From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f73.google.com (mail-pj1-f73.google.com [209.85.216.73]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2675A28D8FD for ; Tue, 17 Feb 2026 23:05:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.73 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771369502; cv=none; b=u3xl6rCqiniGCDHTMymQ6GeW73b+QCL85tUd5RMYlCvfVKDjsajk3KcXc7WefnSpnADSNmjSuWIXad3UIx5O9Ic+4b772D4vPoCJQsRlYWDhkLI6w0xOYmbkE1Mu8tH0Dgzk+gz/XJZ2ri3XoJjrda610lmLg5MVHTxqj/X0U4k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771369502; c=relaxed/simple; bh=Nb9uO6XAB2riMcSXkiGPR3StBCYmptBJJoYo8dSh3k4=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=ORmbOsapxtsn/sAznVrqOfeocUkktW6B6cKBIBp0N8Kwtgsb3qnaIXnS1FnLv0SD7ISy23yVVQ/cZ3R6iXHrpXRfa4yxn36dFXfZV9ugQaajwS77pvHc6D3FM1Ptxvcov6+aKaQksMj8YOvn+zx7bPvYcy3WTImycfyovxMUl/g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=FWiOH1KI; arc=none smtp.client-ip=209.85.216.73 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="FWiOH1KI" Received: by mail-pj1-f73.google.com with SMTP id 98e67ed59e1d1-354bee18a62so3577301a91.0 for ; Tue, 17 Feb 2026 15:05:00 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1771369500; x=1771974300; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=Nb9uO6XAB2riMcSXkiGPR3StBCYmptBJJoYo8dSh3k4=; b=FWiOH1KIv/HDNKDK2kDyZ7eTMCtCghzcmD587SyjpT0XwzYQNMFW0uRyVQSo/E5Ohb EjnZfIkgMiOCqyl5rbFPcvyjMs0w/XKVDY/+9jFMhXlsYgcnxFoU/FmNzo810+EE/AuE 9ppIJiGgLlDUDFRu/Yr1e4NiJ/cMfMPxnJiliHIf6ZeMCQcYdJrvWicOjS9rn2HsrLyz Dpcp+yoLV65pEptfykKB3/857KdYbMsVvaHvpvMZs5GOe1vHXyFzxEV2ynLXhQk89X9h PDW0V3Ha6PrnLflhd9dD0jJuOAvxAEuB6L7r6h+hyrFGp9JuA1FzslIKF8P73vL85sUX aJrg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1771369500; x=1771974300; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=Nb9uO6XAB2riMcSXkiGPR3StBCYmptBJJoYo8dSh3k4=; b=Rz+Hfa8tBEXRLOeYa05exBuIOBJtA80yNNn40T0HbGmj/7LMn6Xe6DTy1cPtkSHCei SFoMszBajc3cHQ57ApXekcuYXMAVunwAMRfPkaIYAmBu+Cq4lVUQZXucW/yDeFkH8512 /CVuXqgm1JhEML9PhKiZenZOcG7k/yr+ViX3TrfWFNK6CoIYuV3y1/hxWnm+yegZTTa3 uR7fMycRReO35wOh9wjMISHsRLf4hw82wWJJI/1gbxUzY09SVTfR22RE8e9weA3CQl7m YB5NvUVeeSWiWngBydv5ZE8eUYja4axOvi3s2Iq5QDqZRZC0myeEx2GrodawWwhieqGi WAWg== X-Forwarded-Encrypted: i=1; AJvYcCWRIPOOyHlkOxe6t5bwDTRF993Y2tZte5OqbCiq8KiNAYg8Ye6LTD5428H1tJlQtM7IUS235NTqvd7DXSo=@vger.kernel.org X-Gm-Message-State: AOJu0Ywi00qmR4bzvBQ6Cy2kfavhwpa30U1njPIlo86kOe2xf0Kk67aU REhcddZFdr6vsA0zwqvpDcZni5+5N0MuWUnYb+dL0Zh0kqniKvER6ORYMpNZGThdh44qlDVJYY7 uBqPrRA== X-Received: from pjpt8.prod.google.com ([2002:a17:90a:a188:b0:34b:fe89:512c]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:2c90:b0:34a:b8e0:dd64 with SMTP id 98e67ed59e1d1-356aaa9bb34mr11781376a91.1.1771369500107; Tue, 17 Feb 2026 15:05:00 -0800 (PST) Date: Tue, 17 Feb 2026 15:04:58 -0800 In-Reply-To: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <86ad28b767524e1e654b9c960e39ca8bfb24c114.1770071243.git.ackerleytng@google.com> Message-ID: Subject: Re: [RFC PATCH v2 09/37] KVM: guest_memfd: Add support for KVM_SET_MEMORY_ATTRIBUTES2 From: Sean Christopherson To: Ackerley Tng Cc: kvm@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-trace-kernel@vger.kernel.org, x86@kernel.org, aik@amd.com, andrew.jones@linux.dev, binbin.wu@linux.intel.com, bp@alien8.de, brauner@kernel.org, chao.p.peng@intel.com, chao.p.peng@linux.intel.com, chenhuacai@kernel.org, corbet@lwn.net, dave.hansen@linux.intel.com, david@kernel.org, hpa@zytor.com, ira.weiny@intel.com, jgg@nvidia.com, jmattson@google.com, jroedel@suse.de, jthoughton@google.com, maobibo@loongson.cn, mathieu.desnoyers@efficios.com, maz@kernel.org, mhiramat@kernel.org, michael.roth@amd.com, mingo@redhat.com, mlevitsk@redhat.com, oupton@kernel.org, pankaj.gupta@amd.com, pbonzini@redhat.com, prsampat@amd.com, qperret@google.com, ricarkol@google.com, rick.p.edgecombe@intel.com, rientjes@google.com, rostedt@goodmis.org, shivankg@amd.com, shuah@kernel.org, steven.price@arm.com, tabba@google.com, tglx@linutronix.de, vannapurve@google.com, vbabka@suse.cz, willy@infradead.org, wyihan@google.com, yan.y.zhao@intel.com Content-Type: text/plain; charset="us-ascii" On Sat, Feb 14, 2026, Ackerley Tng wrote: > Sean is against deferring whether to preserve memory to the underlying > hardware because that is letting (effectively) micro-architectural > behavior to define KVM's ABI. KVM's uAPI cannot let behavior be > undefined, or be based on vendor, and maybe even on firmware version. Concretely, we'll end up with a giant mess if TDX and/or SNP adds support for preserving contents on conversion.