linux-kernel - Re: [PATCH v2 1/2] KVM: Introduce KVM_EXIT

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] [day] [month] [year] [list]

Message-ID: <CAAH4kHYncFsa=5NZVX35jk3jicx1fnYTHsLwapHmJ03+TNKa9w@mail.gmail.com>
Date: Tue, 19 Nov 2024 20:55:40 -0800
From: Dionna Amalie Glaze <dionnaglaze@...gle.com>
To: Michael Roth <michael.roth@....com>
Cc: kvm@...r.kernel.org, linux-coco@...ts.linux.dev, 
	linux-kernel@...r.kernel.org, x86@...nel.org, pbonzini@...hat.com, 
	seanjc@...gle.com, jroedel@...e.de, thomas.lendacky@....com, 
	pgonda@...gle.com, ashish.kalra@....com, bp@...en8.de, pankaj.gupta@....com, 
	liam.merwick@...cle.com
Subject: Re: [PATCH v2 1/2] KVM: Introduce KVM_EXIT_COCO exit type

On Tue, Nov 19, 2024 at 8:54 PM Dionna Amalie Glaze
<dionnaglaze@...gle.com> wrote:
>
> On Tue, Nov 19, 2024 at 5:51 AM Michael Roth <michael.roth@....com> wrote:
> >
> > +struct kvm_exit_coco {
> > +#define KVM_EXIT_COCO_REQ_CERTS                0
> > +#define KVM_EXIT_COCO_MAX              1
> > +       __u8 nr;
> > +       __u8 pad0[7];
> > +       __u32 ret;
> > +       __u32 pad1;
> > +       union {
> > +               struct {
> > +                       __u64 gfn;
> > +                       __u32 npages;
>
> Should this not also include a vmm_err code to report to the guest? We
> need some way for user space to indicate that KVM should write the
> vmm_err to the upper 32 bits of exit_info_2.
> I don't think we have a snapshot of the GHCB accessible to userspace.
>
> I'm still not quite able to get a good test of this patch series
> ready. Making the certificate file accessible to the VMM process has
> been unfortunately challenging due to how we manage chroots and VMM
> upgrades.
> Still, I'm stuck in the VMM implementation of grabbing the file lock
> for the certificates and asking myself "how do I tell KVM to write
> exit_info_2 = (2 << 32) | (exit_info_2 & ((1 << 32)-1) before entering
> the guest?"
> A __u32 vmm_err field of this struct would nicely make its size 64-bit aligned..

retracted. I needed to look 2 lines lower. I need to stop working this late.
>
> --
> -Dionna Glaze, PhD, CISSP, CCSP (she/her)



-- 
-Dionna Glaze, PhD, CISSP, CCSP (she/her)