From: Sean Christopherson <sean.j.christopherson@intel.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
Xiaoyao Li <xiaoyao.li@intel.com>
Subject: [PATCH v2 20/66] KVM: x86: Calculate the supported xcr0 mask at load time
Date: Mon, 2 Mar 2020 15:56:23 -0800 [thread overview]
Message-ID: <20200302235709.27467-21-sean.j.christopherson@intel.com> (raw)
In-Reply-To: <20200302235709.27467-1-sean.j.christopherson@intel.com>
Add a new global variable, supported_xcr0, to track which xcr0 bits can
be exposed to the guest instead of calculating the mask on every call.
The supported bits are constant for a given instance of KVM.
This paves the way toward eliminating the ->mpx_supported() call in
kvm_mpx_supported(), e.g. eliminates multiple retpolines in VMX's nested
VM-Enter path, and eventually toward eliminating ->mpx_supported()
altogether.
No functional change intended.
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
arch/x86/kvm/cpuid.c | 32 +++++++++-----------------------
arch/x86/kvm/svm.c | 2 ++
arch/x86/kvm/vmx/vmx.c | 4 ++++
arch/x86/kvm/x86.c | 14 +++++++++++---
arch/x86/kvm/x86.h | 7 +------
5 files changed, 27 insertions(+), 32 deletions(-)
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 85f292088d91..1eb775c33c4e 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -52,16 +52,6 @@ bool kvm_mpx_supported(void)
}
EXPORT_SYMBOL_GPL(kvm_mpx_supported);
-u64 kvm_supported_xcr0(void)
-{
- u64 xcr0 = KVM_SUPPORTED_XCR0 & host_xcr0;
-
- if (!kvm_mpx_supported())
- xcr0 &= ~(XFEATURE_MASK_BNDREGS | XFEATURE_MASK_BNDCSR);
-
- return xcr0;
-}
-
#define F feature_bit
int kvm_update_cpuid(struct kvm_vcpu *vcpu)
@@ -107,8 +97,7 @@ int kvm_update_cpuid(struct kvm_vcpu *vcpu)
vcpu->arch.guest_xstate_size = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET;
} else {
vcpu->arch.guest_supported_xcr0 =
- (best->eax | ((u64)best->edx << 32)) &
- kvm_supported_xcr0();
+ (best->eax | ((u64)best->edx << 32)) & supported_xcr0;
vcpu->arch.guest_xstate_size = best->ebx =
xstate_required_size(vcpu->arch.xcr0, false);
}
@@ -633,14 +622,12 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
goto out;
}
break;
- case 0xd: {
- u64 supported = kvm_supported_xcr0();
-
- entry->eax &= supported;
- entry->ebx = xstate_required_size(supported, false);
+ case 0xd:
+ entry->eax &= supported_xcr0;
+ entry->ebx = xstate_required_size(supported_xcr0, false);
entry->ecx = entry->ebx;
- entry->edx &= supported >> 32;
- if (!supported)
+ entry->edx &= supported_xcr0 >> 32;
+ if (!supported_xcr0)
break;
entry = do_host_cpuid(array, function, 1);
@@ -650,7 +637,7 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
entry->eax &= kvm_cpuid_D_1_eax_x86_features;
cpuid_mask(&entry->eax, CPUID_D_1_EAX);
if (entry->eax & (F(XSAVES)|F(XSAVEC)))
- entry->ebx = xstate_required_size(supported, true);
+ entry->ebx = xstate_required_size(supported_xcr0, true);
else
entry->ebx = 0;
/* Saving XSS controlled state via XSAVES isn't supported. */
@@ -658,7 +645,7 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
entry->edx = 0;
for (i = 2; i < 64; ++i) {
- if (!(supported & BIT_ULL(i)))
+ if (!(supported_xcr0 & BIT_ULL(i)))
continue;
entry = do_host_cpuid(array, function, i);
@@ -666,7 +653,7 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
goto out;
/*
- * The @supported check above should have filtered out
+ * The supported check above should have filtered out
* invalid sub-leafs as well as sub-leafs managed by
* IA32_XSS MSR. Only XCR0-managed sub-leafs should
* reach this point, and they should have a non-zero
@@ -681,7 +668,6 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
entry->edx = 0;
}
break;
- }
/* Intel PT */
case 0x14:
if (!f_intel_pt)
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index fd3fc9fbefff..51db8addda04 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1385,6 +1385,8 @@ static __init int svm_hardware_setup(void)
init_msrpm_offsets();
+ supported_xcr0 &= ~(XFEATURE_MASK_BNDREGS | XFEATURE_MASK_BNDCSR);
+
if (boot_cpu_has(X86_FEATURE_NX))
kvm_enable_efer_bits(EFER_NX);
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 2dcf27e3a7a6..cf874c364c8f 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7655,6 +7655,10 @@ static __init int hardware_setup(void)
WARN_ONCE(host_bndcfgs, "KVM: BNDCFGS in host will be lost");
}
+ if (!kvm_mpx_supported())
+ supported_xcr0 &= ~(XFEATURE_MASK_BNDREGS |
+ XFEATURE_MASK_BNDCSR);
+
if (!cpu_has_vmx_vpid() || !cpu_has_vmx_invvpid() ||
!(cpu_has_vmx_invvpid_single() || cpu_has_vmx_invvpid_global()))
enable_vpid = 0;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index ddd1d296bd20..e3598fe171a5 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -180,6 +180,11 @@ struct kvm_shared_msrs {
static struct kvm_shared_msrs_global __read_mostly shared_msrs_global;
static struct kvm_shared_msrs __percpu *shared_msrs;
+#define KVM_SUPPORTED_XCR0 (XFEATURE_MASK_FP | XFEATURE_MASK_SSE \
+ | XFEATURE_MASK_YMM | XFEATURE_MASK_BNDREGS \
+ | XFEATURE_MASK_BNDCSR | XFEATURE_MASK_AVX512 \
+ | XFEATURE_MASK_PKRU)
+
static u64 __read_mostly host_xss;
struct kvm_stats_debugfs_item debugfs_entries[] = {
@@ -226,6 +231,8 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {
};
u64 __read_mostly host_xcr0;
+u64 __read_mostly supported_xcr0;
+EXPORT_SYMBOL_GPL(supported_xcr0);
struct kmem_cache *x86_fpu_cache;
EXPORT_SYMBOL_GPL(x86_fpu_cache);
@@ -4099,8 +4106,7 @@ static int kvm_vcpu_ioctl_x86_set_xsave(struct kvm_vcpu *vcpu,
* CPUID leaf 0xD, index 0, EDX:EAX. This is for compatibility
* with old userspace.
*/
- if (xstate_bv & ~kvm_supported_xcr0() ||
- mxcsr & ~mxcsr_feature_mask)
+ if (xstate_bv & ~supported_xcr0 || mxcsr & ~mxcsr_feature_mask)
return -EINVAL;
load_xsave(vcpu, (u8 *)guest_xsave->region);
} else {
@@ -7304,8 +7310,10 @@ int kvm_arch_init(void *opaque)
perf_register_guest_info_callbacks(&kvm_guest_cbs);
- if (boot_cpu_has(X86_FEATURE_XSAVE))
+ if (boot_cpu_has(X86_FEATURE_XSAVE)) {
host_xcr0 = xgetbv(XCR_XFEATURE_ENABLED_MASK);
+ supported_xcr0 = host_xcr0 & KVM_SUPPORTED_XCR0;
+ }
kvm_lapic_init();
if (pi_inject_timer == -1)
diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
index 3624665acee4..02b49ee49e24 100644
--- a/arch/x86/kvm/x86.h
+++ b/arch/x86/kvm/x86.h
@@ -280,13 +280,8 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
int emulation_type, void *insn, int insn_len);
enum exit_fastpath_completion handle_fastpath_set_msr_irqoff(struct kvm_vcpu *vcpu);
-#define KVM_SUPPORTED_XCR0 (XFEATURE_MASK_FP | XFEATURE_MASK_SSE \
- | XFEATURE_MASK_YMM | XFEATURE_MASK_BNDREGS \
- | XFEATURE_MASK_BNDCSR | XFEATURE_MASK_AVX512 \
- | XFEATURE_MASK_PKRU)
extern u64 host_xcr0;
-
-extern u64 kvm_supported_xcr0(void);
+extern u64 supported_xcr0;
extern unsigned int min_timer_period_us;
--
2.24.1
next prev parent reply other threads:[~2020-03-02 23:59 UTC|newest]
Thread overview: 95+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-02 23:56 [PATCH v2 00/66] KVM: x86: Introduce KVM cpu caps Sean Christopherson
2020-03-02 23:56 ` [PATCH v2 01/66] KVM: x86: Return -E2BIG when KVM_GET_SUPPORTED_CPUID hits max entries Sean Christopherson
2020-03-03 14:16 ` Paolo Bonzini
2020-03-03 15:17 ` Sean Christopherson
2020-03-03 19:47 ` Jim Mattson
2020-03-02 23:56 ` [PATCH v2 02/66] KVM: x86: Refactor loop around do_cpuid_func() to separate helper Sean Christopherson
2020-03-02 23:56 ` [PATCH v2 03/66] KVM: x86: Simplify handling of Centaur CPUID leafs Sean Christopherson
2020-03-02 23:56 ` [PATCH v2 04/66] KVM: x86: Clean up error handling in kvm_dev_ioctl_get_cpuid() Sean Christopherson
2020-03-02 23:56 ` [PATCH v2 05/66] KVM: x86: Check userapce CPUID array size after validating sub-leaf Sean Christopherson
2020-03-02 23:56 ` [PATCH v2 06/66] KVM: x86: Move CPUID 0xD.1 handling out of the index>0 loop Sean Christopherson
2020-03-02 23:56 ` [PATCH v2 07/66] KVM: x86: Check for CPUID 0xD.N support before validating array size Sean Christopherson
2020-03-02 23:56 ` [PATCH v2 08/66] KVM: x86: Warn on zero-size save state for valid CPUID 0xD.N sub-leaf Sean Christopherson
2020-03-02 23:56 ` [PATCH v2 09/66] KVM: x86: Refactor CPUID 0xD.N sub-leaf entry creation Sean Christopherson
2020-03-02 23:56 ` [PATCH v2 10/66] KVM: x86: Clean up CPUID 0x7 sub-leaf loop Sean Christopherson
2020-03-02 23:56 ` [PATCH v2 11/66] KVM: x86: Drop the explicit @index from do_cpuid_7_mask() Sean Christopherson
2020-03-02 23:56 ` [PATCH v2 12/66] KVM: x86: Drop redundant boot cpu checks on SSBD feature bits Sean Christopherson
2020-03-02 23:56 ` [PATCH v2 13/66] KVM: x86: Consolidate CPUID array max num entries checking Sean Christopherson
2020-03-02 23:56 ` [PATCH v2 14/66] KVM: x86: Hoist loop counter and terminator to top of __do_cpuid_func() Sean Christopherson
2020-03-02 23:56 ` [PATCH v2 15/66] KVM: x86: Refactor CPUID 0x4 and 0x8000001d handling Sean Christopherson
2020-03-02 23:56 ` [PATCH v2 16/66] KVM: x86: Encapsulate CPUID entries and metadata in struct Sean Christopherson
2020-03-02 23:56 ` [PATCH v2 17/66] KVM: x86: Drop redundant array size check Sean Christopherson
2020-03-02 23:56 ` [PATCH v2 18/66] KVM: x86: Use common loop iterator when handling CPUID 0xD.N Sean Christopherson
2020-03-02 23:56 ` [PATCH v2 19/66] KVM: VMX: Add helpers to query Intel PT mode Sean Christopherson
2020-03-02 23:56 ` Sean Christopherson [this message]
2020-03-02 23:56 ` [PATCH v2 21/66] KVM: x86: Use supported_xcr0 to detect MPX support Sean Christopherson
2020-03-03 14:34 ` Paolo Bonzini
2020-03-02 23:56 ` [PATCH v2 22/66] KVM: x86: Make kvm_mpx_supported() an inline function Sean Christopherson
2020-03-02 23:56 ` [PATCH v2 23/66] KVM: x86: Clear output regs for CPUID 0x14 if PT isn't exposed to guest Sean Christopherson
2020-03-02 23:56 ` [PATCH v2 24/66] KVM: x86: Drop explicit @func param from ->set_supported_cpuid() Sean Christopherson
2020-03-02 23:56 ` [PATCH v2 25/66] KVM: x86: Use u32 for holding CPUID register value in helpers Sean Christopherson
2020-03-02 23:56 ` [PATCH v2 26/66] KVM: x86: Replace bare "unsigned" with "unsigned int" in cpuid helpers Sean Christopherson
2020-03-03 15:43 ` Vitaly Kuznetsov
2020-03-02 23:56 ` [PATCH v2 27/66] KVM: x86: Introduce cpuid_entry_{get,has}() accessors Sean Christopherson
2020-03-02 23:56 ` [PATCH v2 28/66] KVM: x86: Introduce cpuid_entry_{change,set,clear}() mutators Sean Christopherson
2020-03-02 23:56 ` [PATCH v2 29/66] KVM: x86: Refactor cpuid_mask() to auto-retrieve the register Sean Christopherson
2020-03-02 23:56 ` [PATCH v2 30/66] KVM: x86: Handle MPX CPUID adjustment in VMX code Sean Christopherson
2020-03-02 23:56 ` [PATCH v2 31/66] KVM: x86: Handle INVPCID " Sean Christopherson
2020-03-02 23:56 ` [PATCH v2 32/66] KVM: x86: Handle UMIP emulation " Sean Christopherson
2020-03-02 23:56 ` [PATCH v2 33/66] KVM: x86: Handle PKU " Sean Christopherson
2020-03-02 23:56 ` [PATCH v2 34/66] KVM: x86: Handle RDTSCP " Sean Christopherson
2020-03-02 23:56 ` [PATCH v2 35/66] KVM: x86: Handle Intel PT " Sean Christopherson
2020-03-02 23:56 ` [PATCH v2 36/66] KVM: x86: Handle GBPAGE CPUID adjustment for EPT " Sean Christopherson
2020-03-03 14:59 ` Paolo Bonzini
2020-03-03 15:35 ` Sean Christopherson
2020-03-03 15:40 ` Paolo Bonzini
2020-03-03 15:44 ` Sean Christopherson
2020-03-03 15:47 ` Paolo Bonzini
2020-03-03 15:54 ` Sean Christopherson
2020-03-02 23:56 ` [PATCH v2 37/66] KVM: x86: Refactor handling of XSAVES CPUID adjustment Sean Christopherson
2020-03-02 23:56 ` [PATCH v2 38/66] KVM: x86: Introduce kvm_cpu_caps to replace runtime CPUID masking Sean Christopherson
2020-03-03 15:51 ` Vitaly Kuznetsov
2020-03-02 23:56 ` [PATCH v2 39/66] KVM: SVM: Convert feature updates from CPUID to KVM cpu caps Sean Christopherson
2020-03-02 23:56 ` [PATCH v2 40/66] KVM: VMX: " Sean Christopherson
2020-03-02 23:56 ` [PATCH v2 41/66] KVM: x86: Move XSAVES CPUID adjust to VMX's KVM cpu cap update Sean Christopherson
2020-03-02 23:56 ` [PATCH v2 42/66] KVM: x86: Add a helper to check kernel support when setting cpu cap Sean Christopherson
2020-03-02 23:56 ` [PATCH v2 43/66] KVM: x86: Use KVM cpu caps to mark CR4.LA57 as not-reserved Sean Christopherson
2020-03-02 23:56 ` [PATCH v2 44/66] KVM: x86: Use KVM cpu caps to track UMIP emulation Sean Christopherson
2020-03-02 23:56 ` [PATCH v2 45/66] KVM: x86: Fold CPUID 0x7 masking back into __do_cpuid_func() Sean Christopherson
2020-03-02 23:56 ` [PATCH v2 46/66] KVM: x86: Remove the unnecessary loop on CPUID 0x7 sub-leafs Sean Christopherson
2020-03-02 23:56 ` [PATCH v2 47/66] KVM: x86: Squash CPUID 0x2.0 insanity for modern CPUs Sean Christopherson
2020-03-02 23:56 ` [PATCH v2 48/66] KVM: x86: Remove stateful CPUID handling Sean Christopherson
2020-03-03 15:59 ` Vitaly Kuznetsov
2020-03-03 19:23 ` Jim Mattson
2020-03-02 23:56 ` [PATCH v2 49/66] KVM: x86: Do host CPUID at load time to mask KVM cpu caps Sean Christopherson
2020-03-02 23:56 ` [PATCH v2 50/66] KVM: x86: Override host CPUID results with kvm_cpu_caps Sean Christopherson
2020-03-03 15:22 ` Paolo Bonzini
2020-03-03 15:56 ` Sean Christopherson
2020-03-02 23:56 ` [PATCH v2 51/66] KVM: x86: Set emulated/transmuted feature bits via kvm_cpu_caps Sean Christopherson
2020-03-02 23:56 ` [PATCH v2 52/66] KVM: x86: Use kvm_cpu_caps to detect Intel PT support Sean Christopherson
2020-03-02 23:56 ` [PATCH v2 53/66] KVM: x86: Do kvm_cpuid_array capacity checks in terminal functions Sean Christopherson
2020-03-03 16:03 ` Vitaly Kuznetsov
2020-03-02 23:56 ` [PATCH v2 54/66] KVM: x86: Use KVM cpu caps to detect MSR_TSC_AUX virt support Sean Christopherson
2020-03-02 23:56 ` [PATCH v2 55/66] KVM: VMX: Directly use VMX capabilities helper to detect RDTSCP support Sean Christopherson
2020-03-02 23:56 ` [PATCH v2 56/66] KVM: x86: Check for Intel PT MSR virtualization using KVM cpu caps Sean Christopherson
2020-03-02 23:57 ` [PATCH v2 57/66] KVM: VMX: Directly query Intel PT mode when refreshing PMUs Sean Christopherson
2020-03-02 23:57 ` [PATCH v2 58/66] KVM: SVM: Refactor logging of NPT enabled/disabled Sean Christopherson
2020-03-02 23:57 ` [PATCH v2 59/66] KVM: x86/mmu: Merge kvm_{enable,disable}_tdp() into a common function Sean Christopherson
2020-03-02 23:57 ` [PATCH v2 60/66] KVM: x86/mmu: Configure max page level during hardware setup Sean Christopherson
2020-03-02 23:57 ` [PATCH v2 61/66] KVM: x86: Don't propagate MMU lpage support to memslot.disallow_lpage Sean Christopherson
2020-03-03 15:31 ` Paolo Bonzini
2020-03-03 16:00 ` Sean Christopherson
2020-03-02 23:57 ` [PATCH v2 62/66] KVM: Drop largepages_enabled and its accessor/mutator Sean Christopherson
2020-03-02 23:57 ` [PATCH v2 63/66] KVM: x86: Move VMX's host_efer to common x86 code Sean Christopherson
2020-03-02 23:57 ` [PATCH v2 64/66] KVM: nSVM: Expose SVM features to L1 iff nested is enabled Sean Christopherson
2020-03-03 16:12 ` Vitaly Kuznetsov
2020-03-03 18:37 ` Jim Mattson
2020-03-02 23:57 ` [PATCH v2 65/66] KVM: nSVM: Advertise and enable NRIPS for L1 iff nrips " Sean Christopherson
2020-03-03 16:14 ` Vitaly Kuznetsov
2020-03-02 23:57 ` [PATCH v2 66/66] KVM: x86: Move nSVM CPUID 0x8000000A handing into common x86 code Sean Christopherson
2020-03-03 15:35 ` Paolo Bonzini
2020-03-03 15:37 ` Sean Christopherson
2020-03-03 16:48 ` [PATCH v2 00/66] KVM: x86: Introduce KVM cpu caps Vitaly Kuznetsov
2020-03-06 8:27 ` Paolo Bonzini
2020-03-09 20:11 ` Sean Christopherson
2020-03-11 18:37 ` Paolo Bonzini
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