The MP spec requires a minimum of 1k alignment. So too does Xen's use of a
single fixmap page to map the IO-APIC.
Reject out-of-spec values so we don't end up in a position where a bad
firmware value causes Xen to use the wrong mapping.
Signed-off-by: Andrew Cooper <andrew.coop...@citrix.com>
---
CC: Jan Beulich <jbeul...@suse.com>
CC: Wei Liu <w...@xen.org>
CC: Roger Pau Monné <roger....@citrix.com>
---
xen/arch/x86/io_apic.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/xen/arch/x86/io_apic.c b/xen/arch/x86/io_apic.c
index 0ef61fb2f167..db1ea6e2f2ca 100644
--- a/xen/arch/x86/io_apic.c
+++ b/xen/arch/x86/io_apic.c
@@ -2589,10 +2589,11 @@ static void __init ioapic_init_mappings(void)
union IO_APIC_reg_01 reg_01;
paddr_t ioapic_phys = mp_ioapics[i].mpc_apicaddr;
- if ( !ioapic_phys )
+ if ( !ioapic_phys || (ioapic_phys & (KB(1) - 1)) )
{
printk(KERN_ERR
- "WARNING: bogus zero IO-APIC address found in MPTABLE,
disabling IO/APIC support!\n");
+ "WARNING: bogus IO-APIC address %08lx found in MPTABLE,
disabling IO/APIC support!\n",
+ ioapic_phys);
smp_found_config = false;
skip_ioapic_setup = true;
break;
--
2.30.2
