From: Neeraj Upadhyay Date: Thu, 28 Aug 2025 11:02:41 +0000 (+0530) Subject: x86/apic: Initialize APIC ID for Secure AVIC X-Git-Tag: v6.18-rc1~185^2~7^2~15 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=45e2cef568cdf87cb06c9783b45c8f08d1ab1cec;p=thirdparty%2Flinux.git x86/apic: Initialize APIC ID for Secure AVIC Initialize the APIC ID in the Secure AVIC APIC backing page with the APIC_ID MSR value read from the hypervisor. CPU topology evaluation later during boot would catch and report any duplicate APIC ID for two CPUs. Signed-off-by: Neeraj Upadhyay Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Tianyu Lan Link: https://lore.kernel.org/20250828110255.208779-2-Neeraj.Upadhyay@amd.com --- diff --git a/arch/x86/kernel/apic/x2apic_savic.c b/arch/x86/kernel/apic/x2apic_savic.c index 5479605429c1a..56c51ea4e5ab7 100644 --- a/arch/x86/kernel/apic/x2apic_savic.c +++ b/arch/x86/kernel/apic/x2apic_savic.c @@ -150,6 +150,12 @@ static void savic_setup(void) enum es_result res; unsigned long gpa; + /* + * Before Secure AVIC is enabled, APIC MSR reads are intercepted. + * APIC_ID MSR read returns the value from the hypervisor. + */ + apic_set_reg(ap, APIC_ID, native_apic_msr_read(APIC_ID)); + gpa = __pa(ap); /*