From patchwork Fri May 20 12:09:31 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Julien Grall X-Patchwork-Id: 12856715 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 lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 819E9C433EF for ; Fri, 20 May 2022 12:14:57 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.333990.557961 (Exim 4.92) (envelope-from ) id 1ns1Wo-0003o1-AC; Fri, 20 May 2022 12:14:46 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 333990.557961; Fri, 20 May 2022 12:14:46 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1ns1Wn-0003ji-Sm; Fri, 20 May 2022 12:14:45 +0000 Received: by outflank-mailman (input) for mailman id 333990; Fri, 20 May 2022 12:14:43 +0000 Received: from mail.xenproject.org ([104.130.215.37]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1ns1Wl-0003NV-SG for xen-devel@lists.xenproject.org; Fri, 20 May 2022 12:14:43 +0000 Received: from xenbits.xenproject.org ([104.239.192.120]) by mail.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1ns1Wl-0005wS-IR; Fri, 20 May 2022 12:14:43 +0000 Received: from 54-240-197-232.amazon.com ([54.240.197.232] helo=dev-dsk-jgrall-1b-035652ec.eu-west-1.amazon.com) by xenbits.xenproject.org with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.92) (envelope-from ) id 1ns1Sl-0001lI-Nm; Fri, 20 May 2022 12:10:36 +0000 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=xXyiaAqaXOE8UjksPYWndQvCCsS0jnjjnrlX2Gok8p4=; b=xkgAUx/nd4GGJbbvcAtEElB/+V ZOrrVNlIN7mSVaB1/vbRHaovXTkHyRSNQKsmcT+4u9Y1HcZ3KxKZwkDsnkHe5l4l4MYYzXX7cfL5e 7tC996Az2c/Dw7GUKuajB29F3rPAwQSOEXcB+gJWDbrI4awHqt+jBXC7iESLGFQ50/bM=; From: Julien Grall To: xen-devel@lists.xenproject.org Cc: julien@xen.org, Wei Liu , Stefano Stabellini , Bertrand Marquis , Volodymyr Babchuk , George Dunlap , Hongyan Xia , Julien Grall , Jan Beulich , Wei Liu , Andrew Cooper , =?utf-8?q?Roger_Pau_Monn=C3=A9?= Subject: [PATCH 10/16] xen/arm: add Persistent Map (PMAP) infrastructure Date: Fri, 20 May 2022 13:09:31 +0100 Message-Id: <20220520120937.28925-11-julien@xen.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20220520120937.28925-1-julien@xen.org> References: <20220520120937.28925-1-julien@xen.org> MIME-Version: 1.0 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. The PMAP infrastructure is implemented in common code with some arch helpers to set/clear the page-table entries and convertion between a fixmap slot to a virtual address... As mfn_to_xen_entry() now needs to be exported, take the opportunity to swich 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 Reviewed-by: Luca Fancellu Tested-by: Luca Fancellu Reviewed-by: Stefano Stabellini --- Changes in v4: - Move xen_fixmap in fixmap.h and add a comment about its usage. - Update comments - Use DECLARE_BITMAP() - Replace local_irq_{enable, disable} with an ASSERT() as there should be no user of pmap() in interrupt context. Changes in v3: - s/BITS_PER_LONG/BITS_PER_BYTE/ - Move pmap to common code Changes in v2: - New patch Cc: Jan Beulich Cc: Wei Liu Cc: Andrew Cooper Cc: Roger Pau Monné --- xen/arch/arm/Kconfig | 1 + xen/arch/arm/include/asm/fixmap.h | 24 +++++++++++ xen/arch/arm/include/asm/lpae.h | 8 ++++ xen/arch/arm/include/asm/pmap.h | 32 ++++++++++++++ xen/arch/arm/mm.c | 7 +-- xen/common/Kconfig | 3 ++ xen/common/Makefile | 1 + xen/common/pmap.c | 72 +++++++++++++++++++++++++++++++ xen/include/xen/pmap.h | 16 +++++++ 9 files changed, 158 insertions(+), 6 deletions(-) create mode 100644 xen/arch/arm/include/asm/pmap.h create mode 100644 xen/common/pmap.c create mode 100644 xen/include/xen/pmap.h diff --git a/xen/arch/arm/Kconfig b/xen/arch/arm/Kconfig index ecfa6822e4d3..a89a67802aa9 100644 --- a/xen/arch/arm/Kconfig +++ b/xen/arch/arm/Kconfig @@ -14,6 +14,7 @@ config ARM select HAS_DEVICE_TREE select HAS_PASSTHROUGH select HAS_PDX + select HAS_PMAP select IOMMU_FORCE_PT_SHARE config ARCH_DEFCONFIG diff --git a/xen/arch/arm/include/asm/fixmap.h b/xen/arch/arm/include/asm/fixmap.h index 1cee51e52ab9..365a2385a087 100644 --- a/xen/arch/arm/include/asm/fixmap.h +++ b/xen/arch/arm/include/asm/fixmap.h @@ -5,20 +5,44 @@ #define __ASM_FIXMAP_H #include +#include /* Fixmap slots */ #define FIXMAP_CONSOLE 0 /* The primary UART */ #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) /* Start of PMAP */ +#define FIXMAP_PMAP_END (FIXMAP_PMAP_BEGIN + NUM_FIX_PMAP - 1) /* End of PMAP */ + +#define FIXMAP_LAST FIXMAP_PMAP_END + +#define FIXADDR_START FIXMAP_ADDR(0) +#define FIXADDR_TOP FIXMAP_ADDR(FIXMAP_LAST) #ifndef __ASSEMBLY__ +/* + * Direct access to xen_fixmap[] should only happen when {set, + * clear}_fixmap() is unusable (e.g. where we would end up to + * recursively call the helpers). + */ +extern lpae_t xen_fixmap[XEN_PT_LPAE_ENTRIES]; + /* Map a page in a fixmap entry */ extern void set_fixmap(unsigned map, mfn_t mfn, unsigned attributes); /* Remove a mapping from a fixmap entry */ extern void clear_fixmap(unsigned map); +#define fix_to_virt(slot) ((void *)FIXMAP_ADDR(slot)) + +static inline unsigned int virt_to_fix(vaddr_t vaddr) +{ + BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START); + + return ((vaddr - FIXADDR_START) >> PAGE_SHIFT); +} + #endif /* __ASSEMBLY__ */ #endif /* __ASM_FIXMAP_H */ diff --git a/xen/arch/arm/include/asm/lpae.h b/xen/arch/arm/include/asm/lpae.h index aecb320dec45..fc19cbd84772 100644 --- a/xen/arch/arm/include/asm/lpae.h +++ b/xen/arch/arm/include/asm/lpae.h @@ -4,6 +4,7 @@ #ifndef __ASSEMBLY__ #include +#include /* * WARNING! Unlike the x86 pagetable code, where l1 is the lowest level and @@ -168,6 +169,13 @@ static inline bool lpae_is_superpage(lpae_t pte, unsigned int level) third_table_offset(addr) \ } +/* + * 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__ */ /* diff --git a/xen/arch/arm/include/asm/pmap.h b/xen/arch/arm/include/asm/pmap.h new file mode 100644 index 000000000000..74398b4c4fe6 --- /dev/null +++ b/xen/arch/arm/include/asm/pmap.h @@ -0,0 +1,32 @@ +#ifndef __ASM_PMAP_H__ +#define __ASM_PMAP_H__ + +#include + +#include + +static inline void arch_pmap_map(unsigned int slot, mfn_t mfn) +{ + lpae_t *entry = &xen_fixmap[slot]; + lpae_t pte; + + ASSERT(!lpae_is_valid(*entry)); + + pte = mfn_to_xen_entry(mfn, PAGE_HYPERVISOR_RW); + pte.pt.table = 1; + write_pte(entry, pte); +} + +static inline void arch_pmap_unmap(unsigned int slot) +{ + lpae_t pte = {}; + + write_pte(&xen_fixmap[slot], pte); + + flush_xen_tlb_range_va_local(FIXMAP_ADDR(slot), PAGE_SIZE); +} + +void arch_pmap_map_slot(unsigned int slot, mfn_t mfn); +void arch_pmap_clear_slot(void *ptr); + +#endif /* __ASM_PMAP_H__ */ diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c index 52b2a0394047..bd1348a99716 100644 --- a/xen/arch/arm/mm.c +++ b/xen/arch/arm/mm.c @@ -305,12 +305,7 @@ void dump_hyp_walk(vaddr_t addr) dump_pt_walk(ttbr, addr, HYP_PT_ROOT_LEVEL, 1); } -/* - * 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 = (lpae_t) { .pt = { diff --git a/xen/common/Kconfig b/xen/common/Kconfig index d921c74d615e..5b6b2406c028 100644 --- a/xen/common/Kconfig +++ b/xen/common/Kconfig @@ -49,6 +49,9 @@ config HAS_KEXEC config HAS_PDX bool +config HAS_PMAP + bool + config HAS_SCHED_GRANULARITY bool diff --git a/xen/common/Makefile b/xen/common/Makefile index b1e076c30b81..3baf83d527d8 100644 --- a/xen/common/Makefile +++ b/xen/common/Makefile @@ -29,6 +29,7 @@ obj-y += notifier.o obj-y += page_alloc.o obj-$(CONFIG_HAS_PDX) += pdx.o obj-$(CONFIG_PERF_COUNTERS) += perfc.o +obj-bin-$(CONFIG_HAS_PMAP) += pmap.init.o obj-y += preempt.o obj-y += random.o obj-y += rangeset.o diff --git a/xen/common/pmap.c b/xen/common/pmap.c new file mode 100644 index 000000000000..9355cacb7373 --- /dev/null +++ b/xen/common/pmap.c @@ -0,0 +1,72 @@ +#include +#include +#include +#include + +#include +#include + +/* + * Simple mapping infrastructure to map / unmap pages in fixed map. + * This is used to set the page table before the map domain page infrastructure + * is initialized. + * + * This structure is not protected by any locks, so it must not be used after + * smp bring-up. + */ + +/* Bitmap to track which slot is used */ +static __initdata DECLARE_BITMAP(inuse, NUM_FIX_PMAP); + +void *__init pmap_map(mfn_t mfn) +{ + unsigned int idx; + unsigned int slot; + + ASSERT(system_state < SYS_STATE_smp_boot); + ASSERT(!in_irq()); + + idx = find_first_zero_bit(inuse, NUM_FIX_PMAP); + if ( idx == NUM_FIX_PMAP ) + panic("Out of PMAP slots\n"); + + __set_bit(idx, inuse); + + slot = idx + FIXMAP_PMAP_BEGIN; + ASSERT(slot >= FIXMAP_PMAP_BEGIN && slot <= FIXMAP_PMAP_END); + + /* + * We cannot use set_fixmap() here. We use PMAP when the domain map + * page infrastructure is not yet initialized, 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(). + */ + arch_pmap_map(slot, mfn); + + return fix_to_virt(slot); +} + +void __init pmap_unmap(const void *p) +{ + unsigned int idx; + unsigned int slot = virt_to_fix((unsigned long)p); + + ASSERT(system_state < SYS_STATE_smp_boot); + ASSERT(slot >= FIXMAP_PMAP_BEGIN && slot <= FIXMAP_PMAP_END); + ASSERT(in_irq()); + + idx = slot - FIXMAP_PMAP_BEGIN; + + __clear_bit(idx, inuse); + arch_pmap_unmap(slot); +} + +/* + * Local variables: + * mode: C + * c-file-style: "BSD" + * c-basic-offset: 4 + * indent-tabs-mode: nil + * End: + */ diff --git a/xen/include/xen/pmap.h b/xen/include/xen/pmap.h new file mode 100644 index 000000000000..93e61b10870e --- /dev/null +++ b/xen/include/xen/pmap.h @@ -0,0 +1,16 @@ +#ifndef __XEN_PMAP_H__ +#define __XEN_PMAP_H__ + +/* Large enough for mapping 5 levels of page tables with some headroom */ +#define NUM_FIX_PMAP 8 + +#ifndef __ASSEMBLY__ + +#include + +void *pmap_map(mfn_t mfn); +void pmap_unmap(const void *p); + +#endif /* __ASSEMBLY__ */ + +#endif /* __XEN_PMAP_H__ */