[PATCH v5 6/6] KVM: selftests: Extend set_sregs_test to cover LASS

[Sohil Mehta <sohil.mehta@intel.com>]

Extend set_sregs_test to cover CR4.LASS and verify that KVM_SET_SREGS
accepts CR4.LASS when LASS is supported, and rejects it, without
modifying sregs, when it isn't.

Signed-off-by: Sohil Mehta <sohil.mehta@intel.com>
Tested-by: Kishen Maloor <kishen.maloor@intel.com>
Tested-by: Farrah Chen <farrah.chen@intel.com>
Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>
---
v5:
 - Avoided the CR4 write test specific to LASS.
 - Picked up review and test tags

v4:
 - New patch
---
 tools/testing/selftests/kvm/include/x86/processor.h | 2 ++
 tools/testing/selftests/kvm/x86/set_sregs_test.c    | 3 +++
 2 files changed, 5 insertions(+)

diff --git a/tools/testing/selftests/kvm/include/x86/processor.h b/tools/testing/selftests/kvm/include/x86/processor.h
index 5898a277a2e0..606ee9fe0ddb 100644
--- a/tools/testing/selftests/kvm/include/x86/processor.h
+++ b/tools/testing/selftests/kvm/include/x86/processor.h
@@ -81,6 +81,7 @@ const char *ex_str(int vector);
 #define X86_CR4_SMEP		(1ul << 20)
 #define X86_CR4_SMAP		(1ul << 21)
 #define X86_CR4_PKE		(1ul << 22)
+#define X86_CR4_LASS		(1ul << 27)
 
 struct xstate_header {
 	u64				xstate_bv;
@@ -197,6 +198,7 @@ struct kvm_x86_cpu_feature {
 #define	X86_FEATURE_SPEC_CTRL		KVM_X86_CPU_FEATURE(0x7, 0, EDX, 26)
 #define	X86_FEATURE_ARCH_CAPABILITIES	KVM_X86_CPU_FEATURE(0x7, 0, EDX, 29)
 #define	X86_FEATURE_PKS			KVM_X86_CPU_FEATURE(0x7, 0, ECX, 31)
+#define	X86_FEATURE_LASS		KVM_X86_CPU_FEATURE(0x7, 1, EAX, 6)
 #define	X86_FEATURE_XTILECFG		KVM_X86_CPU_FEATURE(0xD, 0, EAX, 17)
 #define	X86_FEATURE_XTILEDATA		KVM_X86_CPU_FEATURE(0xD, 0, EAX, 18)
 #define	X86_FEATURE_XSAVES		KVM_X86_CPU_FEATURE(0xD, 1, EAX, 3)
diff --git a/tools/testing/selftests/kvm/x86/set_sregs_test.c b/tools/testing/selftests/kvm/x86/set_sregs_test.c
index 5afc4187f5eb..f30dc61fe00f 100644
--- a/tools/testing/selftests/kvm/x86/set_sregs_test.c
+++ b/tools/testing/selftests/kvm/x86/set_sregs_test.c
@@ -72,6 +72,8 @@ static u64 calc_supported_cr4_feature_bits(void)
 		cr4 |= X86_CR4_SMAP;
 	if (kvm_cpu_has(X86_FEATURE_PKU))
 		cr4 |= X86_CR4_PKE;
+	if (kvm_cpu_has(X86_FEATURE_LASS))
+		cr4 |= X86_CR4_LASS;
 
 	return cr4;
 }
@@ -128,6 +130,7 @@ static void test_cr_bits(struct kvm_vcpu *vcpu, u64 cr4)
 	TEST_INVALID_SREG_BIT(vcpu, cr4, sregs, X86_CR4_SMEP);
 	TEST_INVALID_SREG_BIT(vcpu, cr4, sregs, X86_CR4_SMAP);
 	TEST_INVALID_SREG_BIT(vcpu, cr4, sregs, X86_CR4_PKE);
+	TEST_INVALID_SREG_BIT(vcpu, cr4, sregs, X86_CR4_LASS);
 
 	for (i = 32; i < 64; i++)
 		TEST_INVALID_SREG_BIT(vcpu, cr0, sregs, BIT(i));
-- 
2.43.0