Hi Mykola,
On 11/12/2025 18:43, Mykola Kvach wrote:
From: Mykola Kvach <[email protected]>
System suspend may lead to a state where GIC would be powered down.
Therefore, Xen should save/restore the context of GIC on suspend/resume.
Note that the context consists of states of registers which are
controlled by the hypervisor. Other GIC registers which are accessible
by guests are saved/restored on context switch.
Signed-off-by: Mykola Kvach <[email protected]>
---
Changes in V7:
- restore LPI regs on resume
- add timeout during redist disabling
- squash with suspend/resume handling for GICv3 eSPI registers
- drop ITS guard paths so suspend/resume always runs; switch missing ctx
allocation to panic
- trim TODO comments; narrow redistributor storage to PPI icfgr
- keep distributor context allocation even without ITS; adjust resume
to use GENMASK(31, 0) for clearing enables
- drop storage of the SGI configuration register, as SGIs are always
edge-triggered
---
xen/arch/arm/gic-v3-lpi.c | 3 +
xen/arch/arm/gic-v3.c | 319 ++++++++++++++++++++++++-
xen/arch/arm/include/asm/gic_v3_defs.h | 1 +
3 files changed, 320 insertions(+), 3 deletions(-)
diff --git a/xen/arch/arm/gic-v3-lpi.c b/xen/arch/arm/gic-v3-lpi.c
index de5052e5cf..61a6e18303 100644
--- a/xen/arch/arm/gic-v3-lpi.c
+++ b/xen/arch/arm/gic-v3-lpi.c
@@ -391,6 +391,9 @@ static int cpu_callback(struct notifier_block *nfb,
unsigned long action,
switch ( action )
{
case CPU_UP_PREPARE:
+ if ( system_state == SYS_STATE_resume )
+ break;
Do we need this check because we don't free the LPI pending table when
the CPU is turned off?
If so, don't we already have a problem for CPU hotplug because the
percpu area will be freed but not the pending table?
Cheers,
--
Julien Grall
