From: Dave Hansen <dave.hansen@intel.com>
To: Sean Christopherson <seanjc@google.com>
Cc: Yang Weijiang <weijiang.yang@intel.com>,
pbonzini@redhat.com, x86@kernel.org, kvm@vger.kernel.org,
linux-kernel@vger.kernel.org, peterz@infradead.org,
chao.gao@intel.com, rick.p.edgecombe@intel.com,
mlevitsk@redhat.com, john.allen@amd.com
Subject: Re: [PATCH v10 04/27] x86/fpu/xstate: Introduce XFEATURE_MASK_KERNEL_DYNAMIC xfeature set
Date: Tue, 7 May 2024 16:17:09 -0700 [thread overview]
Message-ID: <1159c4e1-dae6-462a-8e34-6f74be4c83b3@intel.com> (raw)
In-Reply-To: <Zjqx8-ZPyB--6Eys@google.com>
On 5/7/24 15:57, Sean Christopherson wrote:
>> So I still prefer calling it "KERNEL" over "GUEST". But I also don't
>> feel strongly about it and I've said my peace. I won't NAK it one way
>> or the other.
> I assume you mean "DYNAMIC" over "GUEST"? I'm ok with DYNAMIC, reflecting the
> impact on each buffer makes sense.
Yes. Silly thinko/typo on my part.
> My one request would be to change the WARN in os_xsave() to fire on CET_KERNEL,
> not KERNEL_DYNAMIC, because it's specifically CET_KERNEL that is guest-only.
> Future dynamic xfeatures could be guest-only, but they could also be dynamic for
> some completely different reason. That was my other hang-up with "DYNAMIC";
> as-is, os_xsave() implies that it really truly is GUEST_ONLY.
>
> diff --git a/arch/x86/kernel/fpu/xstate.h b/arch/x86/kernel/fpu/xstate.h
> index 83ebf1e1cbb4..2a1ff49ccfd5 100644
> --- a/arch/x86/kernel/fpu/xstate.h
> +++ b/arch/x86/kernel/fpu/xstate.h
> @@ -185,8 +185,7 @@ static inline void os_xsave(struct fpstate *fpstate)
> WARN_ON_FPU(!alternatives_patched);
> xfd_validate_state(fpstate, mask, false);
>
> - WARN_ON_FPU(!fpstate->is_guest &&
> - (mask & XFEATURE_MASK_KERNEL_DYNAMIC));
> + WARN_ON_FPU(!fpstate->is_guest && (mask & XFEATURE_MASK_CET_KERNEL));
>
> XSTATE_XSAVE(&fpstate->regs.xsave, lmask, hmask, err);
Yeah, that would make a lot of sense. We could add a more generic
#define for it later if another feature gets added like this.
next prev parent reply other threads:[~2024-05-07 23:17 UTC|newest]
Thread overview: 94+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-19 7:47 [PATCH v10 00/27] Enable CET Virtualization Yang Weijiang
2024-02-19 7:47 ` [PATCH v10 01/27] x86/fpu/xstate: Always preserve non-user xfeatures/flags in __state_perm Yang Weijiang
2024-02-19 7:47 ` [PATCH v10 02/27] x86/fpu/xstate: Refine CET user xstate bit enabling Yang Weijiang
2024-02-19 7:47 ` [PATCH v10 03/27] x86/fpu/xstate: Add CET supervisor mode state support Yang Weijiang
2024-02-19 7:47 ` [PATCH v10 04/27] x86/fpu/xstate: Introduce XFEATURE_MASK_KERNEL_DYNAMIC xfeature set Yang Weijiang
2024-05-01 18:45 ` Sean Christopherson
2024-05-02 17:46 ` Dave Hansen
2024-05-07 22:57 ` Sean Christopherson
2024-05-07 23:17 ` Dave Hansen [this message]
2024-05-08 1:19 ` Yang, Weijiang
2024-02-19 7:47 ` [PATCH v10 05/27] x86/fpu/xstate: Introduce fpu_guest_cfg for guest FPU configuration Yang Weijiang
2024-02-19 7:47 ` [PATCH v10 06/27] x86/fpu/xstate: Create guest fpstate with guest specific config Yang Weijiang
2024-02-19 7:47 ` [PATCH v10 07/27] x86/fpu/xstate: Warn if kernel dynamic xfeatures detected in normal fpstate Yang Weijiang
2024-02-19 7:47 ` [PATCH v10 08/27] KVM: x86: Rework cpuid_get_supported_xcr0() to operate on vCPU data Yang Weijiang
2024-02-19 7:47 ` [PATCH v10 09/27] KVM: x86: Rename kvm_{g,s}et_msr()* to menifest emulation operations Yang Weijiang
2024-05-01 18:54 ` Sean Christopherson
2024-05-06 5:58 ` Yang, Weijiang
2024-02-19 7:47 ` [PATCH v10 10/27] KVM: x86: Refine xsave-managed guest register/MSR reset handling Yang Weijiang
2024-02-20 3:04 ` Chao Gao
2024-02-20 13:23 ` Yang, Weijiang
2024-05-01 20:40 ` Sean Christopherson
2024-05-06 7:26 ` Yang, Weijiang
2024-02-19 7:47 ` [PATCH v10 11/27] KVM: x86: Add kvm_msr_{read,write}() helpers Yang Weijiang
2024-02-19 7:47 ` [PATCH v10 12/27] KVM: x86: Report XSS as to-be-saved if there are supported features Yang Weijiang
2024-02-19 7:47 ` [PATCH v10 13/27] KVM: x86: Refresh CPUID on write to guest MSR_IA32_XSS Yang Weijiang
2024-02-20 8:51 ` Chao Gao
2024-05-01 20:43 ` Sean Christopherson
2024-05-06 7:30 ` Yang, Weijiang
2024-02-19 7:47 ` [PATCH v10 14/27] KVM: x86: Initialize kvm_caps.supported_xss Yang Weijiang
2024-02-19 7:47 ` [PATCH v10 15/27] KVM: x86: Load guest FPU state when access XSAVE-managed MSRs Yang Weijiang
2024-02-19 7:47 ` [PATCH v10 16/27] KVM: x86: Add fault checks for guest CR4.CET setting Yang Weijiang
2024-02-19 7:47 ` [PATCH v10 17/27] KVM: x86: Report KVM supported CET MSRs as to-be-saved Yang Weijiang
2024-05-01 22:40 ` Sean Christopherson
2024-05-06 8:31 ` Yang, Weijiang
2024-05-07 17:27 ` Sean Christopherson
2024-05-08 7:00 ` Yang, Weijiang
2024-02-19 7:47 ` [PATCH v10 18/27] KVM: VMX: Introduce CET VMCS fields and control bits Yang Weijiang
2024-02-19 7:47 ` [PATCH v10 19/27] KVM: x86: Use KVM-governed feature framework to track "SHSTK/IBT enabled" Yang Weijiang
2024-02-19 7:47 ` [PATCH v10 20/27] KVM: VMX: Emulate read and write to CET MSRs Yang Weijiang
2024-03-12 22:55 ` Sean Christopherson
2024-03-13 9:43 ` Yang, Weijiang
2024-03-13 16:00 ` Sean Christopherson
2024-02-19 7:47 ` [PATCH v10 21/27] KVM: x86: Save and reload SSP to/from SMRAM Yang Weijiang
2024-05-01 22:50 ` Sean Christopherson
2024-05-06 8:41 ` Yang, Weijiang
2024-02-19 7:47 ` [PATCH v10 22/27] KVM: VMX: Set up interception for CET MSRs Yang Weijiang
2024-05-01 23:07 ` Sean Christopherson
2024-05-06 8:48 ` Yang, Weijiang
2024-02-19 7:47 ` [PATCH v10 23/27] KVM: VMX: Set host constant supervisor states to VMCS fields Yang Weijiang
2024-02-19 7:47 ` [PATCH v10 24/27] KVM: x86: Enable CET virtualization for VMX and advertise to userspace Yang Weijiang
2024-05-01 23:15 ` Sean Christopherson
2024-05-01 23:24 ` Edgecombe, Rick P
2024-05-06 9:19 ` Yang, Weijiang
2024-05-06 16:54 ` Sean Christopherson
2024-05-07 2:37 ` Yang, Weijiang
2024-05-06 17:05 ` Edgecombe, Rick P
2024-05-06 23:33 ` Sean Christopherson
2024-05-06 23:53 ` Edgecombe, Rick P
2024-05-07 14:21 ` Sean Christopherson
2024-05-07 14:45 ` Edgecombe, Rick P
2024-05-07 15:08 ` Sean Christopherson
2024-05-07 15:33 ` Edgecombe, Rick P
2024-05-16 7:13 ` Yang, Weijiang
2024-05-16 14:39 ` Sean Christopherson
2024-05-16 15:36 ` Dave Hansen
2024-05-16 16:58 ` Sean Christopherson
2024-05-17 8:27 ` Yang, Weijiang
2024-05-17 8:57 ` Thomas Gleixner
2024-05-17 14:26 ` Sean Christopherson
2024-05-20 9:43 ` Yang, Weijiang
2024-05-20 17:09 ` Sean Christopherson
2024-05-20 17:15 ` Dave Hansen
2024-05-22 9:03 ` Yang, Weijiang
2024-05-22 15:06 ` Edgecombe, Rick P
2024-05-23 10:07 ` Yang, Weijiang
2024-05-22 8:41 ` Yang, Weijiang
2024-05-27 9:05 ` Yang, Weijiang
2024-05-01 23:34 ` Sean Christopherson
2024-05-06 9:41 ` Yang, Weijiang
2024-05-16 7:20 ` Yang, Weijiang
2024-05-16 14:43 ` Sean Christopherson
2024-05-17 8:04 ` Yang, Weijiang
2024-02-19 7:47 ` [PATCH v10 25/27] KVM: nVMX: Introduce new VMX_BASIC bit for event error_code delivery to L1 Yang Weijiang
2024-05-01 23:19 ` Sean Christopherson
2024-05-06 9:19 ` Yang, Weijiang
2024-02-19 7:47 ` [PATCH v10 26/27] KVM: nVMX: Enable CET support for nested guest Yang Weijiang
2024-05-01 23:23 ` Sean Christopherson
2024-05-06 9:25 ` Yang, Weijiang
2024-02-19 7:47 ` [PATCH v10 27/27] KVM: x86: Don't emulate instructions guarded by CET Yang Weijiang
2024-05-01 23:24 ` Sean Christopherson
2024-05-06 9:26 ` Yang, Weijiang
2024-03-06 14:44 ` [PATCH v10 00/27] Enable CET Virtualization Yang, Weijiang
2024-05-01 23:27 ` Sean Christopherson
2024-05-06 9:31 ` Yang, Weijiang
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