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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 92F36C433EF for ; Wed, 11 May 2022 11:21:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236775AbiEKLVN (ORCPT ); Wed, 11 May 2022 07:21:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41096 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237381AbiEKLVF (ORCPT ); Wed, 11 May 2022 07:21:05 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id EC1C07A82E for ; Wed, 11 May 2022 04:21:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1652268063; 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=eJ1KZyjyXF/tGtlejNex1S6i6BxFqFTF0Dz+yunplNk=; b=LwYjYvQ7XvjvcaRA6xmlgxCB0r3y4GUyAB4E/WuDHYiA3UZCVWt0/ED7x6Nf1S0I+U+Py7 i9sC2m0iIzLITPk/898ZcMH7XkZl+JWmVhjx87uk2sJGL5DIZ9UdIYlKJA76XGu0q9H07z Wt49tSsDzgnOTrSt2c1yUf4vh9RT+cA= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-445-jfkDCbqkNauI4uUmtMPUAg-1; Wed, 11 May 2022 07:20:55 -0400 X-MC-Unique: jfkDCbqkNauI4uUmtMPUAg-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 5FDDA1D32364; Wed, 11 May 2022 11:20:55 +0000 (UTC) Received: from starship (unknown [10.40.192.26]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1D0CC42B943; Wed, 11 May 2022 11:20:52 +0000 (UTC) Message-ID: Subject: Re: [PATCH v3 03/34] KVM: x86: hyper-v: Add helper to read hypercall data for array From: Maxim Levitsky To: Vitaly Kuznetsov , kvm@vger.kernel.org, Paolo Bonzini Cc: Sean Christopherson , Wanpeng Li , Jim Mattson , Michael Kelley , Siddharth Chandrasekaran , linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org Date: Wed, 11 May 2022 14:20:52 +0300 In-Reply-To: <20220414132013.1588929-4-vkuznets@redhat.com> References: <20220414132013.1588929-1-vkuznets@redhat.com> <20220414132013.1588929-4-vkuznets@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 2.85 on 10.11.54.9 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2022-04-14 at 15:19 +0200, Vitaly Kuznetsov wrote: > From: Sean Christopherson > > Move the guts of kvm_get_sparse_vp_set() to a helper so that the code for > reading a guest-provided array can be reused in the future, e.g. for > getting a list of virtual addresses whose TLB entries need to be flushed. > > Opportunisticaly swap the order of the data and XMM adjustment so that > the XMM/gpa offsets are bundled together. > > No functional change intended. > > Signed-off-by: Sean Christopherson > Signed-off-by: Vitaly Kuznetsov > --- > arch/x86/kvm/hyperv.c | 53 +++++++++++++++++++++++++++---------------- > 1 file changed, 33 insertions(+), 20 deletions(-) > > diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c > index fb716cf919ed..d66c27fd1e8a 100644 > --- a/arch/x86/kvm/hyperv.c > +++ b/arch/x86/kvm/hyperv.c > @@ -1758,38 +1758,51 @@ struct kvm_hv_hcall { > sse128_t xmm[HV_HYPERCALL_MAX_XMM_REGISTERS]; > }; > > -static u64 kvm_get_sparse_vp_set(struct kvm *kvm, struct kvm_hv_hcall *hc, > - int consumed_xmm_halves, > - u64 *sparse_banks, gpa_t offset) > -{ > - u16 var_cnt; > - int i; > > - if (hc->var_cnt > 64) > - return -EINVAL; > - > - /* Ignore banks that cannot possibly contain a legal VP index. */ > - var_cnt = min_t(u16, hc->var_cnt, KVM_HV_MAX_SPARSE_VCPU_SET_BITS); > +static int kvm_hv_get_hc_data(struct kvm *kvm, struct kvm_hv_hcall *hc, > + u16 orig_cnt, u16 cnt_cap, u64 *data, > + int consumed_xmm_halves, gpa_t offset) > +{ > + /* > + * Preserve the original count when ignoring entries via a "cap", KVM > + * still needs to validate the guest input (though the non-XMM path > + * punts on the checks). > + */ > + u16 cnt = min(orig_cnt, cnt_cap); > + int i, j; > > if (hc->fast) { > /* > * Each XMM holds two sparse banks, but do not count halves that > * have already been consumed for hypercall parameters. > */ > - if (hc->var_cnt > 2 * HV_HYPERCALL_MAX_XMM_REGISTERS - consumed_xmm_halves) > + if (orig_cnt > 2 * HV_HYPERCALL_MAX_XMM_REGISTERS - consumed_xmm_halves) > return HV_STATUS_INVALID_HYPERCALL_INPUT; > - for (i = 0; i < var_cnt; i++) { > - int j = i + consumed_xmm_halves; > + > + for (i = 0; i < cnt; i++) { > + j = i + consumed_xmm_halves; > if (j % 2) > - sparse_banks[i] = sse128_hi(hc->xmm[j / 2]); > + data[i] = sse128_hi(hc->xmm[j / 2]); > else > - sparse_banks[i] = sse128_lo(hc->xmm[j / 2]); > + data[i] = sse128_lo(hc->xmm[j / 2]); > } > return 0; > } > > - return kvm_read_guest(kvm, hc->ingpa + offset, sparse_banks, > - var_cnt * sizeof(*sparse_banks)); > + return kvm_read_guest(kvm, hc->ingpa + offset, data, > + cnt * sizeof(*data)); > +} > + > +static u64 kvm_get_sparse_vp_set(struct kvm *kvm, struct kvm_hv_hcall *hc, > + u64 *sparse_banks, int consumed_xmm_halves, > + gpa_t offset) > +{ > + if (hc->var_cnt > 64) > + return -EINVAL; > + > + /* Cap var_cnt to ignore banks that cannot contain a legal VP index. */ > + return kvm_hv_get_hc_data(kvm, hc, hc->var_cnt, KVM_HV_MAX_SPARSE_VCPU_SET_BITS, > + sparse_banks, consumed_xmm_halves, offset); > } > > static inline int hv_tlb_flush_ring_free(struct kvm_vcpu_hv *hv_vcpu, > @@ -1937,7 +1950,7 @@ static u64 kvm_hv_flush_tlb(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc) > if (!hc->var_cnt) > goto ret_success; > > - if (kvm_get_sparse_vp_set(kvm, hc, 2, sparse_banks, > + if (kvm_get_sparse_vp_set(kvm, hc, sparse_banks, 2, > offsetof(struct hv_tlb_flush_ex, > hv_vp_set.bank_contents))) > return HV_STATUS_INVALID_HYPERCALL_INPUT; > @@ -2048,7 +2061,7 @@ static u64 kvm_hv_send_ipi(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc) > if (!hc->var_cnt) > goto ret_success; > > - if (kvm_get_sparse_vp_set(kvm, hc, 1, sparse_banks, > + if (kvm_get_sparse_vp_set(kvm, hc, sparse_banks, 1, > offsetof(struct hv_send_ipi_ex, > vp_set.bank_contents))) > return HV_STATUS_INVALID_HYPERCALL_INPUT; I don't see anything wrong, but I don't know this area that well, so I might have missed something. Best regards, Maxim Levitsky