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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 45/66] KVM: x86: Fold CPUID 0x7 masking back into __do_cpuid_func()
Date: Mon,  2 Mar 2020 15:56:48 -0800	[thread overview]
Message-ID: <20200302235709.27467-46-sean.j.christopherson@intel.com> (raw)
In-Reply-To: <20200302235709.27467-1-sean.j.christopherson@intel.com>

Move the CPUID 0x7 masking back into __do_cpuid_func() now that the
size of the code has been trimmed down significantly.

Tweak the WARN case, which is impossible to hit unless the CPU is
completely broken, to break the loop before creating the bogus entry.

Opportunustically reorder the cpuid_entry_set() calls and shorten the
comment about emulation to further reduce the footprint of CPUID 0x7.

Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
 arch/x86/kvm/cpuid.c | 62 ++++++++++++++++----------------------------
 1 file changed, 22 insertions(+), 40 deletions(-)

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 1c361a65ee03..e3e5a7b83b5b 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -464,44 +464,6 @@ static int __do_cpuid_func_emulated(struct kvm_cpuid_array *array, u32 func)
 	return 0;
 }
 
-static inline void do_cpuid_7_mask(struct kvm_cpuid_entry2 *entry)
-{
-	switch (entry->index) {
-	case 0:
-		entry->eax = min(entry->eax, 1u);
-		cpuid_entry_mask(entry, CPUID_7_0_EBX);
-		/* TSC_ADJUST is emulated */
-		cpuid_entry_set(entry, X86_FEATURE_TSC_ADJUST);
-		cpuid_entry_mask(entry, CPUID_7_ECX);
-		cpuid_entry_mask(entry, CPUID_7_EDX);
-		if (boot_cpu_has(X86_FEATURE_IBPB) && boot_cpu_has(X86_FEATURE_IBRS))
-			cpuid_entry_set(entry, X86_FEATURE_SPEC_CTRL);
-		if (boot_cpu_has(X86_FEATURE_STIBP))
-			cpuid_entry_set(entry, X86_FEATURE_INTEL_STIBP);
-		if (boot_cpu_has(X86_FEATURE_AMD_SSBD))
-			cpuid_entry_set(entry, X86_FEATURE_SPEC_CTRL_SSBD);
-		/*
-		 * We emulate ARCH_CAPABILITIES in software even
-		 * if the host doesn't support it.
-		 */
-		cpuid_entry_set(entry, X86_FEATURE_ARCH_CAPABILITIES);
-		break;
-	case 1:
-		cpuid_entry_mask(entry, CPUID_7_1_EAX);
-		entry->ebx = 0;
-		entry->ecx = 0;
-		entry->edx = 0;
-		break;
-	default:
-		WARN_ON_ONCE(1);
-		entry->eax = 0;
-		entry->ebx = 0;
-		entry->ecx = 0;
-		entry->edx = 0;
-		break;
-	}
-}
-
 static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
 {
 	struct kvm_cpuid_entry2 *entry;
@@ -563,14 +525,34 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
 		break;
 	/* function 7 has additional index. */
 	case 7:
-		do_cpuid_7_mask(entry);
+		entry->eax = min(entry->eax, 1u);
+		cpuid_entry_mask(entry, CPUID_7_0_EBX);
+		cpuid_entry_mask(entry, CPUID_7_ECX);
+		cpuid_entry_mask(entry, CPUID_7_EDX);
+
+		/* TSC_ADJUST and ARCH_CAPABILITIES are emulated in software. */
+		cpuid_entry_set(entry, X86_FEATURE_TSC_ADJUST);
+		cpuid_entry_set(entry, X86_FEATURE_ARCH_CAPABILITIES);
+
+		if (boot_cpu_has(X86_FEATURE_IBPB) && boot_cpu_has(X86_FEATURE_IBRS))
+			cpuid_entry_set(entry, X86_FEATURE_SPEC_CTRL);
+		if (boot_cpu_has(X86_FEATURE_STIBP))
+			cpuid_entry_set(entry, X86_FEATURE_INTEL_STIBP);
+		if (boot_cpu_has(X86_FEATURE_AMD_SSBD))
+			cpuid_entry_set(entry, X86_FEATURE_SPEC_CTRL_SSBD);
 
 		for (i = 1, max_idx = entry->eax; i <= max_idx; i++) {
+			if (WARN_ON_ONCE(i > 1))
+				break;
+
 			entry = do_host_cpuid(array, function, i);
 			if (!entry)
 				goto out;
 
-			do_cpuid_7_mask(entry);
+			cpuid_entry_mask(entry, CPUID_7_1_EAX);
+			entry->ebx = 0;
+			entry->ecx = 0;
+			entry->edx = 0;
 		}
 		break;
 	case 9:
-- 
2.24.1


  parent reply	other threads:[~2020-03-03  0:02 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 ` [PATCH v2 20/66] KVM: x86: Calculate the supported xcr0 mask at load time Sean Christopherson
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 ` Sean Christopherson [this message]
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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