[PATCH 6/9] KVM: selftests: Add a helper to check EPT/VPID capabilities

From: David Matlack <dmatlack@google.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Ben Gardon <bgardon@google.com>,
	Sean Christopherson <seanjc@google.com>,
	Oliver Upton <oupton@google.com>, Peter Xu <peterx@redhat.com>,
	Vitaly Kuznetsov <vkuznets@redhat.com>,
	Andrew Jones <drjones@redhat.com>,
	"open list:KERNEL VIRTUAL MACHINE (KVM)" <kvm@vger.kernel.org>,
	David Matlack <dmatlack@google.com>
Subject: [PATCH 6/9] KVM: selftests: Add a helper to check EPT/VPID capabilities
Date: Fri, 29 Apr 2022 18:39:32 +0000	[thread overview]
Message-ID: <20220429183935.1094599-7-dmatlack@google.com> (raw)
In-Reply-To: <20220429183935.1094599-1-dmatlack@google.com>

Create a small helper function to check if a given EPT/VPID capability
is supported. This will be re-used in a follow-up commit to check for 1G
page support.

No functional change intended.

Signed-off-by: David Matlack <dmatlack@google.com>
---
 tools/testing/selftests/kvm/lib/x86_64/vmx.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/kvm/lib/x86_64/vmx.c b/tools/testing/selftests/kvm/lib/x86_64/vmx.c
index 715b58f1f7bc..3862d93a18ac 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/vmx.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/vmx.c
@@ -198,6 +198,11 @@ bool load_vmcs(struct vmx_pages *vmx)
 	return true;
 }
 
+static bool ept_vpid_cap_supported(uint64_t mask)
+{
+	return rdmsr(MSR_IA32_VMX_EPT_VPID_CAP) & mask;
+}
+
 /*
  * Initialize the control fields to the most basic settings possible.
  */
@@ -215,7 +220,7 @@ static inline void init_vmcs_control_fields(struct vmx_pages *vmx)
 		struct eptPageTablePointer eptp = {
 			.memory_type = VMX_BASIC_MEM_TYPE_WB,
 			.page_walk_length = 3, /* + 1 */
-			.ad_enabled = !!(rdmsr(MSR_IA32_VMX_EPT_VPID_CAP) & VMX_EPT_VPID_CAP_AD_BITS),
+			.ad_enabled = ept_vpid_cap_supported(VMX_EPT_VPID_CAP_AD_BITS),
 			.address = vmx->eptp_gpa >> PAGE_SHIFT_4K,
 		};
 
-- 
2.36.0.464.gb9c8b46e94-goog

