linux-kernel - RE: [PATCH V8.1 5/9] x86/sev-es: Expose sev_es_ghcb_hv_call() to call ghcb hv call out of sev code

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

Message-ID: <MWHPR21MB1593716CD7DDE1326AC93AD4D7809@MWHPR21MB1593.namprd21.prod.outlook.com>
Date:   Fri, 22 Oct 2021 20:58:00 +0000
From:   Michael Kelley <mikelley@...rosoft.com>
To:     Tianyu Lan <ltykernel@...il.com>,
        KY Srinivasan <kys@...rosoft.com>,
        Haiyang Zhang <haiyangz@...rosoft.com>,
        Stephen Hemminger <sthemmin@...rosoft.com>,
        "wei.liu@...nel.org" <wei.liu@...nel.org>,
        Dexuan Cui <decui@...rosoft.com>,
        "tglx@...utronix.de" <tglx@...utronix.de>,
        "mingo@...hat.com" <mingo@...hat.com>,
        "bp@...en8.de" <bp@...en8.de>, "x86@...nel.org" <x86@...nel.org>,
        "hpa@...or.com" <hpa@...or.com>,
        "dave.hansen@...ux.intel.com" <dave.hansen@...ux.intel.com>,
        "luto@...nel.org" <luto@...nel.org>,
        "peterz@...radead.org" <peterz@...radead.org>,
        "davem@...emloft.net" <davem@...emloft.net>,
        "kuba@...nel.org" <kuba@...nel.org>,
        "gregkh@...uxfoundation.org" <gregkh@...uxfoundation.org>,
        "arnd@...db.de" <arnd@...db.de>,
        "brijesh.singh@....com" <brijesh.singh@....com>,
        "jroedel@...e.de" <jroedel@...e.de>,
        Tianyu Lan <Tianyu.Lan@...rosoft.com>,
        "thomas.lendacky@....com" <thomas.lendacky@....com>,
        "pgonda@...gle.com" <pgonda@...gle.com>,
        "akpm@...ux-foundation.org" <akpm@...ux-foundation.org>,
        "kirill.shutemov@...ux.intel.com" <kirill.shutemov@...ux.intel.com>,
        "rppt@...nel.org" <rppt@...nel.org>,
        "david@...hat.com" <david@...hat.com>,
        "aneesh.kumar@...ux.ibm.com" <aneesh.kumar@...ux.ibm.com>,
        "saravanand@...com" <saravanand@...com>,
        "rientjes@...gle.com" <rientjes@...gle.com>
CC:     "linux-arch@...r.kernel.org" <linux-arch@...r.kernel.org>,
        "linux-hyperv@...r.kernel.org" <linux-hyperv@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "netdev@...r.kernel.org" <netdev@...r.kernel.org>,
        vkuznets <vkuznets@...hat.com>,
        "konrad.wilk@...cle.com" <konrad.wilk@...cle.com>,
        "hch@....de" <hch@....de>,
        "robin.murphy@....com" <robin.murphy@....com>,
        "joro@...tes.org" <joro@...tes.org>,
        "parri.andrea@...il.com" <parri.andrea@...il.com>,
        "dave.hansen@...el.com" <dave.hansen@...el.com>
Subject: RE: [PATCH V8.1 5/9] x86/sev-es: Expose sev_es_ghcb_hv_call() to call
 ghcb hv call out of sev code

From: Tianyu Lan <ltykernel@...il.com> Sent: Friday, October 22, 2021 6:37 AM
> 
> Hyper-V needs to call ghcb hv call to write/read MSR in Isolation VM.
> So expose sev_es_ghcb_hv_call() to call it in the Hyper-V code.
> 
> Hyper-V Isolation VM is unenlightened guests and run a paravisor in the
> VMPL0 for communicating and GHCB pages are being allocated and set up by
> that paravisor. Linux gets ghcb page pa via MSR_AMD64_SEV_ES_GHCB
> from paravisor and should not change it. Add set_ghcb_msr parameter for
> sev_es_ghcb_hv_call() and not set ghcb page pa when it's false.
> 
> Signed-off-by: Tianyu Lan <Tianyu.Lan@...rosoft.com>
> ---
> Change since v8:
>         Fix commit in the sev_es_ghcb_hv_call().
> 
>  arch/x86/include/asm/sev.h   | 12 ++++++++++++
>  arch/x86/kernel/sev-shared.c | 25 ++++++++++++++++---------
>  arch/x86/kernel/sev.c        | 13 +++++++------
>  3 files changed, 35 insertions(+), 15 deletions(-)
> 
> diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h
> index fa5cd05d3b5b..5b7f7e2b81f7 100644
> --- a/arch/x86/include/asm/sev.h
> +++ b/arch/x86/include/asm/sev.h
> @@ -81,12 +81,24 @@ static __always_inline void sev_es_nmi_complete(void)
>  		__sev_es_nmi_complete();
>  }
>  extern int __init sev_es_efi_map_ghcbs(pgd_t *pgd);
> +extern enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb,
> +					  bool set_ghcb_msr,
> +					  struct es_em_ctxt *ctxt,
> +					  u64 exit_code, u64 exit_info_1,
> +					  u64 exit_info_2);
>  #else
>  static inline void sev_es_ist_enter(struct pt_regs *regs) { }
>  static inline void sev_es_ist_exit(void) { }
>  static inline int sev_es_setup_ap_jump_table(struct real_mode_header *rmh) { return 0; }
>  static inline void sev_es_nmi_complete(void) { }
>  static inline int sev_es_efi_map_ghcbs(pgd_t *pgd) { return 0; }
> +static inline enum
> +es_result sev_es_ghcb_hv_call(struct ghcb *ghcb,
> +			      bool set_ghcb_msr, u64 exit_code,

The "struct es_em_ctxt *ctxt" argument is missing from this declaration,
which would presumably produce a compile error.

> +			      u64 exit_info_1, u64 exit_info_2)
> +{
> +	return ES_VMM_ERROR;
> +}
>  #endif
> 
>  #endif