Restricted injection is a feature which enforces additional interrupt and event
injection security protections for a SEV-SNP guest. It disables all
hypervisor-based interrupt queuing and event injection of all vectors except
a new exception vector, #HV (28), which is reserved for SNP guest use, but
never generated by hardware. #HV is only allowed to be injected into VMSAs that
execute with Restricted Injection.
The guests running with the SNP restricted injection feature active limit the
host to ringing a doorbell with a #HV exception.
Define two fields in the #HV doorbell page: a pending event field, and an
EOI assist.
Create the structure definition for the #HV doorbell page as per GHCB
specification.
Co-developed-by: Thomas Lendacky <thomas.lendacky@xxxxxxx>
Signed-off-by: Thomas Lendacky <thomas.lendacky@xxxxxxx>
Signed-off-by: Melody Wang <huibo.wang@xxxxxxx>
---
arch/x86/include/asm/svm.h | 33 +++++++++++++++++++++++++++++++++
1 file changed, 33 insertions(+)
diff --git a/arch/x86/include/asm/svm.h b/arch/x86/include/asm/svm.h
index 2b59b9951c90..95cb9a62f477 100644
--- a/arch/x86/include/asm/svm.h
+++ b/arch/x86/include/asm/svm.h
@@ -239,6 +239,39 @@ struct __attribute__ ((__packed__)) vmcb_control_area {
#define SVM_TSC_RATIO_MAX 0x000000ffffffffffULL
#define SVM_TSC_RATIO_DEFAULT 0x0100000000ULL
+/*
+ * Hypervisor doorbell page:
+ *
+ * Used when restricted injection is enabled for a VM. One page in size that
+ * is shared between the guest and hypervisor to communicate exception and
+ * interrupt events.
+ */
+struct hvdb_events {
+ /* First 64 bytes of HV doorbell page defined in GHCB specification */
+ union {
+ struct {
+ /* Non-maskable event indicators */
+ u16 vector: 8,
+ nmi: 1,
+ mce: 1,
+ reserved2: 5,
+ no_further_signal: 1;
+ };
+
+ u16 pending_events;
+ };
+
+ u8 no_eoi_required;
+
+ u8 reserved3[61];
+};
+
+struct hvdb {
+ struct hvdb_events events;
+
+ /* Remainder of the page is for software use */
+ u8 reserved[PAGE_SIZE - sizeof(struct hvdb_events)];
+};
/* AVIC */
#define AVIC_LOGICAL_ID_ENTRY_GUEST_PHYSICAL_ID_MASK (0xFFULL)
--
2.34.1
