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spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1jHUbx-0008IC-83; Thu, 26 Mar 2020 15:40:01 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1jHUbw-0008I6-Gq for xen-devel@lists.xenproject.org; Thu, 26 Mar 2020 15:40:00 +0000 X-Inumbo-ID: 0ce49ca8-6f78-11ea-8813-12813bfff9fa Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id 0ce49ca8-6f78-11ea-8813-12813bfff9fa; Thu, 26 Mar 2020 15:39:59 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 8A431ABF6; Thu, 26 Mar 2020 15:39:58 +0000 (UTC) To: julien@xen.org References: <20200322161418.31606-1-julien@xen.org> <20200322161418.31606-6-julien@xen.org> From: Jan Beulich Message-ID: Date: Thu, 26 Mar 2020 16:39:47 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.6.0 MIME-Version: 1.0 In-Reply-To: <20200322161418.31606-6-julien@xen.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [Xen-devel] [PATCH 05/17] xen/x86: Remove the non-typesafe version of pagetable_* helpers X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Kevin Tian , Wei Liu , Andrew Cooper , Julien Grall , Tim Deegan , George Dunlap , Jun Nakajima , xen-devel@lists.xenproject.org, =?UTF-8?Q?Roger_Pau_Monn=c3=a9?= Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" On 22.03.2020 17:14, julien@xen.org wrote: > --- a/xen/arch/x86/domain.c > +++ b/xen/arch/x86/domain.c > @@ -952,25 +952,27 @@ int arch_set_info_guest( > } > else > { > - unsigned long pfn = pagetable_get_pfn(v->arch.guest_table); > + mfn_t mfn = pagetable_get_mfn(v->arch.guest_table); > bool fail; > > if ( !compat ) > { > - fail = xen_pfn_to_cr3(pfn) != c.nat->ctrlreg[3]; > + fail = mfn_to_cr3(mfn) != c.nat->ctrlreg[3]; The patch, besides a few other comments further down, looks fine on its own, but I don't think it can be acked without seeing the effects of the adjustments pending to the patch introducing mfn_to_cr3() and friends. > @@ -3116,24 +3116,24 @@ int vcpu_destroy_pagetables(struct vcpu *v) > > /* Free that page if non-zero */ > do { > - if ( mfn ) > + if ( !mfn_eq(mfn, _mfn(0)) ) I admit I'm not fully certain either, but at the first glance if ( mfn_x(mfn) ) would seem more in line with the original code to me (and then also elsewhere). > @@ -3560,19 +3561,18 @@ long do_mmuext_op( > if ( unlikely(rc) ) > break; > > - old_mfn = pagetable_get_pfn(curr->arch.guest_table_user); > + old_mfn = pagetable_get_mfn(curr->arch.guest_table_user); > /* > * This is particularly important when getting restarted after the > * previous attempt got preempted in the put-old-MFN phase. > */ > - if ( old_mfn == op.arg1.mfn ) > + if ( mfn_eq(old_mfn, new_mfn) ) > break; > > - if ( op.arg1.mfn != 0 ) > + if ( !mfn_eq(new_mfn, _mfn(0)) ) At least here I would clearly prefer the old code to be kept. > @@ -3580,19 +3580,19 @@ long do_mmuext_op( > else if ( rc != -ERESTART ) > gdprintk(XENLOG_WARNING, > "Error %d installing new mfn %" PRI_mfn "\n", > - rc, op.arg1.mfn); > + rc, mfn_x(new_mfn)); Here I'm also not sure I see the point of the conversion. > @@ -2351,11 +2351,11 @@ int sh_safe_not_to_sync(struct vcpu *v, mfn_t gl1mfn) > ASSERT(mfn_valid(smfn)); > #endif > > - if ( pagetable_get_pfn(v->arch.shadow_table[0]) == mfn_x(smfn) > + if ( mfn_eq(pagetable_get_mfn(v->arch.shadow_table[0]), smfn) > #if (SHADOW_PAGING_LEVELS == 3) > - || pagetable_get_pfn(v->arch.shadow_table[1]) == mfn_x(smfn) > - || pagetable_get_pfn(v->arch.shadow_table[2]) == mfn_x(smfn) > - || pagetable_get_pfn(v->arch.shadow_table[3]) == mfn_x(smfn) > + || mfn_eq(pagetable_get_mfn(v->arch.shadow_table[1]), smfn) > + || mfn_eq(pagetable_get_mfn(v->arch.shadow_table[2]), smfn) > + || mfn_eq(pagetable_get_mfn(v->arch.shadow_table[3]), smfn) > #endif > ) While here moving the || to their designated places would make the code look worse overall, ... > @@ -3707,7 +3707,7 @@ sh_update_linear_entries(struct vcpu *v) > > /* Don't try to update the monitor table if it doesn't exist */ > if ( shadow_mode_external(d) > - && pagetable_get_pfn(v->arch.monitor_table) == 0 ) > + && pagetable_is_null(v->arch.monitor_table) ) ... could I talk you into moving the && here to the end of the previous line, as you're touching this anyway? Also, seeing there's quite a few conversions to pagetable_is_null() and also seeing that this patch is quite big - could this conversion be split out? > @@ -213,17 +214,17 @@ static inline l4_pgentry_t l4e_from_paddr(paddr_t pa, unsigned int flags) > #ifndef __ASSEMBLY__ > > /* Page-table type. */ > -typedef struct { u64 pfn; } pagetable_t; > -#define pagetable_get_paddr(x) ((paddr_t)(x).pfn << PAGE_SHIFT) > +typedef struct { mfn_t mfn; } pagetable_t; > +#define PAGETABLE_NULL_MFN _mfn(0) I'd prefer to get away without this constant. Jan