From: Dexuan Cui <decui@microsoft.com>
To: vkuznets <vkuznets@redhat.com>
Cc: "linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>,
"arnd@arndb.de" <arnd@arndb.de>, "bp@alien8.de" <bp@alien8.de>,
"daniel.lezcano@linaro.org" <daniel.lezcano@linaro.org>,
Haiyang Zhang <haiyangz@microsoft.com>,
"hpa@zytor.com" <hpa@zytor.com>,
KY Srinivasan <kys@microsoft.com>,
"linux-hyperv@vger.kernel.org" <linux-hyperv@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"mingo@redhat.com" <mingo@redhat.com>,
"sashal@kernel.org" <sashal@kernel.org>,
Stephen Hemminger <sthemmin@microsoft.com>,
"tglx@linutronix.de" <tglx@linutronix.de>,
"x86@kernel.org" <x86@kernel.org>,
Michael Kelley <mikelley@microsoft.com>,
Sasha Levin <Alexander.Levin@microsoft.com>
Subject: RE: [PATCH v5 1/3] x86/hyper-v: Suspend/resume the hypercall page for hibernation
Date: Mon, 30 Sep 2019 18:49:33 +0000 [thread overview]
Message-ID: <PU1P153MB0169804D32B95E0A145CD0B9BF820@PU1P153MB0169.APCP153.PROD.OUTLOOK.COM> (raw)
In-Reply-To: <877e5u6re3.fsf@vitty.brq.redhat.com>
> From: Vitaly Kuznetsov <vkuznets@redhat.com>
> Sent: Friday, September 27, 2019 2:05 AM
> To: Dexuan Cui <decui@microsoft.com>
>
> Dexuan Cui <decui@microsoft.com> writes:
> ...
> > So, I'm pretty sure no IPI can happen between hv_suspend() and
> hv_resume().
> > self-IPI is not supposed to happen either, since interrupts are disabled.
> >
> > IMO TLB flush should not be an issue either, unless the kernel changes page
> > tables between hv_suspend() and hv_resume(), which is not the case as I
> > checked the related code, but it looks in theory that might happen, say, in
> > the future, so if you insist we should save the variable "hv_hypercall_pg"
> > to a temporary variable and set the "hv_hypercall_pg" to NULL before we
> > disable the hypercall page
>
> Let's do it as a future proof so we can keep relying on !hv_hypercall_pg
> everywhere we need. No need to change this patch IMO, a follow-up would
> do.
> Vitaly
Now I think it would be better to do it in this patch. :-)
I'll post a v6 to follow your suggestion.
Thanks,
-- Dexuan
next prev parent reply other threads:[~2019-09-30 20:44 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-05 22:47 [PATCH v5 0/3] Enhance Hyper-V for hibernation Dexuan Cui
2019-09-05 22:47 ` [PATCH v5 1/3] x86/hyper-v: Suspend/resume the hypercall page " Dexuan Cui
2019-09-26 10:44 ` Vitaly Kuznetsov
2019-09-27 6:48 ` Dexuan Cui
2019-09-27 9:05 ` Vitaly Kuznetsov
2019-09-30 18:49 ` Dexuan Cui [this message]
2019-09-05 22:47 ` [PATCH v5 2/3] x86/hyper-v: Implement hv_is_hibernation_supported() Dexuan Cui
2019-09-05 22:47 ` [PATCH v5 3/3] clocksource/drivers: Suspend/resume Hyper-V clocksource for hibernation Dexuan Cui
2019-09-25 23:21 ` Daniel Lezcano
2019-09-25 23:35 ` Dexuan Cui
2019-09-26 13:16 ` Daniel Lezcano
2019-09-27 5:57 ` Dexuan Cui
2019-09-25 22:49 ` [PATCH v5 0/3] Enhance Hyper-V " Dexuan Cui
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