From: Chao Gao <chao.gao@intel.com>
To: Yang Weijiang <weijiang.yang@intel.com>
Cc: <seanjc@google.com>, <pbonzini@redhat.com>, <kvm@vger.kernel.org>,
<linux-kernel@vger.kernel.org>, <peterz@infradead.org>,
<rppt@kernel.org>, <binbin.wu@linux.intel.com>,
<rick.p.edgecombe@intel.com>, <john.allen@amd.com>,
Zhang Yi Z <yi.z.zhang@linux.intel.com>
Subject: Re: [PATCH v3 07/21] KVM:x86: Refresh CPUID on write to guest MSR_IA32_XSS
Date: Thu, 25 May 2023 14:10:10 +0800 [thread overview]
Message-ID: <ZG77wu4PyBn1z587@chao-email> (raw)
In-Reply-To: <20230511040857.6094-8-weijiang.yang@intel.com>
On Thu, May 11, 2023 at 12:08:43AM -0400, Yang Weijiang wrote:
>Update CPUID(EAX=0DH,ECX=1) when the guest's XSS is modified.
>CPUID(EAX=0DH,ECX=1).EBX reports current required storage size for all
>features enabled via XCR0 | XSS so that guest can allocate correct xsave
>buffer.
>
>Note, KVM does not yet support any XSS based features, i.e. supported_xss
>is guaranteed to be zero at this time.
>
>Co-developed-by: Zhang Yi Z <yi.z.zhang@linux.intel.com>
>Signed-off-by: Zhang Yi Z <yi.z.zhang@linux.intel.com>
>Signed-off-by: Yang Weijiang <weijiang.yang@intel.com>
>---
> arch/x86/kvm/cpuid.c | 7 +++++--
> arch/x86/kvm/x86.c | 6 ++++--
> 2 files changed, 9 insertions(+), 4 deletions(-)
>
>diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
>index 123bf8b97a4b..cbb1b8a65502 100644
>--- a/arch/x86/kvm/cpuid.c
>+++ b/arch/x86/kvm/cpuid.c
>@@ -277,8 +277,11 @@ static void __kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu, struct kvm_cpuid_e
>
> best = cpuid_entry2_find(entries, nent, 0xD, 1);
> if (best && (cpuid_entry_has(best, X86_FEATURE_XSAVES) ||
>- cpuid_entry_has(best, X86_FEATURE_XSAVEC)))
>- best->ebx = xstate_required_size(vcpu->arch.xcr0, true);
>+ cpuid_entry_has(best, X86_FEATURE_XSAVEC))) {
Align indentation.
if (best && (cpuid_entry_has(best, X86_FEATURE_XSAVES) ||
cpuid_entry_has(best, X86_FEATURE_XSAVEC))) {
>+ u64 xstate = vcpu->arch.xcr0 | vcpu->arch.ia32_xss;
>+
>+ best->ebx = xstate_required_size(xstate, true);
>+ }
>
> best = __kvm_find_kvm_cpuid_features(vcpu, entries, nent);
> if (kvm_hlt_in_guest(vcpu->kvm) && best &&
>diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
>index 33a780fe820b..ab3360a10933 100644
>--- a/arch/x86/kvm/x86.c
>+++ b/arch/x86/kvm/x86.c
>@@ -3776,8 +3776,10 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
> */
> if (data & ~kvm_caps.supported_xss)
Shouldn't we check against the supported value of _this_ guest? similar to
guest_supported_xcr0.
> return 1;
>- vcpu->arch.ia32_xss = data;
>- kvm_update_cpuid_runtime(vcpu);
>+ if (vcpu->arch.ia32_xss != data) {
>+ vcpu->arch.ia32_xss = data;
>+ kvm_update_cpuid_runtime(vcpu);
>+ }
> break;
> case MSR_SMI_COUNT:
> if (!msr_info->host_initiated)
>--
>2.27.0
>
next prev parent reply other threads:[~2023-05-25 6:10 UTC|newest]
Thread overview: 99+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-11 4:08 [PATCH v3 00/21] Enable CET Virtualization Yang Weijiang
2023-05-11 4:08 ` [PATCH v3 01/21] x86/shstk: Add Kconfig option for shadow stack Yang Weijiang
2023-05-11 4:08 ` [PATCH v3 02/21] x86/cpufeatures: Add CPU feature flags for shadow stacks Yang Weijiang
2023-05-11 4:08 ` [PATCH v3 03/21] x86/cpufeatures: Enable CET CR4 bit for shadow stack Yang Weijiang
2023-05-11 4:08 ` [PATCH v3 04/21] x86/fpu/xstate: Introduce CET MSR and XSAVES supervisor states Yang Weijiang
2023-05-11 4:08 ` [PATCH v3 05/21] x86/fpu: Add helper for modifying xstate Yang Weijiang
2023-05-11 4:08 ` [PATCH v3 06/21] KVM:x86: Report XSS as to-be-saved if there are supported features Yang Weijiang
2023-05-24 7:06 ` Chao Gao
2023-05-24 8:19 ` Yang, Weijiang
2023-05-11 4:08 ` [PATCH v3 07/21] KVM:x86: Refresh CPUID on write to guest MSR_IA32_XSS Yang Weijiang
2023-05-25 6:10 ` Chao Gao [this message]
2023-05-30 3:51 ` Yang, Weijiang
2023-05-30 12:08 ` Chao Gao
2023-05-31 1:11 ` Yang, Weijiang
2023-06-15 23:45 ` Sean Christopherson
2023-06-16 1:58 ` Yang, Weijiang
2023-06-23 23:21 ` Sean Christopherson
2023-06-26 9:24 ` Yang, Weijiang
2023-05-11 4:08 ` [PATCH v3 08/21] KVM:x86: Init kvm_caps.supported_xss with supported feature bits Yang Weijiang
2023-06-06 8:38 ` Chao Gao
2023-06-08 5:42 ` Yang, Weijiang
2023-05-11 4:08 ` [PATCH v3 09/21] KVM:x86: Load guest FPU state when accessing xsaves-managed MSRs Yang Weijiang
2023-06-15 23:50 ` Sean Christopherson
2023-06-16 2:02 ` Yang, Weijiang
2023-05-11 4:08 ` [PATCH v3 10/21] KVM:x86: Add #CP support in guest exception classification Yang Weijiang
2023-06-06 9:08 ` Chao Gao
2023-06-08 6:01 ` Yang, Weijiang
2023-06-15 23:58 ` Sean Christopherson
2023-06-16 6:56 ` Yang, Weijiang
2023-06-16 18:57 ` Sean Christopherson
2023-06-19 9:28 ` Yang, Weijiang
2023-06-30 9:34 ` Yang, Weijiang
2023-06-30 10:27 ` Chao Gao
2023-06-30 12:05 ` Yang, Weijiang
2023-06-30 15:05 ` Neiger, Gil
2023-06-30 15:15 ` Sean Christopherson
2023-07-01 1:58 ` Yang, Weijiang
2023-07-01 1:54 ` Yang, Weijiang
2023-06-30 15:07 ` Sean Christopherson
2023-06-30 15:21 ` Neiger, Gil
2023-07-01 1:57 ` Yang, Weijiang
2023-05-11 4:08 ` [PATCH v3 11/21] KVM:VMX: Introduce CET VMCS fields and control bits Yang Weijiang
2023-05-11 4:08 ` [PATCH v3 12/21] KVM:x86: Add fault checks for guest CR4.CET setting Yang Weijiang
2023-06-06 11:03 ` Chao Gao
2023-06-08 6:06 ` Yang, Weijiang
2023-05-11 4:08 ` [PATCH v3 13/21] KVM:VMX: Emulate reads and writes to CET MSRs Yang Weijiang
2023-05-23 8:21 ` Binbin Wu
2023-05-24 2:49 ` Yang, Weijiang
2023-06-23 23:53 ` Sean Christopherson
2023-06-26 14:05 ` Yang, Weijiang
2023-06-26 21:15 ` Sean Christopherson
2023-06-27 3:32 ` Yang, Weijiang
2023-06-27 14:55 ` Sean Christopherson
2023-06-28 1:42 ` Yang, Weijiang
2023-07-07 9:10 ` Yang, Weijiang
2023-07-07 15:28 ` Neiger, Gil
2023-07-12 16:42 ` Sean Christopherson
2023-05-11 4:08 ` [PATCH v3 14/21] KVM:VMX: Add a synthetic MSR to allow userspace to access GUEST_SSP Yang Weijiang
2023-05-23 8:57 ` Binbin Wu
2023-05-24 2:55 ` Yang, Weijiang
2023-05-11 4:08 ` [PATCH v3 15/21] KVM:x86: Report CET MSRs as to-be-saved if CET is supported Yang Weijiang
2023-05-11 4:08 ` [PATCH v3 16/21] KVM:x86: Save/Restore GUEST_SSP to/from SMM state save area Yang Weijiang
2023-06-23 22:30 ` Sean Christopherson
2023-06-26 8:59 ` Yang, Weijiang
2023-06-26 21:20 ` Sean Christopherson
2023-06-27 3:50 ` Yang, Weijiang
2023-05-11 4:08 ` [PATCH v3 17/21] KVM:VMX: Pass through user CET MSRs to the guest Yang Weijiang
2023-05-11 4:08 ` [PATCH v3 18/21] KVM:x86: Enable CET virtualization for VMX and advertise to userspace Yang Weijiang
2023-05-24 6:35 ` Chenyi Qiang
2023-05-24 8:07 ` Yang, Weijiang
2023-05-11 4:08 ` [PATCH v3 19/21] KVM:nVMX: Enable user CET support for nested VMX Yang Weijiang
2023-05-11 4:08 ` [PATCH v3 20/21] KVM:x86: Enable kernel IBT support for guest Yang Weijiang
2023-06-24 0:03 ` Sean Christopherson
2023-06-26 12:10 ` Yang, Weijiang
2023-06-26 20:50 ` Sean Christopherson
2023-06-27 1:53 ` Yang, Weijiang
2023-05-11 4:08 ` [PATCH v3 21/21] KVM:x86: Support CET supervisor shadow stack MSR access Yang Weijiang
2023-06-15 23:30 ` [PATCH v3 00/21] Enable CET Virtualization Sean Christopherson
2023-06-16 0:00 ` Sean Christopherson
2023-06-16 1:00 ` Yang, Weijiang
2023-06-16 8:25 ` Yang, Weijiang
2023-06-16 17:56 ` Sean Christopherson
2023-06-19 6:41 ` Yang, Weijiang
2023-06-23 20:51 ` Sean Christopherson
2023-06-26 6:46 ` Yang, Weijiang
2023-07-17 7:44 ` Yang, Weijiang
2023-07-19 19:41 ` Sean Christopherson
2023-07-19 20:26 ` Sean Christopherson
2023-07-20 1:58 ` Yang, Weijiang
2023-07-19 20:36 ` Peter Zijlstra
2023-07-20 5:26 ` Pankaj Gupta
2023-07-20 8:03 ` Peter Zijlstra
2023-07-20 8:09 ` Peter Zijlstra
2023-07-20 9:14 ` Pankaj Gupta
2023-07-20 10:46 ` Andrew Cooper
2023-07-20 1:55 ` Yang, Weijiang
2023-07-10 0:28 ` Yang, Weijiang
2023-07-10 22:18 ` Sean Christopherson
2023-07-11 1:24 ` Yang, Weijiang
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