From: Dave Hansen <dave.hansen@intel.com>
To: Sean Christopherson <seanjc@google.com>,
"H. Peter Anvin" <hpa@zytor.com>
Cc: Rick P Edgecombe <rick.p.edgecombe@intel.com>,
Vishal L Verma <vishal.l.verma@intel.com>,
Kai Huang <kai.huang@intel.com>, "bp@alien8.de" <bp@alien8.de>,
"x86@kernel.org" <x86@kernel.org>,
"kas@kernel.org" <kas@kernel.org>,
"mingo@redhat.com" <mingo@redhat.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"dave.hansen@linux.intel.com" <dave.hansen@linux.intel.com>,
"tglx@kernel.org" <tglx@kernel.org>,
"pbonzini@redhat.com" <pbonzini@redhat.com>,
"linux-coco@lists.linux.dev" <linux-coco@lists.linux.dev>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>
Subject: Re: [PATCH v2 2/5] x86/virt/tdx: Pull kexec cache flush logic into arch/x86
Date: Wed, 1 Apr 2026 11:30:21 -0700 [thread overview]
Message-ID: <93153bca-6668-47f6-8dcc-7baaaa5b2ec6@intel.com> (raw)
In-Reply-To: <ac1f9KntTv0SaktS@google.com>
On 4/1/26 11:12, Sean Christopherson wrote:
> Sorry, "costly" wasn't the right word. I know WBINVD super
> expensive, but unless someone cares deeply about the latency of
> offlining a CPU after its down TDX stuff, the "cost" is effectively
> zero.
I once increased the CPU online/offline latency once and got nastygrams
from folks. IIRC, I added a synchronize_rcu() which incurs way more
latency than WBINVD, but folks _do_ care about CPU online/offline
latency surprisingly.
In this case, though, I'm happy to add the WBINVD for simplicity and
wait for a possible repeat of the torches an pitchforks.
next prev parent reply other threads:[~2026-04-01 18:30 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-23 20:59 [PATCH v2 0/5] Fuller TDX kexec support Vishal Verma
2026-03-23 20:59 ` [PATCH v2 1/5] x86/tdx: Move all TDX error defines into <asm/shared/tdx_errno.h> Vishal Verma
2026-03-24 9:49 ` Chao Gao
2026-03-31 19:30 ` Sean Christopherson
2026-03-31 21:46 ` Edgecombe, Rick P
2026-03-23 20:59 ` [PATCH v2 2/5] x86/virt/tdx: Pull kexec cache flush logic into arch/x86 Vishal Verma
2026-03-24 10:03 ` Chao Gao
2026-03-30 11:42 ` Kiryl Shutsemau
2026-03-31 19:22 ` Sean Christopherson
2026-03-31 22:21 ` Edgecombe, Rick P
2026-03-31 23:04 ` Sean Christopherson
2026-03-31 23:29 ` Edgecombe, Rick P
2026-04-01 15:03 ` Dave Hansen
2026-04-01 17:42 ` H. Peter Anvin
2026-04-01 18:12 ` Sean Christopherson
2026-04-01 18:30 ` Dave Hansen [this message]
2026-03-23 20:59 ` [PATCH v2 3/5] x86/virt/tdx: Add SEAMCALL wrapper for TDH.SYS.DISABLE Vishal Verma
2026-03-23 21:54 ` Verma, Vishal L
2026-03-23 22:40 ` Huang, Kai
2026-03-24 10:18 ` Chao Gao
2026-03-30 11:58 ` Kiryl Shutsemau
2026-03-30 19:25 ` Edgecombe, Rick P
2026-03-31 12:18 ` Kiryl Shutsemau
2026-03-31 18:22 ` Verma, Vishal L
2026-03-31 21:36 ` Edgecombe, Rick P
2026-04-01 9:26 ` Kiryl Shutsemau
2026-04-01 14:24 ` Dave Hansen
2026-03-23 20:59 ` [PATCH v2 4/5] x86/tdx: Disable the TDX module during kexec and kdump Vishal Verma
2026-03-23 22:41 ` Huang, Kai
2026-03-30 12:03 ` Kiryl Shutsemau
2026-03-23 20:59 ` [PATCH v2 5/5] x86/virt/tdx: Remove kexec docs Vishal Verma
2026-03-23 22:41 ` Huang, Kai
2026-03-30 12:04 ` Kiryl Shutsemau
2026-04-22 12:45 ` [PATCH] x86/tdx, KVM: fix HKID leak when kexec is initiated with active TDs Nowicki, Robert
2026-04-22 13:14 ` Sean Christopherson
[not found] ` <CH3PR11MB843450CBD154D42B31D15E93832D2@CH3PR11MB8434.namprd11.prod.outlook.com>
2026-04-22 13:34 ` Sean Christopherson
2026-04-22 14:29 ` Edgecombe, Rick P
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