/*
- Use nested page tables by default. Note, NPT may get forced off by
- svm_hardware_setup() if it's unsupported by hardware or the host kernel.
@@ -3231,6 +3234,19 @@ static int invpcid_interception(struct kvm_vcpu *vcpu) return kvm_handle_invpcid(vcpu, type, gva); } +static int bus_lock_exit(struct kvm_vcpu *vcpu) +{
- struct vcpu_svm *svm = to_svm(vcpu);
- vcpu->run->exit_reason = KVM_EXIT_X86_BUS_LOCK;
- vcpu->run->flags |= KVM_RUN_X86_BUS_LOCK;
- /* Reload the counter again */
- svm->vmcb->control.bus_lock_counter = bus_lock_counter;
- return 0;
+}
static int (*const svm_exit_handlers[])(struct kvm_vcpu *vcpu) = { [SVM_EXIT_READ_CR0] = cr_interception, [SVM_EXIT_READ_CR3] = cr_interception, @@ -3298,6 +3314,7 @@ static int (*const svm_exit_handlers[])(struct kvm_vcpu *vcpu) = { [SVM_EXIT_CR4_WRITE_TRAP] = cr_trap, [SVM_EXIT_CR8_WRITE_TRAP] = cr_trap, [SVM_EXIT_INVPCID] = invpcid_interception,
- [SVM_EXIT_BUS_LOCK] = bus_lock_exit, [SVM_EXIT_NPF] = npf_interception, [SVM_EXIT_RSM] = rsm_interception, [SVM_EXIT_AVIC_INCOMPLETE_IPI] = avic_incomplete_ipi_interception,
@@ -4356,6 +4373,27 @@ static void svm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu)
Why on earth is this in svm_vcpu_after_set_cpuid()? This has nothing to do with guest CPUID.>
Sorry, my bad. I will move it to init_vmcb().
set_msr_interception(vcpu, svm->msrpm, MSR_IA32_FLUSH_CMD, 0, !!guest_cpuid_has(vcpu, X86_FEATURE_FLUSH_L1D));
- if (cpu_feature_enabled(X86_FEATURE_BUS_LOCK_THRESHOLD) &&
This should be a slow path, there's zero reason to check for host support as bus_lock_detection_enabled should be allowed if and only if it's supported.>
Agreed. I will remove this check.
vcpu->kvm->arch.bus_lock_detection_enabled) {svm_set_intercept(svm, INTERCEPT_BUSLOCK);/** The CPU decrements the bus lock counter every time a bus lock* is detected. Once the counter reaches zero a VMEXIT_BUSLOCK* is generated. A value of zero for bus lock counter means a* VMEXIT_BUSLOCK at every bus lock detection.** Currently, default value for bus_lock_counter is set to 10.Please don't document the default _here_. Because inevitably this will become stale when the default changes.
Ack.
* So, the VMEXIT_BUSLOCK is generated after every 10 bus locks* detected.*/svm->vmcb->control.bus_lock_counter = bus_lock_counter;pr_debug("Setting buslock counter to %u\n", bus_lock_counter);- } else {
svm_clr_intercept(svm, INTERCEPT_BUSLOCK);svm->vmcb->control.bus_lock_counter = 0;- }
- if (sev_guest(vcpu->kvm)) sev_vcpu_after_set_cpuid(svm);
@@ -5149,6 +5187,11 @@ static __init void svm_set_cpu_caps(void) kvm_cpu_cap_set(X86_FEATURE_SVME_ADDR_CHK); }
- if (cpu_feature_enabled(X86_FEATURE_BUS_LOCK_THRESHOLD)) {
pr_info("Bus Lock Threashold supported\n");kvm_caps.has_bus_lock_exit = true;- }
- /* CPUID 0x80000008 */ if (boot_cpu_has(X86_FEATURE_LS_CFG_SSBD) || boot_cpu_has(X86_FEATURE_AMD_SSBD))
diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h index d80a4c6b5a38..2a77232105da 100644 --- a/arch/x86/kvm/x86.h +++ b/arch/x86/kvm/x86.h @@ -58,6 +58,7 @@ void kvm_spurious_fault(void); #define KVM_VMX_DEFAULT_PLE_WINDOW_MAX UINT_MAX #define KVM_SVM_DEFAULT_PLE_WINDOW_MAX USHRT_MAX #define KVM_SVM_DEFAULT_PLE_WINDOW 3000 +#define KVM_SVM_DEFAULT_BUS_LOCK_COUNTER 10
There's zero reason this needs to be in x86.h. I don't even see a reason to have a #define, there's literally one user.
Yeah. I agree. I remove it from V2.
- Manali