On Sat, 2022-05-07 at 21:39 -0500, Suravee Suthikulpanit wrote: > Add CPUID check for the x2APIC virtualization (x2AVIC) feature. > If available, the SVM driver can support both AVIC and x2AVIC modes > when load the kvm_amd driver with avic=1. The operating mode will be > determined at runtime depending on the guest APIC mode. > > Reviewed-by: Maxim Levitsky <mlevitsk@xxxxxxxxxx> > Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@xxxxxxx> > --- > arch/x86/include/asm/svm.h | 3 +++ > arch/x86/kvm/svm/avic.c | 51 ++++++++++++++++++++++++++++++++++++++ > arch/x86/kvm/svm/svm.c | 15 ++--------- > arch/x86/kvm/svm/svm.h | 1 + > 4 files changed, 57 insertions(+), 13 deletions(-) > > diff --git a/arch/x86/include/asm/svm.h b/arch/x86/include/asm/svm.h > index f70a5108d464..2c2a104b777e 100644 > --- a/arch/x86/include/asm/svm.h > +++ b/arch/x86/include/asm/svm.h > @@ -195,6 +195,9 @@ struct __attribute__ ((__packed__)) vmcb_control_area { > #define AVIC_ENABLE_SHIFT 31 > #define AVIC_ENABLE_MASK (1 << AVIC_ENABLE_SHIFT) > > +#define X2APIC_MODE_SHIFT 30 > +#define X2APIC_MODE_MASK (1 << X2APIC_MODE_SHIFT) > + > #define LBR_CTL_ENABLE_MASK BIT_ULL(0) > #define VIRTUAL_VMLOAD_VMSAVE_ENABLE_MASK BIT_ULL(1) > > diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c > index a8f514212b87..95006bbdf970 100644 > --- a/arch/x86/kvm/svm/avic.c > +++ b/arch/x86/kvm/svm/avic.c > @@ -40,6 +40,15 @@ > #define AVIC_GATAG_TO_VMID(x) ((x >> AVIC_VCPU_ID_BITS) & AVIC_VM_ID_MASK) > #define AVIC_GATAG_TO_VCPUID(x) (x & AVIC_VCPU_ID_MASK) > > +enum avic_modes { > + AVIC_MODE_NONE = 0, > + AVIC_MODE_X1, > + AVIC_MODE_X2, > +}; > + > +static bool force_avic; > +module_param_unsafe(force_avic, bool, 0444); > + > /* Note: > * This hash table is used to map VM_ID to a struct kvm_svm, > * when handling AMD IOMMU GALOG notification to schedule in > @@ -50,6 +59,7 @@ static DEFINE_HASHTABLE(svm_vm_data_hash, SVM_VM_DATA_HASH_BITS); > static u32 next_vm_id = 0; > static bool next_vm_id_wrapped = 0; > static DEFINE_SPINLOCK(svm_vm_data_hash_lock); > +static enum avic_modes avic_mode; > > /* > * This is a wrapper of struct amd_iommu_ir_data. > @@ -1077,3 +1087,44 @@ void avic_vcpu_unblocking(struct kvm_vcpu *vcpu) > > avic_vcpu_load(vcpu); > } > + > +/* > + * Note: > + * - The module param avic enable both xAPIC and x2APIC mode. > + * - Hypervisor can support both xAVIC and x2AVIC in the same guest. > + * - The mode can be switched at run-time. > + */ > +bool avic_hardware_setup(struct kvm_x86_ops *x86_ops) > +{ > + if (!npt_enabled) > + return false; > + > + if (boot_cpu_has(X86_FEATURE_AVIC)) { > + avic_mode = AVIC_MODE_X1; > + pr_info("AVIC enabled\n"); > + } else if (force_avic) { > + /* > + * Some older systems does not advertise AVIC support. > + * See Revision Guide for specific AMD processor for more detail. > + */ > + avic_mode = AVIC_MODE_X1; > + pr_warn("AVIC is not supported in CPUID but force enabled"); > + pr_warn("Your system might crash and burn"); > + } > + > + /* AVIC is a prerequisite for x2AVIC. */ > + if (boot_cpu_has(X86_FEATURE_X2AVIC)) { > + if (avic_mode == AVIC_MODE_X1) { > + avic_mode = AVIC_MODE_X2; > + pr_info("x2AVIC enabled\n"); > + } else { > + pr_warn(FW_BUG "Cannot support x2AVIC due to AVIC is disabled"); > + pr_warn(FW_BUG "Try enable AVIC using force_avic option"); > + } > + } > + > + if (avic_mode != AVIC_MODE_NONE) > + amd_iommu_register_ga_log_notifier(&avic_ga_log_notifier); > + > + return !!avic_mode; > +} > diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c > index 3b49337998ec..74e6f86f5dc3 100644 > --- a/arch/x86/kvm/svm/svm.c > +++ b/arch/x86/kvm/svm/svm.c > @@ -188,9 +188,6 @@ module_param(tsc_scaling, int, 0444); > static bool avic; > module_param(avic, bool, 0444); > > -static bool force_avic; > -module_param_unsafe(force_avic, bool, 0444); > - > bool __read_mostly dump_invalid_vmcb; > module_param(dump_invalid_vmcb, bool, 0644); > > @@ -4913,17 +4910,9 @@ static __init int svm_hardware_setup(void) > nrips = false; > } > > - enable_apicv = avic = avic && npt_enabled && (boot_cpu_has(X86_FEATURE_AVIC) || force_avic); > + enable_apicv = avic = avic && avic_hardware_setup(&svm_x86_ops); > > - if (enable_apicv) { > - if (!boot_cpu_has(X86_FEATURE_AVIC)) { > - pr_warn("AVIC is not supported in CPUID but force enabled"); > - pr_warn("Your system might crash and burn"); > - } else > - pr_info("AVIC enabled\n"); > - > - amd_iommu_register_ga_log_notifier(&avic_ga_log_notifier); > - } else { > + if (!enable_apicv) { > svm_x86_ops.vcpu_blocking = NULL; > svm_x86_ops.vcpu_unblocking = NULL; > svm_x86_ops.vcpu_get_apicv_inhibit_reasons = NULL; > diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h > index 32220a1b0ea2..678fc7757fe4 100644 > --- a/arch/x86/kvm/svm/svm.h > +++ b/arch/x86/kvm/svm/svm.h > @@ -603,6 +603,7 @@ extern struct kvm_x86_nested_ops svm_nested_ops; > > /* avic.c */ > > +bool avic_hardware_setup(struct kvm_x86_ops *ops); > int avic_ga_log_notifier(u32 ga_tag); > void avic_vm_destroy(struct kvm *kvm); > int avic_vm_init(struct kvm *kvm); Looks great! Best regars, Maxim Levitsky