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authorIngo Molnar <mingo@kernel.org>2025-04-22 08:31:41 +0200
committerIngo Molnar <mingo@kernel.org>2025-04-22 08:31:41 +0200
commitc96f564e6f943cf5d8536e1c43f243aa7c42b4ed (patch)
treeada98ccab9b31fe9519b4e6ea2beec63ad98cb16 /arch/x86/kernel/acpi/boot.c
parent321550859f3bd64f547d0b4e9fbd97bd539ef47c (diff)
parent06e09002bc1d46505d6b3bd947ebaf3cec7acab8 (diff)
Merge branch 'x86/cpu' into x86/microcode, to pick up dependent commits
Avoid a conflict in <asm/cpufeatures.h> by merging pending x86/cpu changes. Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/acpi/boot.c')
-rw-r--r--arch/x86/kernel/acpi/boot.c11
1 files changed, 11 insertions, 0 deletions
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index dae6a73be40e..9fa321a95eb3 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -23,6 +23,8 @@
#include <linux/serial_core.h>
#include <linux/pgtable.h>
+#include <xen/xen.h>
+
#include <asm/e820/api.h>
#include <asm/irqdomain.h>
#include <asm/pci_x86.h>
@@ -1729,6 +1731,15 @@ int __init acpi_mps_check(void)
{
#if defined(CONFIG_X86_LOCAL_APIC) && !defined(CONFIG_X86_MPPARSE)
/* mptable code is not built-in*/
+
+ /*
+ * Xen disables ACPI in PV DomU guests but it still emulates APIC and
+ * supports SMP. Returning early here ensures that APIC is not disabled
+ * unnecessarily and the guest is not limited to a single vCPU.
+ */
+ if (xen_pv_domain() && !xen_initial_domain())
+ return 0;
+
if (acpi_disabled || acpi_noirq) {
pr_warn("MPS support code is not built-in, using acpi=off or acpi=noirq or pci=noacpi may have problem\n");
return 1;