From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5EBFCC17440 for ; Wed, 13 Nov 2019 01:10:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 38BA521A49 for ; Wed, 13 Nov 2019 01:10:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573607455; bh=UHojKoHJkSEXKX2pCIHTRX25I6EJIfI6hK+0Q8psVrY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=Q/8oFTdjN9aL2fx9dr09UBtdgrOpQV4bRJYfb4Ec//+maKD6EW1X/7ppXQkASiNhI UAo8ZTxmnAXpXgdTWc95HzMFt/eOrSN5DSE2Eztz8IbP1wt+F9RlTEtFXGlm+mqgYM S6wzLR4woPJ/xWzv7+RzUcvOUBWW7i8TKAcuauyY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727312AbfKMBKy (ORCPT ); Tue, 12 Nov 2019 20:10:54 -0500 Received: from mail.kernel.org ([198.145.29.99]:43868 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726979AbfKMBKy (ORCPT ); Tue, 12 Nov 2019 20:10:54 -0500 Received: from localhost (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 6B7BC21A49; Wed, 13 Nov 2019 01:10:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573607452; bh=UHojKoHJkSEXKX2pCIHTRX25I6EJIfI6hK+0Q8psVrY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=DzoCk/LEjfy/7ut5nKnxEQq7QeB7s//h6mMkiYHXigi2Qe+mtvTPQlKD/xYiEjoA+ kcbKq3J2tjphzECfvFU/8c6aBJN1YRBe4nTWHWPvXcTWAkFRfQdQmulqsmTMKeC7Ww KKujlcFDotf3FJEAXhmL4esuTG/xQ0GE8CzblrAg= Date: Tue, 12 Nov 2019 20:10:51 -0500 From: Sasha Levin To: Paolo Bonzini Cc: Sean Christopherson , stable@vger.kernel.org, Greg Kroah-Hartman , linux-kernel@vger.kernel.org Subject: Re: [PATCH 4.19 STABLE] KVM: x86: introduce is_pae_paging Message-ID: <20191113011051.GJ8496@sasha-vm> References: <20191111225423.29309-1-sean.j.christopherson@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Nov 12, 2019 at 12:05:44AM +0100, Paolo Bonzini wrote: >On 11/11/19 23:54, Sean Christopherson wrote: >> From: Paolo Bonzini >> >> Upstream commit bf03d4f9334728bf7c8ffc7de787df48abd6340e. >> >> Checking for 32-bit PAE is quite common around code that fiddles with >> the PDPTRs. Add a function to compress all checks into a single >> invocation. >> >> Moving to the common helper also fixes a subtle bug in kvm_set_cr3() >> where it fails to check is_long_mode() and results in KVM incorrectly >> attempting to load PDPTRs for a 64-bit guest. >> >> Reviewed-by: Sean Christopherson >> Signed-off-by: Paolo Bonzini >> [sean: backport to 4.x; handle vmx.c split in 5.x, call out the bugfix] >> Signed-off-by: Sean Christopherson >> --- >> arch/x86/kvm/vmx.c | 7 +++---- >> arch/x86/kvm/x86.c | 8 ++++---- >> arch/x86/kvm/x86.h | 5 +++++ >> 3 files changed, 12 insertions(+), 8 deletions(-) >> >> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c >> index 6f7b3acdab26..83acaed244ba 100644 >> --- a/arch/x86/kvm/vmx.c >> +++ b/arch/x86/kvm/vmx.c >> @@ -5181,7 +5181,7 @@ static void ept_load_pdptrs(struct kvm_vcpu *vcpu) >> (unsigned long *)&vcpu->arch.regs_dirty)) >> return; >> >> - if (is_paging(vcpu) && is_pae(vcpu) && !is_long_mode(vcpu)) { >> + if (is_pae_paging(vcpu)) { >> vmcs_write64(GUEST_PDPTR0, mmu->pdptrs[0]); >> vmcs_write64(GUEST_PDPTR1, mmu->pdptrs[1]); >> vmcs_write64(GUEST_PDPTR2, mmu->pdptrs[2]); >> @@ -5193,7 +5193,7 @@ static void ept_save_pdptrs(struct kvm_vcpu *vcpu) >> { >> struct kvm_mmu *mmu = vcpu->arch.walk_mmu; >> >> - if (is_paging(vcpu) && is_pae(vcpu) && !is_long_mode(vcpu)) { >> + if (is_pae_paging(vcpu)) { >> mmu->pdptrs[0] = vmcs_read64(GUEST_PDPTR0); >> mmu->pdptrs[1] = vmcs_read64(GUEST_PDPTR1); >> mmu->pdptrs[2] = vmcs_read64(GUEST_PDPTR2); >> @@ -12021,8 +12021,7 @@ static int nested_vmx_load_cr3(struct kvm_vcpu *vcpu, unsigned long cr3, bool ne >> * If PAE paging and EPT are both on, CR3 is not used by the CPU and >> * must not be dereferenced. >> */ >> - if (!is_long_mode(vcpu) && is_pae(vcpu) && is_paging(vcpu) && >> - !nested_ept) { >> + if (is_pae_paging(vcpu) && !nested_ept) { >> if (!load_pdptrs(vcpu, vcpu->arch.walk_mmu, cr3)) { >> *entry_failure_code = ENTRY_FAIL_PDPTE; >> return 1; >> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c >> index 6ae8a013af31..b9b87fb75ac0 100644 >> --- a/arch/x86/kvm/x86.c >> +++ b/arch/x86/kvm/x86.c >> @@ -633,7 +633,7 @@ bool pdptrs_changed(struct kvm_vcpu *vcpu) >> gfn_t gfn; >> int r; >> >> - if (is_long_mode(vcpu) || !is_pae(vcpu) || !is_paging(vcpu)) >> + if (!is_pae_paging(vcpu)) >> return false; >> >> if (!test_bit(VCPU_EXREG_PDPTR, >> @@ -884,8 +884,8 @@ int kvm_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3) >> if (is_long_mode(vcpu) && >> (cr3 & rsvd_bits(cpuid_maxphyaddr(vcpu), 63))) >> return 1; >> - else if (is_pae(vcpu) && is_paging(vcpu) && >> - !load_pdptrs(vcpu, vcpu->arch.walk_mmu, cr3)) >> + else if (is_pae_paging(vcpu) && >> + !load_pdptrs(vcpu, vcpu->arch.walk_mmu, cr3)) >> return 1; >> >> kvm_mmu_new_cr3(vcpu, cr3, skip_tlb_flush); >> @@ -8312,7 +8312,7 @@ static int __set_sregs(struct kvm_vcpu *vcpu, struct kvm_sregs *sregs) >> kvm_update_cpuid(vcpu); >> >> idx = srcu_read_lock(&vcpu->kvm->srcu); >> - if (!is_long_mode(vcpu) && is_pae(vcpu) && is_paging(vcpu)) { >> + if (is_pae_paging(vcpu)) { >> load_pdptrs(vcpu, vcpu->arch.walk_mmu, kvm_read_cr3(vcpu)); >> mmu_reset_needed = 1; >> } >> diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h >> index 3a91ea760f07..608e5f8c5d0a 100644 >> --- a/arch/x86/kvm/x86.h >> +++ b/arch/x86/kvm/x86.h >> @@ -139,6 +139,11 @@ static inline int is_paging(struct kvm_vcpu *vcpu) >> return likely(kvm_read_cr0_bits(vcpu, X86_CR0_PG)); >> } >> >> +static inline bool is_pae_paging(struct kvm_vcpu *vcpu) >> +{ >> + return !is_long_mode(vcpu) && is_pae(vcpu) && is_paging(vcpu); >> +} >> + >> static inline u32 bit(int bitno) >> { >> return 1 << (bitno & 31); >> > >Acked-by: Paolo Bonzini Queued up for 4.19, thank you. -- Thanks, Sasha