x86/shutdown: change default reboot method preference

The current logic to chose the preferred reboot method is based on the mode Xen
has been booted into, so if the box is booted from UEFI, the preferred reboot
method will be to use the ResetSystem() run time service call.

However, that method seems to be widely untested, and quite often leads to a
result similar to:

Hardware Dom0 shutdown: rebooting machine
----[ Xen-4.18-unstable  x86_64  debug=y  Tainted:   C    ]----
CPU:    0
RIP:    e008:[<0000000000000017>] 0000000000000017
RFLAGS: 0000000000010202   CONTEXT: hypervisor
[...]
Xen call trace:
   [<0000000000000017>] R 0000000000000017
   [<ffff83207eff7b50>] S ffff83207eff7b50
   [<ffff82d0403525aa>] F machine_restart+0x1da/0x261
   [<ffff82d04035263c>] F apic_wait_icr_idle+0/0x37
   [<ffff82d040233689>] F smp_call_function_interrupt+0xc7/0xcb
   [<ffff82d040352f05>] F call_function_interrupt+0x20/0x34
   [<ffff82d04033b0d5>] F do_IRQ+0x150/0x6f3
   [<ffff82d0402018c2>] F common_interrupt+0x132/0x140
   [<ffff82d040283d33>] F arch/x86/acpi/cpu_idle.c#acpi_idle_do_entry+0x113/0x129
   [<ffff82d04028436c>] F arch/x86/acpi/cpu_idle.c#acpi_processor_idle+0x3eb/0x5f7
   [<ffff82d04032a549>] F arch/x86/domain.c#idle_loop+0xec/0xee

****************************************
Panic on CPU 0:
FATAL TRAP: vector = 6 (invalid opcode)
****************************************

Which in most cases does lead to a reboot, however that's unreliable.

Change the default reboot preference to prefer ACPI over UEFI if available and
not in reduced hardware mode.

This is in line to what Linux does, so it's unlikely to cause issues on current
and future hardware, since there's a much higher chance of vendors testing
hardware with Linux rather than Xen.

Add a special case for one Acer model that does require being rebooted using
ResetSystem().  See Linux commit 0082517fa4bce for rationale.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Acked-By: Oleksii Kurochko <oleksii.kurochko@gmail.com>
master commit: d81dd31303513a1626973778d557a6493d86511a
master date: 2024-08-05 10:16:54 +0200

diff --git a/CHANGELOG.md b/CHANGELOG.md
index ceca12eb5f583f802e6f0edba44da99162d4fbd7..666d7f0d491719d751ccbec811d6c5aeb772be33 100644 (file)
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,12 @@ Notable changes to Xen will be documented in this file.
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 
+## [4.18.4](https://xenbits.xenproject.org/gitweb/?p=xen.git;a=shortlog;h=RELEASE-4.18.4)
+
+### Changed
+ - On x86:
+   - Prefer ACPI reboot over UEFI ResetSystem() run time service call.
+
 ## [4.18.3](https://xenbits.xen.org/gitweb/?p=xen.git;a=shortlog;h=RELEASE-4.18.3)
 
 ### Changed

diff --git a/xen/arch/x86/shutdown.c b/xen/arch/x86/shutdown.c
index 7619544d14dae2ac3bf08b41bcd435919876fcf7..3816ede1afe568b6d11a8882e986d5ac3eca70a5 100644 (file)
--- a/xen/arch/x86/shutdown.c
+++ b/xen/arch/x86/shutdown.c
@@ -150,19 +150,20 @@ static void default_reboot_type(void)
 
     if ( xen_guest )
         reboot_type = BOOT_XEN;
+    else if ( !acpi_disabled && !acpi_gbl_reduced_hardware )
+        reboot_type = BOOT_ACPI;
     else if ( efi_enabled(EFI_RS) )
         reboot_type = BOOT_EFI;
-    else if ( acpi_disabled )
-        reboot_type = BOOT_KBD;
     else
-        reboot_type = BOOT_ACPI;
+        reboot_type = BOOT_KBD;
 }
 
 static int __init cf_check override_reboot(const struct dmi_system_id *d)
 {
     enum reboot_type type = (long)d->driver_data;
 
-    if ( type == BOOT_ACPI && acpi_disabled )
+    if ( (type == BOOT_ACPI && acpi_disabled) ||
+         (type == BOOT_EFI && !efi_enabled(EFI_RS)) )
         type = BOOT_KBD;
 
     if ( reboot_type != type )
@@ -172,6 +173,7 @@ static int __init cf_check override_reboot(const struct dmi_system_id *d)
             [BOOT_KBD]  = "keyboard controller",
             [BOOT_ACPI] = "ACPI",
             [BOOT_CF9]  = "PCI",
+            [BOOT_EFI]  = "UEFI",
         };
 
         reboot_type = type;
@@ -530,6 +532,15 @@ static const struct dmi_system_id __initconstrel reboot_dmi_table[] = {
             DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge R740"),
         },
     },
+    {    /* Handle problems with rebooting on Acer TravelMate X514-51T. */
+        .callback = override_reboot,
+        .driver_data = (void *)(long)BOOT_EFI,
+        .ident = "Acer TravelMate X514-51T",
+        .matches = {
+            DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
+            DMI_MATCH(DMI_PRODUCT_NAME, "TravelMate X514-51T"),
+        },
+    },
     { }
 };