linux-kernel - RE: [PATCH 0/4] x86/Hyper-V: Unload vmbus channel in hv panic callback

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <87mu8c22ky.fsf@vitty.brq.redhat.com>
Date:   Thu, 19 Mar 2020 09:03:57 +0100
From:   Vitaly Kuznetsov <vkuznets@...hat.com>
To:     Michael Kelley <mikelley@...rosoft.com>,
        "ltykernel\@gmail.com" <ltykernel@...il.com>
Cc:     Tianyu Lan <Tianyu.Lan@...rosoft.com>,
        "linux-hyperv\@vger.kernel.org" <linux-hyperv@...r.kernel.org>,
        "linux-kernel\@vger.kernel.org" <linux-kernel@...r.kernel.org>,
        KY Srinivasan <kys@...rosoft.com>,
        Haiyang Zhang <haiyangz@...rosoft.com>,
        Stephen Hemminger <sthemmin@...rosoft.com>,
        Wei Liu <liuwe@...rosoft.com>,
        "tglx\@linutronix.de" <tglx@...utronix.de>,
        "mingo\@redhat.com" <mingo@...hat.com>,
        "bp\@alien8.de" <bp@...en8.de>, "hpa\@zytor.com" <hpa@...or.com>,
        "x86\@kernel.org" <x86@...nel.org>
Subject: RE: [PATCH 0/4] x86/Hyper-V: Unload vmbus channel in hv panic callback

Michael Kelley <mikelley@...rosoft.com> writes:

>> > --- a/drivers/hv/vmbus_drv.c
>> > +++ b/drivers/hv/vmbus_drv.c
>> > @@ -53,9 +53,12 @@ static int hyperv_panic_event(struct notifier_block *nb, unsigned
>> long val,
>> >  {
>> >  	struct pt_regs *regs;
>> >
>> > -	regs = current_pt_regs();
>> > +	vmbus_initiate_unload(true);
>> >
>> > -	hyperv_report_panic(regs, val);
>> > +	if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
>> 
>> With Michael's effors to make code in drivers/hv arch agnostic, I think
>> we need a better, arch-neutral way.
>
> Vitaly -- could you elaborate on what part is not arch-neutral?  I don't see
> a problem.  ms_hyperv and the misc_features field exist for both the x86
> and ARM64 code branches.  It turns out the particular bit for
> GUEST_CRASH_MSR_AVAILABLE is different on the two architectures, but
> the compiler will do the right thing.
>

Ah, apologies, missed the fact that we also call it
'HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE' - I have to admit I was confused
by the 'MSR' part. We can probably rename this to something like
HV_FEATURE_GUEST_CRASH_REGS_AVAILABLE - but not as part of the series.

-- 
Vitaly