From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-yw1-f182.google.com (mail-yw1-f182.google.com [209.85.128.182]) by mx.groups.io with SMTP id smtpd.web09.20452.1655397862406408394 for ; Thu, 16 Jun 2022 09:44:22 -0700 Authentication-Results: mx.groups.io; dkim=pass header.i=@google.com header.s=20210112 header.b=rgpG9R6s; spf=pass (domain: google.com, ip: 209.85.128.182, mailfrom: dionnaglaze@google.com) Received: by mail-yw1-f182.google.com with SMTP id 00721157ae682-3176d94c236so19456667b3.3 for ; Thu, 16 Jun 2022 09:44:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=AS5E4FDWdOSeYkHOJ5XD1U4f8J9Kn5fmkYIbWxcyIgE=; b=rgpG9R6sXKEIKtEZfC+VFIVsj6odBW7W5Rd+Qu01l1FDGB7OaFs7cFSyN060+fsCqI 6wIb8YidYuTTVVI0X1Dd+jkHlMDrN0D2D4urEtO9fQshqMwFdxjdohcJ3ydZnPnRrsS+ DdO48SMF9IYBTGr50NByXVNReRDdoziwflSF0FRpZRcozyoyMnxsMzD/FQoJ10oo1Byy s3lqrAGNJbSOMeof9REMxVlLBXbJwflEEW6+v5BNaUZhllse+mK8qS8Cscr4AETGtNt+ KKl/hSoMqioLdgKb+Smoh9AeO3SmX/3rm+55Q1siZMliewCLRvHFUwBjiXuuxSbh9xQS jkgQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=AS5E4FDWdOSeYkHOJ5XD1U4f8J9Kn5fmkYIbWxcyIgE=; b=RcQ51RPYmm5V6Ydr/nORjGqd6BlrXBJzTXCqHDl0DfkD9LQnu/yzV0TCg884kV+23L 3Z32FTbD+pFt07yHKCAUrRsM+xZw9jHOvdCJbiw/AXMPDqt8CQaZ5x3AV2PaFXWvfw0k nTz14jZOAyYE5WtWJji9csQZwgkuDU2PvI2sV5sRZycibO/f5gByKSX//A8Eq/7PVGJ6 /QTL/ZGpNrkJVXDQkhjsQrz57W0eFniG1qbJJ5umwkOjgJYPyMB2Y9h92W/kZL03FdQB hAZgxtf7oBJmbMeqSkFc8dIiEMEfViEwFDOG2PRERLLdpN1jIgJkH4H4htFzFYUMNOm0 3jfg== X-Gm-Message-State: AJIora8K9dJhN6b+cGp4+YHGw7JqUq2BgZvzyUh8yNEa0BgOPr+Uau76 k77/PWki0TyAEs3gtpkkEO04lptsRTi54doLL5H1/Q== X-Google-Smtp-Source: AGRyM1uVLE87ar/gOZ7y5FfoVF3aCzfg79p2zlqKUhuSK/aeDEC9VtCQ2UN927PPEGy0HWR3SHi/uT8JnTGip2/9dW4= X-Received: by 2002:a81:8347:0:b0:317:6828:3de with SMTP id t68-20020a818347000000b00317682803demr5192584ywf.463.1655397861465; Thu, 16 Jun 2022 09:44:21 -0700 (PDT) MIME-Version: 1.0 References: <20220607104550.hz6c7etgxtksylwu@sirius.home.kraxel.org> <20220608061805.vvsjiqt55rqnl3fw@sirius.home.kraxel.org> <20220615080508.oqjojsevfxc4pw3f@sirius.home.kraxel.org> In-Reply-To: From: "Dionna Glaze" Date: Thu, 16 Jun 2022 09:44:10 -0700 Message-ID: Subject: Re: [edk2-devel] [PATCH 07/14] OvmfPkg: Add PCD and DEFINEs for Lazy Accept page. To: "Xu, Min M" Cc: "devel@edk2.groups.io" , Gerd Hoffmann , "Aktas, Erdem" , James Bottomley , "Yao, Jiewen" , Tom Lendacky Content-Type: text/plain; charset="UTF-8" > A question: is there some performance impact when accepting all memory under 4GB? On SEV-SNP, we accept the HOBs 0-0xA000 and 0x10_0000-0xC00_0000, which takes a couple seconds, which is non-negligible. For VMs that want to boot very fast and still have access to a lot of memory in the long run (e.g., a UEFI app as an enclave or sandbox), I admit it's not my favorite solution. That being said, supporting unaccepted memory in the guest means that the 4GB solution doesn't preclude an accept-on-demand solution in the future in the case that there is demand. -- -Dionna Glaze, PhD (she/her)