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[50.57.142.19]) by mx.google.com with ESMTPS id u2si12821089qak.58.2014.10.16.07.50.46 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Thu, 16 Oct 2014 07:50:47 -0700 (PDT) Received-SPF: none (google.com: xen-devel-bounces@lists.xen.org does not designate permitted sender hosts) client-ip=50.57.142.19; Received: from localhost ([127.0.0.1] helo=lists.xen.org) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1XemLy-0002T7-Kp; Thu, 16 Oct 2014 14:48:34 +0000 Received: from mail6.bemta14.messagelabs.com ([193.109.254.103]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1XemLx-0002Si-9L for xen-devel@lists.xensource.com; Thu, 16 Oct 2014 14:48:33 +0000 Received: from [193.109.254.147:12720] by server-13.bemta-14.messagelabs.com id 91/AE-19311-0CADF345; Thu, 16 Oct 2014 14:48:32 +0000 X-Env-Sender: Stefano.Stabellini@citrix.com X-Msg-Ref: server-7.tower-27.messagelabs.com!1413470906!13195141!3 X-Originating-IP: [66.165.176.89] X-SpamReason: No, hits=0.0 required=7.0 tests=sa_preprocessor: VHJ1c3RlZCBJUDogNjYuMTY1LjE3Ni44OSA9PiAyMDMwMDc=\n X-StarScan-Received: X-StarScan-Version: 6.12.3; banners=-,-,- X-VirusChecked: Checked Received: (qmail 3693 invoked from network); 16 Oct 2014 14:48:31 -0000 Received: from smtp.citrix.com (HELO SMTP.CITRIX.COM) (66.165.176.89) by server-7.tower-27.messagelabs.com with RC4-SHA encrypted SMTP; 16 Oct 2014 14:48:31 -0000 X-IronPort-AV: E=Sophos;i="5.04,732,1406592000"; d="scan'208";a="181975780" Received: from ukmail1.uk.xensource.com (10.80.16.128) by smtprelay.citrix.com (10.13.107.78) with Microsoft SMTP Server id 14.3.181.6; Thu, 16 Oct 2014 10:48:22 -0400 Received: from kaball.uk.xensource.com ([10.80.2.59]) by ukmail1.uk.xensource.com with esmtp (Exim 4.69) (envelope-from ) id 1XemLh-00040J-5Y; Thu, 16 Oct 2014 15:48:17 +0100 From: Stefano Stabellini To: Date: Thu, 16 Oct 2014 15:45:53 +0100 Message-ID: <1413470755-30991-6-git-send-email-stefano.stabellini@eu.citrix.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: References: MIME-Version: 1.0 X-DLP: MIA2 Cc: julien.grall@citrix.com, Ian.Campbell@citrix.com, Stefano Stabellini Subject: [Xen-devel] [PATCH v6 6/8] xen/arm: introduce GNTTABOP_cache_flush X-BeenThere: xen-devel@lists.xen.org X-Mailman-Version: 2.1.13 Precedence: list List-Id: List-Unsubscribe: , List-Post: , List-Help: , List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org X-Removed-Original-Auth: Dkim didn't pass. X-Original-Sender: stefano.stabellini@eu.citrix.com X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of patch+caf_=patchwork-forward=linaro.org@linaro.org designates 209.85.215.46 as permitted sender) smtp.mail=patch+caf_=patchwork-forward=linaro.org@linaro.org Mailing-list: list patchwork-forward@linaro.org; contact patchwork-forward+owners@linaro.org X-Google-Group-Id: 836684582541 List-Archive: Introduce a new hypercall to perform cache maintenance operation on behalf of the guest. The argument is a machine address and a size. The implementation checks that the memory range is owned by the guest or the guest has been granted access to it by another domain. Introduce grant_map_exists: an internal grant table function to check whether an mfn has been granted to a given domain on a target grant table. As grant_map_exists loops over all the guest grant table entries, limit DEFAULT_MAX_NR_GRANT_FRAMES to 10 to cap the loop to 5000 iterations max. Warn if the user sets max_grant_frames higher than 10. Signed-off-by: Stefano Stabellini --- Changes in v6: - set DEFAULT_MAX_NR_GRANT_FRAMES to 10; - warn if max_grant_frames > 10. Changes in v5: - make mfn mfn unsigned long; - remove unhelpful error message; - handle errors returned by cache maintenance functions. Changes in v4: - ASSERT(spin_is_locked); - return instead of break in grant_map_exists; - pass a pointer to __gnttab_cache_flush; - code style; - unsigned int iterator in gnttab_cache_flush; - return ret instead -ret; - cflush.offset >= PAGE_SIZE return -EINVAL. Changes in v3: - reduce the time the grant_table lock is held; - fix warning message; - s/EFAULT/EPERM; - s/llx/PRIx64; - check offset and size independetly before checking their sum; - rcu_lock_current_domain cannot fail; - s/ENOSYS/EOPNOTSUPP; - use clean_and_invalidate_xen_dcache_va_range to do both operations at once; - fold grant_map_exists in this patch; - support "count" argument; - make correspondent changes to compat/grant_table.c; - introduce GNTTAB_CACHE_SOURCE_GREF to select the type of input in the union; - rename size field to length; - make length and offset uint16_t; - only take spin_lock if d != owner. Changes in v2: - do not check for mfn_to_page errors; - take a reference to the page; - replace printk with gdprintk; - split long line; - remove out label; - move rcu_lock_current_domain down before the loop. - move the hypercall to GNTTABOP; - take a spin_lock before calling grant_map_exists. --- xen/common/compat/grant_table.c | 8 +++ xen/common/grant_table.c | 137 ++++++++++++++++++++++++++++++++++++++ xen/include/public/grant_table.h | 20 ++++++ xen/include/xen/grant_table.h | 2 +- xen/include/xlat.lst | 1 + 5 files changed, 167 insertions(+), 1 deletion(-) diff --git a/xen/common/compat/grant_table.c b/xen/common/compat/grant_table.c index 2dc1e44..5130c35 100644 --- a/xen/common/compat/grant_table.c +++ b/xen/common/compat/grant_table.c @@ -51,6 +51,10 @@ CHECK_gnttab_get_version; CHECK_gnttab_swap_grant_ref; #undef xen_gnttab_swap_grant_ref +#define xen_gnttab_cache_flush gnttab_cache_flush +CHECK_gnttab_cache_flush; +#undef xen_gnttab_cache_flush + int compat_grant_table_op(unsigned int cmd, XEN_GUEST_HANDLE_PARAM(void) cmp_uop, unsigned int count) @@ -106,6 +110,10 @@ int compat_grant_table_op(unsigned int cmd, CASE(swap_grant_ref); #endif +#ifndef CHECK_gnttab_cache_flush + CASE(cache_flush); +#endif + #undef CASE default: return do_grant_table_op(cmd, cmp_uop, count); diff --git a/xen/common/grant_table.c b/xen/common/grant_table.c index 345be82..2124444 100644 --- a/xen/common/grant_table.c +++ b/xen/common/grant_table.c @@ -489,6 +489,34 @@ static int _set_status(unsigned gt_version, return _set_status_v2(domid, readonly, mapflag, shah, act, status); } +static bool_t grant_map_exists(const struct domain *ld, + struct grant_table *rgt, + unsigned long mfn) +{ + const struct active_grant_entry *act; + grant_ref_t ref; + + ASSERT(spin_is_locked(&rgt->lock)); + + for ( ref = 0; ref != nr_grant_entries(rgt); ref++ ) + { + act = &active_entry(rgt, ref); + + if ( !act->pin ) + continue; + + if ( act->domid != ld->domain_id ) + continue; + + if ( act->frame != mfn ) + continue; + + return 1; + } + + return 0; +} + static void mapcount( struct grant_table *lgt, struct domain *rd, unsigned long mfn, unsigned int *wrc, unsigned int *rdc) @@ -2487,6 +2515,97 @@ gnttab_swap_grant_ref(XEN_GUEST_HANDLE_PARAM(gnttab_swap_grant_ref_t) uop, return 0; } +static int __gnttab_cache_flush(gnttab_cache_flush_t *cflush) +{ + struct domain *d, *owner; + struct page_info *page; + unsigned long mfn; + void *v; + int ret = 0; + + if ( (cflush->offset >= PAGE_SIZE) || + (cflush->length > PAGE_SIZE) || + (cflush->offset + cflush->length > PAGE_SIZE) ) + return -EINVAL; + + if ( cflush->length == 0 || cflush->op == 0 ) + return 0; + + /* currently unimplemented */ + if ( cflush->op & GNTTAB_CACHE_SOURCE_GREF ) + return -EOPNOTSUPP; + + d = rcu_lock_current_domain(); + mfn = cflush->a.dev_bus_addr >> PAGE_SHIFT; + + if ( !mfn_valid(mfn) ) + { + rcu_unlock_domain(d); + return -EINVAL; + } + + page = mfn_to_page(mfn); + owner = page_get_owner_and_reference(page); + if ( !owner ) + { + rcu_unlock_domain(d); + return -EPERM; + } + + if ( d != owner ) + { + spin_lock(&owner->grant_table->lock); + + if ( !grant_map_exists(d, owner->grant_table, mfn) ) + { + spin_unlock(&owner->grant_table->lock); + rcu_unlock_domain(d); + put_page(page); + return -EINVAL; + } + } + + v = map_domain_page(mfn); + v += cflush->offset; + + if ( (cflush->op & GNTTAB_CACHE_INVAL) && (cflush->op & GNTTAB_CACHE_CLEAN) ) + ret = clean_and_invalidate_dcache_va_range(v, cflush->length); + else if ( cflush->op & GNTTAB_CACHE_INVAL ) + ret = invalidate_dcache_va_range(v, cflush->length); + else if ( cflush->op & GNTTAB_CACHE_CLEAN ) + ret = clean_dcache_va_range(v, cflush->length); + + if ( d != owner ) + spin_unlock(&owner->grant_table->lock); + unmap_domain_page(v); + put_page(page); + + return ret; +} + +static long +gnttab_cache_flush(XEN_GUEST_HANDLE_PARAM(gnttab_cache_flush_t) uop, + unsigned int count) +{ + int ret; + unsigned int i; + gnttab_cache_flush_t op; + + for ( i = 0; i < count; i++ ) + { + if ( i && hypercall_preempt_check() ) + return i; + if ( unlikely(__copy_from_guest(&op, uop, 1)) ) + return -EFAULT; + ret = __gnttab_cache_flush(&op); + if ( ret < 0 ) + return ret; + guest_handle_add_offset(uop, 1); + } + return 0; +} + + long do_grant_table_op( unsigned int cmd, XEN_GUEST_HANDLE_PARAM(void) uop, unsigned int count) @@ -2616,6 +2735,20 @@ do_grant_table_op( } break; } + case GNTTABOP_cache_flush: + { + XEN_GUEST_HANDLE_PARAM(gnttab_cache_flush_t) cflush = + guest_handle_cast(uop, gnttab_cache_flush_t); + if ( unlikely(!guest_handle_okay(cflush, count)) ) + goto out; + rc = gnttab_cache_flush(cflush, count); + if ( rc > 0 ) + { + guest_handle_add_offset(cflush, rc); + uop = guest_handle_cast(cflush, void); + } + break; + } default: rc = -ENOSYS; break; @@ -2953,6 +3086,10 @@ static int __init gnttab_usage_init(void) if ( !max_maptrack_frames ) max_maptrack_frames = MAX_MAPTRACK_TO_GRANTS_RATIO * max_grant_frames; + if ( max_grant_frames > DEFAULT_MAX_NR_GRANT_FRAMES ) + printk(XENLOG_WARNING "An high gnttab_max_frames can seriously slow down the hypervisor.\n" + "It is recommended to set gnttab_max_frames to %d max.\n", DEFAULT_MAX_NR_GRANT_FRAMES); + register_keyhandler('g', &gnttab_usage_print_all_keyhandler); return 0; } diff --git a/xen/include/public/grant_table.h b/xen/include/public/grant_table.h index b8a3d6c..20d4e77 100644 --- a/xen/include/public/grant_table.h +++ b/xen/include/public/grant_table.h @@ -309,6 +309,7 @@ typedef uint16_t grant_status_t; #define GNTTABOP_get_status_frames 9 #define GNTTABOP_get_version 10 #define GNTTABOP_swap_grant_ref 11 +#define GNTTABOP_cache_flush 12 #endif /* __XEN_INTERFACE_VERSION__ */ /* ` } */ @@ -574,6 +575,25 @@ struct gnttab_swap_grant_ref { typedef struct gnttab_swap_grant_ref gnttab_swap_grant_ref_t; DEFINE_XEN_GUEST_HANDLE(gnttab_swap_grant_ref_t); +/* + * Issue one or more cache maintenance operations on a portion of a + * page granted to the calling domain by a foreign domain. + */ +struct gnttab_cache_flush { + union { + uint64_t dev_bus_addr; + grant_ref_t ref; + } a; + uint16_t offset; /* offset from start of grant */ + uint16_t length; /* size within the grant */ +#define GNTTAB_CACHE_CLEAN (1<<0) +#define GNTTAB_CACHE_INVAL (1<<1) +#define GNTTAB_CACHE_SOURCE_GREF (1<<31) + uint32_t op; +}; +typedef struct gnttab_cache_flush gnttab_cache_flush_t; +DEFINE_XEN_GUEST_HANDLE(gnttab_cache_flush_t); + #endif /* __XEN_INTERFACE_VERSION__ */ /* diff --git a/xen/include/xen/grant_table.h b/xen/include/xen/grant_table.h index 9f3a1f3..77328cd 100644 --- a/xen/include/xen/grant_table.h +++ b/xen/include/xen/grant_table.h @@ -47,7 +47,7 @@ #ifndef DEFAULT_MAX_NR_GRANT_FRAMES /* to allow arch to override */ /* Default maximum size of a grant table. [POLICY] */ -#define DEFAULT_MAX_NR_GRANT_FRAMES 32 +#define DEFAULT_MAX_NR_GRANT_FRAMES 10 #endif #ifndef max_nr_grant_frames /* to allow arch to override */ /* The maximum size of a grant table. */ diff --git a/xen/include/xlat.lst b/xen/include/xlat.lst index 234b668..9ce9fee 100644 --- a/xen/include/xlat.lst +++ b/xen/include/xlat.lst @@ -51,6 +51,7 @@ ? grant_entry_header grant_table.h ? grant_entry_v2 grant_table.h ? gnttab_swap_grant_ref grant_table.h +? gnttab_cache_flush grant_table.h ? kexec_exec kexec.h ! kexec_image kexec.h ! kexec_range kexec.h