Huang
2022-11-23 22:57 ` Dave Hansen
2022-11-24 11:46 ` Huang, Kai
2022-11-28 16:39 ` Dave Hansen
2022-11-28 22:48 ` Huang, Kai
2022-11-28 22:56 ` Dave Hansen
2022-11-28 23:14 ` Huang, Kai
2022-11-21 0:26 ` [PATCH v7 14/20] x86/virt/tdx: Set up reserved areas for all TDMRs Kai Huang
2022-11-23 23:39 ` Dave Hansen
2022-11-28 9:14 ` Huang, Kai
2022-11-28 13:18 ` Dave Hansen
2022-11-28 22:24 ` Huang, Kai
2022-11-28 22:58 ` Dave Hansen
2022-11-28 23:10 ` Huang, Kai
2022-11-21 0:26 ` [PATCH v7 15/20] x86/virt/tdx: Reserve TDX module global KeyID Kai Huang
2022-11-23 23:40 ` Dave Hansen
2022-11-24 22:39 ` Huang, Kai
2022-11-21 0:26 ` [PATCH v7 16/20] x86/virt/tdx: Configure TDX module with TDMRs and " Kai Huang
2022-11-23 23:56 ` Dave Hansen
2022-11-25 0:59 ` Huang, Kai
2022-11-25 1:18 ` Dave Hansen
2022-11-25 1:44 ` Huang, Kai
2022-11-21 0:26 ` [PATCH v7 17/20] x86/virt/tdx: Configure global KeyID on all packages Kai Huang
2022-11-24 0:28 ` Dave Hansen
2022-11-24 22:28 ` Huang, Kai
2022-11-25 0:08 ` Huang, Kai
2022-11-30 3:35 ` Binbin Wu
2022-11-30 8:34 ` Huang, Kai
2022-11-30 14:04 ` kirill.shutemov
2022-11-30 15:13 ` Dave Hansen
2022-11-30 20:17 ` Huang, Kai
2022-11-30 17:37 ` Dave Hansen
2022-11-21 0:26 ` [PATCH v7 18/20] x86/virt/tdx: Initialize all TDMRs Kai Huang
2022-11-24 0:42 ` Dave Hansen
2022-11-25 2:27 ` Huang, Kai
2022-11-21 0:26 ` [PATCH v7 19/20] x86/virt/tdx: Flush cache in kexec() when TDX is enabled Kai Huang
2022-11-21 0:26 ` [PATCH v7 20/20] Documentation/x86: Add documentation for TDX host support Kai Huang
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