1 files changed, 49 insertions, 14 deletions

diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index f3154ca41ac4..da3972fe5a7a 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -11,25 +11,14 @@
 #include <asm/paravirt.h>
 #include <asm/mshyperv.h>
 
+union hv_ghcb;
+
 DECLARE_STATIC_KEY_FALSE(isolation_type_snp);
 
 typedef int (*hyperv_fill_flush_list_func)(
 		struct hv_guest_mapping_flush_list *flush,
 		void *data);
 
-static inline void hv_set_register(unsigned int reg, u64 value)
-{
-	wrmsrl(reg, value);
-}
-
-static inline u64 hv_get_register(unsigned int reg)
-{
-	u64 value;
-
-	rdmsrl(reg, value);
-	return value;
-}
-
 #define hv_get_raw_timer() rdtsc_ordered()
 
 void hyperv_vector_handler(struct pt_regs *regs);
@@ -41,7 +30,7 @@ extern void *hv_hypercall_pg;
 
 extern u64 hv_current_partition_id;
 
-extern void __percpu **hv_ghcb_pg;
+extern union hv_ghcb  __percpu **hv_ghcb_pg;
 
 int hv_call_deposit_pages(int node, u64 partition_id, u32 num_pages);
 int hv_call_add_logical_proc(int node, u32 lp_index, u32 acpi_id);
@@ -193,6 +182,50 @@ int hv_map_ioapic_interrupt(int ioapic_id, bool level, int vcpu, int vector,
 		struct hv_interrupt_entry *entry);
 int hv_unmap_ioapic_interrupt(int ioapic_id, struct hv_interrupt_entry *entry);
 int hv_set_mem_host_visibility(unsigned long addr, int numpages, bool visible);
+
+#ifdef CONFIG_AMD_MEM_ENCRYPT
+void hv_ghcb_msr_write(u64 msr, u64 value);
+void hv_ghcb_msr_read(u64 msr, u64 *value);
+#else
+static inline void hv_ghcb_msr_write(u64 msr, u64 value) {}
+static inline void hv_ghcb_msr_read(u64 msr, u64 *value) {}
+#endif
+
+extern bool hv_isolation_type_snp(void);
+
+static inline bool hv_is_synic_reg(unsigned int reg)
+{
+	if ((reg >= HV_REGISTER_SCONTROL) &&
+	    (reg <= HV_REGISTER_SINT15))
+		return true;
+	return false;
+}
+
+static inline u64 hv_get_register(unsigned int reg)
+{
+	u64 value;
+
+	if (hv_is_synic_reg(reg) && hv_isolation_type_snp())
+		hv_ghcb_msr_read(reg, &value);
+	else
+		rdmsrl(reg, value);
+	return value;
+}
+
+static inline void hv_set_register(unsigned int reg, u64 value)
+{
+	if (hv_is_synic_reg(reg) && hv_isolation_type_snp()) {
+		hv_ghcb_msr_write(reg, value);
+
+		/* Write proxy bit via wrmsl instruction */
+		if (reg >= HV_REGISTER_SINT0 &&
+		    reg <= HV_REGISTER_SINT15)
+			wrmsrl(reg, value | 1 << 20);
+	} else {
+		wrmsrl(reg, value);
+	}
+}
+
 #else /* CONFIG_HYPERV */
 static inline void hyperv_init(void) {}
 static inline void hyperv_setup_mmu_ops(void) {}
@@ -209,6 +242,8 @@ static inline int hyperv_flush_guest_mapping_range(u64 as,
 {
 	return -1;
 }
+static inline void hv_set_register(unsigned int reg, u64 value) { }
+static inline u64 hv_get_register(unsigned int reg) { return 0; }
 static inline int hv_set_mem_host_visibility(unsigned long addr, int numpages,
 					     bool visible)
 {