... and move the type itself to linux-compat.h.

While doing so,
- convert __read_mostly to __ro_after_init for respective variables
  having their type changed (for acpi_numa add the attribute anew),
- in cpuid_hypervisor_leaves() drop a cast altogether,
- switch an adjacent struct arch_irq_desc field to bool.

Signed-off-by: Jan Beulich <jbeulich@suse.com>

--- a/xen/arch/x86/apic.c
+++ b/xen/arch/x86/apic.c
@@ -71,7 +71,7 @@ static struct {
 /*
  * Knob to control our willingness to enable the local APIC.
  */
-static s8 __initdata enable_local_apic; /* -1=force-disable, +1=force-enable */
+static int8_t __initdata enable_local_apic; /* -1=force-disable, +1=force-enable */
 
 /*
  * Debug level
--- a/xen/arch/x86/cpu/amd.c
+++ b/xen/arch/x86/cpu/amd.c
@@ -46,7 +46,7 @@ static unsigned int __initdata opt_cpuid
 integer_param("cpuid_mask_thermal_ecx", opt_cpuid_mask_thermal_ecx);
 
 /* 1 = allow, 0 = don't allow guest creation, -1 = don't allow boot */
-s8 __read_mostly opt_allow_unsafe;
+int8_t __ro_after_init opt_allow_unsafe;
 boolean_param("allow_unsafe", opt_allow_unsafe);
 
 /* Signal whether the ACPI C1E quirk is required. */
--- a/xen/arch/x86/e820.c
+++ b/xen/arch/x86/e820.c
@@ -27,7 +27,7 @@ static unsigned long long __initdata opt
 size_param("availmem", opt_availmem);
 
 /* opt_nomtrr_check: Don't clip ram to highest cacheable MTRR. */
-static s8 __initdata e820_mtrr_clip = -1;
+static int8_t __initdata e820_mtrr_clip = -1;
 boolean_param("e820-mtrr-clip", e820_mtrr_clip);
 
 /* opt_e820_verbose: Be verbose about clipping, the original e820, &c */
--- a/xen/arch/x86/hvm/quirks.c
+++ b/xen/arch/x86/hvm/quirks.c
@@ -11,7 +11,7 @@
 #include <xen/param.h>
 #include <asm/hvm/support.h>
 
-s8 __read_mostly hvm_port80_allowed = -1;
+int8_t __ro_after_init hvm_port80_allowed = -1;
 boolean_param("hvm_port80", hvm_port80_allowed);
 
 static int __init cf_check dmi_hvm_deny_port80(const struct dmi_system_id *id)
--- a/xen/arch/x86/hvm/vmx/vmcs.c
+++ b/xen/arch/x86/hvm/vmx/vmcs.c
@@ -59,7 +59,7 @@ static unsigned int __ro_after_init vm_n
 integer_param("vm-notify-window", vm_notify_window);
 
 static bool __read_mostly opt_ept_pml = true;
-static s8 __read_mostly opt_ept_ad = -1;
+static int8_t __ro_after_init opt_ept_ad = -1;
 int8_t __read_mostly opt_ept_exec_sp = -1;
 
 static int __init cf_check parse_ept_param(const char *s)
--- a/xen/arch/x86/include/asm/acpi.h
+++ b/xen/arch/x86/include/asm/acpi.h
@@ -100,7 +100,7 @@ extern unsigned long acpi_wakeup_address
 
 #define ARCH_HAS_POWER_INIT	1
 
-extern s8 acpi_numa;
+extern int8_t acpi_numa;
 
 extern struct acpi_sleep_info acpi_sinfo;
 #define acpi_video_flags bootsym(video_flags)
--- a/xen/arch/x86/include/asm/amd.h
+++ b/xen/arch/x86/include/asm/amd.h
@@ -160,7 +160,7 @@
 struct cpuinfo_x86;
 int cpu_has_amd_erratum(const struct cpuinfo_x86 *cpu, int osvw_id, ...);
 
-extern s8 opt_allow_unsafe;
+extern int8_t opt_allow_unsafe;
 
 void fam10h_check_enable_mmcfg(void);
 void check_enable_amd_mmconf_dmi(void);
--- a/xen/arch/x86/include/asm/hvm/hvm.h
+++ b/xen/arch/x86/include/asm/hvm/hvm.h
@@ -241,7 +241,7 @@ struct hvm_function_table {
 
 extern struct hvm_function_table hvm_funcs;
 extern bool hvm_enabled;
-extern s8 hvm_port80_allowed;
+extern int8_t hvm_port80_allowed;
 
 extern const struct hvm_function_table *start_svm(void);
 extern const struct hvm_function_table *start_vmx(void);
--- a/xen/arch/x86/include/asm/irq.h
+++ b/xen/arch/x86/include/asm/irq.h
@@ -80,8 +80,8 @@ struct arch_irq_desc {
         cpumask_var_t pending_mask;
         vmask_t *used_vectors;
         unsigned move_cleanup_count;
-        u8 move_in_progress : 1;
-        s8 used;
+        bool move_in_progress : 1;
+        int8_t used;
         /*
          * Weak reference to domain having permission over this IRQ (which can
          * be different from the domain actually having the IRQ assigned)
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -170,7 +170,7 @@ static uint32_t __ro_after_init base_dis
       is_pv_domain(d)) ?                                        \
      L1_DISALLOW_MASK : (L1_DISALLOW_MASK & ~PAGE_CACHE_ATTRS))
 
-static s8 __read_mostly opt_mmio_relax;
+static int8_t __ro_after_init opt_mmio_relax;
 
 static int __init cf_check parse_mmio_relax(const char *s)
 {
--- a/xen/arch/x86/msi.c
+++ b/xen/arch/x86/msi.c
@@ -35,7 +35,7 @@
 #include <xsm/xsm.h>
 #include <xen/vpci.h>
 
-static s8 __read_mostly use_msi = -1;
+static int8_t __ro_after_init use_msi = -1;
 boolean_param("msi", use_msi);
 
 static void __pci_disable_msix(struct msi_desc *entry);
--- a/xen/arch/x86/numa.c
+++ b/xen/arch/x86/numa.c
@@ -25,7 +25,7 @@ nodeid_t apicid_to_node[MAX_LOCAL_APIC]
     [0 ... MAX_LOCAL_APIC-1] = NUMA_NO_NODE
 };
 
-s8 acpi_numa = 0;
+int8_t __ro_after_init acpi_numa = 0;
 
 int __init arch_numa_setup(const char *opt)
 {
--- a/xen/arch/x86/oprofile/op_model_athlon.c
+++ b/xen/arch/x86/oprofile/op_model_athlon.c
@@ -157,7 +157,7 @@ static inline u64 op_amd_randomize_ibs_o
          * IbsOpMaxCnt must fit in the range from 0x0081 to
          * 0xff80.
          */
-        val += (s8)(random >> 4);
+        val += (int8_t)(random >> 4);
     else
         val |= (u64)(random & IBS_RANDOM_MASK) << 32;
 
--- a/xen/arch/x86/setup.c
+++ b/xen/arch/x86/setup.c
@@ -166,7 +166,7 @@ unsigned long __read_mostly mmu_cr4_feat
 
 /* smep: Enable/disable Supervisor Mode Execution Protection */
 #define SMEP_HVM_ONLY (-2)
-static s8 __initdata opt_smep = -1;
+static int8_t __initdata opt_smep = -1;
 
 /*
  * Initial domain place holder. Needs to be global so it can be created in
@@ -203,7 +203,7 @@ custom_param("smep", parse_smep_param);
 
 /* smap: Enable/disable Supervisor Mode Access Prevention */
 #define SMAP_HVM_ONLY (-2)
-static s8 __initdata opt_smap = -1;
+static int8_t __initdata opt_smap = -1;
 
 static int __init cf_check parse_smap_param(const char *s)
 {
--- a/xen/arch/x86/traps.c
+++ b/xen/arch/x86/traps.c
@@ -1116,7 +1116,7 @@ void cpuid_hypervisor_leaves(const struc
             res->a = offset;
             res->b = offset >> 32;
             res->c = d->arch.vtsc_to_ns.mul_frac;
-            res->d = (s8)d->arch.vtsc_to_ns.shift;
+            res->d = d->arch.vtsc_to_ns.shift;
             break;
         }
 
--- a/xen/include/acpi/cpufreq/cpufreq.h
+++ b/xen/include/acpi/cpufreq/cpufreq.h
@@ -79,7 +79,7 @@ struct cpufreq_policy {
 
     bool                resume; /* flag for cpufreq 1st run
                                  * S3 wakeup, hotplug cpu, etc */
-    s8                  turbo;  /* tristate flag: 0 for unsupported
+    int8_t              turbo;  /* tristate flag: 0 for unsupported
                                  * -1 for disable, 1 for enabled
                                  * See CPUFREQ_TURBO_* below for defines */
 };
--- a/xen/include/xen/linux-compat.h
+++ b/xen/include/xen/linux-compat.h
@@ -11,7 +11,7 @@
 
 #include <xen/types.h>
 
-typedef int8_t  __s8;
+typedef int8_t  s8, __s8;
 typedef uint8_t __u8;
 typedef int16_t __s16;
 typedef int32_t __s32;
--- a/xen/include/xen/types.h
+++ b/xen/include/xen/types.h
@@ -5,7 +5,6 @@
 #include <xen/stdint.h>
 
 /* Linux inherited types which are being phased out */
-typedef int8_t s8;
 typedef uint8_t u8;
 typedef int16_t s16;
 typedef uint16_t u16, __u16;

On 29/08/2024 12:59 pm, Jan Beulich wrote:
> ... and move the type itself to linux-compat.h.
>
> While doing so,
> - convert __read_mostly to __ro_after_init for respective variables
>   having their type changed (for acpi_numa add the attribute anew),
> - in cpuid_hypervisor_leaves() drop a cast altogether,
> - switch an adjacent struct arch_irq_desc field to bool.
>
> Signed-off-by: Jan Beulich <jbeulich@suse.com>

Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>

The __read_mostly -> __ro_after_init changes are safe as far as I can tell.

use_msi is in desperate need of renaming to opt_msi.

~Andrew