From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:60890) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aH8g4-0002v0-7b for qemu-devel@nongnu.org; Thu, 07 Jan 2016 06:24:25 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aH8g0-00050x-HW for qemu-devel@nongnu.org; Thu, 07 Jan 2016 06:24:24 -0500 Received: from mail-wm0-x22d.google.com ([2a00:1450:400c:c09::22d]:37255) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aH8g0-00050r-86 for qemu-devel@nongnu.org; Thu, 07 Jan 2016 06:24:20 -0500 Received: by mail-wm0-x22d.google.com with SMTP id f206so118212005wmf.0 for ; Thu, 07 Jan 2016 03:24:20 -0800 (PST) Sender: Paolo Bonzini References: <1449768334-12782-1-git-send-email-lersek@redhat.com> <20151210195336.459c0c64@igors-macbook-pro.local> <568AA993.2090006@redhat.com> <568E38F2.1010507@redhat.com> <20160107132159-mutt-send-email-mst@redhat.com> From: Paolo Bonzini Message-ID: <568E4ADF.4020808@redhat.com> Date: Thu, 7 Jan 2016 12:24:15 +0100 MIME-Version: 1.0 In-Reply-To: <20160107132159-mutt-send-email-mst@redhat.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] hw/i386: fill in the CENTURY field of the FADT (FACP) ACPI table List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" Cc: Ruiyu Ni , Eduardo Habkost , qemu-devel@nongnu.org, Igor Mammedov , Laszlo Ersek , Richard Henderson On 07/01/2016 12:22, Michael S. Tsirkin wrote: > On Thu, Jan 07, 2016 at 11:07:46AM +0100, Paolo Bonzini wrote: >> >> >> On 04/01/2016 18:19, Laszlo Ersek wrote: >>> On 12/10/15 19:53, Igor Mammedov wrote: >>>> On Thu, 10 Dec 2015 18:25:34 +0100 >>>> Laszlo Ersek wrote: >>>> >>>>> The ACPI specification (minimally versions 1.0b through 6.0) define >>>>> the FADT.CENTURY field as: >>>>> >>>>> The RTC CMOS RAM index to the century of data value (hundred and >>>>> thousand year decimals). If this field contains a zero, then the RTC >>>>> centenary feature is not supported. If this field has a non-zero >>>>> value, then this field contains an index into RTC RAM space that OSPM >>>>> can use to program the centenary field. >>>>> >>>>> The x86 targets generate ACPI payload, emulate an RTC >>>>> (CONFIG_MC146818RTC), and that RTC supports the "centenary >>>>> feature" (see occurrences of RTC_CENTURY in cmos_ioport_write() and >>>>> cmos_ioport_read() in "hw/timer/mc146818rtc.c".) >>>>> >>>>> However, FADT.CENTURY is left at zero currently: >>>>> >>>>> [06Ch 0108 1] RTC Century Index : 00 >>>>> >>>>> which -- according to analysis done by Ruiyu Ni at Intel -- should >>>>> cause Linux and Windows 8+ to think the RTC centenary feature is >>>>> unavailable, and cause Windows 7 to (incorrectly) assume that the >>>>> offset to use is constant 0x32. (0x32 happens to be the right value >>>>> on QEMU, but Windows 7 is wrong to assume anything at all). >>>>> >>>>> Exposing the right nonzero offset in FADT.CENTURY informs Linux and >>>>> Windows 8+ about the right capabilities of the hardware, plus it >>>>> retrofits our FADT to Windows 7's behavior. >>>>> >>>>> Regression tested with the following guests (all UEFI installs): >>>>> - i386 Q35: Fedora 21 ("Fedlet" edition) >>>>> - x86_64: >>>>> - i440fx: >>>>> - Fedora 21 >>>>> - RHEL 6 and 7 >>>>> - Windows 7 and 10 >>>>> - Windows Server 2008 R2 and 2012 R2 >>>>> - Q35: >>>>> - Fedora 22 >>>>> - Windows 8.1 >>>>> >>>>> Cc: "Michael S. Tsirkin" (supporter:ACPI/SMBIOS) >>>>> Cc: Igor Mammedov (supporter:ACPI/SMBIOS) >>>>> Cc: Paolo Bonzini (maintainer:X86) >>>>> Cc: Richard Henderson (maintainer:X86) >>>>> Cc: Eduardo Habkost (maintainer:X86) >>>>> Cc: Ruiyu Ni >>>>> Signed-off-by: Laszlo Ersek >>>>> --- >>>>> hw/i386/acpi-build.c | 2 ++ >>>>> 1 file changed, 2 insertions(+) >>>>> >>>>> diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c >>>>> index 95e0c65..c5e6c4b 100644 >>>>> --- a/hw/i386/acpi-build.c >>>>> +++ b/hw/i386/acpi-build.c >>>>> @@ -42,6 +42,7 @@ >>>>> #include "sysemu/tpm.h" >>>>> #include "hw/acpi/tpm.h" >>>>> #include "sysemu/tpm_backend.h" >>>>> +#include "hw/timer/mc146818rtc_regs.h" >>>>> >>>>> /* Supported chipsets: */ >>>>> #include "hw/acpi/piix4.h" >>>>> @@ -334,6 +335,7 @@ static void fadt_setup(AcpiFadtDescriptorRev1 >>>>> *fadt, AcpiPmInfo *pm) if (max_cpus > 8) { >>>>> fadt->flags |= cpu_to_le32(1 << >>>>> ACPI_FADT_F_FORCE_APIC_CLUSTER_MODEL); } >>>>> + fadt->century = RTC_CENTURY; >>>>> } >>>>> >>>>> >>>> >>>> Reviewed-by: Igor Mammedov >>>> >>> >>> Thanks. >>> >>> Can someone please pick up this patch? >> >> It should probably go in through Michael's tree, but I've queued it too >> so that it isn't forgotten. >> >> Paolo > > Yes - thanks! > I picked this up - should I add your Reviewed-by tag? Sure! Reviewed-by: Paolo Bonzini Paolo