From patchwork Wed Apr 6 20:41:47 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Michael S. Tsirkin" X-Patchwork-Id: 90070 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [199.232.76.165]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 5EB61B6F75 for ; Thu, 7 Apr 2011 06:47:13 +1000 (EST) Received: from localhost ([127.0.0.1]:59823 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Q7ZbL-0005Kx-3m for incoming@patchwork.ozlabs.org; Wed, 06 Apr 2011 16:45:19 -0400 Received: from [140.186.70.92] (port=48986 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Q7ZYZ-0003Sf-Lh for qemu-devel@nongnu.org; Wed, 06 Apr 2011 16:43:59 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Q7ZYF-0001yg-8C for qemu-devel@nongnu.org; Wed, 06 Apr 2011 16:42:08 -0400 Received: from mx1.redhat.com ([209.132.183.28]:44761) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Q7ZYE-0001yY-Vd for qemu-devel@nongnu.org; Wed, 06 Apr 2011 16:42:07 -0400 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id p36Kg5HX011799 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Wed, 6 Apr 2011 16:42:05 -0400 Received: from redhat.com (vpn-200-170.tlv.redhat.com [10.35.200.170]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with SMTP id p36Kg2nK006838; Wed, 6 Apr 2011 16:42:03 -0400 Date: Wed, 6 Apr 2011 23:41:47 +0300 From: "Michael S. Tsirkin" To: qemu-devel@nongnu.org Message-ID: <25254bbc4d91408b6be706d095e3fbc60a972db4.1302121974.git.mst@redhat.com> References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-Mutt-Fcc: =sent User-Agent: Mutt/1.5.21 (2010-09-15) X-Scanned-By: MIMEDefang 2.68 on 10.5.11.22 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 209.132.183.28 Cc: Subject: [Qemu-devel] [PATCH RFC 2/5] kvm: halve number of set memory calls for vga X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org use the new api to reduce the number of these (expensive) system calls. Note: using this API, we should be able to get rid of vga_dirty_log_xxx APIs. Using them doesn't affect the performance though because we detects the log_dirty flag set and ignores the call. Signed-off-by: Michael S. Tsirkin --- kvm-all.c | 59 ++++++++++++++++++++++++++++++++++++----------------------- 1 files changed, 36 insertions(+), 23 deletions(-) diff --git a/kvm-all.c b/kvm-all.c index 1647e1a..7ace9a2 100644 --- a/kvm-all.c +++ b/kvm-all.c @@ -245,48 +245,60 @@ err: /* * dirty pages logging control */ -static int kvm_dirty_pages_log_change(target_phys_addr_t phys_addr, - ram_addr_t size, int flags, int mask) + +static int kvm_mem_flags(KVMState *s, bool log_dirty) +{ + return log_dirty ? KVM_MEM_LOG_DIRTY_PAGES : 0; +} + +static int kvm_slot_dirty_pages_log_change(KVMSlot *mem, bool log_dirty) { KVMState *s = kvm_state; - KVMSlot *mem = kvm_lookup_matching_slot(s, phys_addr, phys_addr + size); + int flags, mask = KVM_MEM_LOG_DIRTY_PAGES; int old_flags; - if (mem == NULL) { - fprintf(stderr, "BUG: %s: invalid parameters " TARGET_FMT_plx "-" - TARGET_FMT_plx "\n", __func__, phys_addr, - (target_phys_addr_t)(phys_addr + size - 1)); - return -EINVAL; - } - old_flags = mem->flags; - flags = (mem->flags & ~mask) | flags; + flags = (mem->flags & ~mask) | kvm_mem_flags(s, log_dirty); mem->flags = flags; /* If nothing changed effectively, no need to issue ioctl */ if (s->migration_log) { flags |= KVM_MEM_LOG_DIRTY_PAGES; } + if (flags == old_flags) { - return 0; + return 0; } return kvm_set_user_memory_region(s, mem); } +static int kvm_dirty_pages_log_change(target_phys_addr_t phys_addr, + ram_addr_t size, bool log_dirty) +{ + KVMState *s = kvm_state; + KVMSlot *mem = kvm_lookup_matching_slot(s, phys_addr, phys_addr + size); + + if (mem == NULL) { + fprintf(stderr, "BUG: %s: invalid parameters " TARGET_FMT_plx "-" + TARGET_FMT_plx "\n", __func__, phys_addr, + (target_phys_addr_t)(phys_addr + size - 1)); + return -EINVAL; + } + return kvm_slot_dirty_pages_log_change(mem, log_dirty); +} + static int kvm_log_start(CPUPhysMemoryClient *client, target_phys_addr_t phys_addr, ram_addr_t size) { - return kvm_dirty_pages_log_change(phys_addr, size, KVM_MEM_LOG_DIRTY_PAGES, - KVM_MEM_LOG_DIRTY_PAGES); + return kvm_dirty_pages_log_change(phys_addr, size, true); } static int kvm_log_stop(CPUPhysMemoryClient *client, target_phys_addr_t phys_addr, ram_addr_t size) { - return kvm_dirty_pages_log_change(phys_addr, size, 0, - KVM_MEM_LOG_DIRTY_PAGES); + return kvm_dirty_pages_log_change(phys_addr, size, false); } static int kvm_set_migration_log(int enable) @@ -495,7 +507,7 @@ kvm_check_extension_list(KVMState *s, const KVMCapabilityInfo *list) } static void kvm_set_phys_mem(target_phys_addr_t start_addr, ram_addr_t size, - ram_addr_t phys_offset) + ram_addr_t phys_offset, bool log_dirty) { KVMState *s = kvm_state; ram_addr_t flags = phys_offset & ~TARGET_PAGE_MASK; @@ -520,7 +532,8 @@ static void kvm_set_phys_mem(target_phys_addr_t start_addr, ram_addr_t size, (start_addr + size <= mem->start_addr + mem->memory_size) && (phys_offset - start_addr == mem->phys_offset - mem->start_addr)) { /* The new slot fits into the existing one and comes with - * identical parameters - nothing to be done. */ + * identical parameters - update flags and done. */ + kvm_slot_dirty_pages_log_change(mem, log_dirty); return; } @@ -550,7 +563,7 @@ static void kvm_set_phys_mem(target_phys_addr_t start_addr, ram_addr_t size, mem->memory_size = old.memory_size; mem->start_addr = old.start_addr; mem->phys_offset = old.phys_offset; - mem->flags = 0; + mem->flags = kvm_mem_flags(s, log_dirty); err = kvm_set_user_memory_region(s, mem); if (err) { @@ -571,7 +584,7 @@ static void kvm_set_phys_mem(target_phys_addr_t start_addr, ram_addr_t size, mem->memory_size = start_addr - old.start_addr; mem->start_addr = old.start_addr; mem->phys_offset = old.phys_offset; - mem->flags = 0; + mem->flags = kvm_mem_flags(s, log_dirty); err = kvm_set_user_memory_region(s, mem); if (err) { @@ -590,7 +603,7 @@ static void kvm_set_phys_mem(target_phys_addr_t start_addr, ram_addr_t size, size_delta = mem->start_addr - old.start_addr; mem->memory_size = old.memory_size - size_delta; mem->phys_offset = old.phys_offset + size_delta; - mem->flags = 0; + mem->flags = kvm_mem_flags(s, log_dirty); err = kvm_set_user_memory_region(s, mem); if (err) { @@ -613,7 +626,7 @@ static void kvm_set_phys_mem(target_phys_addr_t start_addr, ram_addr_t size, mem->memory_size = size; mem->start_addr = start_addr; mem->phys_offset = phys_offset; - mem->flags = 0; + mem->flags = kvm_mem_flags(s, log_dirty); err = kvm_set_user_memory_region(s, mem); if (err) { @@ -628,7 +641,7 @@ static void kvm_client_set_memory(struct CPUPhysMemoryClient *client, ram_addr_t size, ram_addr_t phys_offset, bool log_dirty) { - kvm_set_phys_mem(start_addr, size, phys_offset); + kvm_set_phys_mem(start_addr, size, phys_offset, log_dirty); } static int kvm_client_sync_dirty_bitmap(struct CPUPhysMemoryClient *client,