If QEMU is using KVM, and KVM is capable of running in radix mode,
guests can be run in real-mode without allocating a HPT (because KVM
will use a minimal RPT). So in this case, we avoid creating the HPT
at reset time and later (during CAS) create it if it is necessary.
Signed-off-by: Sam Bobroff <sam.bobr...@au1.ibm.com>
---
v2:
* This patch has been mostly rewritten to move the late HPT allocation to CAS.
This allows a guest to start in radix mode (when it's in real mode) and then
change to hash, even if it is a legacy guest and will not call
h_register_process_table().
* Added an exported function to spapr.c to perform HPT allocation and adjust
the vrma if necessary. This makes it possible to allocate the HPT from
h_client_architecture_support() in spapr_hcall.c.
hw/ppc/spapr.c | 24 +++++++++++++++---------
hw/ppc/spapr_hcall.c | 10 ++++++++++
include/hw/ppc/spapr.h | 1 +
3 files changed, 26 insertions(+), 9 deletions(-)
diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index ca3812555f..dfee0f685f 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -1123,6 +1123,17 @@ static void spapr_reallocate_hpt(sPAPRMachineState
*spapr, int shift,
}
}
+void spapr_setup_hpt_and_vrma(sPAPRMachineState *spapr)
+{
+ spapr_reallocate_hpt(spapr,
+
spapr_hpt_shift_for_ramsize(MACHINE(qdev_get_machine())->maxram_size),
+ &error_fatal);
+ if (spapr->vrma_adjust) {
+ spapr->rma_size = kvmppc_rma_size(spapr_node0_size(),
+ spapr->htab_shift);
+ }
+}
+
static void find_unknown_sysbus_device(SysBusDevice *sbdev, void *opaque)
{
bool matched = false;
@@ -1151,15 +1162,10 @@ static void ppc_spapr_reset(void)
/* Check for unknown sysbus devices */
foreach_dynamic_sysbus_device(find_unknown_sysbus_device, NULL);
- /* Allocate and/or reset the hash page table */
- spapr_reallocate_hpt(spapr,
- spapr_hpt_shift_for_ramsize(machine->maxram_size),
- &error_fatal);
-
- /* Update the RMA size if necessary */
- if (spapr->vrma_adjust) {
- spapr->rma_size = kvmppc_rma_size(spapr_node0_size(),
- spapr->htab_shift);
+ /* If using KVM with radix mode available, VCPUs can be started
+ * without a HPT because KVM will start them in radix mode. */
+ if (!(kvm_enabled() && kvmppc_has_cap_mmu_radix())) {
+ spapr_setup_hpt_and_vrma(spapr);
}
qemu_devices_reset();
diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c
index 42d20e0b92..cea34073aa 100644
--- a/hw/ppc/spapr_hcall.c
+++ b/hw/ppc/spapr_hcall.c
@@ -1002,6 +1002,16 @@ static target_ulong
h_client_architecture_support(PowerPCCPU *cpu,
ov5_updates = spapr_ovec_new();
spapr->cas_reboot = spapr_ovec_diff(ov5_updates,
ov5_cas_old, spapr->ov5_cas);
+ if (kvm_enabled()) {
+ if (kvmppc_has_cap_mmu_radix()) {
+ /* If the HPT hasn't yet been set up (see
+ * ppc_spapr_reset()), and it's needed, do it now: */
+ if (!spapr_ovec_test(ov5_updates, OV5_MMU_RADIX)) {
+ /* legacy hash or new hash: */
+ spapr_setup_hpt_and_vrma(spapr);
+ }
+ }
+ }
if (!spapr->cas_reboot) {
spapr->cas_reboot =
diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
index f9b17d860a..a30cbc485c 100644
--- a/include/hw/ppc/spapr.h
+++ b/include/hw/ppc/spapr.h
@@ -590,6 +590,7 @@ void spapr_dt_events(sPAPRMachineState *sm, void *fdt);
int spapr_h_cas_compose_response(sPAPRMachineState *sm,
target_ulong addr, target_ulong size,
sPAPROptionVector *ov5_updates);
+void spapr_setup_hpt_and_vrma(sPAPRMachineState *spapr);
sPAPRTCETable *spapr_tce_new_table(DeviceState *owner, uint32_t liobn);
void spapr_tce_table_enable(sPAPRTCETable *tcet,
uint32_t page_shift, uint64_t bus_offset,
--
2.11.0
