Date: Fri, 20 Mar 2020 17:49:38 -0700 From: John-Mark Gurney <jmg@funkthat.com> To: Wanpeng Qian <wanpengqian@gmail.com> Cc: FreeBSD virtualization <freebsd-virtualization@freebsd.org> Subject: Re: bhyve: passthrough SMART info from host nvme controller Message-ID: <20200321004938.GO4213@funkthat.com> In-Reply-To: <CANBJ%2BxTVV3gOv7%2B8Qq9Aq1PaHEo=W%2BNMuqMwZCD7uvU80NFLmA@mail.gmail.com> References: <CANBJ%2BxRdvTUHV0PQeBK2y2bCWDi5idqrD-AsHCT02fWkBLzeQQ@mail.gmail.com> <20200318175901.GI4213@funkthat.com> <CANBJ%2BxTVV3gOv7%2B8Qq9Aq1PaHEo=W%2BNMuqMwZCD7uvU80NFLmA@mail.gmail.com>
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Wanpeng Qian wrote this message on Thu, Mar 19, 2020 at 12:09 +0900:
> > Can't you do what something like pci_passthru.c does in passthru_init,
> > and open /dev/nvme0 in pci_nvme_init?
>
> Yes, you are correct. but that will make /dev/nvme0 keep open all the time.
> I just thinking when guest fire a logpage command, open the /dev/nvme0
> and get the SMART info. then close /dev/nvme0.
But as you point out, the only way to have that happen is to remove
capsicum, but that would make byhve overall LESS secure.
Even if you were able to open /dev/nvme0 at any time after the process
was locked down, it doesn't provide additional security, as any
attacker could just open it up, and do the operation...
So, I'm really confused as to what the benefit of not opening it at
the start is..
> On Thu, Mar 19, 2020 at 2:59 AM John-Mark Gurney <jmg@funkthat.com> wrote:
> >
> > Wanpeng Qian wrote this message on Wed, Mar 18, 2020 at 13:05 +0900:
> > > But currently bhyve has Capsicum capability, I cannot
> > > open /dev/nvme0 within pci_nvme.c without extra code.
> > > (currently I just disable the Capsicum capability)
> > >
> > > any feedback?
> >
> > Can't you do what something like pci_passthru.c does in passthru_init,
> > and open /dev/nvme0 in pci_nvme_init?
> >
> > Or am I missing something?
--
John-Mark Gurney Voice: +1 415 225 5579
"All that I will do, has been done, All that I have, has not."
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