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authorGerd Hoffmann <kraxel@redhat.com>2024-08-29 09:20:29 +0200
committermergify[bot] <37929162+mergify[bot]@users.noreply.github.com>2024-09-13 20:33:10 +0000
commit121af960e2ac152be2c441837595a4c6e2a143f5 (patch)
tree84005fca871c04ad79d42eecdb1f15da40636295 /OvmfPkg/CpuHotplugSmm
parentec18fa81d311663e24e9b9ad61b90b38862a1ea8 (diff)
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OvmfPkg/CpuHotplugSmm: delay SMM exit
Let APs wait until the BSP has completed the register updates to remove the CPU. This makes sure all APs stay in SMM mode until the CPU hot-unplug operation is complete, which in turn makes sure the ACPI lock is released only after the CPU hot-unplug operation is complete. Some background: The CPU hotplug SMI is triggered from an ACPI function which is protected by an ACPI lock. The ACPI function is in the ACPI tables generated by qemu. Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Diffstat (limited to 'OvmfPkg/CpuHotplugSmm')
-rw-r--r--OvmfPkg/CpuHotplugSmm/CpuHotplug.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/OvmfPkg/CpuHotplugSmm/CpuHotplug.c b/OvmfPkg/CpuHotplugSmm/CpuHotplug.c
index d504163026..5af78211d3 100644
--- a/OvmfPkg/CpuHotplugSmm/CpuHotplug.c
+++ b/OvmfPkg/CpuHotplugSmm/CpuHotplug.c
@@ -355,6 +355,11 @@ EjectCpu (
//
QemuSelector = mCpuHotEjectData->QemuSelectorMap[ProcessorNum];
if (QemuSelector == CPU_EJECT_QEMU_SELECTOR_INVALID) {
+ /* wait until BSP is done */
+ while (mCpuHotEjectData->Handler != NULL) {
+ CpuPause ();
+ }
+
return;
}