From 9478956794c11239b7c1c3ef9ce95c883bb839a3 Mon Sep 17 00:00:00 2001 From: Daniel Henrique Barboza Date: Tue, 13 Feb 2018 15:37:16 -0200 Subject: [PATCH] hw/ppc/spapr_hcall: set htab_shift after kvmppc_resize_hpt_commit Newer kernels have a htab resize capability when adding or remove memory. At these situations, the guest kernel might reallocate its htab to a more suitable size based on the resulting memory. However, we're not setting the new value back into the machine state when a KVM guest resizes its htab. At first this doesn't seem harmful, but when migrating or saving the guest state (via virsh managedsave, for instance) this mismatch between the htab size of QEMU and the kernel makes the guest hangs when trying to load its state. Inside h_resize_hpt_commit, the hypercall that commits the hash page resize changes, let's set spapr->htab_shift to the new value if we're sure that kvmppc_resize_hpt_commit were successful. While we're here, add a "not RADIX" sanity check as it is already done in the related hypercall h_resize_hpt_prepare. Fixes: https://github.com/open-power-host-os/qemu/issues/28 Reported-by: Satheesh Rajendran Signed-off-by: Daniel Henrique Barboza Signed-off-by: David Gibson --- hw/ppc/spapr_hcall.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c index 76422cfac10..19865604806 100644 --- a/hw/ppc/spapr_hcall.c +++ b/hw/ppc/spapr_hcall.c @@ -731,11 +731,21 @@ static target_ulong h_resize_hpt_commit(PowerPCCPU *cpu, return H_AUTHORITY; } + if (!spapr->htab_shift) { + /* Radix guest, no HPT */ + return H_NOT_AVAILABLE; + } + trace_spapr_h_resize_hpt_commit(flags, shift); rc = kvmppc_resize_hpt_commit(cpu, flags, shift); if (rc != -ENOSYS) { - return resize_hpt_convert_rc(rc); + rc = resize_hpt_convert_rc(rc); + if (rc == H_SUCCESS) { + /* Need to set the new htab_shift in the machine state */ + spapr->htab_shift = shift; + } + return rc; } if (flags != 0) { -- 2.39.5