Re: [PATCH v4 21/27] ARM: vITS: handle MOVI command

[Julien Grall <julien.grall@arm.com>]

Hi Andre,

On 03/04/17 21:28, Andre Przywara wrote:
> The MOVI command moves the interrupt affinity from one redistributor
> (read: VCPU) to another.
> For now migration of "live" LPIs is not yet implemented, but we store
> the changed affinity in the host LPI structure and in our virtual ITTE.
>
> Signed-off-by: Andre Przywara <andre.przywara@arm.com>
> ---
>  xen/arch/arm/gic-v3-its.c        | 24 ++++++++++++++++++++++++
>  xen/arch/arm/gic-v3-lpi.c        | 13 +++++++++++++
>  xen/arch/arm/vgic-v3-its.c       | 24 ++++++++++++++++++++++++
>  xen/include/asm-arm/gic_v3_its.h |  4 ++++
>  4 files changed, 65 insertions(+)
>
> diff --git a/xen/arch/arm/gic-v3-its.c b/xen/arch/arm/gic-v3-its.c
> index 3bc1e58..f611e2f 100644
> --- a/xen/arch/arm/gic-v3-its.c
> +++ b/xen/arch/arm/gic-v3-its.c
> @@ -835,6 +835,30 @@ struct pending_irq *gicv3_assign_guest_event(struct domain *d,
>      return pirq;
>  }
>
> +/* Changes the target VCPU for a given host LPI assigned to a domain. */
> +int gicv3_lpi_change_vcpu(struct domain *d, paddr_t doorbell,
> +                          uint32_t vdevid, uint32_t veventid,
> +                          unsigned int vcpu_id)
> +{
> +    uint32_t host_lpi;
> +    struct its_devices *dev;
> +
> +    spin_lock(&d->arch.vgic.its_devices_lock);
> +    dev = get_its_device(d, doorbell, vdevid);
> +    if ( dev )
> +        host_lpi = get_host_lpi(dev, veventid);
> +    else
> +        host_lpi = 0;
> +    spin_unlock(&d->arch.vgic.its_devices_lock);
> +
> +    if ( !host_lpi )
> +        return -ENOENT;
> +
> +    gicv3_lpi_update_host_vcpuid(host_lpi, vcpu_id);
> +
> +    return 0;
> +}
> +
>  /* Scan the DT for any ITS nodes and create a list of host ITSes out of it. */
>  void gicv3_its_dt_init(const struct dt_device_node *node)
>  {
> diff --git a/xen/arch/arm/gic-v3-lpi.c b/xen/arch/arm/gic-v3-lpi.c
> index 067ccb2..94c3646 100644
> --- a/xen/arch/arm/gic-v3-lpi.c
> +++ b/xen/arch/arm/gic-v3-lpi.c
> @@ -206,6 +206,19 @@ void gicv3_lpi_update_host_entry(uint32_t host_lpi, int domain_id,
>      write_u64_atomic(&hlpip->data, hlpi.data);
>  }
>
> +int gicv3_lpi_update_host_vcpuid(uint32_t host_lpi, unsigned int vcpu_id)
> +{
> +    union host_lpi *hlpip;
> +
> +    host_lpi -= LPI_OFFSET;

The same ASSERT would be needed here.

> +
> +    hlpip = &lpi_data.host_lpis[host_lpi / HOST_LPIS_PER_PAGE][host_lpi % HOST_LPIS_PER_PAGE];
> +
> +    write_u16_atomic(&hlpip->vcpu_id, vcpu_id);
> +
> +    return 0;
> +}
> +
>  static int gicv3_lpi_allocate_pendtable(uint64_t *reg)
>  {
>      uint64_t val;
> diff --git a/xen/arch/arm/vgic-v3-its.c b/xen/arch/arm/vgic-v3-its.c
> index e9a309d..a2758cd 100644
> --- a/xen/arch/arm/vgic-v3-its.c
> +++ b/xen/arch/arm/vgic-v3-its.c
> @@ -455,6 +455,24 @@ static int its_handle_mapti(struct virt_its *its, uint64_t *cmdptr)
>      return 0;
>  }
>
> +static int its_handle_movi(struct virt_its *its, uint64_t *cmdptr)
> +{
> +    uint32_t devid = its_cmd_get_deviceid(cmdptr);
> +    uint32_t eventid = its_cmd_get_id(cmdptr);
> +    int collid = its_cmd_get_collection(cmdptr);
> +    struct vcpu *vcpu;
> +
> +    if ( !write_itte(its, devid, eventid, collid, SKIP_LPI_UPDATE, &vcpu) )
> +        return -1;
> +
> +    /* TODO: lookup currently-in-guest virtual IRQs and migrate them */
> +
> +    gicv3_lpi_change_vcpu(its->d,
> +                          its->doorbell_address, devid, eventid, vcpu->vcpu_id);
> +
> +    return 0;
> +}
> +
>  #define ITS_CMD_BUFFER_SIZE(baser)      ((((baser) & 0xff) + 1) << 12)
>
>  static int vgic_its_handle_cmds(struct domain *d, struct virt_its *its,
> @@ -508,6 +526,12 @@ static int vgic_its_handle_cmds(struct domain *d, struct virt_its *its,
>          case GITS_CMD_MAPTI:
>              ret = its_handle_mapti(its, cmdptr);
>              break;
> +        case GITS_CMD_MOVALL:
> +            gdprintk(XENLOG_G_INFO, "ITS: ignoring MOVALL command\n");

Why MOVALL is not implemented?

> +            break;
> +        case GITS_CMD_MOVI:
> +            ret = its_handle_movi(its, cmdptr);
> +            break;
>          case GITS_CMD_SYNC:
>              /* We handle ITS commands synchronously, so we ignore SYNC. */
>  	    break;
> diff --git a/xen/include/asm-arm/gic_v3_its.h b/xen/include/asm-arm/gic_v3_its.h
> index eeffd58..3b5f898 100644
> --- a/xen/include/asm-arm/gic_v3_its.h
> +++ b/xen/include/asm-arm/gic_v3_its.h
> @@ -169,8 +169,12 @@ void gicv3_free_host_lpi_block(uint32_t first_lpi);
>  struct pending_irq *gicv3_assign_guest_event(struct domain *d, paddr_t doorbell,
>                                               uint32_t devid, uint32_t eventid,
>                                               struct vcpu *v, uint32_t virt_lpi);
> +int gicv3_lpi_change_vcpu(struct domain *d, paddr_t doorbell,
> +                          uint32_t devid, uint32_t eventid,
> +                          unsigned int vcpu_id);
>  void gicv3_lpi_update_host_entry(uint32_t host_lpi, int domain_id,
>                                   unsigned int vcpu_id, uint32_t virt_lpi);
> +int gicv3_lpi_update_host_vcpuid(uint32_t host_lpi, unsigned int vcpu_id);
>
>  #else
>
>

Cheers,

-- 
Julien Grall

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