Re: [Xen-devel] [PATCH RFC 05/13] xen: implement Xen IO APIC ops

[John Baldwin <jhb@xxxxxxxxxxx>]

On Tuesday, December 24, 2013 6:20:54 am Roger Pau Monne wrote:
> Implement a different set of hooks for IO APIC to use when running
> under Xen Dom0.
> ---
>  sys/x86/xen/pv.c |   44 ++++++++++++++++++++++++++++++++++++++++++++
>  1 files changed, 44 insertions(+), 0 deletions(-)
> 
> diff --git a/sys/x86/xen/pv.c b/sys/x86/xen/pv.c
> index ab4afba..e5ad200 100644
> --- a/sys/x86/xen/pv.c
> +++ b/sys/x86/xen/pv.c
> @@ -49,6 +49,7 @@ __FBSDID("$FreeBSD$");
>  #include <vm/vm_pager.h>
>  #include <vm/vm_param.h>
>  
> +#include <x86/apicreg.h>
>  #include <machine/sysarch.h>
>  #include <machine/clock.h>
>  #include <machine/pc/bios.h>
> @@ -58,6 +59,7 @@ __FBSDID("$FreeBSD$");
>  #include <xen/xen-os.h>
>  #include <xen/hypervisor.h>
>  #include <xen/pv.h>
> +#include <xen/xen_intr.h>
>  
>  #include <xen/interface/vcpu.h>
>  
> @@ -73,6 +75,11 @@ static caddr_t xen_pv_parse_preload_data(u_int64_t);
>  static void xen_pv_parse_memmap(caddr_t, vm_paddr_t *, int *);
>  
>  static void xen_pv_set_init_ops(void);
> +
> +static u_int xen_pv_ioapic_read(volatile ioapic_t *, int);
> +static void xen_pv_ioapic_write(volatile ioapic_t *, int, u_int);
> +static void xen_pv_ioapic_register_intr(struct ioapic_intsrc *);
> +
>  /*---------------------------- Extern Declarations 
---------------------------*/
>  /* Variables used by amd64 mp_machdep to start APs */
>  extern struct mtx ap_boot_mtx;
> @@ -92,6 +99,13 @@ struct init_ops xen_init_ops = {
>       .parse_memmap =         xen_pv_parse_memmap,
>  };
>  
> +/* Xen ioapic_ops implementation */
> +struct ioapic_ops xen_ioapic_ops = {
> +     .read =                 xen_pv_ioapic_read,
> +     .write =                xen_pv_ioapic_write,
> +     .register_intr =        xen_pv_ioapic_register_intr,
> +};
> +
>  static struct
>  {
>       const char      *ev;
> @@ -342,6 +356,34 @@ xen_pv_parse_memmap(caddr_t kmdp, vm_paddr_t *physmap, 
int *physmap_idx)
>       bios_add_smap_entries(xen_smap, size, physmap, physmap_idx);
>  }
>  
> +static u_int
> +xen_pv_ioapic_read(volatile ioapic_t *apic, int reg)
> +{
> +     struct physdev_apic apic_op;
> +     int rc;
> +
> +     mtx_assert(&icu_lock, MA_OWNED);
> +
> +     apic_op.apic_physbase = pmap_kextract((vm_offset_t) apic);

Seems a shame to have to do this.  I wouldn't mind if you changed the 
read/write callbacks to take 'struct ioapic *' instead and then use the 
'io_paddr' member.  I do think that would be cleaner.

> +     apic_op.reg = reg;
> +     rc = HYPERVISOR_physdev_op(PHYSDEVOP_apic_read, &apic_op);
> +     if (rc)
> +             panic("apic_read operation failed");
> +
> +     return (apic_op.value);
> +}
> +
> +static void
> +xen_pv_ioapic_write(volatile ioapic_t *apic, int reg, u_int val)
> +{
> +}

I guess not allowing writes is on purpose?

> +
> +static void
> +xen_pv_ioapic_register_intr(struct ioapic_intsrc *pin)
> +{
> +     xen_register_pirq(pin->io_irq, pin->io_activehi, pin->io_edgetrigger);
> +}
> +
>  static void
>  xen_pv_set_init_ops(void)
>  {
> @@ -349,4 +391,6 @@ xen_pv_set_init_ops(void)
>       init_ops = xen_init_ops;
>       /* Disable lapic */
>       lapic_disabled = true;
> +     /* IOAPIC ops for Xen PV */
> +     ioapic_ops = xen_ioapic_ops;
>  }
> -- 
> 1.7.7.5 (Apple Git-26)
> 
> 

-- 
John Baldwin

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