From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f202.google.com (mail-pl1-f202.google.com [209.85.214.202]) (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 39BB622AE7C for ; Tue, 29 Apr 2025 16:47:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.202 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745945229; cv=none; b=P2UpkcyBLJLhYE8+OWbG01Mpm0M6ZolknQNSuSj2F8ymDUDm2w2M4Xea78toF037l8PxOZ0dKII70CwdoOWu8lwByP1aO6jJxy9Dh9+dNpG2/BTUwajkporZTF1jE5C5U+rYBNy8ewVHWDNqul21CO3qTacpP+O3r+gekrU/mGY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745945229; c=relaxed/simple; bh=qlFvxx4vXvnODB8SoWH3xuEvm1Y153RCIqWfvQ/U/y4=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=FNCfKUxC4sgOEDeEM+6jNVx0Bm4+3QciXdhW6GAN3BA0Fg/VBt74niGCL6XQGrXyX/3KGlklqmGCSbj9mzlvD5LLFWe44uhaOxhOUuCSPNp46BO1WkZF/R+idFhIm83qgxlSG1murIOjERUrQ2do0zBqnfePhrJQTJW+xYaYcMA= 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=xs6mboXV; arc=none smtp.client-ip=209.85.214.202 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="xs6mboXV" Received: by mail-pl1-f202.google.com with SMTP id d9443c01a7336-224364f2492so44636765ad.3 for ; Tue, 29 Apr 2025 09:47:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1745945227; x=1746550027; 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=wW/3FZ3J3LaAvhXz6pT2crJdAdy3SR7TNiF8mMPwO1Q=; b=xs6mboXVlGD+BH2zve2YBAbk4KBGyCaNrvAwyNBDcfljAoG+r7IYuWims9T8x5P/dr Vm04r0EoeA1t3mfpLESBzm1qQtgNhrgsruiZhAcoPc51qD3VLqPrMVLhR9ahc0LYWi34 8CWRJoR3ZNrBZPCsZHwkIrQh9C+PKhqcVbqeGkCudaWiouwPyZ3bjzDsEh45YgtjIB8Y F/CBN8n4UPXDLcorHhw3KHlZHcDjFHE8jg2d+J6WkBOmTdGIkNy+PPj26RqZWpBpvXxU bFNgkfCZ6WUUeCwh/JRSciT9j90ufh9ltvGR/zoSraID7tWarTKNq0hC0YbHHYpM0Mbo z9Dw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1745945227; x=1746550027; 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=wW/3FZ3J3LaAvhXz6pT2crJdAdy3SR7TNiF8mMPwO1Q=; b=xG4g5Xpl84697g/G5I1cskUIZz9Hu6aSJXSqT4ixz0TjXXvQEQYTtxxyTWw8f4GNXW F80w2Ybii7NXmx61ZK6pM8EMyGgiHhWlzXxik4xEPAUjT/2duAtH35++3QwQFrH7bUDT RAkFJBHg4EgF5MHO06456JlabVXTlAED5eOmuFzeHxuyZsDjc+nG20mVKXO6d5fnyLhT PwYMtrFOqmbgkkioR3R/hDVn1r+srNQxCCBBdR+CM/N2x2il4RylTkrimTEUqEsNgh+1 tqsBlTnyC22Jel15Pikbak0O6AsyVjb5ERsvcypPKBCf7XysZeqVIldxDJaaSDPM/EJt NzBQ== X-Gm-Message-State: AOJu0YwZfqYw5FFfdChhJMkhB+mpAn33bYQ1BTYzd0CNT5B34snnDbNo jS41jSv+2+20bYSaTbdhfX3PZiu0rg3a5pmFDAMmHGSKOR7MJB5ECilEXv2knW1XTMzQSBvfeWt zww== X-Google-Smtp-Source: AGHT+IGYwDoIc1CopaCdHjCVbP+lhIKe9ljwxlXcpMm19QspT63vXrrMoXbX4A+F0QMnlUB0WIYfJez9VZY= X-Received: from pllo4.prod.google.com ([2002:a17:902:7784:b0:223:4788:2e83]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:903:1249:b0:216:794f:6d7d with SMTP id d9443c01a7336-22df359328dmr941965ad.48.1745945227521; Tue, 29 Apr 2025 09:47:07 -0700 (PDT) Date: Tue, 29 Apr 2025 09:47:06 -0700 In-Reply-To: Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250402002936.960678-1-seanjc@google.com> Message-ID: Subject: Re: [ANNOUNCE] PUCK Agenda - 2025.04.02 - No Topic From: Sean Christopherson To: Ackerley Tng Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, roypat@amazon.co.uk, kalyazin@amazon.com, Fuad Tabba , Vishal Annapurve , david@redhat.com Content-Type: text/plain; charset="us-ascii" On Tue, Apr 29, 2025, Ackerley Tng wrote: > > Would like to add an agenda item for 2025-04-30's PUCK meeting: KVM > memory attributes vs guest_memfd shareability. Does next week work for you? I.e. May 7th. I won't be able to make tomorrow's PUCK (about to send a cancelation mail). > guest_memfd tracks shareability to determine whether a page can be > faulted by the host into userspace. > > pKVM does not use kvm->mem_attr_array for tracking private/shared status > of a page, and for Coco VMs like TDX, there seems to be duplicate > tracking of private/shared status in guest_memfd's shareability and in > KVM's memory attributes. > > I would like to discuss a proposal for shared/private conversions to be > performed through a guest_memfd (not KVM) ioctl instead of using > KVM_SET_MEMORY_ATTRIBUTES, where Coco VMs using guest_memfd for both > shared and private memory can be able to (with some other changes around > KVM memory attributes) skip tracking private/shared in KVM's memory > attributes. Has the proposal been posted on-list anywhere? I haven't been following the guest_memfd threads very closely (understatement).