hv: APIs for building x2APIC ID and LDR

x2APIC ID and LDR are in different format compared to xAPIC mode of operation.
This patch adds code to build ID and LDR when guest uses vLAPIC in x2APIC mode.

Tracked-On: #1626
Signed-off-by: Sainath Grandhi <sainath.grandhi@intel.com>
Reviewed-by: Xu Anthony <anthony.xu@intel.com>

Author: Sainath Grandhi

hypervisor/arch/x86/guest/vlapic.c

@@ -49,6 +49,8 @@ static inline uint32_t prio(uint32_t x)
 #define	APICBASE_BSP		0x00000100UL
 #define	APICBASE_X2APIC		0x00000400U
 #define	APICBASE_ENABLED	0x00000800UL
+#define LOGICAL_ID_MASK         0xFU
+#define CLUSTER_ID_MASK         0xFFFF0U
 
 #define ACRN_DBG_LAPIC	6U
 
@@ -102,6 +104,8 @@ static void vlapic_set_error(struct acrn_vlapic *vlapic, uint32_t mask);
 
 static void vlapic_timer_expired(void *data);
 
+static inline bool is_x2apic_enabled(const struct acrn_vlapic *vlapic);
+
 static struct acrn_vlapic *
 vm_lapic_from_vcpu_id(struct vm *vm, uint16_t vcpu_id)
 {
@@ -180,13 +184,29 @@ vlapic_build_id(const struct acrn_vlapic *vlapic)
 	}
 #endif
 
-	lapic_regs_id = (uint32_t)vlapic_id << APIC_ID_SHIFT;
+	if (is_x2apic_enabled(vlapic)) {
+		lapic_regs_id = vlapic_id;
+	} else {
+		lapic_regs_id = (uint32_t)vlapic_id << APIC_ID_SHIFT;
+	}
 
 	dev_dbg(ACRN_DBG_LAPIC, "vlapic APIC PAGE ID : 0x%08x", lapic_regs_id);
 
 	return lapic_regs_id;
 }
 
+static inline void vlapic_build_x2apic_id(struct acrn_vlapic *vlapic)
+{
+	struct lapic_regs *lapic;
+	uint32_t logical_id, cluster_id;
+
+	lapic = &(vlapic->apic_page);
+	lapic->id.v = vlapic_build_id(vlapic);
+	logical_id = lapic->id.v & LOGICAL_ID_MASK;
+	cluster_id = (lapic->id.v & CLUSTER_ID_MASK) >> 4U;
+	lapic->ldr.v = (cluster_id << 16U) | (1U << logical_id);
+}
+
 static void
 vlapic_dfr_write_handler(struct acrn_vlapic *vlapic)
 {
@@ -1672,6 +1692,17 @@ static int
 vlapic_set_apicbase(struct acrn_vlapic *vlapic, uint64_t new)
 {
 
+	uint64_t changed;
+	changed = vlapic->msr_apicbase ^ new;
+
+	if (changed == APICBASE_X2APIC) {
+		if ((new & APICBASE_X2APIC) == APICBASE_X2APIC) {
+			vlapic->msr_apicbase = new;
+			vlapic_build_x2apic_id(vlapic);
+			return 0;
+		}
+	}
+
 	if (vlapic->msr_apicbase != new) {
 		dev_dbg(ACRN_DBG_LAPIC,
 			"NOT support to change APIC_BASE MSR from %#lx to %#lx",