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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D6699C433EF for ; Fri, 22 Oct 2021 14:51:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BF302610FF for ; Fri, 22 Oct 2021 14:51:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233151AbhJVOxc (ORCPT ); Fri, 22 Oct 2021 10:53:32 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:50862 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232926AbhJVOx1 (ORCPT ); Fri, 22 Oct 2021 10:53:27 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1634914268; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=guXApxPR4iadrMYvuxdEZS4OExcn8OfGfvxMcVFcOL0=; b=Ai9XTvWSyJ1mB06GPvTBGucAfXThhGOnZ5B4YPm2GxwiRcLjp+1Ljp6R1WhXh5+i9xj0Zv 2uIkJUZS/K78TRzUOv0mcWNVcR7ni57HYV8jMq8XGHBnUDTmCjRw2SMjejxZ1ORmZinjMl IGwN4Wjv5P6pP8RfLqmDMe+y+mlp8h8= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-278-iapKII4XM26oS-ZRfJxXwg-1; Fri, 22 Oct 2021 10:51:05 -0400 X-MC-Unique: iapKII4XM26oS-ZRfJxXwg-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 082F6879500; Fri, 22 Oct 2021 14:51:04 +0000 (UTC) Received: from starship (unknown [10.40.192.246]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9CB0560854; Fri, 22 Oct 2021 14:50:48 +0000 (UTC) Message-ID: Subject: Re: [PATCH v3 7/8] nSVM: use vmcb_ctrl_area_cached instead of vmcb_control_area in struct svm_nested_state From: Maxim Levitsky To: Emanuele Giuseppe Esposito , kvm@vger.kernel.org Cc: Paolo Bonzini , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, "H. Peter Anvin" , linux-kernel@vger.kernel.org Date: Fri, 22 Oct 2021 17:50:47 +0300 In-Reply-To: <20211011143702.1786568-8-eesposit@redhat.com> References: <20211011143702.1786568-1-eesposit@redhat.com> <20211011143702.1786568-8-eesposit@redhat.com> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.36.5 (3.36.5-2.fc32) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2021-10-11 at 10:37 -0400, Emanuele Giuseppe Esposito wrote: > This requires changing all vmcb_is_intercept(&svm->nested.ctl, ...) > calls with vmcb12_is_intercept(). > > In addition, in svm_get_nested_state() user space expects a > vmcb_control_area struct, so we need to copy back all fields > in a temporary structure to provide to the user space. > > Signed-off-by: Emanuele Giuseppe Esposito > --- > arch/x86/kvm/svm/nested.c | 41 +++++++++++++++++++++++---------------- > arch/x86/kvm/svm/svm.c | 4 ++-- > arch/x86/kvm/svm/svm.h | 8 ++++---- > 3 files changed, 30 insertions(+), 23 deletions(-) > > diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c > index c84cded1dcf6..13be1002ad1c 100644 > --- a/arch/x86/kvm/svm/nested.c > +++ b/arch/x86/kvm/svm/nested.c > @@ -58,8 +58,9 @@ static void svm_inject_page_fault_nested(struct kvm_vcpu *vcpu, struct x86_excep > struct vcpu_svm *svm = to_svm(vcpu); > WARN_ON(!is_guest_mode(vcpu)); > > - if (vmcb_is_intercept(&svm->nested.ctl, INTERCEPT_EXCEPTION_OFFSET + PF_VECTOR) && > - !svm->nested.nested_run_pending) { > + if (vmcb12_is_intercept(&svm->nested.ctl, > + INTERCEPT_EXCEPTION_OFFSET + PF_VECTOR) && > + !svm->nested.nested_run_pending) { > svm->vmcb->control.exit_code = SVM_EXIT_EXCP_BASE + PF_VECTOR; > svm->vmcb->control.exit_code_hi = 0; > svm->vmcb->control.exit_info_1 = fault->error_code; > @@ -121,7 +122,8 @@ static void nested_svm_uninit_mmu_context(struct kvm_vcpu *vcpu) > > void recalc_intercepts(struct vcpu_svm *svm) > { > - struct vmcb_control_area *c, *h, *g; > + struct vmcb_control_area *c, *h; > + struct vmcb_ctrl_area_cached *g; > unsigned int i; > > vmcb_mark_dirty(svm->vmcb, VMCB_INTERCEPTS); > @@ -172,7 +174,7 @@ static bool nested_svm_vmrun_msrpm(struct vcpu_svm *svm) > */ > int i; > > - if (!(vmcb_is_intercept(&svm->nested.ctl, INTERCEPT_MSR_PROT))) > + if (!(vmcb12_is_intercept(&svm->nested.ctl, INTERCEPT_MSR_PROT))) > return true; > > for (i = 0; i < MSRPM_OFFSETS; i++) { > @@ -208,9 +210,9 @@ static bool nested_svm_check_bitmap_pa(struct kvm_vcpu *vcpu, u64 pa, u32 size) > } > > static bool nested_vmcb_check_controls(struct kvm_vcpu *vcpu, > - struct vmcb_control_area *control) > + struct vmcb_ctrl_area_cached *control) > { > - if (CC(!vmcb_is_intercept(control, INTERCEPT_VMRUN))) > + if (CC(!vmcb12_is_intercept(control, INTERCEPT_VMRUN))) > return false; > > if (CC(control->asid == 0)) > @@ -960,7 +962,7 @@ static int nested_svm_exit_handled_msr(struct vcpu_svm *svm) > u32 offset, msr, value; > int write, mask; > > - if (!(vmcb_is_intercept(&svm->nested.ctl, INTERCEPT_MSR_PROT))) > + if (!(vmcb12_is_intercept(&svm->nested.ctl, INTERCEPT_MSR_PROT))) > return NESTED_EXIT_HOST; > > msr = svm->vcpu.arch.regs[VCPU_REGS_RCX]; > @@ -987,7 +989,7 @@ static int nested_svm_intercept_ioio(struct vcpu_svm *svm) > u8 start_bit; > u64 gpa; > > - if (!(vmcb_is_intercept(&svm->nested.ctl, INTERCEPT_IOIO_PROT))) > + if (!(vmcb12_is_intercept(&svm->nested.ctl, INTERCEPT_IOIO_PROT))) > return NESTED_EXIT_HOST; > > port = svm->vmcb->control.exit_info_1 >> 16; > @@ -1018,12 +1020,12 @@ static int nested_svm_intercept(struct vcpu_svm *svm) > vmexit = nested_svm_intercept_ioio(svm); > break; > case SVM_EXIT_READ_CR0 ... SVM_EXIT_WRITE_CR8: { > - if (vmcb_is_intercept(&svm->nested.ctl, exit_code)) > + if (vmcb12_is_intercept(&svm->nested.ctl, exit_code)) > vmexit = NESTED_EXIT_DONE; > break; > } > case SVM_EXIT_READ_DR0 ... SVM_EXIT_WRITE_DR7: { > - if (vmcb_is_intercept(&svm->nested.ctl, exit_code)) > + if (vmcb12_is_intercept(&svm->nested.ctl, exit_code)) > vmexit = NESTED_EXIT_DONE; > break; > } > @@ -1041,7 +1043,7 @@ static int nested_svm_intercept(struct vcpu_svm *svm) > break; > } > default: { > - if (vmcb_is_intercept(&svm->nested.ctl, exit_code)) > + if (vmcb12_is_intercept(&svm->nested.ctl, exit_code)) > vmexit = NESTED_EXIT_DONE; > } > } > @@ -1119,7 +1121,7 @@ static void nested_svm_inject_exception_vmexit(struct vcpu_svm *svm) > > static inline bool nested_exit_on_init(struct vcpu_svm *svm) > { > - return vmcb_is_intercept(&svm->nested.ctl, INTERCEPT_INIT); > + return vmcb12_is_intercept(&svm->nested.ctl, INTERCEPT_INIT); > } > > static int svm_check_nested_events(struct kvm_vcpu *vcpu) > @@ -1250,6 +1252,7 @@ static int svm_get_nested_state(struct kvm_vcpu *vcpu, > u32 user_data_size) > { > struct vcpu_svm *svm; > + struct vmcb_control_area ctl_temp; > struct kvm_nested_state kvm_state = { > .flags = 0, > .format = KVM_STATE_NESTED_FORMAT_SVM, > @@ -1291,7 +1294,8 @@ static int svm_get_nested_state(struct kvm_vcpu *vcpu, > */ > if (clear_user(user_vmcb, KVM_STATE_NESTED_SVM_VMCB_SIZE)) > return -EFAULT; > - if (copy_to_user(&user_vmcb->control, &svm->nested.ctl, > + nested_copy_vmcb_cache_to_control(&ctl_temp, &svm->nested.ctl); > + if (copy_to_user(&user_vmcb->control, &ctl_temp, > sizeof(user_vmcb->control))) > return -EFAULT; > if (copy_to_user(&user_vmcb->save, &svm->vmcb01.ptr->save, > @@ -1362,8 +1366,9 @@ static int svm_set_nested_state(struct kvm_vcpu *vcpu, > goto out_free; > > ret = -EINVAL; > - if (!nested_vmcb_check_controls(vcpu, ctl)) > - goto out_free; > + nested_copy_vmcb_control_to_cache(svm, ctl); > + if (!nested_vmcb_check_controls(vcpu, &svm->nested.ctl)) > + goto out_free_ctl; I also don't like this, like about writing and clearing of svm->nested.save in patch 4. Unlike the former case, this case is functionally correct, but still a failure will leave partially initialized state (which you zero at the end to make it better, but it is best that failure would leave the state untouched). Since loading/saving the nested state is anything but performance critical code, I would prefer to also copy control area to a temp variable, and then pass it to __nested_vmcb_check_controls. Other than that, this patch looks good. Best regards, Maxim Levitsky > > /* > * Processor state contains L2 state. Check that it is > @@ -1371,7 +1376,7 @@ static int svm_set_nested_state(struct kvm_vcpu *vcpu, > */ > cr0 = kvm_read_cr0(vcpu); > if (((cr0 & X86_CR0_CD) == 0) && (cr0 & X86_CR0_NW)) > - goto out_free; > + goto out_free_ctl; > > /* > * Validate host state saved from before VMRUN (see > @@ -1417,7 +1422,6 @@ static int svm_set_nested_state(struct kvm_vcpu *vcpu, > svm->nested.vmcb12_gpa = kvm_state->hdr.svm.vmcb_pa; > > svm_copy_vmrun_state(&svm->vmcb01.ptr->save, save); > - nested_copy_vmcb_control_to_cache(svm, ctl); > > svm_switch_vmcb(svm, &svm->nested.vmcb02); > nested_vmcb02_prepare_control(svm); > @@ -1427,6 +1431,9 @@ static int svm_set_nested_state(struct kvm_vcpu *vcpu, > out_free_save: > memset(&svm->nested.save, 0, sizeof(struct vmcb_save_area_cached)); > > +out_free_ctl: > + memset(&svm->nested.ctl, 0, sizeof(struct vmcb_ctrl_area_cached)); > + > out_free: > kfree(save); > kfree(ctl); > diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c > index 1b6d25c6e0ae..d866eea39777 100644 > --- a/arch/x86/kvm/svm/svm.c > +++ b/arch/x86/kvm/svm/svm.c > @@ -2465,7 +2465,7 @@ static bool check_selective_cr0_intercepted(struct kvm_vcpu *vcpu, > bool ret = false; > > if (!is_guest_mode(vcpu) || > - (!(vmcb_is_intercept(&svm->nested.ctl, INTERCEPT_SELECTIVE_CR0)))) > + (!(vmcb12_is_intercept(&svm->nested.ctl, INTERCEPT_SELECTIVE_CR0)))) > return false; > > cr0 &= ~SVM_CR0_SELECTIVE_MASK; > @@ -4184,7 +4184,7 @@ static int svm_check_intercept(struct kvm_vcpu *vcpu, > info->intercept == x86_intercept_clts) > break; > > - if (!(vmcb_is_intercept(&svm->nested.ctl, > + if (!(vmcb12_is_intercept(&svm->nested.ctl, > INTERCEPT_SELECTIVE_CR0))) > break; > > diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h > index 78006245e334..051b7d0a13a1 100644 > --- a/arch/x86/kvm/svm/svm.h > +++ b/arch/x86/kvm/svm/svm.h > @@ -156,7 +156,7 @@ struct svm_nested_state { > bool nested_run_pending; > > /* cache for control fields of the guest */ > - struct vmcb_control_area ctl; > + struct vmcb_ctrl_area_cached ctl; > struct vmcb_save_area_cached save; > > bool initialized; > @@ -491,17 +491,17 @@ static inline bool nested_svm_virtualize_tpr(struct kvm_vcpu *vcpu) > > static inline bool nested_exit_on_smi(struct vcpu_svm *svm) > { > - return vmcb_is_intercept(&svm->nested.ctl, INTERCEPT_SMI); > + return vmcb12_is_intercept(&svm->nested.ctl, INTERCEPT_SMI); > } > > static inline bool nested_exit_on_intr(struct vcpu_svm *svm) > { > - return vmcb_is_intercept(&svm->nested.ctl, INTERCEPT_INTR); > + return vmcb12_is_intercept(&svm->nested.ctl, INTERCEPT_INTR); > } > > static inline bool nested_exit_on_nmi(struct vcpu_svm *svm) > { > - return vmcb_is_intercept(&svm->nested.ctl, INTERCEPT_NMI); > + return vmcb12_is_intercept(&svm->nested.ctl, INTERCEPT_NMI); > } > > int enter_svm_guest_mode(struct kvm_vcpu *vcpu, u64 vmcb_gpa, struct vmcb *vmcb12);