[PATCH v2 50/66] KVM: x86: Override host CPUID results with kvm_cpu_caps

Sean Christopherson
2020-03-02T23:57:35Z

Override CPUID entries with kvm_cpu_caps during KVM_GET_SUPPORTED_CPUID
instead of masking the host CPUID result, which is redundant now that
the host CPUID is incorporated into kvm_cpu_caps at runtime.

No functional change intended.

Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
arch/x86/kvm/cpuid.c | 28 ++++++++++++++--------------
1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index ec8e24b1c1a7..5fef02dbf4e1 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -261,13 +261,13 @@ int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu,
return r;
}

-static __always_inline void cpuid_entry_mask(struct kvm_cpuid_entry2 *entry,
- enum cpuid_leafs leaf)
+static __always_inline void cpuid_entry_override(struct kvm_cpuid_entry2 *entry,
+ enum cpuid_leafs leaf)
{
u32 *reg = cpuid_entry_get_reg(entry, leaf * 32);

BUILD_BUG_ON(leaf >= ARRAY_SIZE(kvm_cpu_caps));
- *reg &= kvm_cpu_caps[leaf];
+ *reg = kvm_cpu_caps[leaf];
}

static __always_inline void kvm_cpu_cap_mask(enum cpuid_leafs leaf, u32 mask)
@@ -490,8 +490,8 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
entry->eax = min(entry->eax, 0x1fU);
break;
case 1:
- cpuid_entry_mask(entry, CPUID_1_EDX);
- cpuid_entry_mask(entry, CPUID_1_ECX);
+ cpuid_entry_override(entry, CPUID_1_EDX);
+ cpuid_entry_override(entry, CPUID_1_ECX);
/* we support x2apic emulation even if host does not support
* it since we emulate x2apic in software */
cpuid_entry_set(entry, X86_FEATURE_X2APIC);
@@ -536,9 +536,9 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
/* function 7 has additional index. */
case 7:
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);
+ cpuid_entry_override(entry, CPUID_7_0_EBX);
+ cpuid_entry_override(entry, CPUID_7_ECX);
+ cpuid_entry_override(entry, CPUID_7_EDX);

/* TSC_ADJUST and ARCH_CAPABILITIES are emulated in software. */
cpuid_entry_set(entry, X86_FEATURE_TSC_ADJUST);
@@ -557,7 +557,7 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
if (!entry)
goto out;

- cpuid_entry_mask(entry, CPUID_7_1_EAX);
+ cpuid_entry_override(entry, CPUID_7_1_EAX);
entry->ebx = 0;
entry->ecx = 0;
entry->edx = 0;
@@ -623,7 +623,7 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
if (!entry)
goto out;

- cpuid_entry_mask(entry, CPUID_D_1_EAX);
+ cpuid_entry_override(entry, CPUID_D_1_EAX);
if (entry->eax & (F(XSAVES)|F(XSAVEC)))
entry->ebx = xstate_required_size(supported_xcr0, true);
else
@@ -702,8 +702,8 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
entry->eax = min(entry->eax, 0x8000001f);
break;
case 0x80000001:
- cpuid_entry_mask(entry, CPUID_8000_0001_EDX);
- cpuid_entry_mask(entry, CPUID_8000_0001_ECX);
+ cpuid_entry_override(entry, CPUID_8000_0001_EDX);
+ cpuid_entry_override(entry, CPUID_8000_0001_ECX);
break;
case 0x80000007: /* Advanced power management */
/* invariant TSC is CPUID.80000007H:EDX[8] */
@@ -721,7 +721,7 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
g_phys_as = phys_as;
entry->eax = g_phys_as | (virt_as << 8);
entry->edx = 0;
- cpuid_entry_mask(entry, CPUID_8000_0008_EBX);
+ cpuid_entry_override(entry, CPUID_8000_0008_EBX);
/*
* AMD has separate bits for each SPEC_CTRL bit.
* arch/x86/kernel/cpu/bugs.c is kind enough to
@@ -763,7 +763,7 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
entry->eax = min(entry->eax, 0xC0000004);
break;
case 0xC0000001:
- cpuid_entry_mask(entry, CPUID_C000_0001_EDX);
+ cpuid_entry_override(entry, CPUID_C000_0001_EDX);
break;
case 3: /* Processor serial number */
case 5: /* MONITOR/MWAIT */
--
2.24.1