Re: [PATCH v3 08/11] pvh/acpi: Handle ACPI accesses for PVH guests

[Paul Durrant <Paul.Durrant@citrix.com>]

> -----Original Message-----
> From: Boris Ostrovsky [mailto:boris.ostrovsky@oracle.com]
> Sent: 21 November 2016 21:01
> To: xen-devel@lists.xen.org
> Cc: jbeulich@suse.com; Andrew Cooper <Andrew.Cooper3@citrix.com>;
> Wei Liu <wei.liu2@citrix.com>; Ian Jackson <Ian.Jackson@citrix.com>; Roger
> Pau Monne <roger.pau@citrix.com>; Boris Ostrovsky
> <boris.ostrovsky@oracle.com>; Paul Durrant <Paul.Durrant@citrix.com>
> Subject: [PATCH v3 08/11] pvh/acpi: Handle ACPI accesses for PVH guests
> 
> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

Reviewed-by: Paul Durrant <paul.durrant@citrix.com>

> ---
> CC: Paul Durrant <paul.durrant@citrix.com>
> ---
> Changes in v3:
> * Introduce a mask for pm1a and gpe0 that lists bits that a
>   guest can operate on.
> * Lots of small changes.
> 
>  xen/arch/x86/hvm/ioreq.c         | 87
> +++++++++++++++++++++++++++++++++++++++-
>  xen/include/asm-x86/hvm/domain.h |  6 +++
>  2 files changed, 92 insertions(+), 1 deletion(-)
> 
> diff --git a/xen/arch/x86/hvm/ioreq.c b/xen/arch/x86/hvm/ioreq.c
> index 51bb399..4ab0d0a 100644
> --- a/xen/arch/x86/hvm/ioreq.c
> +++ b/xen/arch/x86/hvm/ioreq.c
> @@ -16,6 +16,7 @@
>   * this program; If not, see <http://www.gnu.org/licenses/>.
>   */
> 
> +#include <xen/acpi.h>
>  #include <xen/config.h>
>  #include <xen/ctype.h>
>  #include <xen/init.h>
> @@ -1383,7 +1384,91 @@ static int hvm_access_cf8(
>  static int acpi_ioaccess(
>      int dir, unsigned int port, unsigned int bytes, uint32_t *val)
>  {
> -    return X86EMUL_UNHANDLEABLE;
> +    uint8_t *reg = NULL;
> +    const uint8_t *mask = NULL;
> +    bool is_cpu_map = false;
> +    struct domain *currd = current->domain;
> +    const static uint8_t pm1a_mask[4] =
> {ACPI_BITMASK_GLOBAL_LOCK_STATUS, 0,
> +                                         ACPI_BITMASK_GLOBAL_LOCK_ENABLE, 0};
> +    const static uint8_t gpe0_mask[4] = {1U << XEN_GPE0_CPUHP_BIT, 0,
> +                                         1U << XEN_GPE0_CPUHP_BIT, 0};
> +
> +    BUILD_BUG_ON((ACPI_PM1A_EVT_BLK_LEN != 4) ||
> +                 (ACPI_GPE0_BLK_LEN_V1 != 4));
> +
> +    ASSERT(!has_acpi_ff(currd));
> +
> +    switch ( port )
> +    {
> +    case ACPI_PM1A_EVT_BLK_ADDRESS_V1 ...
> +         ACPI_PM1A_EVT_BLK_ADDRESS_V1 + ACPI_PM1A_EVT_BLK_LEN - 1:
> +        reg = currd->arch.hvm_domain.acpi_io.pm1a;
> +        mask = pm1a_mask;
> +        break;
> +
> +    case ACPI_GPE0_BLK_ADDRESS_V1 ...
> +         ACPI_GPE0_BLK_ADDRESS_V1 + ACPI_GPE0_BLK_LEN_V1 - 1:
> +        reg = currd->arch.hvm_domain.acpi_io.gpe;
> +        mask = gpe0_mask;
> +        break;
> +
> +    case XEN_ACPI_CPU_MAP ...
> +         XEN_ACPI_CPU_MAP + XEN_ACPI_CPU_MAP_LEN - 1:
> +        is_cpu_map = true;
> +        break;
> +
> +    default:
> +        return X86EMUL_UNHANDLEABLE;
> +    }
> +
> +    if ( bytes == 0 )
> +        return X86EMUL_OKAY;
> +
> +    if ( dir == IOREQ_READ )
> +    {
> +        if ( is_cpu_map )
> +        {
> +            unsigned int first_byte = port - XEN_ACPI_CPU_MAP;
> +
> +            /*
> +             * Clear bits that we are about to read to in case we
> +             * copy fewer than @bytes.
> +             */
> +            *val &= (~((1ULL << (bytes * 8)) - 1)) & 0xffffffff;
> +
> +            if ( ((currd->max_vcpus + 7) / 8) > first_byte )
> +            {
> +                memcpy(val, (uint8_t *)currd->avail_vcpus + first_byte,
> +                       min(bytes, ((currd->max_vcpus + 7) / 8) - first_byte));
> +            }
> +        }
> +        else
> +            memcpy(val, &reg[port & 3], bytes);
> +    }
> +    else
> +    {
> +        unsigned int idx = port & 3;
> +        unsigned int i;
> +        uint8_t *ptr;
> +
> +        if ( is_cpu_map )
> +            /*
> +             * CPU map is only read by DSDT's PRSC method and should never
> +             * be written by a guest.
> +             */
> +            return X86EMUL_UNHANDLEABLE;
> +
> +        ptr = (uint8_t *)val;
> +        for ( i = 0; i < bytes; i++, idx++ )
> +        {
> +            if ( idx < 2 ) /* status, write 1 to clear. */
> +                reg[idx] &= ~(mask[i] & ptr[i]);
> +            else           /* enable */
> +                reg[idx] |= (mask[i] & ptr[i]);
> +        }
> +    }
> +
> +    return X86EMUL_OKAY;
>  }
> 
>  void hvm_ioreq_init(struct domain *d)
> diff --git a/xen/include/asm-x86/hvm/domain.h b/xen/include/asm-
> x86/hvm/domain.h
> index f34d784..f492a2b 100644
> --- a/xen/include/asm-x86/hvm/domain.h
> +++ b/xen/include/asm-x86/hvm/domain.h
> @@ -87,6 +87,12 @@ struct hvm_domain {
>      } ioreq_server;
>      struct hvm_ioreq_server *default_ioreq_server;
> 
> +    /* PVH guests */
> +    struct {
> +        uint8_t pm1a[ACPI_PM1A_EVT_BLK_LEN];
> +        uint8_t gpe[ACPI_GPE0_BLK_LEN_V1];
> +    } acpi_io;
> +
>      /* Cached CF8 for guest PCI config cycles */
>      uint32_t                pci_cf8;
> 
> --
> 2.7.4


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