From: Sean Christopherson <seanjc@google.com>
To: Robert Hoo <robert.hu@linux.intel.com>
Cc: pbonzini@redhat.com, vkuznets@redhat.com, wanpengli@tencent.com,
jmattson@google.com, joro@8bytes.org, chang.seok.bae@intel.com,
kvm@vger.kernel.org, robert.hu@intel.com
Subject: Re: [RFC PATCH 02/12] x86/cpufeature: Add CPUID.19H:{EBX,ECX} cpuid leaves
Date: Mon, 5 Apr 2021 15:32:58 +0000 [thread overview]
Message-ID: <YGstqj6YH96jrlAl@google.com> (raw)
In-Reply-To: <1611565580-47718-3-git-send-email-robert.hu@linux.intel.com>
On Mon, Jan 25, 2021, Robert Hoo wrote:
> Though KeyLocker is generally enumerated by
> CPUID.(07H,0):ECX.KL[bit23], CPUID.19H:{EBX,ECX} enumerate
> more details of KeyLocker supporting status.
>
> CPUID.19H:EBX
> bit0 enumerates if OS (CR4.KeyLocker) and BIOS have enabled KeyLocker.
> bit2 enumerates if wide Key Locker instructions are supported.
> bit4 enumerates if IWKey backup is supported.
> CPUID.19H:ECX
> bit0 enumerates if the NoBackup parameter to LOADIWKEY is supported.
> bit1 enumerates if IWKey randomization is supported.
>
> Define these 2 cpuid_leafs so that get_cpu_cap() will have these
> capabilities included, which will be the knowledge source of KVM on
> host KeyLocker capabilities.
>
> Most of above features don't have the necessity to appear in /proc/cpuinfo,
> except "iwkey_rand", which we think might be interesting for user to easily
> know if his system is using randomized IWKey.
>
> Signed-off-by: Robert Hoo <robert.hu@linux.intel.com>
> ---
> arch/x86/include/asm/cpufeature.h | 6 ++++--
> arch/x86/include/asm/cpufeatures.h | 11 ++++++++++-
> arch/x86/include/asm/disabled-features.h | 2 +-
> arch/x86/include/asm/required-features.h | 2 +-
> arch/x86/kernel/cpu/common.c | 7 +++++++
> 5 files changed, 23 insertions(+), 5 deletions(-)
>
> diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
> index 59bf91c..f9fea5f 100644
> --- a/arch/x86/include/asm/cpufeature.h
> +++ b/arch/x86/include/asm/cpufeature.h
> @@ -30,6 +30,8 @@ enum cpuid_leafs
> CPUID_7_ECX,
> CPUID_8000_0007_EBX,
> CPUID_7_EDX,
> + CPUID_19_EBX,
> + CPUID_19_ECX,
> };
>
> #ifdef CONFIG_X86_FEATURE_NAMES
> @@ -89,7 +91,7 @@ enum cpuid_leafs
> CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 17, feature_bit) || \
> CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 18, feature_bit) || \
> REQUIRED_MASK_CHECK || \
> - BUILD_BUG_ON_ZERO(NCAPINTS != 19))
> + BUILD_BUG_ON_ZERO(NCAPINTS != 21))
>
> #define DISABLED_MASK_BIT_SET(feature_bit) \
> ( CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 0, feature_bit) || \
> @@ -112,7 +114,7 @@ enum cpuid_leafs
> CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 17, feature_bit) || \
> CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 18, feature_bit) || \
> DISABLED_MASK_CHECK || \
> - BUILD_BUG_ON_ZERO(NCAPINTS != 19))
> + BUILD_BUG_ON_ZERO(NCAPINTS != 21))
>
> #define cpu_has(c, bit) \
> (__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 : \
> diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
> index 8f2f050..d4a883a 100644
> --- a/arch/x86/include/asm/cpufeatures.h
> +++ b/arch/x86/include/asm/cpufeatures.h
> @@ -13,7 +13,7 @@
> /*
> * Defines x86 CPU feature bits
> */
> -#define NCAPINTS 19 /* N 32-bit words worth of info */
> +#define NCAPINTS 21 /* N 32-bit words worth of info */
> #define NBUGINTS 1 /* N 32-bit bug flags */
>
> /*
> @@ -382,6 +382,15 @@
> #define X86_FEATURE_CORE_CAPABILITIES (18*32+30) /* "" IA32_CORE_CAPABILITIES MSR */
> #define X86_FEATURE_SPEC_CTRL_SSBD (18*32+31) /* "" Speculative Store Bypass Disable */
>
> +/* Intel-defined KeyLocker feature CPUID level 0x00000019 (EBX), word 20*/
> +#define X86_FEATURE_KL_INS_ENABLED (19*32 + 0) /* "" Key Locker instructions */
> +#define X86_FEATURE_KL_WIDE (19*32 + 2) /* "" Wide Key Locker instructions */
> +#define X86_FEATURE_IWKEY_BACKUP (19*32 + 4) /* "" IWKey backup */
> +
> +/* Intel-defined KeyLocker feature CPUID level 0x00000019 (ECX), word 21*/
> +#define X86_FEATURE_IWKEY_NOBACKUP (20*32 + 0) /* "" NoBackup parameter to LOADIWKEY */
> +#define X86_FEATURE_IWKEY_RAND (20*32 + 1) /* IWKey Randomization */
These should probably go into a Linux-defined leaf, I'm guessing neither leaf
will be anywhere near full, at least in Linux. KVM's reverse-CPUID code will
likely/hopefully be gaining support for scattered leafs in the near future[*],
that side of things should be a non-issue if/when this lands.
https://lkml.kernel.org/r/02455fc7521e9f1dc621b57c02c52cd04ce07797.1616136308.git.kai.huang@intel.com
next prev parent reply other threads:[~2021-04-05 15:33 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-25 9:06 [RFC PATCH 00/12] KVM: Support Intel KeyLocker Robert Hoo
2021-01-25 9:06 ` [RFC PATCH 01/12] x86/keylocker: Move LOADIWKEY opcode definition from keylocker.c to keylocker.h Robert Hoo
2021-01-25 9:06 ` [RFC PATCH 02/12] x86/cpufeature: Add CPUID.19H:{EBX,ECX} cpuid leaves Robert Hoo
2021-04-05 15:32 ` Sean Christopherson [this message]
2021-04-06 3:34 ` Robert Hoo
2021-01-25 9:06 ` [RFC PATCH 03/12] kvm/vmx: Introduce the new tertiary processor-based VM-execution controls Robert Hoo
2021-01-25 9:41 ` Vitaly Kuznetsov
2021-01-26 9:27 ` Robert Hoo
2021-02-03 6:32 ` Robert Hoo
2021-02-03 8:45 ` Vitaly Kuznetsov
2021-04-05 15:38 ` Sean Christopherson
2021-04-06 3:37 ` Robert Hoo
2021-01-25 9:06 ` [RFC PATCH 04/12] kvm/vmx: enable LOADIWKEY vm-exit support in " Robert Hoo
2021-01-25 9:06 ` [RFC PATCH 05/12] kvm/vmx: Add KVM support on KeyLocker operations Robert Hoo
2021-04-05 16:25 ` Sean Christopherson
2021-04-08 5:44 ` Robert Hoo
2021-01-25 9:06 ` [RFC PATCH 06/12] kvm/cpuid: Enumerate KeyLocker feature in KVM Robert Hoo
2021-01-25 9:06 ` [RFC PATCH 07/12] kvm/vmx/nested: Support new IA32_VMX_PROCBASED_CTLS3 vmx feature control MSR Robert Hoo
2021-04-05 15:44 ` Sean Christopherson
2021-04-08 5:45 ` Robert Hoo
2021-01-25 9:06 ` [RFC PATCH 08/12] kvm/vmx: Refactor vmx_compute_tertiary_exec_control() Robert Hoo
2021-04-05 15:46 ` Sean Christopherson
2021-04-08 5:45 ` Robert Hoo
2021-01-25 9:06 ` [RFC PATCH 09/12] kvm/vmx/vmcs12: Add Tertiary Exec-Control field in vmcs12 Robert Hoo
2021-01-25 9:06 ` [RFC PATCH 10/12] kvm/vmx/nested: Support tertiary VM-Exec control in vmcs02 Robert Hoo
2021-01-25 9:06 ` [RFC PATCH 11/12] kvm/vmx/nested: Support CR4.KL in nested Robert Hoo
2021-01-25 9:06 ` [RFC PATCH 12/12] kvm/vmx/nested: Enable nested LOADIWKey VM-exit Robert Hoo
2021-04-05 16:03 ` [RFC PATCH 00/12] KVM: Support Intel KeyLocker Sean Christopherson
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