From patchwork Fri May 29 11:11:47 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hongyan Xia X-Patchwork-Id: 11578325 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 97BAA912 for ; Fri, 29 May 2020 11:13:17 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 7415D207D4 for ; Fri, 29 May 2020 11:13:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=xen.org header.i=@xen.org header.b="o2JKyP3N" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7415D207D4 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=xen.org Authentication-Results: mail.kernel.org; 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 4.92) (envelope-from ) id 1jecvz-0004n6-Vt; Fri, 29 May 2020 11:12:19 +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 4.92) (envelope-from ) id 1jecvy-0004mm-S9 for xen-devel@lists.xenproject.org; Fri, 29 May 2020 11:12:18 +0000 X-Inumbo-ID: 4102c85a-a19d-11ea-a898-12813bfff9fa Received: from mail.xenproject.org (unknown [104.130.215.37]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id 4102c85a-a19d-11ea-a898-12813bfff9fa; Fri, 29 May 2020 11:12:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=xen.org; s=20200302mail; h=References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From: Sender:Reply-To:MIME-Version:Content-Type:Content-Transfer-Encoding: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=U9cLqBwN1ctta6xGvOhwYBfX8v2oSfZhysMp6/YsWG8=; b=o2JKyP3Nt8m+1kDKpHx406WlU8 s2jjRargfDKvJ08wcpCBDmYCqrNBPirBGOokoe8L+ZfOXQx29nHRnwgBNYW364h0CGNpqE3BsTnUx tNGcqR+jBAES2joXbCvzpdBDThkfwtsP2y3+cCnIJ2VfwyPCpT7QLcr+5XNrAUeDONj4=; Received: from xenbits.xenproject.org ([104.239.192.120]) by mail.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1jecvv-00021x-Gh; Fri, 29 May 2020 11:12:15 +0000 Received: from 54-240-197-236.amazon.com ([54.240.197.236] helo=u1bbd043a57dd5a.ant.amazon.com) by xenbits.xenproject.org with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1jecvv-0006tM-2E; Fri, 29 May 2020 11:12:15 +0000 From: Hongyan Xia To: xen-devel@lists.xenproject.org Subject: [PATCH v7 03/15] x86/mm: rewrite virt_to_xen_l*e Date: Fri, 29 May 2020 12:11:47 +0100 Message-Id: X-Mailer: git-send-email 2.17.1 In-Reply-To: References: In-Reply-To: References: X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Stefano Stabellini , julien@xen.org, Wei Liu , Andrew Cooper , Ian Jackson , George Dunlap , Jan Beulich , =?utf-8?q?Roger_Pau_Monn=C3=A9?= Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" From: Wei Liu Rewrite those functions to use the new APIs. Modify its callers to unmap the pointer returned. Since alloc_xen_pagetable_new() is almost never useful unless accompanied by page clearing and a mapping, introduce a helper alloc_map_clear_xen_pt() for this sequence. Note that the change of virt_to_xen_l1e() also requires vmap_to_mfn() to unmap the page, which requires domain_page.h header in vmap. Signed-off-by: Wei Liu Signed-off-by: Hongyan Xia Reviewed-by: Jan Beulich --- Changed in v7: - remove a comment. - use l1e_get_mfn() instead of converting things back and forth. - add alloc_map_clear_xen_pt(). - unmap before the next mapping to reduce mapcache pressure. - use normal unmap calls instead of the macro in error paths because unmap can handle NULL now. --- xen/arch/x86/domain_page.c | 11 +++-- xen/arch/x86/mm.c | 96 +++++++++++++++++++++++++++----------- xen/common/vmap.c | 1 + xen/include/asm-x86/mm.h | 1 + xen/include/asm-x86/page.h | 8 +++- 5 files changed, 86 insertions(+), 31 deletions(-) diff --git a/xen/arch/x86/domain_page.c b/xen/arch/x86/domain_page.c index b03728e18e..dc8627c1b5 100644 --- a/xen/arch/x86/domain_page.c +++ b/xen/arch/x86/domain_page.c @@ -333,21 +333,24 @@ void unmap_domain_page_global(const void *ptr) mfn_t domain_page_map_to_mfn(const void *ptr) { unsigned long va = (unsigned long)ptr; - const l1_pgentry_t *pl1e; + l1_pgentry_t l1e; if ( va >= DIRECTMAP_VIRT_START ) return _mfn(virt_to_mfn(ptr)); if ( va >= VMAP_VIRT_START && va < VMAP_VIRT_END ) { - pl1e = virt_to_xen_l1e(va); + const l1_pgentry_t *pl1e = virt_to_xen_l1e(va); + BUG_ON(!pl1e); + l1e = *pl1e; + unmap_domain_page(pl1e); } else { ASSERT(va >= MAPCACHE_VIRT_START && va < MAPCACHE_VIRT_END); - pl1e = &__linear_l1_table[l1_linear_offset(va)]; + l1e = __linear_l1_table[l1_linear_offset(va)]; } - return l1e_get_mfn(*pl1e); + return l1e_get_mfn(l1e); } diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c index 462682ba70..b67ecf4107 100644 --- a/xen/arch/x86/mm.c +++ b/xen/arch/x86/mm.c @@ -4948,8 +4948,28 @@ void free_xen_pagetable_new(mfn_t mfn) free_xenheap_page(mfn_to_virt(mfn_x(mfn))); } +void *alloc_map_clear_xen_pt(mfn_t *pmfn) +{ + mfn_t mfn = alloc_xen_pagetable_new(); + void *ret; + + if ( mfn_eq(mfn, INVALID_MFN) ) + return NULL; + + if ( pmfn ) + *pmfn = mfn; + ret = map_domain_page(mfn); + clear_page(ret); + + return ret; +} + static DEFINE_SPINLOCK(map_pgdir_lock); +/* + * For virt_to_xen_lXe() functions, they take a virtual address and return a + * pointer to Xen's LX entry. Caller needs to unmap the pointer. + */ static l3_pgentry_t *virt_to_xen_l3e(unsigned long v) { l4_pgentry_t *pl4e; @@ -4958,33 +4978,33 @@ static l3_pgentry_t *virt_to_xen_l3e(unsigned long v) if ( !(l4e_get_flags(*pl4e) & _PAGE_PRESENT) ) { bool locking = system_state > SYS_STATE_boot; - l3_pgentry_t *l3t = alloc_xen_pagetable(); + mfn_t l3mfn; + l3_pgentry_t *l3t = alloc_map_clear_xen_pt(&l3mfn); if ( !l3t ) return NULL; - clear_page(l3t); + UNMAP_DOMAIN_PAGE(l3t); if ( locking ) spin_lock(&map_pgdir_lock); if ( !(l4e_get_flags(*pl4e) & _PAGE_PRESENT) ) { - l4_pgentry_t l4e = l4e_from_paddr(__pa(l3t), __PAGE_HYPERVISOR); + l4_pgentry_t l4e = l4e_from_mfn(l3mfn, __PAGE_HYPERVISOR); l4e_write(pl4e, l4e); efi_update_l4_pgtable(l4_table_offset(v), l4e); - l3t = NULL; + l3mfn = INVALID_MFN; } if ( locking ) spin_unlock(&map_pgdir_lock); - if ( l3t ) - free_xen_pagetable(l3t); + free_xen_pagetable_new(l3mfn); } - return l4e_to_l3e(*pl4e) + l3_table_offset(v); + return map_l3t_from_l4e(*pl4e) + l3_table_offset(v); } static l2_pgentry_t *virt_to_xen_l2e(unsigned long v) { - l3_pgentry_t *pl3e; + l3_pgentry_t *pl3e, l3e; pl3e = virt_to_xen_l3e(v); if ( !pl3e ) @@ -4993,31 +5013,37 @@ static l2_pgentry_t *virt_to_xen_l2e(unsigned long v) if ( !(l3e_get_flags(*pl3e) & _PAGE_PRESENT) ) { bool locking = system_state > SYS_STATE_boot; - l2_pgentry_t *l2t = alloc_xen_pagetable(); + mfn_t l2mfn; + l2_pgentry_t *l2t = alloc_map_clear_xen_pt(&l2mfn); if ( !l2t ) + { + unmap_domain_page(pl3e); return NULL; - clear_page(l2t); + } + UNMAP_DOMAIN_PAGE(l2t); if ( locking ) spin_lock(&map_pgdir_lock); if ( !(l3e_get_flags(*pl3e) & _PAGE_PRESENT) ) { - l3e_write(pl3e, l3e_from_paddr(__pa(l2t), __PAGE_HYPERVISOR)); - l2t = NULL; + l3e_write(pl3e, l3e_from_mfn(l2mfn, __PAGE_HYPERVISOR)); + l2mfn = INVALID_MFN; } if ( locking ) spin_unlock(&map_pgdir_lock); - if ( l2t ) - free_xen_pagetable(l2t); + free_xen_pagetable_new(l2mfn); } BUG_ON(l3e_get_flags(*pl3e) & _PAGE_PSE); - return l3e_to_l2e(*pl3e) + l2_table_offset(v); + l3e = *pl3e; + unmap_domain_page(pl3e); + + return map_l2t_from_l3e(l3e) + l2_table_offset(v); } l1_pgentry_t *virt_to_xen_l1e(unsigned long v) { - l2_pgentry_t *pl2e; + l2_pgentry_t *pl2e, l2e; pl2e = virt_to_xen_l2e(v); if ( !pl2e ) @@ -5026,26 +5052,32 @@ l1_pgentry_t *virt_to_xen_l1e(unsigned long v) if ( !(l2e_get_flags(*pl2e) & _PAGE_PRESENT) ) { bool locking = system_state > SYS_STATE_boot; - l1_pgentry_t *l1t = alloc_xen_pagetable(); + mfn_t l1mfn; + l1_pgentry_t *l1t = alloc_map_clear_xen_pt(&l1mfn); if ( !l1t ) + { + unmap_domain_page(pl2e); return NULL; - clear_page(l1t); + } + UNMAP_DOMAIN_PAGE(l1t); if ( locking ) spin_lock(&map_pgdir_lock); if ( !(l2e_get_flags(*pl2e) & _PAGE_PRESENT) ) { - l2e_write(pl2e, l2e_from_paddr(__pa(l1t), __PAGE_HYPERVISOR)); - l1t = NULL; + l2e_write(pl2e, l2e_from_mfn(l1mfn, __PAGE_HYPERVISOR)); + l1mfn = INVALID_MFN; } if ( locking ) spin_unlock(&map_pgdir_lock); - if ( l1t ) - free_xen_pagetable(l1t); + free_xen_pagetable_new(l1mfn); } BUG_ON(l2e_get_flags(*pl2e) & _PAGE_PSE); - return l2e_to_l1e(*pl2e) + l1_table_offset(v); + l2e = *pl2e; + unmap_domain_page(pl2e); + + return map_l1t_from_l2e(l2e) + l1_table_offset(v); } /* Convert to from superpage-mapping flags for map_pages_to_xen(). */ @@ -5068,8 +5100,8 @@ int map_pages_to_xen( unsigned int flags) { bool locking = system_state > SYS_STATE_boot; - l3_pgentry_t *pl3e, ol3e; - l2_pgentry_t *pl2e, ol2e; + l3_pgentry_t *pl3e = NULL, ol3e; + l2_pgentry_t *pl2e = NULL, ol2e; l1_pgentry_t *pl1e, ol1e; unsigned int i; int rc = -ENOMEM; @@ -5090,6 +5122,10 @@ int map_pages_to_xen( while ( nr_mfns != 0 ) { + /* Clean up mappings mapped in the previous iteration. */ + UNMAP_DOMAIN_PAGE(pl3e); + UNMAP_DOMAIN_PAGE(pl2e); + pl3e = virt_to_xen_l3e(virt); if ( !pl3e ) @@ -5258,6 +5294,8 @@ int map_pages_to_xen( pl1e = virt_to_xen_l1e(virt); if ( pl1e == NULL ) goto out; + + UNMAP_DOMAIN_PAGE(pl1e); } else if ( l2e_get_flags(*pl2e) & _PAGE_PSE ) { @@ -5434,6 +5472,8 @@ int map_pages_to_xen( rc = 0; out: + unmap_domain_page(pl2e); + unmap_domain_page(pl3e); return rc; } @@ -5457,7 +5497,7 @@ int populate_pt_range(unsigned long virt, unsigned long nr_mfns) int modify_xen_mappings(unsigned long s, unsigned long e, unsigned int nf) { bool locking = system_state > SYS_STATE_boot; - l3_pgentry_t *pl3e; + l3_pgentry_t *pl3e = NULL; l2_pgentry_t *pl2e; l1_pgentry_t *pl1e; unsigned int i; @@ -5473,6 +5513,9 @@ int modify_xen_mappings(unsigned long s, unsigned long e, unsigned int nf) while ( v < e ) { + /* Clean up mappings mapped in the previous iteration. */ + UNMAP_DOMAIN_PAGE(pl3e); + pl3e = virt_to_xen_l3e(v); if ( !pl3e || !(l3e_get_flags(*pl3e) & _PAGE_PRESENT) ) @@ -5701,6 +5744,7 @@ int modify_xen_mappings(unsigned long s, unsigned long e, unsigned int nf) rc = 0; out: + unmap_domain_page(pl3e); return rc; } diff --git a/xen/common/vmap.c b/xen/common/vmap.c index faebc1ddf1..9964ab2096 100644 --- a/xen/common/vmap.c +++ b/xen/common/vmap.c @@ -1,6 +1,7 @@ #ifdef VMAP_VIRT_START #include #include +#include #include #include #include diff --git a/xen/include/asm-x86/mm.h b/xen/include/asm-x86/mm.h index 3d3f9d49ac..42d1a78731 100644 --- a/xen/include/asm-x86/mm.h +++ b/xen/include/asm-x86/mm.h @@ -587,6 +587,7 @@ void *alloc_xen_pagetable(void); void free_xen_pagetable(void *v); mfn_t alloc_xen_pagetable_new(void); void free_xen_pagetable_new(mfn_t mfn); +void *alloc_map_clear_xen_pt(mfn_t *pmfn); l1_pgentry_t *virt_to_xen_l1e(unsigned long v); diff --git a/xen/include/asm-x86/page.h b/xen/include/asm-x86/page.h index 5acf3d3d5a..3854feb3ea 100644 --- a/xen/include/asm-x86/page.h +++ b/xen/include/asm-x86/page.h @@ -291,7 +291,13 @@ void copy_page_sse2(void *, const void *); #define pfn_to_paddr(pfn) __pfn_to_paddr(pfn) #define paddr_to_pfn(pa) __paddr_to_pfn(pa) #define paddr_to_pdx(pa) pfn_to_pdx(paddr_to_pfn(pa)) -#define vmap_to_mfn(va) _mfn(l1e_get_pfn(*virt_to_xen_l1e((unsigned long)(va)))) + +#define vmap_to_mfn(va) ({ \ + const l1_pgentry_t *pl1e_ = virt_to_xen_l1e((unsigned long)(va)); \ + mfn_t mfn_ = l1e_get_mfn(*pl1e_); \ + unmap_domain_page(pl1e_); \ + mfn_; }) + #define vmap_to_page(va) mfn_to_page(vmap_to_mfn(va)) #endif /* !defined(__ASSEMBLY__) */