[PATCH V4 06/11] KVM: x86: Add a function to get the number of address ranges

[Luwei Kang <luwei.kang@xxxxxxxxx>]

CPUID.(EAX=14H,ECX=1H).EAX[2:0] enumerates the number of
Intel Processor Trace configurable Address Ranges for filtering.

Signed-off-by: Luwei Kang <luwei.kang@xxxxxxxxx>
---
 arch/x86/include/asm/kvm_host.h |  1 +
 arch/x86/kvm/x86.c              | 13 +++++++++++++
 2 files changed, 14 insertions(+)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 6480faa..c120202 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1217,6 +1217,7 @@ int kvm_task_switch(struct kvm_vcpu *vcpu, u16 tss_selector, int idt_index,
 unsigned long kvm_get_rflags(struct kvm_vcpu *vcpu);
 void kvm_set_rflags(struct kvm_vcpu *vcpu, unsigned long rflags);
 bool kvm_rdpmc(struct kvm_vcpu *vcpu);
+unsigned int kvm_get_pt_addr_cnt(void);
 
 void kvm_queue_exception(struct kvm_vcpu *vcpu, unsigned nr);
 void kvm_queue_exception_e(struct kvm_vcpu *vcpu, unsigned nr, u32 error_code);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index faf843c..b19a749 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -991,6 +991,19 @@ bool kvm_rdpmc(struct kvm_vcpu *vcpu)
 }
 EXPORT_SYMBOL_GPL(kvm_rdpmc);
 
+unsigned int kvm_get_pt_addr_cnt(void)
+{
+	unsigned int eax, ebx, ecx, edx;
+	/*
+	 * - CPUID function 14H, sub-function 1:
+	 *   EAX[2:0] enumerates the number of Intel Processor
+	 *   Trace configurable Address Ranges for filtering.
+	 */
+	cpuid_count(0x14, 1, &eax, &ebx, &ecx, &edx);
+	return (eax & 0x7);
+}
+EXPORT_SYMBOL_GPL(kvm_get_pt_addr_cnt);
+
 /*
  * List of msr numbers which we expose to userspace through KVM_GET_MSRS
  * and KVM_SET_MSRS, and KVM_GET_MSR_INDEX_LIST.
-- 
1.8.3.1