On Wed, 11 Oct 2017 11:06:49 +1100 David Gibson <da...@gibson.dropbear.id.au> wrote:
> In order to prevent the guest from forcing the allocation of large amounts > of qemu memory (or host kernel memory, in the case of KVM HV), we limit > the size of Hashed Page Table (HPT) it is allowed to allocated, based on > its RAM size. > > However, the current calculation is not correct: it only adds up the size > of plugged memory, ignoring the base memory size. This patch corrects it. > > While we're there, use get_plugged_memory_size() instead of directly > calling pc_existing_dimms_capacity(). The only difference is that it > will abort on failure, which is right: a failure here indicates something > wrong within qemu. > > Signed-off-by: David Gibson <da...@gibson.dropbear.id.au> > --- > hw/ppc/spapr_hcall.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > Changes in v2: > * Also remove redundant initializer of current_ram_size > * And use ram_size machine attribute instead of the ram_size global. Reviewed-by: Greg Kurz <gr...@kaod.org> > diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c > index 8d72bb7c1c..0d59d1534d 100644 > --- a/hw/ppc/spapr_hcall.c > +++ b/hw/ppc/spapr_hcall.c > @@ -472,7 +472,7 @@ static target_ulong h_resize_hpt_prepare(PowerPCCPU *cpu, > target_ulong flags = args[0]; > int shift = args[1]; > sPAPRPendingHPT *pending = spapr->pending_hpt; > - uint64_t current_ram_size = MACHINE(spapr)->ram_size; > + uint64_t current_ram_size; > int rc; > > if (spapr->resize_hpt == SPAPR_RESIZE_HPT_DISABLED) { > @@ -494,7 +494,7 @@ static target_ulong h_resize_hpt_prepare(PowerPCCPU *cpu, > return H_PARAMETER; > } > > - current_ram_size = pc_existing_dimms_capacity(&error_fatal); > + current_ram_size = MACHINE(spapr)->ram_size + get_plugged_memory_size(); > > /* We only allow the guest to allocate an HPT one order above what > * we'd normally give them (to stop a small guest claiming a huge