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

[Miles Glenn <milesg@linux.ibm.com>]

Caleb, why not add this commit to your other submission of patches
titled "Snapshot support for several ppc devices"?

-Glenn

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
>  }