Re: [PATCH] pnv/psi: Add VMSTATE information to PnvPsi

[Caleb Schlossin <calebs@linux.ibm.com>]

On 12/12/25 11:05 AM, Miles Glenn wrote:
> Caleb, why not add this commit to your other submission of patches
> titled "Snapshot support for several ppc devices"?
> 
> -Glenn

PSI vmstate support commit now included with the second patch set here: https://lore.kernel.org/qemu-devel/20251215171813.1670241-1-calebs@linux.ibm.com/T/#t

> 
> On Thu, 2025-12-11 at 11:00 -0600, Caleb Schlossin wrote:
>> PnvPsi needs to be able to save/load snapshots.  Add VMSTATE information
>> to the device class and a post_load() method to restore dynamic data items and
>> memory region mappings.
>>
>> Signed-off-by: Michael Kowal <kowal@linux.ibm.com>
>> Signed-off-by: Caleb Schlossin <calebs@linux.ibm.com>
>> ---
>>  hw/ppc/pnv_psi.c | 46 ++++++++++++++++++++++++++++++++++++++++++++--
>>  1 file changed, 44 insertions(+), 2 deletions(-)
>>
>> diff --git a/hw/ppc/pnv_psi.c b/hw/ppc/pnv_psi.c
>> index 5d947d8b52..88d5f1d45d 100644
>> --- a/hw/ppc/pnv_psi.c
>> +++ b/hw/ppc/pnv_psi.c
>> @@ -25,6 +25,7 @@
>>  #include "qemu/module.h"
>>  #include "system/reset.h"
>>  #include "qapi/error.h"
>> +#include "migration/vmstate.h"
>>  
>>  
>>  #include "hw/ppc/fdt.h"
>> @@ -35,6 +36,8 @@
>>  
>>  #include <libfdt.h>
>>  
>> +#undef PSI_DEBUG
>> +
>>  #define PSIHB_XSCOM_FIR_RW      0x00
>>  #define PSIHB_XSCOM_FIR_AND     0x01
>>  #define PSIHB_XSCOM_FIR_OR      0x02
>> @@ -130,12 +133,11 @@ static void pnv_psi_set_bar(PnvPsi *psi, uint64_t bar)
>>  {
>>      PnvPsiClass *ppc = PNV_PSI_GET_CLASS(psi);
>>      MemoryRegion *sysmem = get_system_memory();
>> -    uint64_t old = psi->regs[PSIHB_XSCOM_BAR];
>>  
>>      psi->regs[PSIHB_XSCOM_BAR] = bar & (ppc->bar_mask | PSIHB_BAR_EN);
>>  
>>      /* Update MR, always remove it first */
>> -    if (old & PSIHB_BAR_EN) {
>> +    if (memory_region_is_mapped(&psi->regs_mr)) {
>>          memory_region_del_subregion(sysmem, &psi->regs_mr);
>>      }
>>  
>> @@ -975,6 +977,40 @@ static void pnv_psi_register_types(void)
>>  
>>  type_init(pnv_psi_register_types);
>>  
>> +#ifdef PSI_DEBUG
>> +static void psi_regs_pic_print_info(uint64_t *regs, uint32_t nr_regs,
>> +                                    GString *buf) {
>> +    uint i, prev_idx = -1;
>> +    uint64_t  reg1, prev_reg1 = -1;
>> +    uint64_t  reg2, prev_reg2 = -1;
>> +    uint64_t  reg3, prev_reg3 = -1;
>> +    uint64_t  reg4, prev_reg4 = -1;
>> +    for (i = 0; i < nr_regs; i = i + 4) {
>> +        /* Don't print if values do not change, but print last*/
>> +        reg1 = regs[i];
>> +        reg2 = regs[i + 1];
>> +        reg3 = regs[i + 2];
>> +        reg4 = regs[i + 3];
>> +        if (reg1 == prev_reg1 && reg2 == prev_reg2 &&
>> +            reg3 == prev_reg3 && reg4 == prev_reg4 &&
>> +            i < (nr_regs - 4)) {
>> +            if (i == (prev_idx + 4)) {
>> +                g_string_append_printf(buf, "        . . .\n");
>> +            }
>> +            continue;
>> +        }
>> +
>> +        g_string_append_printf(buf, "  [%03X] 0x%016lX %016lX %016lX %016lX\n",
>> +            i, reg1, reg2, reg3, reg4);
>> +        prev_idx = i;
>> +        prev_reg1 = reg1;
>> +        prev_reg2 = reg2;
>> +        prev_reg3 = reg3;
>> +        prev_reg4 = reg4;
>> +    }
>> +}
>> +#endif
>> +
>>  void pnv_psi_pic_print_info(Pnv9Psi *psi9, GString *buf)
>>  {
>>      PnvPsi *psi = PNV_PSI(psi9);
>> @@ -985,4 +1021,10 @@ void pnv_psi_pic_print_info(Pnv9Psi *psi9, GString *buf)
>>      g_string_append_printf(buf, "PSIHB Source %08x .. %08x\n",
>>                             offset, offset + psi9->source.nr_irqs - 1);
>>      xive_source_pic_print_info(&psi9->source, offset, buf);
>> +#ifdef PSI_DEBUG
>> +    /* Print PSI registers */
>> +    g_string_append_printf(buf, "\nPSI Regs[0x0..%X]\n",
>> +                           PSIHB_XSCOM_MAX);
>> +    psi_regs_pic_print_info(psi->regs, PSIHB_XSCOM_MAX, buf);
>> +#endif
>>  }
>