[PATCH v2 37/66] KVM: x86: Refactor handling of XSAVES CPUID adjustment

Sean Christopherson
2020-03-02T23:57:59Z

Invert the handling of XSAVES, i.e. set it based on boot_cpu_has() by
default, in preparation for adding KVM cpu caps, which will generate the
mask at load time before ->xsaves_supported() is ready.

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 | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index aacfd6af774a..c2e70cd0dbf1 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -422,7 +422,6 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
unsigned f_gbpages = 0;
unsigned f_lm = 0;
#endif
- unsigned f_xsaves = kvm_x86_ops->xsaves_supported() ? F(XSAVES) : 0;
unsigned f_intel_pt = kvm_x86_ops->pt_supported() ? F(INTEL_PT) : 0;

/* cpuid 1.edx */
@@ -479,7 +478,7 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)

/* cpuid 0xD.1.eax */
const u32 kvm_cpuid_D_1_eax_x86_features =
- F(XSAVEOPT) | F(XSAVEC) | F(XGETBV1) | f_xsaves;
+ F(XSAVEOPT) | F(XSAVEC) | F(XGETBV1) | F(XSAVES);

/* all calls to cpuid_count() should be made on the same cpu */
get_cpu();
@@ -610,6 +609,10 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)

entry->eax &= kvm_cpuid_D_1_eax_x86_features;
cpuid_entry_mask(entry, CPUID_D_1_EAX);
+
+ if (!kvm_x86_ops->xsaves_supported())
+ cpuid_entry_clear(entry, X86_FEATURE_XSAVES);
+
if (entry->eax & (F(XSAVES)|F(XSAVEC)))
entry->ebx = xstate_required_size(supported_xcr0, true);
else
--
2.24.1