[PATCH v2 09/11] KVM: SVM: Add VNMI bit definition

From: Maxim Levitsky
Date: Tue Nov 29 2022 - 14:42:18 EST


From: Santosh Shukla <santosh.shukla@xxxxxxx>

VNMI exposes 3 capability bits (V_NMI, V_NMI_MASK, and V_NMI_ENABLE) to
virtualize NMI and NMI_MASK, Those capability bits are part of
VMCB::intr_ctrl -
V_NMI(11) - Indicates whether a virtual NMI is pending in the guest.
V_NMI_MASK(12) - Indicates whether virtual NMI is masked in the guest.
V_NMI_ENABLE(26) - Enables the NMI virtualization feature for the guest.

When Hypervisor wants to inject NMI, it will set V_NMI bit, Processor
will clear the V_NMI bit and Set the V_NMI_MASK which means the Guest is
handling NMI, After the guest handled the NMI, The processor will clear
the V_NMI_MASK on the successful completion of IRET instruction Or if
VMEXIT occurs while delivering the virtual NMI.

To enable the VNMI capability, Hypervisor need to program
V_NMI_ENABLE bit 1.

Reviewed-by: Maxim Levitsky <mlevitsk@xxxxxxxxxx>
Signed-off-by: Santosh Shukla <santosh.shukla@xxxxxxx>
---
arch/x86/include/asm/svm.h | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/arch/x86/include/asm/svm.h b/arch/x86/include/asm/svm.h
index cb1ee53ad3b189..26d6f549ce2b46 100644
--- a/arch/x86/include/asm/svm.h
+++ b/arch/x86/include/asm/svm.h
@@ -203,6 +203,13 @@ struct __attribute__ ((__packed__)) vmcb_control_area {
#define X2APIC_MODE_SHIFT 30
#define X2APIC_MODE_MASK (1 << X2APIC_MODE_SHIFT)

+#define V_NMI_PENDING_SHIFT 11
+#define V_NMI_PENDING (1 << V_NMI_PENDING_SHIFT)
+#define V_NMI_MASK_SHIFT 12
+#define V_NMI_MASK (1 << V_NMI_MASK_SHIFT)
+#define V_NMI_ENABLE_SHIFT 26
+#define V_NMI_ENABLE (1 << V_NMI_ENABLE_SHIFT)
+
#define LBR_CTL_ENABLE_MASK BIT_ULL(0)
#define VIRTUAL_VMLOAD_VMSAVE_ENABLE_MASK BIT_ULL(1)

--
2.26.3