From nobody Mon Feb 9 16:45:42 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zoho.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1488286234253977.1045431637925; Tue, 28 Feb 2017 04:50:34 -0800 (PST) Received: from localhost ([::1]:60749 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cihEe-00080d-R2 for importer@patchew.org; Tue, 28 Feb 2017 07:50:32 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40119) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cih5v-0008JF-UI for qemu-devel@nongnu.org; Tue, 28 Feb 2017 07:41:33 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cih5u-0000Ki-HZ for qemu-devel@nongnu.org; Tue, 28 Feb 2017 07:41:31 -0500 Received: from mx1.redhat.com ([209.132.183.28]:59420) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cih5u-0000Kd-9O for qemu-devel@nongnu.org; Tue, 28 Feb 2017 07:41:30 -0500 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 52E50C04B943; Tue, 28 Feb 2017 12:41:30 +0000 (UTC) Received: from dgilbert-t530.redhat.com (ovpn-117-149.ams2.redhat.com [10.36.117.149]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id v1SCewtF019858; Tue, 28 Feb 2017 07:41:28 -0500 From: "Dr. David Alan Gilbert (git)" To: qemu-devel@nongnu.org Date: Tue, 28 Feb 2017 12:40:44 +0000 Message-Id: <20170228124056.5074-16-dgilbert@redhat.com> In-Reply-To: <20170228124056.5074-1-dgilbert@redhat.com> References: <20170228124056.5074-1-dgilbert@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Tue, 28 Feb 2017 12:41:30 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL 15/27] exec: ram_block_discard_range X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: lvivier@redhat.com, pasic@linux.vnet.ibm.com, vsementsov@virtuozzo.com, quintela@redhat.com, ashijeetacharya@gmail.com, marcandre.lureau@redhat.com, danielhb@linux.vnet.ibm.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" From: "Dr. David Alan Gilbert" Create ram_block_discard_range in exec.c to replace postcopy_ram_discard_range and most of ram_discard_range. Those two routines are a bit of a weird combination, and ram_discard_range is about to get more complex for hugepages. It's OS dependent code (so shouldn't be in migration/ram.c) but it needs quite a bit of the innards of RAMBlock so doesn't belong in the os*.c. Signed-off-by: Dr. David Alan Gilbert Reviewed-by: Juan Quintela Reviewed-by: Laurent Vivier Message-Id: <20170224182844.32452-5-dgilbert@redhat.com> Signed-off-by: Dr. David Alan Gilbert --- exec.c | 54 ++++++++++++++++++++++++++++++++++++= ++++ include/exec/cpu-common.h | 1 + include/migration/postcopy-ram.h | 7 ------ migration/postcopy-ram.c | 30 +--------------------- migration/ram.c | 24 +++--------------- migration/trace-events | 2 +- 6 files changed, 60 insertions(+), 58 deletions(-) diff --git a/exec.c b/exec.c index 3adf2b1..8ac556a 100644 --- a/exec.c +++ b/exec.c @@ -45,6 +45,7 @@ #include "exec/address-spaces.h" #include "sysemu/xen-mapcache.h" #include "trace-root.h" + #endif #include "exec/cpu-all.h" #include "qemu/rcu_queue.h" @@ -3294,4 +3295,57 @@ int qemu_ram_foreach_block(RAMBlockIterFunc func, vo= id *opaque) rcu_read_unlock(); return ret; } + +/* + * Unmap pages of memory from start to start+length such that + * they a) read as 0, b) Trigger whatever fault mechanism + * the OS provides for postcopy. + * The pages must be unmapped by the end of the function. + * Returns: 0 on success, none-0 on failure + * + */ +int ram_block_discard_range(RAMBlock *rb, uint64_t start, size_t length) +{ + int ret =3D -1; + + uint8_t *host_startaddr =3D rb->host + start; + + if ((uintptr_t)host_startaddr & (rb->page_size - 1)) { + error_report("ram_block_discard_range: Unaligned start address: %p= ", + host_startaddr); + goto err; + } + + if ((start + length) <=3D rb->used_length) { + uint8_t *host_endaddr =3D host_startaddr + length; + if ((uintptr_t)host_endaddr & (rb->page_size - 1)) { + error_report("ram_block_discard_range: Unaligned end address: = %p", + host_endaddr); + goto err; + } + + errno =3D ENOTSUP; /* If we are missing MADVISE etc */ + +#if defined(CONFIG_MADVISE) + /* Note: We need the madvise MADV_DONTNEED behaviour of definitely + * freeing the page. + */ + ret =3D madvise(host_startaddr, length, MADV_DONTNEED); +#endif + if (ret) { + ret =3D -errno; + error_report("ram_block_discard_range: Failed to discard range= " + "%s:%" PRIx64 " +%zx (%d)", + rb->idstr, start, length, ret); + } + } else { + error_report("ram_block_discard_range: Overrun block '%s' (%" PRIu= 64 + "/%zx/" RAM_ADDR_FMT")", + rb->idstr, start, length, rb->used_length); + } + +err: + return ret; +} + #endif diff --git a/include/exec/cpu-common.h b/include/exec/cpu-common.h index bd15853..1350c2e 100644 --- a/include/exec/cpu-common.h +++ b/include/exec/cpu-common.h @@ -105,6 +105,7 @@ typedef int (RAMBlockIterFunc)(const char *block_name, = void *host_addr, ram_addr_t offset, ram_addr_t length, void *opaque); =20 int qemu_ram_foreach_block(RAMBlockIterFunc func, void *opaque); +int ram_block_discard_range(RAMBlock *rb, uint64_t start, size_t length); =20 #endif =20 diff --git a/include/migration/postcopy-ram.h b/include/migration/postcopy-= ram.h index b6a7491f..43bbbca 100644 --- a/include/migration/postcopy-ram.h +++ b/include/migration/postcopy-ram.h @@ -35,13 +35,6 @@ int postcopy_ram_incoming_init(MigrationIncomingState *m= is, size_t ram_pages); int postcopy_ram_incoming_cleanup(MigrationIncomingState *mis); =20 /* - * Discard the contents of 'length' bytes from 'start' - * We can assume that if we've been called postcopy_ram_hosttest returned = true - */ -int postcopy_ram_discard_range(MigrationIncomingState *mis, uint8_t *start, - size_t length); - -/* * Userfault requires us to mark RAM as NOHUGEPAGE prior to discard * however leaving it until after precopy means that most of the precopy * data is still THPd diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c index a40dddb..1e3d22f 100644 --- a/migration/postcopy-ram.c +++ b/migration/postcopy-ram.c @@ -200,27 +200,6 @@ out: return ret; } =20 -/** - * postcopy_ram_discard_range: Discard a range of memory. - * We can assume that if we've been called postcopy_ram_hosttest returned = true. - * - * @mis: Current incoming migration state. - * @start, @length: range of memory to discard. - * - * returns: 0 on success. - */ -int postcopy_ram_discard_range(MigrationIncomingState *mis, uint8_t *start, - size_t length) -{ - trace_postcopy_ram_discard_range(start, length); - if (madvise(start, length, MADV_DONTNEED)) { - error_report("%s MADV_DONTNEED: %s", __func__, strerror(errno)); - return -1; - } - - return 0; -} - /* * Setup an area of RAM so that it *can* be used for postcopy later; this * must be done right at the start prior to pre-copy. @@ -239,7 +218,7 @@ static int init_range(const char *block_name, void *hos= t_addr, * - we're going to get the copy from the source anyway. * (Precopy will just overwrite this data, so doesn't need the discard) */ - if (postcopy_ram_discard_range(mis, host_addr, length)) { + if (ram_discard_range(mis, block_name, 0, length)) { return -1; } =20 @@ -658,13 +637,6 @@ int postcopy_ram_incoming_cleanup(MigrationIncomingSta= te *mis) return -1; } =20 -int postcopy_ram_discard_range(MigrationIncomingState *mis, uint8_t *start, - size_t length) -{ - assert(0); - return -1; -} - int postcopy_ram_prepare_discard(MigrationIncomingState *mis) { assert(0); diff --git a/migration/ram.c b/migration/ram.c index 7c5cdf9..44fe960 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -1890,6 +1890,8 @@ int ram_discard_range(MigrationIncomingState *mis, { int ret =3D -1; =20 + trace_ram_discard_range(block_name, start, length); + rcu_read_lock(); RAMBlock *rb =3D qemu_ram_block_by_name(block_name); =20 @@ -1899,27 +1901,7 @@ int ram_discard_range(MigrationIncomingState *mis, goto err; } =20 - uint8_t *host_startaddr =3D rb->host + start; - - if ((uintptr_t)host_startaddr & (qemu_host_page_size - 1)) { - error_report("ram_discard_range: Unaligned start address: %p", - host_startaddr); - goto err; - } - - if ((start + length) <=3D rb->used_length) { - uint8_t *host_endaddr =3D host_startaddr + length; - if ((uintptr_t)host_endaddr & (qemu_host_page_size - 1)) { - error_report("ram_discard_range: Unaligned end address: %p", - host_endaddr); - goto err; - } - ret =3D postcopy_ram_discard_range(mis, host_startaddr, length); - } else { - error_report("ram_discard_range: Overrun block '%s' (%" PRIu64 - "/%zx/" RAM_ADDR_FMT")", - block_name, start, length, rb->used_length); - } + ret =3D ram_block_discard_range(rb, start, length); =20 err: rcu_read_unlock(); diff --git a/migration/trace-events b/migration/trace-events index fa660e3..7372ce2 100644 --- a/migration/trace-events +++ b/migration/trace-events @@ -68,6 +68,7 @@ get_queued_page_not_dirty(const char *block_name, uint64_= t tmp_offset, uint64_t migration_bitmap_sync_start(void) "" migration_bitmap_sync_end(uint64_t dirty_pages) "dirty_pages %" PRIu64 migration_throttle(void) "" +ram_discard_range(const char *rbname, uint64_t start, size_t len) "%s: sta= rt: %" PRIx64 " %zx" ram_load_postcopy_loop(uint64_t addr, int flags) "@%" PRIx64 " %x" ram_postcopy_send_discard_bitmap(void) "" ram_save_queue_pages(const char *rbname, size_t start, size_t len) "%s: st= art: %zx len: %zx" @@ -176,7 +177,6 @@ rdma_start_outgoing_migration_after_rdma_source_init(vo= id) "" # migration/postcopy-ram.c postcopy_discard_send_finish(const char *ramblock, int nwords, int ncmds) = "%s mask words sent=3D%d in %d commands" postcopy_discard_send_range(const char *ramblock, unsigned long start, uns= igned long length) "%s:%lx/%lx" -postcopy_ram_discard_range(void *start, size_t length) "%p,+%zx" postcopy_cleanup_range(const char *ramblock, void *host_addr, size_t offse= t, size_t length) "%s: %p offset=3D%zx length=3D%zx" postcopy_init_range(const char *ramblock, void *host_addr, size_t offset, = size_t length) "%s: %p offset=3D%zx length=3D%zx" postcopy_nhp_range(const char *ramblock, void *host_addr, size_t offset, s= ize_t length) "%s: %p offset=3D%zx length=3D%zx" --=20 2.9.3