[PATCH v8 03/10] KVM: x86: Stuff vCPU's PAT with default value at RESET, not creation

Sean Christopherson
2024-06-05T23:19:28Z

Move the stuffing of the vCPU's PAT to the architectural "default" value
from kvm_arch_vcpu_create() to kvm_vcpu_reset(), guarded by !init_event,
to better capture that the default value is the value "Following Power-up
or Reset". E.g. setting PAT only during creation would break if KVM were
to expose a RESET ioctl() to userspace (which is unlikely, but that's not
a good reason to have unintuitive code).

No functional change.

Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Reviewed-by: Kai Huang <kai.huang@intel.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/kvm/x86.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 4157602c964e..887d29db0e05 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -12226,8 +12226,6 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)
vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu);
vcpu->arch.reserved_gpa_bits = kvm_vcpu_reserved_gpa_bits_raw(vcpu);

- vcpu->arch.pat = MSR_IA32_CR_PAT_DEFAULT;
-
kvm_async_pf_hash_reset(vcpu);

vcpu->arch.perf_capabilities = kvm_caps.supported_perf_cap;
@@ -12393,6 +12391,8 @@ void kvm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event)
if (!init_event) {
vcpu->arch.smbase = 0x30000;

+ vcpu->arch.pat = MSR_IA32_CR_PAT_DEFAULT;
+
vcpu->arch.msr_misc_features_enables = 0;
vcpu->arch.ia32_misc_enable_msr = MSR_IA32_MISC_ENABLE_PEBS_UNAVAIL |
MSR_IA32_MISC_ENABLE_BTS_UNAVAIL;
--
2.45.1.467.gbab1589fc0-goog