linux-kernel - Re: [PATCH Part1 RFC v4 25/36] x86/boot: Add Confidential Computing type to setup

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]

Message-ID: <YR47IEALXIvAGmy8@zn.tnic>
Date:   Thu, 19 Aug 2021 13:06:08 +0200
From:   Borislav Petkov <bp@...en8.de>
To:     Brijesh Singh <brijesh.singh@....com>,
        Ard Biesheuvel <ardb@...nel.org>
Cc:     x86@...nel.org, linux-kernel@...r.kernel.org, kvm@...r.kernel.org,
        linux-efi@...r.kernel.org, platform-driver-x86@...r.kernel.org,
        linux-coco@...ts.linux.dev, linux-mm@...ck.org,
        linux-crypto@...r.kernel.org, Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Joerg Roedel <jroedel@...e.de>,
        Tom Lendacky <thomas.lendacky@....com>,
        "H. Peter Anvin" <hpa@...or.com>,
        Paolo Bonzini <pbonzini@...hat.com>,
        Sean Christopherson <seanjc@...gle.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Andy Lutomirski <luto@...nel.org>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        Sergio Lopez <slp@...hat.com>, Peter Gonda <pgonda@...gle.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>,
        David Rientjes <rientjes@...gle.com>,
        Dov Murik <dovmurik@...ux.ibm.com>,
        Tobin Feldman-Fitzthum <tobin@....com>,
        Michael Roth <michael.roth@....com>,
        Vlastimil Babka <vbabka@...e.cz>, tony.luck@...el.com,
        brijesh.ksingh@...il.com
Subject: Re: [PATCH Part1 RFC v4 25/36] x86/boot: Add Confidential Computing
 type to setup_data

(Moving Ard to To: for the EFI bits)

On Wed, Jul 07, 2021 at 01:14:55PM -0500, Brijesh Singh wrote:
> While launching the encrypted guests, the hypervisor may need to provide
> some additional information during the guest boot. When booting under the
> EFI based BIOS, the EFI configuration table contains an entry for the
> confidential computing blob that contains the required information.
> 
> To support booting encrypted guests on non-EFI VM, the hypervisor needs to
> pass this additional information to the kernel with a different method.
> 
> For this purpose, introduce SETUP_CC_BLOB type in setup_data to hold the
> physical address of the confidential computing blob location. The boot
> loader or hypervisor may choose to use this method instead of EFI
> configuration table. The CC blob location scanning should give preference
> to setup_data data over the EFI configuration table.
> 
> In AMD SEV-SNP, the CC blob contains the address of the secrets and CPUID
> pages. The secrets page includes information such as a VM to PSP
> communication key and CPUID page contains PSP filtered CPUID values.
> Define the AMD SEV confidential computing blob structure.
> 
> While at it, define the EFI GUID for the confidential computing blob.
> 
> Signed-off-by: Brijesh Singh <brijesh.singh@....com>
> ---
>  arch/x86/include/asm/sev.h            | 12 ++++++++++++
>  arch/x86/include/uapi/asm/bootparam.h |  1 +
>  include/linux/efi.h                   |  1 +
>  3 files changed, 14 insertions(+)
> 
> diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h
> index f68c9e2c3851..e41bd55dba5d 100644
> --- a/arch/x86/include/asm/sev.h
> +++ b/arch/x86/include/asm/sev.h
> @@ -44,6 +44,18 @@ struct es_em_ctxt {
>  
>  void do_vc_no_ghcb(struct pt_regs *regs, unsigned long exit_code);
>  
> +/* AMD SEV Confidential computing blob structure */
> +#define CC_BLOB_SEV_HDR_MAGIC	0x45444d41
> +struct cc_blob_sev_info {
> +	u32 magic;
> +	u16 version;
> +	u16 reserved;
> +	u64 secrets_phys;
> +	u32 secrets_len;
> +	u64 cpuid_phys;
> +	u32 cpuid_len;
> +};
> +
>  static inline u64 lower_bits(u64 val, unsigned int bits)
>  {
>  	u64 mask = (1ULL << bits) - 1;
> diff --git a/arch/x86/include/uapi/asm/bootparam.h b/arch/x86/include/uapi/asm/bootparam.h
> index b25d3f82c2f3..1ac5acca72ce 100644
> --- a/arch/x86/include/uapi/asm/bootparam.h
> +++ b/arch/x86/include/uapi/asm/bootparam.h
> @@ -10,6 +10,7 @@
>  #define SETUP_EFI			4
>  #define SETUP_APPLE_PROPERTIES		5
>  #define SETUP_JAILHOUSE			6
> +#define SETUP_CC_BLOB			7
>  
>  #define SETUP_INDIRECT			(1<<31)
>  
> diff --git a/include/linux/efi.h b/include/linux/efi.h
> index 6b5d36babfcc..75aeb2a56888 100644
> --- a/include/linux/efi.h
> +++ b/include/linux/efi.h
> @@ -344,6 +344,7 @@ void efi_native_runtime_setup(void);
>  #define EFI_CERT_SHA256_GUID			EFI_GUID(0xc1c41626, 0x504c, 0x4092, 0xac, 0xa9, 0x41, 0xf9, 0x36, 0x93, 0x43, 0x28)
>  #define EFI_CERT_X509_GUID			EFI_GUID(0xa5c059a1, 0x94e4, 0x4aa7, 0x87, 0xb5, 0xab, 0x15, 0x5c, 0x2b, 0xf0, 0x72)
>  #define EFI_CERT_X509_SHA256_GUID		EFI_GUID(0x3bd2a492, 0x96c0, 0x4079, 0xb4, 0x20, 0xfc, 0xf9, 0x8e, 0xf1, 0x03, 0xed)
> +#define EFI_CC_BLOB_GUID			EFI_GUID(0x067b1f5f, 0xcf26, 0x44c5, 0x85, 0x54, 0x93, 0xd7, 0x77, 0x91, 0x2d, 0x42)
>  
>  /*
>   * This GUID is used to pass to the kernel proper the struct screen_info
> -- 
> 2.17.1
> 

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette