From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f201.google.com (mail-pf1-f201.google.com [209.85.210.201]) (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 7A74F26291 for ; Wed, 8 May 2024 14:09:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715177391; cv=none; b=bwYVBvGCDThLoR+kChmxXssIUN/1uNaie4oVe8UjCxgH4/nPEmh9cp6YUYjzb1SVpyP42k7go1v7VoL0X1jCO+MBeFoDT2Yb6iEXkPf9/P/v6n0y7gdUqerDmjm0NUKWImwY9OF6wf7dT4TfTxxLBfJduTE59/HephWdbLLWyJE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715177391; c=relaxed/simple; bh=muTBhNKKyfLxTEheuwIpv/vLCE51rLmD3T6Hx58fn3M=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=SDnSwOyAsfivB0k8HRZlyJ1T9rlZA6OtoLt6/KveO5x1j5pV3ujsoL44PzPEf1h/K3KGQZCqc1UhXzH4JUP759lTHQljkCLM++Jd+AXAnj4CdUkxxHoN0e1PfcpxSPV1DUEeA22tPBtkpucpbxbs2o8vsdgZ6iPWiG/wq36MUhQ= 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=tFyi6Qvw; arc=none smtp.client-ip=209.85.210.201 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="tFyi6Qvw" Received: by mail-pf1-f201.google.com with SMTP id d2e1a72fcca58-6f4755be972so2476362b3a.0 for ; Wed, 08 May 2024 07:09:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1715177390; x=1715782190; 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=tfYRBLNRHkcg/E20qzGwgcZT/WOB/w2rN51VWZ00zK0=; b=tFyi6Qvw/TZdeIo1JMZ0FzaDBJmnQUI+8PezOAXrssy0LbjLbBA/W1AfzZjfzRBm7P +hAk4oYrdl6hBz1qnwvtLhaiWj1aGqRQ/5RCI46t30ESgz/v0zNEtk8I+X4nqTILiY9v mdG1Bw2E021l0dukwHoV1I7i1j0z37W47NzaetBOaFZbXntu18MLwYjO+zFJ4mFvsnlw tVnWRKPuyNmwvwSetrxx+9hpoOGAX4C8bmGp4cfb1igaRuBlUVIiWmpZ/FLn7Y27W/Gc 87pfqRwuqSVuKQkir/hYs+YzQLdmmIEvt25v2sntR3hBv8B9eyJWZfmdwJTLVj8pb4VF qKLw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1715177390; x=1715782190; 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=tfYRBLNRHkcg/E20qzGwgcZT/WOB/w2rN51VWZ00zK0=; b=eHfKt+bR2dNq9xIjDIe9rTLbA6XVdkWCF0i5zKl738s5+wnssB0sMKNJ3RaMgTgQiw IYMj6/gxXON21mAkYnbnklZaAOoJ1KvBAXSlLMAanrgWqDvoiO91BMxhxop9XPDUnE5s 8HBosYs+cVzw8IMdpWqYarVQFnUi4/xA34zf+I6FGg6BpzcJ/PBOfKaXKsxaT2H4rGVk FA/CYH+Z3KUzZeEXlRzjfYza/K019NnZEy/FCKldP7Mxd0e9k16ZZbRWM+y/Q3EWQan7 FVOeZMWHHgRXaNOpxaGySRYUjjnD2ENJs9tYRUYPy4zDNHAEY/8qekmxGmLrSJf44pcW 1hPQ== X-Gm-Message-State: AOJu0Yz+9CkQlZ6XAitQTEXXyUVEM25chzldF6gl8Kiu1ZbY3yktfLLS R9QcaWld5Qy5P2DkiVt8u6RuGy0cN3Sxcpiojxwh5qPisB7C2ONj5jgMYgXq2C5PWa3PedOnX8C 8aQ== X-Google-Smtp-Source: AGHT+IE2rUI5EkfgYoBnp8g96Y58xo4YXn7sORjIu0h8BzTG170CsrfIpe2Be3EiWLRkSErVbLNTtu3fDaA= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a05:6a00:3a1a:b0:6f3:8468:432f with SMTP id d2e1a72fcca58-6f49c3047f1mr178093b3a.3.1715177389800; Wed, 08 May 2024 07:09:49 -0700 (PDT) Date: Wed, 8 May 2024 07:09:48 -0700 In-Reply-To: <20240508064205.15301-1-tao1.su@linux.intel.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240508064205.15301-1-tao1.su@linux.intel.com> Message-ID: Subject: Re: [PATCH] KVM: selftests: x86: Prioritize getting max_gfn from GuestPhysBits From: Sean Christopherson To: Tao Su Cc: kvm@vger.kernel.org, pbonzini@redhat.com, chao.gao@intel.com, xiaoyao.li@intel.com Content-Type: text/plain; charset="us-ascii" On Wed, May 08, 2024, Tao Su wrote: > Use the max mappable GPA via GuestPhysBits advertised by KVM to calculate > max_gfn. Currently some selftests (e.g. access_tracking_perf_test, > dirty_log_test...) add RAM regions close to max_gfn, so guest may access > GPA beyond its mappable range and cause infinite loop. > > Prioritize obtaining pa_bits from the GuestPhysBits field advertised by > KVM, so max_gfn can be limited to the mappable range. > > Signed-off-by: Tao Su > --- > This patch is based on https://github.com/kvm-x86/linux/commit/b628cb523c65 > --- > tools/testing/selftests/kvm/include/x86_64/processor.h | 1 + > tools/testing/selftests/kvm/lib/x86_64/processor.c | 4 +++- > 2 files changed, 4 insertions(+), 1 deletion(-) > > diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h > index 81ce37ec407d..ff99f66d81a0 100644 > --- a/tools/testing/selftests/kvm/include/x86_64/processor.h > +++ b/tools/testing/selftests/kvm/include/x86_64/processor.h > @@ -282,6 +282,7 @@ struct kvm_x86_cpu_property { > #define X86_PROPERTY_MAX_EXT_LEAF KVM_X86_CPU_PROPERTY(0x80000000, 0, EAX, 0, 31) > #define X86_PROPERTY_MAX_PHY_ADDR KVM_X86_CPU_PROPERTY(0x80000008, 0, EAX, 0, 7) > #define X86_PROPERTY_MAX_VIRT_ADDR KVM_X86_CPU_PROPERTY(0x80000008, 0, EAX, 8, 15) > +#define X86_PROPERTY_MAX_GUEST_PHY_ADDR KVM_X86_CPU_PROPERTY(0x80000008, 0, EAX, 16, 23) > #define X86_PROPERTY_SEV_C_BIT KVM_X86_CPU_PROPERTY(0x8000001F, 0, EBX, 0, 5) > #define X86_PROPERTY_PHYS_ADDR_REDUCTION KVM_X86_CPU_PROPERTY(0x8000001F, 0, EBX, 6, 11) > > diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c > index 74a4c736c9ae..6c69f1dfeed2 100644 > --- a/tools/testing/selftests/kvm/lib/x86_64/processor.c > +++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c > @@ -1074,7 +1074,9 @@ void kvm_get_cpu_address_width(unsigned int *pa_bits, unsigned int *va_bits) > *pa_bits = kvm_cpu_has(X86_FEATURE_PAE) ? 36 : 32; > *va_bits = 32; > } else { > - *pa_bits = kvm_cpu_property(X86_PROPERTY_MAX_PHY_ADDR); > + *pa_bits = kvm_cpu_property(X86_PROPERTY_MAX_GUEST_PHY_ADDR); > + if (*pa_bits == 0) > + *pa_bits = kvm_cpu_property(X86_PROPERTY_MAX_PHY_ADDR); This is the wrong place to incorporaate the max mappable GPA. The pa_bits field should reflect the "real" MAXPHYADDR, it's vm->max_gfn that needs to be adjusted, and x86 selftests already overrides vm_compute_max_gfn() specifically to deal with goofy edge cases like this. > *va_bits = kvm_cpu_property(X86_PROPERTY_MAX_VIRT_ADDR); > } > } > > base-commit: dccb07f2914cdab2ac3a5b6c98406f765acab803 > -- > 2.34.1 >