From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58987) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZgwHn-0004oc-Vu for qemu-devel@nongnu.org; Tue, 29 Sep 2015 10:53:46 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZgwHi-0005UF-74 for qemu-devel@nongnu.org; Tue, 29 Sep 2015 10:53:43 -0400 Received: from mx1.redhat.com ([209.132.183.28]:54881) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZgwHh-0005U8-W3 for qemu-devel@nongnu.org; Tue, 29 Sep 2015 10:53:38 -0400 From: Igor Mammedov Date: Tue, 29 Sep 2015 16:53:29 +0200 Message-Id: <1443538409-145558-3-git-send-email-imammedo@redhat.com> In-Reply-To: <1443538409-145558-1-git-send-email-imammedo@redhat.com> References: <1443538409-145558-1-git-send-email-imammedo@redhat.com> Subject: [Qemu-devel] [PATCH v3 2/2] pc: memhp: force gaps between DIMM's GPA List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: pbonzini@redhat.com, bharata@linux.vnet.ibm.com, ehabkost@redhat.com, david@gibson.dropbear.id.au, mst@redhat.com mapping DIMMs non contiguously allows to workaround virtio bug reported earlier: http://lists.nongnu.org/archive/html/qemu-devel/2015-08/msg00522.html in this case guest kernel doesn't allocate buffers that can cross DIMM boundary keeping each buffer local to a DIMM. Suggested-by: Michael S. Tsirkin Signed-off-by: Igor Mammedov Acked-by: Eduardo Habkost --- v3: use pc_machine_class_init() for default. (Eduardo) v2: make inter_dimm_gap boolean benefit of this workaround is that no guest side changes are required. --- hw/i386/pc.c | 6 ++++-- hw/i386/pc_piix.c | 1 + hw/i386/pc_q35.c | 1 + include/hw/i386/pc.h | 1 + 4 files changed, 7 insertions(+), 2 deletions(-) diff --git a/hw/i386/pc.c b/hw/i386/pc.c index ef02736..efbd41a 100644 --- a/hw/i386/pc.c +++ b/hw/i386/pc.c @@ -1629,6 +1629,7 @@ static void pc_dimm_plug(HotplugHandler *hotplug_dev, HotplugHandlerClass *hhc; Error *local_err = NULL; PCMachineState *pcms = PC_MACHINE(hotplug_dev); + PCMachineClass *pcmc = PC_MACHINE_GET_CLASS(pcms); PCDIMMDevice *dimm = PC_DIMM(dev); PCDIMMDeviceClass *ddc = PC_DIMM_GET_CLASS(dimm); MemoryRegion *mr = ddc->get_memory_region(dimm); @@ -1644,8 +1645,8 @@ static void pc_dimm_plug(HotplugHandler *hotplug_dev, goto out; } - pc_dimm_memory_plug(dev, &pcms->hotplug_memory, mr, align, false, - &local_err); + pc_dimm_memory_plug(dev, &pcms->hotplug_memory, mr, align, + pcmc->inter_dimm_gap, &local_err); if (local_err) { goto out; } @@ -1946,6 +1947,7 @@ static void pc_machine_class_init(ObjectClass *oc, void *data) PCMachineClass *pcmc = PC_MACHINE_CLASS(oc); HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(oc); + pcmc->inter_dimm_gap = true; pcmc->get_hotplug_handler = mc->get_hotplug_handler; mc->get_hotplug_handler = pc_get_hotpug_handler; mc->cpu_index_to_socket_id = pc_cpu_index_to_socket_id; diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c index 3ffb05f..d97ca2a 100644 --- a/hw/i386/pc_piix.c +++ b/hw/i386/pc_piix.c @@ -482,6 +482,7 @@ static void pc_i440fx_2_4_machine_options(MachineClass *m) m->alias = NULL; m->is_default = 0; pcmc->broken_reserved_end = true; + pcmc->inter_dimm_gap = false; SET_MACHINE_COMPAT(m, PC_COMPAT_2_4); } diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c index 1b7d3b6..c28f0da 100644 --- a/hw/i386/pc_q35.c +++ b/hw/i386/pc_q35.c @@ -385,6 +385,7 @@ static void pc_q35_2_4_machine_options(MachineClass *m) pc_q35_2_5_machine_options(m); m->alias = NULL; pcmc->broken_reserved_end = true; + pcmc->inter_dimm_gap = false; SET_MACHINE_COMPAT(m, PC_COMPAT_2_4); } diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h index ab5413f..c13e91d 100644 --- a/include/hw/i386/pc.h +++ b/include/hw/i386/pc.h @@ -60,6 +60,7 @@ struct PCMachineClass { /*< public >*/ bool broken_reserved_end; + bool inter_dimm_gap; HotplugHandler *(*get_hotplug_handler)(MachineState *machine, DeviceState *dev); }; -- 1.8.3.1