Date: Wed, 21 Apr 2021 08:49:41 +0200 From: Michael Tuexen <tuexen@freebsd.org> To: Vincent Milum Jr <freebsd-arm@darkain.com> Cc: Greg V <greg@unrelenting.technology>, freebsd-arm@freebsd.org, Dmitry Skorodumov <sdmitry@parallels.com> Subject: Re: gic-v2 and SGI interrupts on boot CPU Message-ID: <4EC14700-BDC9-4447-8895-370AE82D5DC7@freebsd.org> In-Reply-To: <CAOWUMWH=tqnAVkMP2vL6=Pub54N-wkrZrGBSYDyeotpovpXSJQ@mail.gmail.com> References: <YQXPR01MB4691AB59B8CFBE3521B8002EA1489@YQXPR01MB4691.CANPRD01.PROD.OUTLOOK.COM> <2B7A227B-245F-4F1B-A700-263C3FE56B68@freebsd.org> <13A8B0FE-6300-4980-8DA9-49C7A37840CC@unrelenting.technology> <CAOWUMWES6EoD%2B6K=2ijsSiMoupas=8vi=pii-Hd00o-8b9zk=Q@mail.gmail.com> <CAOWUMWH=tqnAVkMP2vL6=Pub54N-wkrZrGBSYDyeotpovpXSJQ@mail.gmail.com>
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> On 21. Apr 2021, at 06:34, Vincent Milum Jr <freebsd-arm@darkain.com> = wrote: >=20 > Doing some more digging, I came across this post from a while ago. >=20 > https://reviews.freebsd.org/D26975 >=20 > I just built a kernel with this patch, and am now running 8 vCPUs = under Parallels on my MacBook Air M1. I can also confirm that the patch fixes the issue. Thanks a lot for = finding the patch! Best regards Michael >=20 > You can see evidence of it here! >=20 > https://twitter.com/DarkainMX/status/1384724684902600706 >=20 > On Tue, Apr 20, 2021 at 7:59 PM Vincent Milum Jr = <freebsd-arm@darkain.com> wrote: > This may actually be related to the Parallels issue. We had a similar = issue with ESXi ARM Fling initially where it would only work on 1 vCPU = but not more, and it was related to the GIC code. This very much is = worth investigating for getting FreeBSD functional under Parallels! >=20 > Oh, and yes, I've bothered Parallels a lot... I unofficially got a = reply essentially stating that the bug "isn't a priority" (they = primarily care about Windows VMs and seems to only marginally care about = Linux, with FreeBSD and other OSes not even remotely in their sights) >=20 > On Tue, Apr 20, 2021 at 5:40 PM Greg V <greg@unrelenting.technology> = wrote: >=20 >=20 > On April 20, 2021 10:38:44 PM UTC, Michael Tuexen <tuexen@freebsd.org> = wrote: > >> On 21. Apr 2021, at 00:02, Dmitry Skorodumov via freebsd-arm = <freebsd-arm@freebsd.org> wrote: > >>=20 > >> Hi > >>=20 > >>=20 > >> It looks like code for gic-v2 in FreeBSD not quite correctly relies = on implementation defined behaviour of GIC. > >>=20 > >> The = g<file:///Users/sdmitry/Downloads/IHI0048B_b_gic_architecture_specificatio= n.pdf>ic 2.0 spec https://developer.arm.com/documentation/ihi0048/bb = chapter 3.2.2 "Interrupt controls in the GIC" states the following: > >>=20 > >> "Whether SGIs are permanently enabled, or can be enabled and = disabled by writes to the GICD_ISENABLERn and GICD_ICENABLERn, is = IMPLEMENTATION DEFINED." > >>=20 > >> But code in sys/arm/arm/gic.c assumes that SGI are always enabled = and doesn't configure them at initialization. They are initialized only = for secondary CPUs - in arm_gic_init_secondary(). > >>=20 > >> For sure it is a rather minor issue, since all appears to be ok in = gic-v3 (v3 code enables SGIs for all CPUs, including the boot one). And = even if platform supports only gic-v2, likely SGIs are always enabled = anyway. So, my post is rather pedantic notice without real life case. > >Dear all, > > > >if I understand things correctly, the problem described is the cause = which does not > >allow to use more than one CPU core in FreeBSD when running on = Parallels Desktop on > >an M1 based Mac. It runs perfectly well with one core, but with = multiple cores it > >locks up during boot. >=20 > Hmm if I'm reading it correctly, the gicv2 driver *does* do this on = secondary CPUs, just not on the boot one. Which doesn't sound like = something that would cause SMP boot to break but single-core to still = work. >=20 > Seems like people using QEMU with Hypervisor.framework patches do have = SMP working fine: > https://gist.github.com/ctsrc/a1f57933a2cde9abc0f07be12889f97f so go = bother Parallels about their bugs ;) > _______________________________________________ > freebsd-arm@freebsd.org mailing list > https://lists.freebsd.org/mailman/listinfo/freebsd-arm > To unsubscribe, send any mail to "freebsd-arm-unsubscribe@freebsd.org"
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