Re: [PATCH v3 4/9] pnv/xive2: Add NVG and NVC to cache watch facility

["Cédric Le Goater" <clg@kaod.org>]

On 7/16/24 21:56, Michael Kowal wrote:
> From: Frederic Barrat <fbarrat@linux.ibm.com>
> 
> The cache watch facility uses the same register interface to handle
> entries in the NVP, NVG and NVC tables. A bit-field in the 'watchX
> specification' register tells the table type. So far, that bit-field
> was not read and the code assumed a read/write to the NVP table.
> 
> This patch allows to read/write entries in the NVG and NVC table as
> well.
> 
> Signed-off-by: Frederic Barrat <fbarrat@linux.ibm.com>
> Signed-off-by: Michael Kowal <kowal@linux.vnet.ibm.com>

Reviewed-by: Cédric Le Goater <clg@redhat.com>

Thanks,

C.


> ---
>   hw/intc/pnv_xive2.c | 49 +++++++++++++++++++++++++++++++++++----------
>   1 file changed, 38 insertions(+), 11 deletions(-)
> 
> diff --git a/hw/intc/pnv_xive2.c b/hw/intc/pnv_xive2.c
> index 3dbbfddacb..dfb0927fd3 100644
> --- a/hw/intc/pnv_xive2.c
> +++ b/hw/intc/pnv_xive2.c
> @@ -465,10 +465,30 @@ static int pnv_xive2_write_nvp(Xive2Router *xrtr, uint8_t blk, uint32_t idx,
>                                 word_number);
>   }
>   
> -static int pnv_xive2_nvp_update(PnvXive2 *xive, uint8_t watch_engine)
> +static int pnv_xive2_nxc_to_table_type(uint8_t nxc_type, uint32_t *table_type)
>   {
> -    uint8_t  blk;
> -    uint32_t idx;
> +    switch (nxc_type) {
> +    case PC_NXC_WATCH_NXC_NVP:
> +        *table_type = VST_NVP;
> +        break;
> +    case PC_NXC_WATCH_NXC_NVG:
> +        *table_type = VST_NVG;
> +        break;
> +    case PC_NXC_WATCH_NXC_NVC:
> +        *table_type = VST_NVC;
> +        break;
> +    default:
> +        qemu_log_mask(LOG_GUEST_ERROR,
> +                      "XIVE: invalid table type for nxc operation\n");
> +        return -1;
> +    }
> +    return 0;
> +}
> +
> +static int pnv_xive2_nxc_update(PnvXive2 *xive, uint8_t watch_engine)
> +{
> +    uint8_t  blk, nxc_type;
> +    uint32_t idx, table_type = -1;
>       int i, spec_reg, data_reg;
>       uint64_t nxc_watch[4];
>   
> @@ -476,21 +496,24 @@ static int pnv_xive2_nvp_update(PnvXive2 *xive, uint8_t watch_engine)
>   
>       spec_reg = (PC_NXC_WATCH0_SPEC + watch_engine * 0x40) >> 3;
>       data_reg = (PC_NXC_WATCH0_DATA0 + watch_engine * 0x40) >> 3;
> +    nxc_type = GETFIELD(PC_NXC_WATCH_NXC_TYPE, xive->pc_regs[spec_reg]);
>       blk = GETFIELD(PC_NXC_WATCH_BLOCK_ID, xive->pc_regs[spec_reg]);
>       idx = GETFIELD(PC_NXC_WATCH_INDEX, xive->pc_regs[spec_reg]);
>   
> +    assert(pnv_xive2_nxc_to_table_type(nxc_type, &table_type));
> +
>       for (i = 0; i < ARRAY_SIZE(nxc_watch); i++) {
>           nxc_watch[i] = cpu_to_be64(xive->pc_regs[data_reg + i]);
>       }
>   
> -    return pnv_xive2_vst_write(xive, VST_NVP, blk, idx, nxc_watch,
> +    return pnv_xive2_vst_write(xive, table_type, blk, idx, nxc_watch,
>                                 XIVE_VST_WORD_ALL);
>   }
>   
> -static void pnv_xive2_nvp_cache_load(PnvXive2 *xive, uint8_t watch_engine)
> +static void pnv_xive2_nxc_cache_load(PnvXive2 *xive, uint8_t watch_engine)
>   {
> -    uint8_t  blk;
> -    uint32_t idx;
> +    uint8_t  blk, nxc_type;
> +    uint32_t idx, table_type = -1;
>       uint64_t nxc_watch[4] = { 0 };
>       int i, spec_reg, data_reg;
>   
> @@ -498,11 +521,15 @@ static void pnv_xive2_nvp_cache_load(PnvXive2 *xive, uint8_t watch_engine)
>   
>       spec_reg = (PC_NXC_WATCH0_SPEC + watch_engine * 0x40) >> 3;
>       data_reg = (PC_NXC_WATCH0_DATA0 + watch_engine * 0x40) >> 3;
> +    nxc_type = GETFIELD(PC_NXC_WATCH_NXC_TYPE, xive->pc_regs[spec_reg]);
>       blk = GETFIELD(PC_NXC_WATCH_BLOCK_ID, xive->pc_regs[spec_reg]);
>       idx = GETFIELD(PC_NXC_WATCH_INDEX, xive->pc_regs[spec_reg]);
>   
> -    if (pnv_xive2_vst_read(xive, VST_NVP, blk, idx, nxc_watch)) {
> -        xive2_error(xive, "VST: no NVP entry %x/%x !?", blk, idx);
> +    assert(pnv_xive2_nxc_to_table_type(nxc_type, &table_type));
> +
> +    if (pnv_xive2_vst_read(xive, table_type, blk, idx, nxc_watch)) {
> +        xive2_error(xive, "VST: no NXC entry %x/%x in %s table!?",
> +                    blk, idx, vst_infos[table_type].name);
>       }
>   
>       for (i = 0; i < ARRAY_SIZE(nxc_watch); i++) {
> @@ -1432,7 +1459,7 @@ static uint64_t pnv_xive2_ic_pc_read(void *opaque, hwaddr offset,
>           * SPEC register
>           */
>           watch_engine = (offset - PC_NXC_WATCH0_DATA0) >> 6;
> -        pnv_xive2_nvp_cache_load(xive, watch_engine);
> +        pnv_xive2_nxc_cache_load(xive, watch_engine);
>           val = xive->pc_regs[reg];
>           break;
>   
> @@ -1506,7 +1533,7 @@ static void pnv_xive2_ic_pc_write(void *opaque, hwaddr offset,
>           /* writing to DATA0 triggers the cache write */
>           watch_engine = (offset - PC_NXC_WATCH0_DATA0) >> 6;
>           xive->pc_regs[reg] = val;
> -        pnv_xive2_nvp_update(xive, watch_engine);
> +        pnv_xive2_nxc_update(xive, watch_engine);
>           break;
>   
>      /* case PC_NXC_FLUSH_CTRL: */