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Peter Anvin" , "Andy Lutomirski" , "Peter Zijlstra" , "Kiryl Shutsemau (Meta)" , "Rick Edgecombe" , "Andrew Cooper" , "Tony Luck" , "Alexander Shishkin" , linux-kernel@vger.kernel.org, linux-efi@vger.kernel.org, "Maciej Wieczor-Retman" Message-Id: <1664bf5d-f1a9-473f-b78d-8d14f0dd7943@app.fastmail.com> In-Reply-To: References: <20260120234730.2215498-1-sohil.mehta@intel.com> Subject: Re: [PATCH v2 0/3] x86: Extend LASS support to EFI configurations Content-Type: text/plain Content-Transfer-Encoding: 7bit On Tue, 24 Feb 2026, at 19:45, Sohil Mehta wrote: > Hello x86 Maintainers, Ard, > > On 1/20/2026 3:47 PM, Sohil Mehta wrote: >> Solution >> -------- >> These patches take LASS out of the path of all EFI boot and runtime >> service interactions by: >> >> Patch 1: Deferring LASS enabling until userspace comes up, which >> ensures EFI has completed switching to virtual mode and all boot >> services memory has been freed [3]. >> >> Patch 2: Temporarily disabling LASS every time a runtime service is >> executed after boot. Runtime services execute in a special efi_mm >> which doesn't have userspace mapped. So, the security implications of >> disabling LASS are fairly limited [4]. >> > > The patches now have tested-by tags from Maciej and Tony. Also, the > patches apply cleanly on v7.0-rc1. I am hoping to get some review > feedback on the patches before resending another version. > > Ard, are you okay with patch 2 that disables LASS during EFI runtime calls? > Yeah I think that's fine.