Hi,
On 20/11/2019 23:05, Chao Gao wrote:
It helps to distinguish parked CPUs from those are really offlined or
hot-added. We need to know the parked CPUs in order to do a special
check against them to ensure that all CPUs, except those are really
offlined or hot-added, have the same ucode version.
Signed-off-by: Chao Gao <chao....@intel.com>
---
Note that changes on ARM side are untested.
---
xen/arch/arm/smpboot.c | 1 +
xen/arch/x86/cpu/common.c | 4 ++++
xen/arch/x86/smpboot.c | 1 +
xen/common/cpu.c | 4 ++++
xen/include/asm-arm/smp.h | 1 +
xen/include/asm-x86/smp.h | 1 +
xen/include/xen/cpumask.h | 1 +
7 files changed, 13 insertions(+)
diff --git a/xen/arch/arm/smpboot.c b/xen/arch/arm/smpboot.c
index 00b64c3..1b57ba4 100644
--- a/xen/arch/arm/smpboot.c
+++ b/xen/arch/arm/smpboot.c
@@ -39,6 +39,7 @@
cpumask_t cpu_online_map;
cpumask_t cpu_present_map;
cpumask_t cpu_possible_map;
+cpumask_var_t cpu_parked_map;
You define cpu_parked_map but AFAIK it will never get allocated. The
risk here is any access to that variable will result to a fault.
Looking at the changes below, it looks like access in common code will
be protected by park_offline_cpus. This is always false on Arm, so the
compiler should remove any access to cpu_parked_map.
With that in mind, I think it would be best to only provide a prototype
for cpu_parked_map and so the linker can warn if someone used it.
diff --git a/xen/include/asm-arm/smp.h b/xen/include/asm-arm/smp.h
index fdbcefa..4b392fa 100644
--- a/xen/include/asm-arm/smp.h
+++ b/xen/include/asm-arm/smp.h
@@ -19,6 +19,7 @@ DECLARE_PER_CPU(cpumask_var_t, cpu_core_mask);
* would otherwise prefer them to be off?
*/
#define park_offline_cpus false
+extern cpumask_var_t cpu_parked_map;
The prototype should be the same for all architectures. So is there any
reason to duplicate it?
Cheers,
--
Julien Grall
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel
