From: Dave Hansen <dave.hansen@intel.com>
To: Chao Gao <chao.gao@intel.com>,
kvm@vger.kernel.org, linux-coco@lists.linux.dev,
linux-kernel@vger.kernel.org, x86@kernel.org
Cc: binbin.wu@linux.intel.com, dave.hansen@linux.intel.com,
djbw@kernel.org, ira.weiny@intel.com, kai.huang@intel.com,
kas@kernel.org, nik.borisov@suse.com, paulmck@kernel.org,
pbonzini@redhat.com, reinette.chatre@intel.com,
rick.p.edgecombe@intel.com, sagis@google.com, seanjc@google.com,
tony.lindgren@linux.intel.com, vannapurve@google.com,
vishal.l.verma@intel.com, yilun.xu@linux.intel.com,
xiaoyao.li@intel.com, yan.y.zhao@intel.com,
Thomas Gleixner <tglx@kernel.org>, Ingo Molnar <mingo@redhat.com>,
Borislav Petkov <bp@alien8.de>, "H. Peter Anvin" <hpa@zytor.com>
Subject: Re: [PATCH v8 11/21] x86/virt/tdx: Reset software states during TDX module shutdown
Date: Thu, 30 Apr 2026 11:58:12 -0700 [thread overview]
Message-ID: <20f2d821-bfa6-4db2-a968-b5455c7b5007@intel.com> (raw)
In-Reply-To: <20260427152854.101171-12-chao.gao@intel.com>
On 4/27/26 08:28, Chao Gao wrote:
> + /*
> + * Clear global and per-CPU initialization flags so the new module
> + * can be fully re-initialized after a successful update.
> + *
> + * No locks needed as no concurrent accesses can occur here.
> + */
> + tdx_module_initialized = false;
> + sysinit_done = false;
> + sysinit_ret = 0;
> + for_each_possible_cpu(cpu)
> + per_cpu(tdx_lp_initialized, cpu) = false;
This speaks to needing refactoring.
If there's global TDX state, it needs to be in a global TDX state
structure, not scattered across random global variables.
Imagine the structure is:
struct tdx_module_config foo;
That's 0's at boot. You have to init the TDX module to bring it out of
0's to valid state. It actually means something if you do:
memset(&foo, 0, sizeof(foo));
Because it takes it right back to its bss state. That ^ is also handy
because it naturally just works if new state gets added.
Guess what will happen the next time someone adds:
int sysinit_new_fancy_thing;
Someone will forget to add it to this code. Then the module gets updated
and breaks things in fun ways.
next prev parent reply other threads:[~2026-04-30 18:58 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-04-27 15:27 [PATCH v8 00/21] Runtime TDX module update support Chao Gao
2026-04-27 15:27 ` [PATCH v8 01/21] x86/virt/tdx: Move low level SEAMCALL helpers out of <asm/tdx.h> Chao Gao
2026-04-27 18:12 ` Vishal Annapurve
2026-04-27 15:27 ` [PATCH v8 02/21] coco/tdx-host: Introduce a "tdx_host" device Chao Gao
2026-04-27 15:27 ` [PATCH v8 03/21] coco/tdx-host: Expose TDX module version Chao Gao
2026-04-27 15:27 ` [PATCH v8 04/21] x86/virt/seamldr: Introduce a wrapper for P-SEAMLDR SEAMCALLs Chao Gao
2026-04-27 15:27 ` [PATCH v8 05/21] x86/virt/seamldr: Add a helper to retrieve P-SEAMLDR information Chao Gao
2026-04-27 15:28 ` [PATCH v8 06/21] coco/tdx-host: Expose P-SEAMLDR information via sysfs Chao Gao
2026-04-27 15:28 ` [PATCH v8 07/21] coco/tdx-host: Implement firmware upload sysfs ABI for TDX module updates Chao Gao
2026-04-29 23:17 ` Dave Hansen
2026-05-06 2:35 ` Chao Gao
2026-04-27 15:28 ` [PATCH v8 08/21] x86/virt/seamldr: Allocate and populate a module update request Chao Gao
2026-04-30 0:45 ` Dave Hansen
2026-04-30 21:23 ` Edgecombe, Rick P
2026-04-30 21:31 ` Dave Hansen
2026-05-07 13:19 ` Chao Gao
2026-05-08 16:48 ` Dave Hansen
2026-04-27 15:28 ` [PATCH v8 09/21] x86/virt/seamldr: Introduce skeleton for TDX module updates Chao Gao
2026-04-30 20:03 ` Dave Hansen
2026-05-06 13:00 ` Chao Gao
2026-05-06 20:43 ` Dave Hansen
2026-04-27 15:28 ` [PATCH v8 10/21] x86/virt/seamldr: Shut down the current TDX module Chao Gao
2026-04-30 18:52 ` Dave Hansen
2026-05-06 2:56 ` Chao Gao
2026-05-06 20:49 ` Dave Hansen
2026-04-27 15:28 ` [PATCH v8 11/21] x86/virt/tdx: Reset software states during TDX module shutdown Chao Gao
2026-04-30 18:58 ` Dave Hansen [this message]
2026-05-06 6:21 ` Chao Gao
2026-04-27 15:28 ` [PATCH v8 12/21] x86/virt/seamldr: Install a new TDX module Chao Gao
2026-04-30 19:00 ` Dave Hansen
2026-04-30 21:48 ` Edgecombe, Rick P
2026-04-30 22:29 ` Dave Hansen
2026-04-27 15:28 ` [PATCH v8 13/21] x86/virt/seamldr: Do TDX per-CPU initialization after module installation Chao Gao
2026-04-27 15:28 ` [PATCH v8 14/21] x86/virt/tdx: Restore TDX module state Chao Gao
2026-04-27 15:28 ` [PATCH v8 15/21] x86/virt/tdx: Refresh TDX module version after update Chao Gao
2026-04-30 19:14 ` Dave Hansen
2026-04-30 21:35 ` Edgecombe, Rick P
2026-05-06 12:51 ` Chao Gao
2026-04-27 15:28 ` [PATCH v8 16/21] x86/virt/tdx: Reject updates during concurrent TD build Chao Gao
2026-04-30 19:25 ` Dave Hansen
2026-04-27 15:28 ` [PATCH v8 17/21] x86/virt/seamldr: Abort updates on failure Chao Gao
2026-04-30 20:06 ` Dave Hansen
2026-05-08 9:16 ` Chao Gao
2026-04-27 15:28 ` [PATCH v8 18/21] coco/tdx-host: Don't expose P-SEAMLDR features on CPUs with erratum Chao Gao
2026-04-30 20:09 ` Dave Hansen
2026-05-08 9:50 ` Chao Gao
2026-04-27 15:28 ` [PATCH v8 19/21] x86/virt/tdx: Enable TDX module runtime updates Chao Gao
2026-04-27 15:28 ` [PATCH v8 20/21] coco/tdx-host: Document TDX module update compatibility criteria Chao Gao
2026-04-27 15:28 ` [PATCH v8 21/21] x86/virt/tdx: Document TDX module update Chao Gao
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20f2d821-bfa6-4db2-a968-b5455c7b5007@intel.com \
--to=dave.hansen@intel.com \
--cc=binbin.wu@linux.intel.com \
--cc=bp@alien8.de \
--cc=chao.gao@intel.com \
--cc=dave.hansen@linux.intel.com \
--cc=djbw@kernel.org \
--cc=hpa@zytor.com \
--cc=ira.weiny@intel.com \
--cc=kai.huang@intel.com \
--cc=kas@kernel.org \
--cc=kvm@vger.kernel.org \
--cc=linux-coco@lists.linux.dev \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=nik.borisov@suse.com \
--cc=paulmck@kernel.org \
--cc=pbonzini@redhat.com \
--cc=reinette.chatre@intel.com \
--cc=rick.p.edgecombe@intel.com \
--cc=sagis@google.com \
--cc=seanjc@google.com \
--cc=tglx@kernel.org \
--cc=tony.lindgren@linux.intel.com \
--cc=vannapurve@google.com \
--cc=vishal.l.verma@intel.com \
--cc=x86@kernel.org \
--cc=xiaoyao.li@intel.com \
--cc=yan.y.zhao@intel.com \
--cc=yilun.xu@linux.intel.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.