[kvm-unit-tests PATCH 31/39] nVMX: Add helper to get first supported INVVPID type

[Sean Christopherson <seanjc@google.com>]

Deduplicate some clever/interesting code for retrieving the first
supported INVVPID type, and opportunistically avoid RDMSR on every test.

Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 x86/vmx_tests.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/x86/vmx_tests.c b/x86/vmx_tests.c
index 66f374a..f2e24f6 100644
--- a/x86/vmx_tests.c
+++ b/x86/vmx_tests.c
@@ -3197,16 +3197,20 @@ static void try_invvpid(u64 type, u64 vpid, u64 gla)
 	       expected, vmcs_read(VMX_INST_ERROR));
 }
 
+static inline unsigned long get_first_supported_invvpid_type(void)
+{
+	u64 type = ffs(ept_vpid.val >> VPID_CAP_INVVPID_TYPES_SHIFT) - 1;
+
+	__TEST_ASSERT(type >= INVVPID_ADDR && type <= INVVPID_CONTEXT_LOCAL);
+	return type;
+}
+
 static void ds_invvpid(void *data)
 {
-	u64 msr = rdmsr(MSR_IA32_VMX_EPT_VPID_CAP);
-	u64 type = ffs(msr >> VPID_CAP_INVVPID_TYPES_SHIFT) - 1;
-
-	TEST_ASSERT(type >= INVVPID_ADDR && type <= INVVPID_CONTEXT_LOCAL);
 	asm volatile("invvpid %0, %1"
 		     :
 		     : "m"(*(struct invvpid_operand *)data),
-		       "r"(type));
+		       "r"(get_first_supported_invvpid_type()));
 }
 
 /*
@@ -3216,13 +3220,9 @@ static void ds_invvpid(void *data)
  */
 static void ss_invvpid(void *data)
 {
-	u64 msr = rdmsr(MSR_IA32_VMX_EPT_VPID_CAP);
-	u64 type = ffs(msr >> VPID_CAP_INVVPID_TYPES_SHIFT) - 1;
-
-	TEST_ASSERT(type >= INVVPID_ADDR && type <= INVVPID_CONTEXT_LOCAL);
 	asm volatile("sub %%rsp,%0; invvpid (%%rsp,%0,1), %1"
 		     : "+r"(data)
-		     : "r"(type));
+		     : "r"(get_first_supported_invvpid_type()));
 }
 
 static void invvpid_test_gp(void)
-- 
2.34.0.rc2.393.gf8c9666880-goog