6.11-stable review patch. If anyone has any objections, please let me know.
------------------
From: Juergen Gross <jgross@xxxxxxxx>
[ Upstream commit bf56c410162dbf2e27906acbdcd904cbbfdba302 ]
Recent topology checks of the x86 boot code uncovered the need for
PV guests to have the boot cpu marked in the APICBASE MSR.
Fixes: 9d22c96316ac ("x86/topology: Handle bogus ACPI tables correctly")
Reported-by: Niels Dettenbach <nd@xxxxxxxxxxxx>
Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
Reviewed-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
arch/x86/xen/enlighten_pv.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index 2c12ae42dc8bd..d6818c6cafda1 100644
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -1032,6 +1032,10 @@ static u64 xen_do_read_msr(unsigned int msr, int *err)
switch (msr) {
case MSR_IA32_APICBASE:
val &= ~X2APIC_ENABLE;
+ if (smp_processor_id() == 0)
+ val |= MSR_IA32_APICBASE_BSP;
+ else
+ val &= ~MSR_IA32_APICBASE_BSP;
break;
}
return val;
--
2.43.0
