From: "Edgecombe, Rick P" <rick.p.edgecombe@intel.com>
To: "Annapurve, Vishal" <vannapurve@google.com>,
"Huang, Kai" <kai.huang@intel.com>
Cc: "kvm@vger.kernel.org" <kvm@vger.kernel.org>,
"ashish.kalra@amd.com" <ashish.kalra@amd.com>,
"Hansen, Dave" <dave.hansen@intel.com>,
"thomas.lendacky@amd.com" <thomas.lendacky@amd.com>,
"kirill.shutemov@linux.intel.com"
<kirill.shutemov@linux.intel.com>,
"seanjc@google.com" <seanjc@google.com>,
"Chatre, Reinette" <reinette.chatre@intel.com>,
"pbonzini@redhat.com" <pbonzini@redhat.com>,
"mingo@redhat.com" <mingo@redhat.com>,
"Yamahata, Isaku" <isaku.yamahata@intel.com>,
"nik.borisov@suse.com" <nik.borisov@suse.com>,
"tglx@linutronix.de" <tglx@linutronix.de>,
"hpa@zytor.com" <hpa@zytor.com>,
"peterz@infradead.org" <peterz@infradead.org>,
"sagis@google.com" <sagis@google.com>,
"Chen, Farrah" <farrah.chen@intel.com>,
"Gao, Chao" <chao.gao@intel.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"bp@alien8.de" <bp@alien8.de>, "x86@kernel.org" <x86@kernel.org>,
"Williams, Dan J" <dan.j.williams@intel.com>
Subject: Re: [PATCH v3 3/6] x86/kexec: Disable kexec/kdump on platforms with TDX partial write erratum
Date: Wed, 2 Jul 2025 23:57:48 +0000 [thread overview]
Message-ID: <f8dcbe257b3931aec9e199132b678bd7681b7efa.camel@intel.com> (raw)
In-Reply-To: <CAGtprH-q91ajkgzN3Mki9nRt1cJu2fK7XMiZUeJaAfwZOjLduw@mail.gmail.com>
On Wed, 2025-07-02 at 15:16 -0700, Vishal Annapurve wrote:
> > As you said it *should* be safe. The kdump kernel should only read TDX
> > private memory but not write. But I cannot say I am 100% sure (there are
> > many things involved when generating the kdump file such as memory
> > compression) so in internal discussion we thought we should just disable it.
>
> So what's the side-effect of enabling kdump, in the worst case kdump
> kernel crashes and in the most likely scenario kdump will generate a
> lot of important data to analyze from the host failure.
>
> Allowing kdump seems to be a net positive outcome to me. Am I missing
> something? If not, my vote would be to enable/allow kdump for such
> platforms in this series itself.
This reasoning makes sense. But today there is no way to even configure kexec
when TDX is configured. It blocks TDX for distro based hosts. Kdump can always
be expanded in a follow up. The series has been tricky and so it's nice to not
have to tackle all the angles before getting at least some support back.
next prev parent reply other threads:[~2025-07-02 23:57 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-06-26 10:48 [PATCH v3 0/6] TDX host: kexec/kdump support Kai Huang
2025-06-26 10:48 ` [PATCH v3 1/6] x86/sme: Use percpu boolean to control wbinvd during kexec Kai Huang
2025-06-26 17:59 ` Edgecombe, Rick P
2025-06-26 18:42 ` Edgecombe, Rick P
2025-06-27 0:30 ` Huang, Kai
2025-06-30 7:09 ` Binbin Wu
2025-06-27 0:37 ` Huang, Kai
2025-06-27 0:39 ` Edgecombe, Rick P
2025-06-27 1:06 ` Huang, Kai
2025-06-27 15:08 ` Tom Lendacky
2025-06-30 11:35 ` Huang, Kai
2025-06-28 12:50 ` Borislav Petkov
2025-06-28 17:04 ` Tom Lendacky
2025-06-30 11:34 ` Huang, Kai
2025-06-30 11:34 ` Huang, Kai
2025-07-01 12:12 ` Borislav Petkov
2025-07-02 3:06 ` Huang, Kai
2025-06-26 10:48 ` [PATCH v3 2/6] x86/virt/tdx: Mark memory cache state incoherent when making SEAMCALL Kai Huang
2025-06-26 18:37 ` Edgecombe, Rick P
2025-06-26 23:36 ` Huang, Kai
2025-06-27 0:52 ` Edgecombe, Rick P
2025-06-27 1:47 ` Huang, Kai
2025-06-26 10:48 ` [PATCH v3 3/6] x86/kexec: Disable kexec/kdump on platforms with TDX partial write erratum Kai Huang
2025-06-26 18:49 ` Edgecombe, Rick P
2025-07-01 5:37 ` Binbin Wu
2025-07-02 3:12 ` Huang, Kai
2025-07-02 8:25 ` Chao Gao
2025-07-02 8:43 ` Huang, Kai
2025-07-02 22:16 ` Vishal Annapurve
2025-07-02 23:57 ` Edgecombe, Rick P [this message]
2025-06-26 10:48 ` [PATCH v3 4/6] x86/virt/tdx: Remove the !KEXEC_CORE dependency Kai Huang
2025-06-26 18:49 ` Edgecombe, Rick P
2025-06-26 10:48 ` [PATCH v3 5/6] x86/virt/tdx: Update the kexec section in the TDX documentation Kai Huang
2025-06-26 18:51 ` Edgecombe, Rick P
2025-06-26 10:48 ` [PATCH v3 6/6] KVM: TDX: Explicitly do WBINVD upon reboot notifier Kai Huang
2025-06-27 0:01 ` Edgecombe, Rick P
2025-06-27 1:00 ` Huang, Kai
2025-07-01 6:09 ` Binbin Wu
2025-07-02 3:14 ` Huang, Kai
2025-07-02 7:54 ` Chao Gao
2025-07-02 9:22 ` Huang, Kai
2025-07-07 12:37 ` Huang, Kai
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