From: Dan Williams <dan.j.williams@intel.com>
To: Kai Huang <kai.huang@intel.com>, <dave.hansen@intel.com>,
<kirill.shutemov@linux.intel.com>, <tglx@linutronix.de>,
<bp@alien8.de>, <peterz@infradead.org>, <mingo@redhat.com>,
<hpa@zytor.com>, <dan.j.williams@intel.com>, <seanjc@google.com>,
<pbonzini@redhat.com>
Cc: <x86@kernel.org>, <linux-kernel@vger.kernel.org>,
<kvm@vger.kernel.org>, <rick.p.edgecombe@intel.com>,
<isaku.yamahata@intel.com>, <chao.gao@intel.com>,
<binbin.wu@linux.intel.com>, <adrian.hunter@intel.com>,
<kai.huang@intel.com>
Subject: Re: [PATCH v3 8/8] x86/virt/tdx: Don't initialize module that doesn't support NO_RBP_MOD feature
Date: Fri, 6 Sep 2024 16:36:48 -0700 [thread overview]
Message-ID: <66db92101b565_22a229498@dwillia2-xfh.jf.intel.com.notmuch> (raw)
In-Reply-To: <0996e2f1b3e5c72150708b10bff57ad726c69e4b.1724741926.git.kai.huang@intel.com>
How about:
Subject: x86/virt/tdx: Require the module to assert it has the NO_RBP_MOD mitigation
...to avoid the double negative.
Kai Huang wrote:
> Old TDX modules can clobber RBP in the TDH.VP.ENTER SEAMCALL. However
> RBP is used as frame pointer in the x86_64 calling convention, and
> clobbering RBP could result in bad things like being unable to unwind
> the stack if any non-maskable exceptions (NMI, #MC etc) happens in that
> gap.
>
> A new "NO_RBP_MOD" feature was introduced to more recent TDX modules to
> not clobber RBP. This feature is reported in the TDX_FEATURES0 global
> metadata field via bit 18.
>
> Don't initialize the TDX module if this feature is not supported [1].
>
> Link: https://lore.kernel.org/all/c0067319-2653-4cbd-8fee-1ccf21b1e646@suse.com/T/#mef98469c51e2382ead2c537ea189752360bd2bef [1]
Trim this to the direct message-id format, but otherwise:
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
next prev parent reply other threads:[~2024-09-06 23:36 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-08-27 7:14 [PATCH v3 0/8] TDX host: metadata reading tweaks, bug fix and info dump Kai Huang
2024-08-27 7:14 ` [PATCH v3 1/8] x86/virt/tdx: Rename 'struct tdx_tdmr_sysinfo' to reflect the spec better Kai Huang
2024-08-27 13:10 ` Adrian Hunter
2024-08-27 22:20 ` Huang, Kai
2024-09-24 11:39 ` Huang, Kai
2024-08-30 22:05 ` Dan Williams
2024-08-27 7:14 ` [PATCH v3 2/8] x86/virt/tdx: Remove 'struct field_mapping' and implement TD_SYSINFO_MAP() macro Kai Huang
2024-08-29 7:20 ` Adrian Hunter
2024-08-30 10:52 ` Huang, Kai
2024-09-06 21:30 ` Dan Williams
2024-09-09 9:59 ` Huang, Kai
2024-09-06 20:21 ` Dan Williams
2024-09-09 9:59 ` Huang, Kai
2024-08-27 7:14 ` [PATCH v3 3/8] x86/virt/tdx: Prepare to support reading other global metadata fields Kai Huang
2024-08-30 6:43 ` Adrian Hunter
2024-08-30 11:02 ` Huang, Kai
2024-08-30 9:05 ` Nikolay Borisov
2024-08-30 11:09 ` Huang, Kai
2024-09-06 21:34 ` Dan Williams
2024-09-09 12:28 ` Huang, Kai
2024-08-27 7:14 ` [PATCH v3 4/8] x86/virt/tdx: Refine a comment to reflect the latest TDX spec Kai Huang
2024-08-30 6:45 ` Adrian Hunter
2024-08-30 9:14 ` Nikolay Borisov
2024-08-27 7:14 ` [PATCH v3 5/8] x86/virt/tdx: Start to track all global metadata in one structure Kai Huang
2024-08-30 7:02 ` Adrian Hunter
2024-08-30 11:10 ` Huang, Kai
2024-08-30 11:01 ` Nikolay Borisov
2024-08-30 11:57 ` Huang, Kai
2024-08-27 7:14 ` [PATCH v3 6/8] x86/virt/tdx: Print TDX module basic information Kai Huang
2024-09-06 22:46 ` Dan Williams
2024-09-09 10:18 ` Huang, Kai
2024-08-27 7:14 ` [PATCH v3 7/8] x86/virt/tdx: Reduce TDMR's reserved areas by using CMRs to find memory holes Kai Huang
2024-08-30 10:50 ` Adrian Hunter
2024-08-30 11:52 ` Huang, Kai
2024-08-30 12:02 ` Adrian Hunter
2024-08-30 12:27 ` Nikolay Borisov
2024-09-06 23:31 ` Dan Williams
2024-09-09 10:30 ` Huang, Kai
2024-08-27 7:14 ` [PATCH v3 8/8] x86/virt/tdx: Don't initialize module that doesn't support NO_RBP_MOD feature Kai Huang
2024-08-30 11:01 ` Adrian Hunter
2024-09-06 23:36 ` Dan Williams [this message]
2024-09-09 10:21 ` Huang, Kai
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