diff options
| author | Neeraj Upadhyay <Neeraj.Upadhyay@amd.com> | 2025-08-28 16:50:08 +0530 |
|---|---|---|
| committer | Borislav Petkov (AMD) <bp@alien8.de> | 2025-09-01 13:06:08 +0200 |
| commit | c8018325dd3e7c75c19b1e9263c358c4c96214f9 (patch) | |
| tree | 095fe7e698f906ffc58923751d50acb997f9dd22 /arch/x86/kernel | |
| parent | 43b6687ac8777821973d790ff9e9565a84cf6b98 (diff) | |
x86/apic: Add kexec support for Secure AVIC
Add a apic->teardown() callback to disable Secure AVIC before rebooting into
the new kernel. This ensures that the new kernel does not access the old APIC
backing page which was allocated by the previous kernel.
Such accesses can happen if there are any APIC accesses done during the guest
boot before Secure AVIC driver probe is done by the new kernel (as Secure AVIC
would have remained enabled in the Secure AVIC control MSR).
Signed-off-by: Neeraj Upadhyay <Neeraj.Upadhyay@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/20250828112008.209013-1-Neeraj.Upadhyay@amd.com
Diffstat (limited to 'arch/x86/kernel')
| -rw-r--r-- | arch/x86/kernel/apic/apic.c | 3 | ||||
| -rw-r--r-- | arch/x86/kernel/apic/x2apic_savic.c | 8 |
2 files changed, 11 insertions, 0 deletions
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index db18810576bc..680d305589a3 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -1170,6 +1170,9 @@ void disable_local_APIC(void) if (!apic_accessible()) return; + if (apic->teardown) + apic->teardown(); + apic_soft_disable(); #ifdef CONFIG_X86_32 diff --git a/arch/x86/kernel/apic/x2apic_savic.c b/arch/x86/kernel/apic/x2apic_savic.c index d76faeaced83..36e6d0dbcc9c 100644 --- a/arch/x86/kernel/apic/x2apic_savic.c +++ b/arch/x86/kernel/apic/x2apic_savic.c @@ -330,6 +330,13 @@ static void savic_eoi(void) } } +static void savic_teardown(void) +{ + /* Disable Secure AVIC */ + native_wrmsrq(MSR_AMD64_SAVIC_CONTROL, 0); + savic_unregister_gpa(NULL); +} + static void savic_setup(void) { void *ap = this_cpu_ptr(savic_page); @@ -385,6 +392,7 @@ static struct apic apic_x2apic_savic __ro_after_init = { .probe = savic_probe, .acpi_madt_oem_check = savic_acpi_madt_oem_check, .setup = savic_setup, + .teardown = savic_teardown, .dest_mode_logical = false, |