From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46239) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XC2jX-0003vw-95 for qemu-devel@nongnu.org; Tue, 29 Jul 2014 04:26:13 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XC2jR-0008B0-3N for qemu-devel@nongnu.org; Tue, 29 Jul 2014 04:26:07 -0400 Received: from mx1.redhat.com ([209.132.183.28]:55714) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XC2jQ-0008Am-RG for qemu-devel@nongnu.org; Tue, 29 Jul 2014 04:26:01 -0400 Received: from int-mx13.intmail.prod.int.phx2.redhat.com (int-mx13.intmail.prod.int.phx2.redhat.com [10.5.11.26]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s6T8Q0b7021421 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Tue, 29 Jul 2014 04:26:00 -0400 Message-ID: <53D75A94.6000007@redhat.com> Date: Tue, 29 Jul 2014 10:25:56 +0200 From: Paolo Bonzini MIME-Version: 1.0 References: <1406582143-7832-1-git-send-email-mst@redhat.com> In-Reply-To: <1406582143-7832-1-git-send-email-mst@redhat.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] acpi-build: tweak acpi migration limits List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" , qemu-devel@nongnu.org Il 28/07/2014 23:15, Michael S. Tsirkin ha scritto: > - Tweak error message for legacy machine type: > Basically if table size exceeds the limits we set all > bets are off for migration: e.g. it can start failing even > within given qemu minor version simply because of a bugfix. > - Increase table size to 128k. > - Make sure we notice it long before we start getting close to the > 128k limit: warn at 64k. > - Don't fail if we exceed the limit: most people don't care about > migration, even less people care about cross version miration. > > Signed-off-by: Michael S. Tsirkin > --- > hw/i386/acpi-build.c | 16 +++++++++------- > 1 file changed, 9 insertions(+), 7 deletions(-) > > diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c > index 2178894..816c6d9 100644 > --- a/hw/i386/acpi-build.c > +++ b/hw/i386/acpi-build.c > @@ -62,7 +62,7 @@ > #define ACPI_BUILD_LEGACY_CPU_AML_SIZE 97 > #define ACPI_BUILD_ALIGN_SIZE 0x1000 > > -#define ACPI_BUILD_TABLE_SIZE 0x10000 > +#define ACPI_BUILD_TABLE_SIZE 0x20000 > > typedef struct AcpiCpuInfo { > DECLARE_BITMAP(found_cpus, ACPI_CPU_HOTPLUG_ID_LIMIT); > @@ -1586,17 +1586,19 @@ void acpi_build(PcGuestInfo *guest_info, AcpiBuildTables *tables) > ACPI_BUILD_ALIGN_SIZE); > if (tables->table_data->len > legacy_table_size) { > /* Should happen only with PCI bridges and -M pc-i440fx-2.0. */ > - error_report("Warning: migration to QEMU 2.0 may not work."); > + error_report("Warning: migration may not work."); > } > g_array_set_size(tables->table_data, legacy_table_size); > } else { > - if (tables->table_data->len > ACPI_BUILD_TABLE_SIZE) { > + /* Make sure we have a buffer in case we need to resize the tables. */ > + if (tables->table_data->len > ACPI_BUILD_TABLE_SIZE / 2) { > /* As of QEMU 2.1, this fires with 160 VCPUs and 255 memory slots. */ > - error_report("ACPI tables are larger than 64k. Please remove"); > - error_report("CPUs, NUMA nodes, memory slots or PCI bridges."); > - exit(1); > + error_report("Warning: ACPI tables are larger than 64k."); > + error_report("Warning: migration may not work."); > + error_report("Warning: please remove CPUs, NUMA nodes, " > + "memory slots or PCI bridges."); > } > - g_array_set_size(tables->table_data, ACPI_BUILD_TABLE_SIZE); > + acpi_align_size(tables->table_data, ACPI_BUILD_TABLE_SIZE); > } > > acpi_align_size(tables->linker, ACPI_BUILD_ALIGN_SIZE); > Reviewed-by: Paolo Bonzini