linux-kernel - RE: [PATCH 1/6] x86/tdx: Support hypercalls for TDX guests on Hyper-V

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: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Wed, 23 Nov 2022 18:59:15 +0000
From:   Dexuan Cui <decui@...rosoft.com>
To:     Dave Hansen <dave.hansen@...el.com>,
        "'ak@...ux.intel.com'" <ak@...ux.intel.com>,
        "'arnd@...db.de'" <arnd@...db.de>, "'bp@...en8.de'" <bp@...en8.de>,
        "'brijesh.singh@....com'" <brijesh.singh@....com>,
        "Williams, Dan J" <dan.j.williams@...el.com>,
        "'dave.hansen@...ux.intel.com'" <dave.hansen@...ux.intel.com>,
        Haiyang Zhang <haiyangz@...rosoft.com>,
        "'hpa@...or.com'" <hpa@...or.com>,
        "'jane.chu@...cle.com'" <jane.chu@...cle.com>,
        "'kirill.shutemov@...ux.intel.com'" <kirill.shutemov@...ux.intel.com>,
        KY Srinivasan <kys@...rosoft.com>,
        "'linux-arch@...r.kernel.org'" <linux-arch@...r.kernel.org>,
        "'linux-hyperv@...r.kernel.org'" <linux-hyperv@...r.kernel.org>,
        "'luto@...nel.org'" <luto@...nel.org>,
        "'mingo@...hat.com'" <mingo@...hat.com>,
        "'peterz@...radead.org'" <peterz@...radead.org>,
        "'rostedt@...dmis.org'" <rostedt@...dmis.org>,
        "'sathyanarayanan.kuppuswamy@...ux.intel.com'" 
        <sathyanarayanan.kuppuswamy@...ux.intel.com>,
        "'seanjc@...gle.com'" <seanjc@...gle.com>,
        "'tglx@...utronix.de'" <tglx@...utronix.de>,
        "'tony.luck@...el.com'" <tony.luck@...el.com>,
        "'wei.liu@...nel.org'" <wei.liu@...nel.org>,
        "'x86@...nel.org'" <x86@...nel.org>
CC:     "'linux-kernel@...r.kernel.org'" <linux-kernel@...r.kernel.org>
Subject: RE: [PATCH 1/6] x86/tdx: Support hypercalls for TDX guests on Hyper-V

> From: Dave Hansen <dave.hansen@...el.com>
> Sent: Wednesday, November 23, 2022 8:05 AM
> On 11/22/22 17:56, Dexuan Cui wrote:
> >> From: Dexuan Cui
> >> [...]
> >> The existing asm code for __tdx_hypercall() passes through R10~R15
> >> (see TDVMCALL_EXPOSE_REGS_MASK) to the (KVM) hypervisor.
> >>
> >> Unluckily, for Hyper-V, we need to pass through RDX, R8, R10 and R11
> >> to Hyper-V, so I don't think I can use the existing __tdx_hypercall() ?
> > I'm checking with the Hyper-V team to see if it's possible for them
> > to not use RDX and R8, and use R12 and R13 instead. Will keep the
> > thread updated.
> 
> That would be nice.  But, to be honest, I don't expect them to change
> the ABI for one OS.  It's not a big deal to just make the function a bit
> more flexible.

Then I'll implement a C function using __tdx_hypercall() that will
be expaneed by Kirill. Thank you all for the suggestions!