From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from alto.onthenet.com.au (alto.onthenet.com.au [203.13.68.39]) by mx.groups.io with SMTP id smtpd.web09.9976.1625234112709239079 for ; Fri, 02 Jul 2021 06:55:13 -0700 Authentication-Results: mx.groups.io; dkim=missing; spf=none, err=permanent DNS error (domain: iredmail.onthenet.com.au, ip: 203.13.68.39, mailfrom: srs0=t6dg=l2=freebsd.org=grehan@iredmail.onthenet.com.au) Received: from iredmail.onthenet.com.au (iredmail.onthenet.com.au [203.13.68.150]) by alto.onthenet.com.au (Postfix) with ESMTPS id E4C0020C92E8 for ; Fri, 2 Jul 2021 23:55:07 +1000 (AEST) Received: from iredmail.onthenet.com.au (iredmail.onthenet.com.au [127.0.0.1]) by iredmail.onthenet.com.au (Postfix) with ESMTP id DB3E5211FADA for ; Fri, 2 Jul 2021 23:55:07 +1000 (AEST) Received: from iredmail.onthenet.com.au ([127.0.0.1]) by iredmail.onthenet.com.au (iredmail.onthenet.com.au [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id G-7b5dUS3yUQ for ; Fri, 2 Jul 2021 23:55:07 +1000 (AEST) Received: from MacBook-Air-4.local (unknown [120.29.51.224]) by iredmail.onthenet.com.au (Postfix) with ESMTPSA id 984FE211FAD9; Fri, 2 Jul 2021 23:55:06 +1000 (AEST) Subject: Re: [edk2-devel] [PATCH v2 1/2] OvmfPkg/Bhyve: add USB support To: Michael Brown , devel@edk2.groups.io, c.koehne@beckhoff.com Cc: =?UTF-8?Q?Patrick_Br=c3=bcnn?= , "lersek@redhat.com" , "ardb+tianocore@kernel.org" , "jordan.l.justen@intel.com" , "rebecca@bsdio.com" References: <20210624060516.211-1-c.koehne@beckhoff.com> <20210624060516.211-2-c.koehne@beckhoff.com> <8f3f6360-a43e-c83d-b7dd-82d5600a1e28@freebsd.org> <6bde32cf8a874824a1bbd78b75f06adb@beckhoff.com> <981fe2fe-5f69-bb57-dd32-4bafbb841989@freebsd.org> <8a8b3161-0349-76c3-9a50-f24dc5f0b67c@ipxe.org> <848fb5ee-6e52-eed1-0b0d-39e4dda5c5dc@freebsd.org> From: "Peter Grehan" Message-ID: <93721b47-8394-691e-62f7-73db6bd21b15@freebsd.org> Date: Fri, 2 Jul 2021 23:55:06 +1000 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.14; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: X-CMAE-Score: 0 X-CMAE-Analysis: v=2.3 cv=Q6BJH7+a c=1 sm=1 tr=0 a=A6CF0fG5TOl4vs6YHvqXgw==:117 a=y5XNLLSx+aZC9npArTYviw==:17 a=IkcTkHD0fZMA:10 a=e_q4qTt1xDgA:10 a=lj58ZXMEg-G9dvTb-LgA:9 a=QEXdDO2ut3YA:10 wl=host:3 Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: quoted-printable >>> Is that a detail of the current implementation, or a fundamental=20 >>> limitation in the bhyve architecture? >> >> =C2=A0=C2=A0Only two choices ? :) Maybe half way between those points. >=20 > When there is no fundamental limitation, It's not so much a fundamental technical limitation as in a large=20 amount of work in FreeBSD for almost zero return - maybe a fundamental=20 resource limitation. > i.e. when a future version of=20 > the hypervisor may be able to support the feature with no changes to th= e=20 > firmware, then it would be good practice to leave the drivers enabled.=20 > Doing so avoids creating an unnecessarily tight coupling between the=20 > hypervisor and firmware versions. Well versed in those issues :) > More importantly: does it even matter that the hypervisor doesn't=20 > support passthrough of PCI legacy interrupts?=C2=A0 UEFI operates on a=20 > polling basis, with the only active interrupt being some kind of=20 > periodic timer.=C2=A0 Where do you see any requirement for legacy inter= rupts=20 > in the UHCI/EHCI drivers? It creates a case where the o/s booted by EFI isn't able to use those=20 controllers as expected. Anyways, this is more a discussion for the freebsd-virtualization=20 mailing list if you'd like to chat about it more. later, Peter.