acpi/x86: define ACPI IO registers for PVH guests

Define VCPU available map address (used by AML's PRSC method)
and GPE0 CPU hotplug event number. Use these definitions in mk_dsdt
instead hardcoded values.

These definitions will later be used by both the hypervisor and
the toolstack (initially for PVH guests only), thus they are
placed in public headers.

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>

tools/libacpi/mk_dsdt.c

@@ -18,6 +18,7 @@
 #include <stdlib.h>
 #include <stdbool.h>
 #if defined(CONFIG_X86)
+#include <xen/arch-x86/xen.h>
 #include <xen/hvm/hvm_info_table.h>
 #elif defined(CONFIG_ARM_64)
 #include <xen/arch-arm.h>
@@ -244,7 +245,8 @@ int main(int argc, char **argv)
 #endif
 
     /* Operation Region 'PRST': bitmask of online CPUs. */
-    stmt("OperationRegion", "PRST, SystemIO, 0xaf00, 32");
+    stmt("OperationRegion", "PRST, SystemIO, %#x, %d",
+        XEN_ACPI_CPU_MAP, XEN_ACPI_CPU_MAP_LEN);
     push_block("Field", "PRST, ByteAcc, NoLock, Preserve");
     indent(); printf("PRS, %u\n", max_cpus);
     pop_block();
@@ -283,7 +285,8 @@ int main(int argc, char **argv)
     /* Define GPE control method. */
     push_block("Scope", "\\_GPE");
     push_block("Method",
-               dm_version == QEMU_XEN_TRADITIONAL ? "_L02" : "_E02");
+               dm_version == QEMU_XEN_TRADITIONAL ? "_L%02d" : "_E%02d",
+               XEN_ACPI_GPE0_CPUHP_BIT);
     stmt("\\_SB.PRSC ()", NULL);
     pop_block();
     pop_block();

tools/libacpi/static_tables.c

@@ -31,6 +31,10 @@ struct acpi_20_facs Facs = {
  * Fixed ACPI Description Table (FADT).
  */
 
+/*
+ * These values must match register definitions in struct hvm_hw_acpi
+ * (in xen/include/public/arch-x86/hvm/save.h).
+ */
 #define ACPI_PM1A_EVT_BLK_BIT_WIDTH         0x20
 #define ACPI_PM1A_EVT_BLK_BIT_OFFSET        0x00
 #define ACPI_PM1A_CNT_BLK_BIT_WIDTH         0x10

xen/include/public/arch-x86/xen.h

@@ -291,6 +291,13 @@ struct xen_arch_domainconfig {
                                      XEN_X86_EMU_PIT)
     uint32_t emulation_flags;
 };
+
+/* Location of online VCPU bitmap. */
+#define XEN_ACPI_CPU_MAP             0xaf00
+#define XEN_ACPI_CPU_MAP_LEN         ((HVM_MAX_VCPUS + 7) / 8)
+
+/* GPE0 bit set during CPU hotplug */
+#define XEN_ACPI_GPE0_CPUHP_BIT      2
 #endif
 
 #endif /* !__ASSEMBLY__ */