[Qemu-devel] [RFC PATCH v0 2/2] spapr: Abort when HTAB of requested size isn't allocated

[Bharata B Rao <bharata@linux.vnet.ibm.com>]

Terminate the guest when HTAB of requested size isn't allocated by
the host.

When memory hotplug is attempted on a guest that has booted with
less than requested HTAB size, the guest kernel will not be able
to gracefully fail the hotplug request. This patch will ensure that
we never end up in a situation where memory hotplug fails due to
less than requested HTAB size.

Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
---
 hw/ppc/spapr.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 4692122..66446af 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -992,6 +992,10 @@ static void spapr_alloc_htab(sPAPRMachineState *spapr)
 
     if (shift > 0) {
         /* Kernel handles htab, we don't need to allocate one */
+        if (shift != spapr->htab_shift) {
+            error_setg(&error_abort, "Failed to allocated requested HTAB size");
+        }
+
         spapr->htab_shift = shift;
         kvmppc_kern_htab = true;
 
-- 
2.1.0