From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56654) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VjaUP-0007C3-WA for qemu-devel@nongnu.org; Thu, 21 Nov 2013 15:04:44 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VjaUI-0007ad-0a for qemu-devel@nongnu.org; Thu, 21 Nov 2013 15:04:37 -0500 Received: from mx1.redhat.com ([209.132.183.28]:21899) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VjaUH-0007aZ-Ox for qemu-devel@nongnu.org; Thu, 21 Nov 2013 15:04:29 -0500 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 rALK4SZZ030137 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Thu, 21 Nov 2013 15:04:29 -0500 From: Vlad Yasevich Date: Thu, 21 Nov 2013 15:04:19 -0500 Message-Id: <1385064260-20962-2-git-send-email-vyasevic@redhat.com> In-Reply-To: <1385064260-20962-1-git-send-email-vyasevic@redhat.com> References: <1385064260-20962-1-git-send-email-vyasevic@redhat.com> Subject: [Qemu-devel] [RFC PATCH 1/2] e1000: Use Address_Available bit as HW latch List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Vlad Yasevich , alex.williamson@redhat.com, akong@redhat.com, stefanha@redhat.com, mst@redhat.com e1000 provides a E1000_RAH_AV bit on every complete write to the Receive Address Register. We can use this bit 2 ways: 1) To trigger HMP notifications. When the bit is set the mac address is fully set and we can update the HMP. 2) We can turn off he bit on the write to low order bits of the Receive Address Register, so that we would not try to match received traffic to this address when it is not completely set. Signed-off-by: Vlad Yasevich --- hw/net/e1000.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/hw/net/e1000.c b/hw/net/e1000.c index ae63591..82978ea 100644 --- a/hw/net/e1000.c +++ b/hw/net/e1000.c @@ -1106,10 +1106,19 @@ mac_writereg(E1000State *s, int index, uint32_t val) s->mac_reg[index] = val; - if (index == RA || index == RA + 1) { + switch (index) { + case RA: + /* Mask off AV bit on the write of the low dword. The write of + * the high dword will set the bit. This way a half-written + * mac address will not be used to filter on rx. + */ + s->mac_reg[RA+1] &= ~E1000_RAH_AV; + break; + case (RA + 1): macaddr[0] = cpu_to_le32(s->mac_reg[RA]); macaddr[1] = cpu_to_le32(s->mac_reg[RA + 1]); qemu_format_nic_info_str(qemu_get_queue(s->nic), (uint8_t *)macaddr); + break; } } -- 1.8.4.2