From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3B0BA34C121 for ; Mon, 23 Feb 2026 08:58:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771837088; cv=none; b=c1ubevrNADBUqEsnb/1Uc6JG2rJRlwpWSMQFnWUkY7+fXwctjNZ2ue+BknL8aPChatLChPSLysQFroFEdxLAOEijryv51QsJV4hnFgEErQecWc2nelOgSSZqDHpHNNMEpkqj8CVsqJGkqmtZSIiILm+hLj8P1+0tZsYNL8LoL8s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771837088; c=relaxed/simple; bh=TJbxqHVs+e50jZZ4SLCFVeSNZh3JxXe/D2GgxbkHo4Q=; h=From:To:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=rKSo9ZhnmYnjXbBP+j67Lm0XGOAcma3aNek97jfTLqiMjdM9WVX15qCaKTYAyyi3QlF3WWwKC7iH4+tfranV9Qay7dIBw9edCeqXbYrcIvOKkMFt37kBzhqfX2unZCQbt48Y9nh3xQb9AZiF5jAzU8A+IfrwV+hYjoPPaYbcmYc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=AWDbWvHz; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b=SMmwNACt; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="AWDbWvHz"; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b="SMmwNACt" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1771837085; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=3cWctW69aIH0GXOOoxbqXQgAV5r2o6fzbkGEycK6FGA=; b=AWDbWvHzK4wC7tdMyOraD6+wGU8EGpha/lRldfTSOMlxjL0BEngwLD+sMyvFBGjPOE5fYf YFC/LDl4q1hkrRaKCTm6K5aauYQFknuni9omP038JCSEkvLpOmm8Ne42EJtBm9X7o8NUgU aImfygN8TyUMdRjQQoM5aWx1cLQY0uM= Received: from mail-wr1-f72.google.com (mail-wr1-f72.google.com [209.85.221.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-177-xax3RSQBN1CRLNlULK5DDA-1; Mon, 23 Feb 2026 03:58:03 -0500 X-MC-Unique: xax3RSQBN1CRLNlULK5DDA-1 X-Mimecast-MFC-AGG-ID: xax3RSQBN1CRLNlULK5DDA_1771837082 Received: by mail-wr1-f72.google.com with SMTP id ffacd0b85a97d-435a2de6ec0so2606893f8f.0 for ; Mon, 23 Feb 2026 00:58:03 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=google; t=1771837082; x=1772441882; darn=vger.kernel.org; h=mime-version:message-id:date:references:in-reply-to:subject:to:from :from:to:cc:subject:date:message-id:reply-to; bh=3cWctW69aIH0GXOOoxbqXQgAV5r2o6fzbkGEycK6FGA=; b=SMmwNACtmRwOS81Q4nfzu0Xh7eTTUPBF5H1j0vXw9ea1X7auA64SylT2ySEo3TCtes CPI71hd33HCQHgX2/D+Krb/i7ph7Ue0qRFd+XQCmWF3jkvQWHLm+CfPHwNOZQpN7wG1S RGEuDqfxGAmxHZKzONIYSLzTiIL0tg/OG8JSsQ3RiI6fG1aGqd0pg3zYB8X6PCuUqeo1 amgzh3RE5XCEOvlW6zo8btjRa9eMyEZ93ORJnf4pUXi+S8k3B6iuHAmbUi5r5WvQ9bHf zCZY82UimowHArhsrKMGlVHB+WNQBf2Cx/ikQNO0srqIc+giBpk4BRZOIT6n+InDxbu7 9qCg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1771837082; x=1772441882; h=mime-version:message-id:date:references:in-reply-to:subject:to:from :x-gm-gg:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=3cWctW69aIH0GXOOoxbqXQgAV5r2o6fzbkGEycK6FGA=; b=tXc2rDytCmj3OrwxYY9sdMjW3Cvx2foE3f2ZbIe7RQQB2RSa/uRY0wTjZrnsu9vT/Y RcN3jrRO7tNipz6jBBgtJYrWhn99HI2A6BqefBibvgqB49hvfmESLST2ipCvqn8RSxpr TatqB5guO64OGCCuCtdUbtvkD1MNmrmtmY6JqotYDPPS0TXN0G9IL9+F9KZB7XWc0FoF SKsWAexOlctYzRIMpE09wFZqVmfst+TUhh9bpCCYjtdzRggZehkAix0E8XksYodE8KwD DtV2CHBlx5+b/+FatIOwPXVqUCV25WlszAdiBAX5uLDTp5aAghSw4LecwDO42a+uOt5O 9LGg== X-Forwarded-Encrypted: i=1; AJvYcCUCoBcZeag8xy/9nrlhzpXVl/qLTEJyxttZcM/Mf8aCRV7GWPDoEFA8rzPiGBRKY5hTq2hgJdxHS3dXN2s=@vger.kernel.org X-Gm-Message-State: AOJu0YzeJkrFasUghoOlQkgK2tuK0BXUlHVuxr24SrGDh68v2XIiwa/Q ryJ60NACPj9cMpY/RPFCvtI1QNcjTsFLc6OWPp3ZreuwY9KCL6Ol857r1aSNm3dUMJ7M/hLs6AS viSRlaAMdl8F+Zw7HAoLO060p5kYcqj/hizA6+YNGlCjcymxHJsf2atyk5LaGtESE8/7DEL/b5Q YPDuQrZb2AWKpHvmpr3WaLkawtpTYigfrEkciN1BO6AsJdNTKZaQ== X-Gm-Gg: ATEYQzxGBfkN2lLE0Q4oT3H9W/n8hEZqHzU8TFvA5OQxC9TTTCXeSU2e+r1P3wv2mPd GOTnjVtHL78X2ZbMdOzXXtcTDbvfWMqWooR6F4WWQQFg8yRQSTW83NH2uE2CPDMFXPTHIow+jYu XWQ6X44a3I1CIZhsp9tNdUaKUQCPMZc+74fX7gIQthLZiwbQdzJlpWFGlwsrtUmIW1qAvUicRbH quYTdlISwiY/2PXK0Pc5TbDC9gsiVdRNRIPJmrfQldaIuMkuXoaAdHGtvEScZ6XvSKtDo8EQag6 ci6gVs9nFAgJm36vn8EFA2jmnCHF2nA3PcP9bcbyqfQjk4vTD9rLlhFSFV+loY21lzgQe35Sx4b YPqvc8ylyzbQ5tveQlQ== X-Received: by 2002:adf:e346:0:b0:437:6efe:94c5 with SMTP id ffacd0b85a97d-4396f1564b2mr10433959f8f.2.1771837082330; Mon, 23 Feb 2026 00:58:02 -0800 (PST) X-Received: by 2002:adf:e346:0:b0:437:6efe:94c5 with SMTP id ffacd0b85a97d-4396f1564b2mr10433921f8f.2.1771837081744; Mon, 23 Feb 2026 00:58:01 -0800 (PST) Received: from fedora (g3.ign.cz. [91.219.240.17]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-43970d4c982sm18127947f8f.31.2026.02.23.00.58.01 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 23 Feb 2026 00:58:01 -0800 (PST) From: Vitaly Kuznetsov To: Manuel Andreas , kvm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] x86/hyper-v: Validate entire GVA range for non-canonical addresses during PV TLB flush In-Reply-To: <00a7a31b-573b-4d92-91f8-7d7e2f88ea48@tum.de> References: <00a7a31b-573b-4d92-91f8-7d7e2f88ea48@tum.de> Date: Mon, 23 Feb 2026 09:58:00 +0100 Message-ID: <87ms0zu99j.fsf@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain Manuel Andreas writes: > In KVM guests with Hyper-V hypercalls enabled, the hypercalls > HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST and HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX > allow a guest to request invalidation of portions of a virtual TLB. > For this, the hypercall parameter includes a list of GVAs that are supposed > to be invalidated. > > Currently, only the base GVA is checked to be canonical. In reality, > this check needs to be performed for the entire range of GVAs. > This still enables guests running on Intel hardware to trigger a > WARN_ONCE in the host (see prior commit below). > > This patch simply moves the check for non-canonical addresses to be > performed for every single GVA of the supplied range. This should also > be more in line with the Hyper-V specification, since, although > unlikely, a range starting with an invalid GVA may still contain > GVAs that are valid. > > Fixes: fa787ac07b3c ("KVM: x86/hyper-v: Skip non-canonical addresses during PV TLB flush") > Signed-off-by: Manuel Andreas > --- > arch/x86/kvm/hyperv.c | 9 +++++---- > 1 file changed, 5 insertions(+), 4 deletions(-) > > diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c > index de92292eb1f5..f4f6accf1a33 100644 > --- a/arch/x86/kvm/hyperv.c > +++ b/arch/x86/kvm/hyperv.c > @@ -1981,16 +1981,17 @@ int kvm_hv_vcpu_flush_tlb(struct kvm_vcpu *vcpu) > if (entries[i] == KVM_HV_TLB_FLUSHALL_ENTRY) > goto out_flush_all; > > - if (is_noncanonical_invlpg_address(entries[i], vcpu)) > - continue; > - > /* > * Lower 12 bits of 'address' encode the number of additional > * pages to flush. > */ > gva = entries[i] & PAGE_MASK; > - for (j = 0; j < (entries[i] & ~PAGE_MASK) + 1; j++) > + for (j = 0; j < (entries[i] & ~PAGE_MASK) + 1; j++) { > + if (is_noncanonical_invlpg_address(gva + j * PAGE_SIZE, vcpu)) > + continue; > + > kvm_x86_call(flush_tlb_gva)(vcpu, gva + j * PAGE_SIZE); > + } > > ++vcpu->stat.tlb_flush; > } Reviewed-by: Vitaly Kuznetsov -- Vitaly