From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-yb1-f201.google.com (mail-yb1-f201.google.com [209.85.219.201]) (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 E3A75199EB4 for ; Mon, 26 Aug 2024 20:28:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.219.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724704109; cv=none; b=XxNRCwPbZhu1xAWK0oKgKsJy7Xh3Ns1Tyh5lF7ge4RUF81KhIoDfFLUSZlBsmrmVaZvaoQ5MiP2Tu88rFaDxK0pDHTcBDsz6hHAneHCRvoOE/Q8ryvfGYBAqf4bNn767IstoFDCkm2DKkA8nFB+450g+NN6H2SaSwG9kO31q0Cs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724704109; c=relaxed/simple; bh=3aLGWNFml1fs6ET7vU4TR6a4dUKkunevdgnP5XM6DFU=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=L6dIx/Q3MWdbhLpdNercRx97MHOFVLbRC3UKnnUJ1+wo4EhPL3RXUnqxbwigjP0X4RojVrUjr0K/IkRU/PvYMXwwuS5898ZX4W6iJyeP/ajIdrVyjGOuADIXkdIqP0uoqRBJnOI3m+MNrOr5gXRz6VGesB954vpwYe2LqV/90B0= 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=c3sDyybO; arc=none smtp.client-ip=209.85.219.201 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="c3sDyybO" Received: by mail-yb1-f201.google.com with SMTP id 3f1490d57ef6-e02b5792baaso7630747276.2 for ; Mon, 26 Aug 2024 13:28:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1724704107; x=1725308907; 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=y4CuIS2O9/fj+lBdt8ymvV+Stc9+h4xTSSAPFKw9WU0=; b=c3sDyybOX74t6cnLJ7vu6bytaZ/pfDV6f3RqG11bxF7Z/PuY1pYdPHkIDyxhMr5Au/ p/uIvSzDTr5ozdbcR7n2PjR1wIwmIQY53QX3K1XS5CtrnxgO0SmhqMEriGnvyl0gWM74 dKrPBP8W7m1aUM/jllUUs6e19cPeioW6Hj2E0M3pBSJyErI/JbUfugalnfQsfyyR3e3v /PpEvX7V13Ft1nGLBn1Fb6F4A1lq9zaEf2En4P/hTA8GBfB6sa49GLKAcLpyoialNNRT ghyHscflNlfsTnHhZxISyXT4SBDgOaj7V57SAkf+gMRXxS2dcXyFTFkxm/pLYktyY02w bHJg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1724704107; x=1725308907; 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=y4CuIS2O9/fj+lBdt8ymvV+Stc9+h4xTSSAPFKw9WU0=; b=AZar0xxjlq0+2HcG3oglkJqd3uVvz4IAk2i2DItUnuHNcybMITB8KTYF/IQfXczleU VWCq/gRPn3JGQpztxltLqNvsgJu2lv8iSia3Pd8WtFK72IfNd8fd5TtGuJFjz29j4rwD P2cPprUox4+1TTBztCoYKKBvahRAPSKGzuDy4LfZiVZSxSoB03HOAs01PlRU3S4VxChr 4iG4gtZMHDQcqA+gKeuaC9+cXSUMx56zh504XIeJxnuUnYfuBwjDic7WxlmSlF8PdLLA ONwGDdTMN6hA8xfJpVvjDUNpIdAKNwaXa0vjmn42/pnSxBWjJug6yIZtMk+vBwphMbWg JOiw== X-Forwarded-Encrypted: i=1; AJvYcCW20kyac4uP0UUVB4tCYH4hbniCedUeDVD/E6BMmtLjdHfnv4M4lzwa9Af0Zt2njqEIua+Laxg/DFL44g0=@vger.kernel.org X-Gm-Message-State: AOJu0YwgbrubAKLj7putnKSsBVctN8IxJTURBqbF9u2G3s3R0ueRn6W+ bcDmNWymHy4PshLbvn9FupcseduP7aBLMlv8+YwViHMB6ncs1XHWTvq0IdtFMYZPs3T7+pgDRSa QQQ== X-Google-Smtp-Source: AGHT+IE3PaHVFO73GTuBHSkg/Bp1BYVf64Z5BDMiZlAp1N72Zy30VoStroBvnjGNz6tOuhVG9XuSt7nX3dw= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a05:6902:202:b0:e0b:a712:2ceb with SMTP id 3f1490d57ef6-e1a2a5a664cmr12509276.5.1724704106889; Mon, 26 Aug 2024 13:28:26 -0700 (PDT) Date: Mon, 26 Aug 2024 13:28:25 -0700 In-Reply-To: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240809190319.1710470-1-seanjc@google.com> <20240809190319.1710470-5-seanjc@google.com> <20240814142256.7neuthobi7k2ilr6@yy-desk-7060> <6fsgci4fceoin7fp3ejeulbaybaitx3yo3nylzecanoba5gvhd@3ubrvlykgonn> Message-ID: Subject: Re: [PATCH 04/22] KVM: x86/mmu: Skip emulation on page fault iff 1+ SPs were unprotected From: Sean Christopherson To: Yao Yuan Cc: Yuan Yao , Paolo Bonzini , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Peter Gonda , Michael Roth , Vishal Annapurve , Ackerly Tng Content-Type: text/plain; charset="us-ascii" On Fri, Aug 23, 2024, Sean Christopherson wrote: > On Thu, Aug 22, 2024, Sean Christopherson wrote: > Intel support is especially misleading, because sharing page tables between EPT > and IA32 is rather nonsensical due to them having different formats. I.e. I doubt > Paolo had a use case for the VMX changes, and was just providing parity with SVM. > Of course, reusing L1's page tables as the NPT tables for L2 is quite crazy too, Actually, it's not _that_ crazy, e.g. KVM s390 does this for last-level page tables so that changes to the host userspace mappings don't require mmu_notifier-induced changes in KVM. > but at least the PTE formats are identical.