[PATCH v2 2/7] hyperv: SVM enlightened TLB flush support flag

Vineeth Pillai
2021-04-15T13:44:13Z

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@linux.microsoft.com>
---
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