From nobody Tue Feb 10 07:22:30 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org ARC-Seal: i=1; a=rsa-sha256; t=1619382754; cv=none; d=zohomail.com; s=zohoarc; b=Es7sdjgJyA5+ciIV2h+ukmFgJMXaBm4Mr+FvmkFeRXY/riXqELLefAulShr4l0e/TwIfNV9e4UvcX30EePCYkb6QhUCimedWZZwjv3ZoH9DRkHUoWDs28DAUPbcgQzI+/Ivb3ZuGQjRnLX4g5J1z5dpZBOYk76k8f34wYG/iOv8= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1619382754; h=Content-Type:Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To; bh=d6/VERpOpmisc9IqH4nSo3nCT42W307X8jAJ7pAR9wY=; b=KURyKEcB5laDPVo5LMY7GzkDRcdNBsZDEzd+ljb/zlyOKFuXyZ5XsqAlAcuqka0h8I75B0rSxcW6nxj2T+HymP/lSVqojQyNhobVRsKoTZM5gzmo/lr07dsPtqYI3vYXUEDGBXwMkw2mYI/qgPE1Y+wbptEsbuHOBs3R1MCrmqw= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Return-Path: Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) by mx.zohomail.com with SMTPS id 1619382754287245.78250236702524; Sun, 25 Apr 2021 13:32:34 -0700 (PDT) Received: from list by lists.xenproject.org with outflank-mailman.117362.223272 (Exim 4.92) (envelope-from ) id 1lalQP-0004VN-K7; Sun, 25 Apr 2021 20:32:17 +0000 Received: by outflank-mailman (output) from mailman id 117362.223272; Sun, 25 Apr 2021 20:32:17 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lalQP-0004Us-5d; Sun, 25 Apr 2021 20:32:17 +0000 Received: by outflank-mailman (input) for mailman id 117362; Sun, 25 Apr 2021 20:32:13 +0000 Received: from mail.xenproject.org ([104.130.215.37]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lalQL-0004RP-Tj for xen-devel@lists.xenproject.org; Sun, 25 Apr 2021 20:32:13 +0000 Received: from xenbits.xenproject.org ([104.239.192.120]) by mail.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lalQL-00019x-B1; Sun, 25 Apr 2021 20:32:13 +0000 Received: from 54-240-197-235.amazon.com ([54.240.197.235] helo=ufe34d9ed68d054.ant.amazon.com) by xenbits.xenproject.org with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1lal8P-0005m7-E0; Sun, 25 Apr 2021 20:13:41 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=xen.org; s=20200302mail; h=Content-Transfer-Encoding:Content-Type:MIME-Version: References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From; bh=d6/VERpOpmisc9IqH4nSo3nCT42W307X8jAJ7pAR9wY=; b=QsI0i3rJK15J/0NratxUSYmB11 vqx01X+WXK6ipXuw4wnzdoVpmp4I6SyXrpjlZ3uWaXiFaxzBYJ7MROjAr/udNlVZ+j6HoMLC89me/ U2gp72yg8I8k7DB5XhtWB8QDPNffTJgN7DfyV3HYm8MATdClvH0+Ka/Pd4dTJNRR7cBU=; From: Julien Grall To: xen-devel@lists.xenproject.org Cc: Wei.Chen@arm.com, Henry.Wang@arm.com, Penny.Zheng@arm.com, Bertrand.Marquis@arm.com, Wei Liu , Stefano Stabellini , Julien Grall , Volodymyr Babchuk , Hongyan Xia , Julien Grall , Jan Beulich , Wei Liu , Andrew Cooper , =?UTF-8?q?Roger=20Pau=20Monn=C3=A9?= , Hongian Xia Subject: [PATCH RFCv2 12/15] xen/arm: add Persistent Map (PMAP) infrastructure Date: Sun, 25 Apr 2021 21:13:15 +0100 Message-Id: <20210425201318.15447-13-julien@xen.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210425201318.15447-1-julien@xen.org> References: <20210425201318.15447-1-julien@xen.org> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable X-ZohoMail-DKIM: pass (identity @xen.org) From: Wei Liu The basic idea is like Persistent Kernel Map (PKMAP) in Linux. We pre-populate all the relevant page tables before the system is fully set up. We will need it on Arm in order to rework the arm64 version of xenheap_setup_mappings() as we may need to use pages allocated from the boot allocator before they are effectively mapped. This infrastructure is not lock-protected therefore can only be used before smpboot. After smpboot, map_domain_page() has to be used. This is based on the x86 version [1] that was originally implemented by Wei Liu. Take the opportunity to switch the parameter attr from unsigned to unsigned int. [1] Signed-off-by: Wei Liu Signed-off-by: Hongyan Xia [julien: Adapted for Arm] Signed-off-by: Julien Grall --- Changes in v2: - New patch Cc: Jan Beulich Cc: Wei Liu Cc: Andrew Cooper Cc: Roger Pau Monn=C3=A9 Cc: Hongian Xia This is mostly a copy of the PMAP infrastructure currently discussed on x86. The only difference is how the page-tables are updated. I think we want to consider to provide a common infrastructure. But I haven't done it yet to gather feedback on the overall series first. --- xen/arch/arm/Makefile | 1 + xen/arch/arm/mm.c | 7 +-- xen/arch/arm/pmap.c | 101 +++++++++++++++++++++++++++++++++++ xen/include/asm-arm/config.h | 2 + xen/include/asm-arm/lpae.h | 8 +++ xen/include/asm-arm/pmap.h | 10 ++++ 6 files changed, 123 insertions(+), 6 deletions(-) create mode 100644 xen/arch/arm/pmap.c create mode 100644 xen/include/asm-arm/pmap.h diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile index ca75f1040dcc..2196ada24941 100644 --- a/xen/arch/arm/Makefile +++ b/xen/arch/arm/Makefile @@ -40,6 +40,7 @@ obj-y +=3D percpu.o obj-y +=3D platform.o obj-y +=3D platform_hypercall.o obj-y +=3D physdev.o +obj-y +=3D pmap.init.o obj-y +=3D processor.o obj-y +=3D psci.o obj-y +=3D setup.o diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c index d090fdfd5994..5e713b599611 100644 --- a/xen/arch/arm/mm.c +++ b/xen/arch/arm/mm.c @@ -288,12 +288,7 @@ void dump_hyp_walk(vaddr_t addr) dump_pt_walk(ttbr, addr, HYP_PT_ROOT_LEVEL, 1); } =20 -/* - * Standard entry type that we'll use to build Xen's own pagetables. - * We put the same permissions at every level, because they're ignored - * by the walker in non-leaf entries. - */ -static inline lpae_t mfn_to_xen_entry(mfn_t mfn, unsigned attr) +lpae_t mfn_to_xen_entry(mfn_t mfn, unsigned int attr) { lpae_t e =3D (lpae_t) { .pt =3D { diff --git a/xen/arch/arm/pmap.c b/xen/arch/arm/pmap.c new file mode 100644 index 000000000000..702b1bde982d --- /dev/null +++ b/xen/arch/arm/pmap.c @@ -0,0 +1,101 @@ +#include +#include + +#include +#include +#include + +/* + * To be able to use FIXMAP_PMAP_BEGIN. + * XXX: move fixmap definition in a separate header + */ +#include + +/* + * Simple mapping infrastructure to map / unmap pages in fixed map. + * This is used to set up the page table for mapcache, which is used + * by map domain page infrastructure. + * + * This structure is not protected by any locks, so it must not be used af= ter + * smp bring-up. + */ + +/* Bitmap to track which slot is used */ +static unsigned long __initdata inuse; + +/* XXX: Find an header to declare it */ +extern lpae_t xen_fixmap[LPAE_ENTRIES]; + +void *__init pmap_map(mfn_t mfn) +{ + unsigned long flags; + unsigned int idx; + vaddr_t linear; + unsigned int slot; + lpae_t *entry, pte; + + BUILD_BUG_ON(sizeof(inuse) * BITS_PER_LONG < NUM_FIX_PMAP); + + ASSERT(system_state < SYS_STATE_smp_boot); + + local_irq_save(flags); + + idx =3D find_first_zero_bit(&inuse, NUM_FIX_PMAP); + if ( idx =3D=3D NUM_FIX_PMAP ) + panic("Out of PMAP slots\n"); + + __set_bit(idx, &inuse); + + slot =3D idx + FIXMAP_PMAP_BEGIN; + ASSERT(slot >=3D FIXMAP_PMAP_BEGIN && slot <=3D FIXMAP_PMAP_END); + + linear =3D FIXMAP_ADDR(slot); + /* + * We cannot use set_fixmap() here. We use PMAP when there is no direc= t map, + * so map_pages_to_xen() called by set_fixmap() needs to map pages on + * demand, which then calls pmap() again, resulting in a loop. Modify = the + * PTEs directly instead. The same is true for pmap_unmap(). + */ + entry =3D &xen_fixmap[third_table_offset(linear)]; + + ASSERT(!lpae_is_valid(*entry)); + + pte =3D mfn_to_xen_entry(mfn, PAGE_HYPERVISOR_RW); + pte.pt.table =3D 1; + write_pte(entry, pte); + + local_irq_restore(flags); + + return (void *)linear; +} + +void __init pmap_unmap(const void *p) +{ + unsigned long flags; + unsigned int idx; + lpae_t *entry; + lpae_t pte =3D { 0 }; + unsigned int slot =3D third_table_offset((vaddr_t)p); + + ASSERT(system_state < SYS_STATE_smp_boot); + ASSERT(slot >=3D FIXMAP_PMAP_BEGIN && slot <=3D FIXMAP_PMAP_END); + + idx =3D slot - FIXMAP_PMAP_BEGIN; + local_irq_save(flags); + + __clear_bit(idx, &inuse); + entry =3D &xen_fixmap[third_table_offset((vaddr_t)p)]; + write_pte(entry, pte); + flush_xen_tlb_range_va_local((vaddr_t)p, PAGE_SIZE); + + local_irq_restore(flags); +} + +/* + * Local variables: + * mode: C + * c-file-style: "BSD" + * c-basic-offset: 4 + * indent-tabs-mode: nil + * End: + */ diff --git a/xen/include/asm-arm/config.h b/xen/include/asm-arm/config.h index 85d4a510ce8a..35050855b6e1 100644 --- a/xen/include/asm-arm/config.h +++ b/xen/include/asm-arm/config.h @@ -180,6 +180,8 @@ #define FIXMAP_MISC 1 /* Ephemeral mappings of hardware */ #define FIXMAP_ACPI_BEGIN 2 /* Start mappings of ACPI tables */ #define FIXMAP_ACPI_END (FIXMAP_ACPI_BEGIN + NUM_FIXMAP_ACPI_PAGES - 1)= /* End mappings of ACPI tables */ +#define FIXMAP_PMAP_BEGIN (FIXMAP_ACPI_END + 1) +#define FIXMAP_PMAP_END (FIXMAP_PMAP_BEGIN + NUM_FIX_PMAP - 1) =20 #define NR_hypercalls 64 =20 diff --git a/xen/include/asm-arm/lpae.h b/xen/include/asm-arm/lpae.h index 310f5225e056..81fd482ab2ce 100644 --- a/xen/include/asm-arm/lpae.h +++ b/xen/include/asm-arm/lpae.h @@ -4,6 +4,7 @@ #ifndef __ASSEMBLY__ =20 #include +#include =20 /* * WARNING! Unlike the x86 pagetable code, where l1 is the lowest level a= nd @@ -168,6 +169,13 @@ static inline bool lpae_is_superpage(lpae_t pte, unsig= ned int level) third_table_offset(addr) \ } =20 +/* + * Standard entry type that we'll use to build Xen's own pagetables. + * We put the same permissions at every level, because they're ignored + * by the walker in non-leaf entries. + */ +lpae_t mfn_to_xen_entry(mfn_t mfn, unsigned int attr); + #endif /* __ASSEMBLY__ */ =20 /* diff --git a/xen/include/asm-arm/pmap.h b/xen/include/asm-arm/pmap.h new file mode 100644 index 000000000000..8e1dce93f8e4 --- /dev/null +++ b/xen/include/asm-arm/pmap.h @@ -0,0 +1,10 @@ +#ifndef __ASM_PMAP_H__ +#define __ARM_PMAP_H__ + +/* Large enough for mapping 5 levels of page tables with some headroom */ +#define NUM_FIX_PMAP 8 + +void *pmap_map(mfn_t mfn); +void pmap_unmap(const void *p); + +#endif /* __ASM_PMAP_H__ */ --=20 2.17.1