[PATCH v4 2/7] hyperv: SVM enlightened TLB flush support flag

[Vineeth Pillai]

Bit 22 of HYPERV_CPUID_FEATURES.EDX is specific to SVM and specifies
support for enlightened TLB flush. With this enlightenment enabled,
ASID invalidations flushes only gva->hpa entries. To flush TLB entries
derived from NPT, hypercalls should be used
(HvFlushGuestPhysicalAddressSpace or HvFlushGuestPhysicalAddressList)

Signed-off-by: Vineeth Pillai <viremana@xxxxxxxxxxxxxxxxxxx>
---
 arch/x86/include/asm/hyperv-tlfs.h | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/arch/x86/include/asm/hyperv-tlfs.h b/arch/x86/include/asm/hyperv-tlfs.h
index 606f5cc579b2..005bf14d0449 100644
--- a/arch/x86/include/asm/hyperv-tlfs.h
+++ b/arch/x86/include/asm/hyperv-tlfs.h
@@ -133,6 +133,15 @@
 #define HV_X64_NESTED_GUEST_MAPPING_FLUSH		BIT(18)
 #define HV_X64_NESTED_MSR_BITMAP			BIT(19)
 
+/*
+ * This is specific to AMD and specifies that enlightened TLB flush is
+ * supported. If guest opts in to this feature, ASID invalidations only
+ * flushes gva -> hpa mapping entries. To flush the TLB entries derived
+ * from NPT, hypercalls should be used (HvFlushGuestPhysicalAddressSpace
+ * or HvFlushGuestPhysicalAddressList).
+ */
+#define HV_X64_NESTED_ENLIGHTENED_TLB			BIT(22)
+
 /* HYPERV_CPUID_ISOLATION_CONFIG.EAX bits. */
 #define HV_PARAVISOR_PRESENT				BIT(0)
 
-- 
2.25.1