Re: [Qemu-devel] [PATCH 09/27] ppc/xive: activate HV support

[David Gibson <david@gibson.dropbear.id.au>]

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On Wed, Mar 06, 2019 at 09:50:14AM +0100, Cédric Le Goater wrote:
> The NSR register of the HV ring has a different, although similar, bit
> layout. TM_QW3_NSR_HE_PHYS bit should now be raised when the
> Hypervisor interrupt line is signaled. Other bits TM_QW3_NSR_HE_POOL
> and TM_QW3_NSR_HE_LSI are not modeled. LSI are for special interrupts
> reserved for HW bringup and the POOL bit is used when signaling a
> group of VPs. This is not currently implemented in Linux but it is in
> pHyp.
> 
> The most important special commands on the HV TIMA page are added to
> let the core manage interrupts : acking and changing the CPU priority.
> 
> Signed-off-by: Cédric Le Goater <clg@kaod.org>
> ---
>  hw/intc/xive.c | 57 +++++++++++++++++++++++++++++++++++++++++++++++---
>  1 file changed, 54 insertions(+), 3 deletions(-)
> 
> diff --git a/hw/intc/xive.c b/hw/intc/xive.c
> index 7d7992c0ce3f..a0b87001da25 100644
> --- a/hw/intc/xive.c
> +++ b/hw/intc/xive.c
> @@ -54,6 +54,8 @@ static uint8_t exception_mask(uint8_t ring)
>      switch (ring) {
>      case TM_QW1_OS:
>          return TM_QW1_NSR_EO;
> +    case TM_QW3_HV_PHYS:
> +        return TM_QW3_NSR_HE;
>      default:
>          g_assert_not_reached();
>      }
> @@ -88,7 +90,16 @@ static void xive_tctx_notify(XiveTCTX *tctx, uint8_t ring)
>      uint8_t *regs = &tctx->regs[ring];
>  
>      if (regs[TM_PIPR] < regs[TM_CPPR]) {
> -        regs[TM_NSR] |= exception_mask(ring);

This means there's only one remaining caller to exception_mask, so it
might be better to just open code it at that site.  That can be a
later cleanup though, so applied to ppc-for-4.0.

> +        switch (ring) {
> +        case TM_QW1_OS:
> +            regs[TM_NSR] |= TM_QW1_NSR_EO;
> +            break;
> +        case TM_QW3_HV_PHYS:
> +            regs[TM_NSR] |= (TM_QW3_NSR_HE_PHYS << 6);
> +            break;
> +        default:
> +            g_assert_not_reached();
> +        }
>          qemu_irq_raise(tctx->output);
>      }
>  }
> @@ -109,6 +120,38 @@ static void xive_tctx_set_cppr(XiveTCTX *tctx, uint8_t ring, uint8_t cppr)
>   * XIVE Thread Interrupt Management Area (TIMA)
>   */
>  
> +static void xive_tm_set_hv_cppr(XiveTCTX *tctx, hwaddr offset,
> +                                uint64_t value, unsigned size)
> +{
> +    xive_tctx_set_cppr(tctx, TM_QW3_HV_PHYS, value & 0xff);
> +}
> +
> +static uint64_t xive_tm_ack_hv_reg(XiveTCTX *tctx, hwaddr offset, unsigned size)
> +{
> +    return xive_tctx_accept(tctx, TM_QW3_HV_PHYS);
> +}
> +
> +static uint64_t xive_tm_pull_pool_ctx(XiveTCTX *tctx, hwaddr offset,
> +                                      unsigned size)
> +{
> +    uint64_t ret;
> +
> +    ret = tctx->regs[TM_QW2_HV_POOL + TM_WORD2] & TM_QW2W2_POOL_CAM;
> +    tctx->regs[TM_QW2_HV_POOL + TM_WORD2] &= ~TM_QW2W2_POOL_CAM;
> +    return ret;
> +}
> +
> +static void xive_tm_vt_push(XiveTCTX *tctx, hwaddr offset,
> +                            uint64_t value, unsigned size)
> +{
> +    tctx->regs[TM_QW3_HV_PHYS + TM_WORD2] = value & 0xff;
> +}
> +
> +static uint64_t xive_tm_vt_poll(XiveTCTX *tctx, hwaddr offset, unsigned size)
> +{
> +    return tctx->regs[TM_QW3_HV_PHYS + TM_WORD2] & 0xff;
> +}
> +
>  /*
>   * Define an access map for each page of the TIMA that we will use in
>   * the memory region ops to filter values when doing loads and stores
> @@ -288,10 +331,16 @@ static const XiveTmOp xive_tm_operations[] = {
>       * effects
>       */
>      { XIVE_TM_OS_PAGE, TM_QW1_OS + TM_CPPR,   1, xive_tm_set_os_cppr, NULL },
> +    { XIVE_TM_HV_PAGE, TM_QW3_HV_PHYS + TM_CPPR, 1, xive_tm_set_hv_cppr, NULL },
> +    { XIVE_TM_HV_PAGE, TM_QW3_HV_PHYS + TM_WORD2, 1, xive_tm_vt_push, NULL },
> +    { XIVE_TM_HV_PAGE, TM_QW3_HV_PHYS + TM_WORD2, 1, NULL, xive_tm_vt_poll },
>  
>      /* MMIOs above 2K : special operations with side effects */
>      { XIVE_TM_OS_PAGE, TM_SPC_ACK_OS_REG,     2, NULL, xive_tm_ack_os_reg },
>      { XIVE_TM_OS_PAGE, TM_SPC_SET_OS_PENDING, 1, xive_tm_set_os_pending, NULL },
> +    { XIVE_TM_HV_PAGE, TM_SPC_ACK_HV_REG,     2, NULL, xive_tm_ack_hv_reg },
> +    { XIVE_TM_HV_PAGE, TM_SPC_PULL_POOL_CTX,  4, NULL, xive_tm_pull_pool_ctx },
> +    { XIVE_TM_HV_PAGE, TM_SPC_PULL_POOL_CTX,  8, NULL, xive_tm_pull_pool_ctx },
>  };
>  
>  static const XiveTmOp *xive_tm_find_op(hwaddr offset, unsigned size, bool write)
> @@ -323,7 +372,7 @@ void xive_tctx_tm_write(XiveTCTX *tctx, hwaddr offset, uint64_t value,
>      const XiveTmOp *xto;
>  
>      /*
> -     * TODO: check V bit in Q[0-3]W2, check PTER bit associated with CPU
> +     * TODO: check V bit in Q[0-3]W2
>       */
>  
>      /*
> @@ -360,7 +409,7 @@ uint64_t xive_tctx_tm_read(XiveTCTX *tctx, hwaddr offset, unsigned size)
>      const XiveTmOp *xto;
>  
>      /*
> -     * TODO: check V bit in Q[0-3]W2, check PTER bit associated with CPU
> +     * TODO: check V bit in Q[0-3]W2
>       */
>  
>      /*
> @@ -472,6 +521,8 @@ static void xive_tctx_reset(void *dev)
>       */
>      tctx->regs[TM_QW1_OS + TM_PIPR] =
>          ipb_to_pipr(tctx->regs[TM_QW1_OS + TM_IPB]);
> +    tctx->regs[TM_QW3_HV_PHYS + TM_PIPR] =
> +        ipb_to_pipr(tctx->regs[TM_QW3_HV_PHYS + TM_IPB]);
>  }
>  
>  static void xive_tctx_realize(DeviceState *dev, Error **errp)

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

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