From: Xin Li <xin3.li@intel.com>
To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org
Cc: seanjc@google.com, pbonzini@redhat.com, corbet@lwn.net,
tglx@linutronix.de, mingo@redhat.com, bp@alien8.de,
dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com,
shuah@kernel.org, vkuznets@redhat.com, peterz@infradead.org,
ravi.v.shankar@intel.com, xin@zytor.com
Subject: [PATCH v2 06/25] KVM: VMX: Defer enabling FRED MSRs save/load until after set CPUID
Date: Wed, 7 Feb 2024 09:26:26 -0800 [thread overview]
Message-ID: <20240207172646.3981-7-xin3.li@intel.com> (raw)
In-Reply-To: <20240207172646.3981-1-xin3.li@intel.com>
Clear FRED VM entry/exit controls when initializing a vCPU, and set
these controls only if FRED is enumerated after set CPUID.
FRED VM entry/exit controls need to be set to establish context
sufficient to support FRED event delivery immediately after VM entry
and exit. However it is not required to save/load FRED MSRs for
a non-FRED guest, which aren't supposed to access FRED MSRs.
Signed-off-by: Xin Li <xin3.li@intel.com>
Tested-by: Shan Kang <shan.kang@intel.com>
---
Changes since v1:
* Use kvm_cpu_cap_has() instead of cpu_feature_enabled() (Chao Gao).
* Clear FRED VM entry/exit controls if FRED is not enumerated (Chao Gao).
* Use guest_can_use() to trace FRED enumeration in a vcpu (Chao Gao).
---
arch/x86/kvm/governed_features.h | 1 +
arch/x86/kvm/vmx/vmx.c | 32 +++++++++++++++++++++++++++++++-
2 files changed, 32 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/governed_features.h b/arch/x86/kvm/governed_features.h
index ad463b1ed4e4..507ca73e52e9 100644
--- a/arch/x86/kvm/governed_features.h
+++ b/arch/x86/kvm/governed_features.h
@@ -17,6 +17,7 @@ KVM_GOVERNED_X86_FEATURE(PFTHRESHOLD)
KVM_GOVERNED_X86_FEATURE(VGIF)
KVM_GOVERNED_X86_FEATURE(VNMI)
KVM_GOVERNED_X86_FEATURE(LAM)
+KVM_GOVERNED_X86_FEATURE(FRED)
#undef KVM_GOVERNED_X86_FEATURE
#undef KVM_GOVERNED_FEATURE
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 4023474ea002..34b6676f60d8 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -4402,6 +4402,9 @@ static u32 vmx_vmentry_ctrl(void)
if (cpu_has_perf_global_ctrl_bug())
vmentry_ctrl &= ~VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL;
+ /* Whether to load guest FRED MSRs is deferred until after set CPUID */
+ vmentry_ctrl &= ~VM_ENTRY_LOAD_IA32_FRED;
+
return vmentry_ctrl;
}
@@ -4430,7 +4433,13 @@ static u32 vmx_vmexit_ctrl(void)
static u64 vmx_secondary_vmexit_ctrl(void)
{
- return vmcs_config.secondary_vmexit_ctrl;
+ u64 secondary_vmexit_ctrl = vmcs_config.secondary_vmexit_ctrl;
+
+ /* Whether to save/load FRED MSRs is deferred until after set CPUID */
+ secondary_vmexit_ctrl &= ~(SECONDARY_VM_EXIT_SAVE_IA32_FRED |
+ SECONDARY_VM_EXIT_LOAD_IA32_FRED);
+
+ return secondary_vmexit_ctrl;
}
static void vmx_refresh_apicv_exec_ctrl(struct kvm_vcpu *vcpu)
@@ -7762,10 +7771,31 @@ static void update_intel_pt_cfg(struct kvm_vcpu *vcpu)
vmx->pt_desc.ctl_bitmask &= ~(0xfULL << (32 + i * 4));
}
+static void vmx_vcpu_config_fred_after_set_cpuid(struct kvm_vcpu *vcpu)
+{
+ struct vcpu_vmx *vmx = to_vmx(vcpu);
+
+ kvm_governed_feature_check_and_set(vcpu, X86_FEATURE_FRED);
+
+ if (guest_can_use(vcpu, X86_FEATURE_FRED)) {
+ vm_entry_controls_setbit(vmx, VM_ENTRY_LOAD_IA32_FRED);
+ secondary_vm_exit_controls_setbit(vmx,
+ SECONDARY_VM_EXIT_SAVE_IA32_FRED |
+ SECONDARY_VM_EXIT_LOAD_IA32_FRED);
+ } else {
+ vm_entry_controls_clearbit(vmx, VM_ENTRY_LOAD_IA32_FRED);
+ secondary_vm_exit_controls_clearbit(vmx,
+ SECONDARY_VM_EXIT_SAVE_IA32_FRED |
+ SECONDARY_VM_EXIT_LOAD_IA32_FRED);
+ }
+}
+
static void vmx_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu)
{
struct vcpu_vmx *vmx = to_vmx(vcpu);
+ vmx_vcpu_config_fred_after_set_cpuid(vcpu);
+
/*
* XSAVES is effectively enabled if and only if XSAVE is also exposed
* to the guest. XSAVES depends on CR4.OSXSAVE, and CR4.OSXSAVE can be
--
2.43.0
next prev parent reply other threads:[~2024-02-07 17:59 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-07 17:26 [PATCH v2 00/25] Enable FRED with KVM VMX Xin Li
2024-02-07 17:26 ` [PATCH v2 01/25] KVM: VMX: Cleanup VMX basic information defines and usages Xin Li
2024-02-07 17:26 ` [PATCH v2 02/25] KVM: VMX: Cleanup VMX misc " Xin Li
2024-02-07 17:26 ` [PATCH v2 03/25] KVM: VMX: Add support for the secondary VM exit controls Xin Li
2024-04-19 10:21 ` Chao Gao
2024-02-07 17:26 ` [PATCH v2 04/25] KVM: x86: Mark CR4.FRED as not reserved Xin Li
2024-04-19 10:22 ` Chao Gao
2024-02-07 17:26 ` [PATCH v2 05/25] KVM: VMX: Initialize FRED VM entry/exit controls in vmcs_config Xin Li
2024-04-19 10:24 ` Chao Gao
2024-02-07 17:26 ` Xin Li [this message]
2024-04-19 11:02 ` [PATCH v2 06/25] KVM: VMX: Defer enabling FRED MSRs save/load until after set CPUID Chao Gao
2024-02-07 17:26 ` [PATCH v2 07/25] KVM: VMX: Set intercept for FRED MSRs Xin Li
2024-04-19 13:35 ` Chao Gao
2024-04-19 17:06 ` Li, Xin3
2024-02-07 17:26 ` [PATCH v2 08/25] KVM: VMX: Initialize VMCS FRED fields Xin Li
2024-04-19 14:01 ` Chao Gao
2024-04-19 17:02 ` Li, Xin3
2024-02-07 17:26 ` [PATCH v2 09/25] KVM: VMX: Switch FRED RSP0 between host and guest Xin Li
2024-04-19 14:23 ` Chao Gao
2024-04-19 16:37 ` Li, Xin3
2024-02-07 17:26 ` [PATCH v2 10/25] KVM: VMX: Add support for FRED context save/restore Xin Li
2024-04-29 6:31 ` Chao Gao
2024-02-07 17:26 ` [PATCH v2 11/25] KVM: x86: Add kvm_is_fred_enabled() Xin Li
2024-04-29 8:24 ` Chao Gao
2024-05-11 1:24 ` Li, Xin3
2024-05-11 1:53 ` Chao Gao
2024-02-07 17:26 ` [PATCH v2 12/25] KVM: VMX: Handle FRED event data Xin Li
2024-04-30 3:14 ` Chao Gao
2024-05-10 9:36 ` Li, Xin3
2024-05-11 3:03 ` Chao Gao
2024-02-07 17:26 ` [PATCH v2 13/25] KVM: VMX: Handle VMX nested exception for FRED Xin Li
2024-04-30 7:34 ` Chao Gao
2024-02-07 17:26 ` [PATCH v2 14/25] KVM: VMX: Disable FRED if FRED consistency checks fail Xin Li
2024-04-30 8:21 ` Chao Gao
2024-02-07 17:26 ` [PATCH v2 15/25] KVM: VMX: Dump FRED context in dump_vmcs() Xin Li
2024-04-30 9:09 ` Chao Gao
2024-02-07 17:26 ` [PATCH v2 16/25] KVM: VMX: Invoke vmx_set_cpu_caps() before nested setup Xin Li
2024-02-07 17:26 ` [PATCH v2 17/25] KVM: nVMX: Add support for the secondary VM exit controls Xin Li
2024-02-07 17:26 ` [PATCH v2 18/25] KVM: nVMX: Add a prerequisite to SHADOW_FIELD_R[OW] macros Xin Li
2024-02-07 17:26 ` [PATCH v2 19/25] KVM: nVMX: Add FRED VMCS fields Xin Li
2024-02-07 17:26 ` [PATCH v2 20/25] KVM: nVMX: Add support for VMX FRED controls Xin Li
2024-02-07 17:26 ` [PATCH v2 21/25] KVM: nVMX: Add VMCS FRED states checking Xin Li
2024-02-07 17:26 ` [PATCH v2 22/25] KVM: x86: Allow FRED/LKGS/WRMSRNS to be exposed to guests Xin Li
2024-02-07 17:26 ` [PATCH v2 23/25] KVM: selftests: Run debug_regs test with FRED enabled Xin Li
2024-02-07 17:26 ` [PATCH v2 24/25] KVM: selftests: Add a new VM guest mode to run user level code Xin Li
2024-02-07 17:26 ` [PATCH v2 25/25] KVM: selftests: Add fred exception tests Xin Li
2024-03-29 20:18 ` Muhammad Usama Anjum
2024-03-29 20:18 ` Muhammad Usama Anjum
2024-04-24 16:08 ` Sean Christopherson
2024-03-27 8:08 ` [PATCH v2 00/25] Enable FRED with KVM VMX Kang, Shan
2024-04-15 17:58 ` Li, Xin3
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