[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH] arm64: xen: Implement EFI reset_system callback
On 18/04/17 20:37, Stefano Stabellini wrote: > On Thu, 6 Apr 2017, Juergen Gross wrote: >> On 06/04/17 18:43, Daniel Kiper wrote: >>> On Thu, Apr 06, 2017 at 06:22:44PM +0200, Juergen Gross wrote: >>>> On 06/04/17 18:06, Daniel Kiper wrote: >>>>> Hi Julien, >>>>> >>>>> On Thu, Apr 06, 2017 at 04:39:13PM +0100, Julien Grall wrote: >>>>>> Hi Daniel, >>>>>> >>>>>> On 06/04/17 16:20, Daniel Kiper wrote: >>>>>>> On Thu, Apr 06, 2017 at 04:38:24PM +0200, Juergen Gross wrote: >>>>>>>> On 06/04/17 16:27, Daniel Kiper wrote: >>>>>>>>> On Thu, Apr 06, 2017 at 09:32:32AM +0100, Julien Grall wrote: >>>>>>>>>> Hi Juergen, >>>>>>>>>> >>>>>>>>>> On 06/04/17 07:23, Juergen Gross wrote: >>>>>>>>>>> On 05/04/17 21:49, Boris Ostrovsky wrote: >>>>>>>>>>>> On 04/05/2017 02:14 PM, Julien Grall wrote: >>>>>>>>>>>>> The x86 code has theoritically a similar issue, altought EFI does >>>>>>>>>>>>> not >>>>>>>>>>>>> seem to be the preferred method. I have left it unimplemented on >>>>>>>>>>>>> x86 and >>>>>>>>>>>>> CCed Linux Xen x86 maintainers to know their view here. >>>>>>>>>>>> >>>>>>>>>>>> (+Daniel) >>>>>>>>>>>> >>>>>>>>>>>> This could be a problem for x86 as well, at least theoretically. >>>>>>>>>>>> xen_machine_power_off() may call pm_power_off(), which is >>>>>>>>>>>> efi.reset_system. >>>>>>>>>>>> >>>>>>>>>>>> So I think we should have a similar routine there. >>>>>>>>>>> >>>>>>>>>>> +1 >>>>>>>>>>> >>>>>>>>>>> I don't see any problem with such a routine added, in contrast to >>>>>>>>>>> potential "reboots" instead of power off without it. >>>>>>>>>>> >>>>>>>>>>> So I think this dummy xen_efi_reset_system() should be added to >>>>>>>>>>> drivers/xen/efi.c instead. >>>>>>>>>> >>>>>>>>>> I will resend the patch during day with xen_efi_reset_system moved >>>>>>>>>> to common code and implement the x86 counterpart (thought, I will >>>>>>>>>> not be able to test it). >>>>>>>>> >>>>>>>>> I think that this is ARM specific issue. On x86 machine_restart() >>>>>>>>> calls >>>>>>>>> xen_restart(). Hence, everything works. So, I think that it should be >>>>>>>>> fixed only for ARM. Anyway, please CC me when you send a patch. >>>>>>>> >>>>>>>> What about xen_machine_power_off() (as stated in Boris' mail)? >>>>>>> >>>>>>> Guys what do you think about that: >>>>>>> >>>>>>> --- a/drivers/firmware/efi/reboot.c >>>>>>> +++ b/drivers/firmware/efi/reboot.c >>>>>>> @@ -55,7 +55,7 @@ static void efi_power_off(void) >>>>>>> >>>>>>> static int __init efi_shutdown_init(void) >>>>>>> { >>>>>>> - if (!efi_enabled(EFI_RUNTIME_SERVICES)) >>>>>>> + if (!efi_enabled(EFI_RUNTIME_SERVICES) || >>>>>>> efi_enabled(EFI_PARAVIRT)) >>>>>>> return -ENODEV; >>>>>>> >>>>>>> if (efi_poweroff_required()) >>>>>>> >>>>>>> >>>>>>> Julien, for ARM64 please take a look at >>>>>>> arch/arm64/kernel/efi.c:efi_poweroff_required(void). >>>>>>> >>>>>>> I hope that tweaks for both files should solve our problem. >>>>>> >>>>>> This sounds good for power off (I haven't tried to power off DOM0 >>>>>> yet). But this will not solve the restart problem (see >>>>>> machine_restart in arch/arm64/kernel/process.c) which call directly >>>>>> efi_reboot. >>>>> >>>>> Hmmm... It seems to me that efi.reset_system override with empty function >>>>> in arch/arm/xen/efi.c is the best solution. So, I see three patches here. >>>>> One for drivers/firmware/efi/reboot.c, one for arch/arm/xen/efi.c and one >>>>> for arch/arm64/kernel/efi.c. Does it make sense? >>>> >>>> I still think the empty function should be in drivers/xen/efi.c and we >>>> should use it in arch/x86/xen/efi.c, too. >>> >>> If you wish we can go that way too. Though I thing that we should fix >>> drivers/firmware/efi/reboot.c:efi_shutdown_init() too. Just in case. >> >> Sure, go ahead. I won't object. > > For the Xen on ARM side, the original patch that started this thread > (20170405181417.15985-1-julien.grall@xxxxxxx) is good to go, right? > As I said: the dummy xen_efi_reset_system() should be in drivers/xen/efi.c Juergen _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx https://lists.xen.org/xen-devel
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