linux-kernel - RE: [PATCH V3 02/13] x86/HV: Initialize shared memory boundary in the Isolation VM.

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: <MWHPR21MB159376E024639D8F0465BCA2D7F99@MWHPR21MB1593.namprd21.prod.outlook.com>
Date:   Thu, 12 Aug 2021 19:18:30 +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>,
        "konrad.wilk@...cle.com" <konrad.wilk@...cle.com>,
        "boris.ostrovsky@...cle.com" <boris.ostrovsky@...cle.com>,
        "jgross@...e.com" <jgross@...e.com>,
        "sstabellini@...nel.org" <sstabellini@...nel.org>,
        "joro@...tes.org" <joro@...tes.org>,
        "will@...nel.org" <will@...nel.org>,
        "davem@...emloft.net" <davem@...emloft.net>,
        "kuba@...nel.org" <kuba@...nel.org>,
        "jejb@...ux.ibm.com" <jejb@...ux.ibm.com>,
        "martin.petersen@...cle.com" <martin.petersen@...cle.com>,
        "arnd@...db.de" <arnd@...db.de>, "hch@....de" <hch@....de>,
        "m.szyprowski@...sung.com" <m.szyprowski@...sung.com>,
        "robin.murphy@....com" <robin.murphy@....com>,
        "thomas.lendacky@....com" <thomas.lendacky@....com>,
        "brijesh.singh@....com" <brijesh.singh@....com>,
        "ardb@...nel.org" <ardb@...nel.org>,
        Tianyu Lan <Tianyu.Lan@...rosoft.com>,
        "pgonda@...gle.com" <pgonda@...gle.com>,
        "martin.b.radev@...il.com" <martin.b.radev@...il.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>,
        "sfr@...b.auug.org.au" <sfr@...b.auug.org.au>,
        "saravanand@...com" <saravanand@...com>,
        "krish.sadhukhan@...cle.com" <krish.sadhukhan@...cle.com>,
        "aneesh.kumar@...ux.ibm.com" <aneesh.kumar@...ux.ibm.com>,
        "xen-devel@...ts.xenproject.org" <xen-devel@...ts.xenproject.org>,
        "rientjes@...gle.com" <rientjes@...gle.com>,
        "hannes@...xchg.org" <hannes@...xchg.org>,
        "tj@...nel.org" <tj@...nel.org>
CC:     "iommu@...ts.linux-foundation.org" <iommu@...ts.linux-foundation.org>,
        "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>,
        "linux-scsi@...r.kernel.org" <linux-scsi@...r.kernel.org>,
        "netdev@...r.kernel.org" <netdev@...r.kernel.org>,
        vkuznets <vkuznets@...hat.com>,
        "parri.andrea@...il.com" <parri.andrea@...il.com>,
        "dave.hansen@...el.com" <dave.hansen@...el.com>
Subject: RE: [PATCH V3 02/13] x86/HV: Initialize shared memory boundary in the
 Isolation VM.

From: Tianyu Lan <ltykernel@...il.com> Sent: Monday, August 9, 2021 10:56 AM
> Subject: [PATCH V3 02/13] x86/HV: Initialize shared memory boundary in the Isolation VM.

As with Patch 1, use the "x86/hyperv:" tag in the Subject line.

> 
> From: Tianyu Lan <Tianyu.Lan@...rosoft.com>
> 
> Hyper-V exposes shared memory boundary via cpuid
> HYPERV_CPUID_ISOLATION_CONFIG and store it in the
> shared_gpa_boundary of ms_hyperv struct. This prepares
> to share memory with host for SNP guest.
> 
> Signed-off-by: Tianyu Lan <Tianyu.Lan@...rosoft.com>
> ---
>  arch/x86/kernel/cpu/mshyperv.c |  2 ++
>  include/asm-generic/mshyperv.h | 12 +++++++++++-
>  2 files changed, 13 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
> index 6b5835a087a3..2b7f396ef1a5 100644
> --- a/arch/x86/kernel/cpu/mshyperv.c
> +++ b/arch/x86/kernel/cpu/mshyperv.c
> @@ -313,6 +313,8 @@ static void __init ms_hyperv_init_platform(void)
>  	if (ms_hyperv.priv_high & HV_ISOLATION) {
>  		ms_hyperv.isolation_config_a = cpuid_eax(HYPERV_CPUID_ISOLATION_CONFIG);
>  		ms_hyperv.isolation_config_b = cpuid_ebx(HYPERV_CPUID_ISOLATION_CONFIG);
> +		ms_hyperv.shared_gpa_boundary =
> +			(u64)1 << ms_hyperv.shared_gpa_boundary_bits;

You could use BIT_ULL() here, but it's kind of a shrug.

> 
>  		pr_info("Hyper-V: Isolation Config: Group A 0x%x, Group B 0x%x\n",
>  			ms_hyperv.isolation_config_a, ms_hyperv.isolation_config_b);
> diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
> index 4269f3174e58..aa26d24a5ca9 100644
> --- a/include/asm-generic/mshyperv.h
> +++ b/include/asm-generic/mshyperv.h
> @@ -35,8 +35,18 @@ struct ms_hyperv_info {
>  	u32 max_vp_index;
>  	u32 max_lp_index;
>  	u32 isolation_config_a;
> -	u32 isolation_config_b;
> +	union {
> +		u32 isolation_config_b;
> +		struct {
> +			u32 cvm_type : 4;
> +			u32 Reserved11 : 1;
> +			u32 shared_gpa_boundary_active : 1;
> +			u32 shared_gpa_boundary_bits : 6;
> +			u32 Reserved12 : 20;

Any reason to name the reserved fields as "11" and "12"?  It
just looks a bit unusual.  And I'd suggest lowercase "r".

> +		};
> +	};
>  	void  __percpu **ghcb_base;
> +	u64 shared_gpa_boundary;
>  };
>  extern struct ms_hyperv_info ms_hyperv;
> 
> --
> 2.25.1