Re: [Xen-devel] [PATCH V2 1/2] x86/altp2m: Add hypercall to set a range of sve bits

[Alexandru Stefan ISAILA <aisaila@bitdefender.com>]

Hi George,

Sorry for the early reminder but v1 you said "Everything else looks OK 
to me." and you did not give a specific ACK. Can you take a look at the 
changes when you have the time?

Thanks,
Alex

On 06.11.2019 17:35, Alexandru Stefan ISAILA wrote:
> By default the sve bits are not set.
> This patch adds a new hypercall, xc_altp2m_set_supress_ve_multi(),
> to set a range of sve bits.
> The core function, p2m_set_suppress_ve_multi(), does not brake in case
> of a error and it is doing a best effort for setting the bits in the
> given range. A check for continuation is made in order to have
> preemption on big ranges.
> 
> Signed-off-by: Alexandru Isaila <aisaila@bitdefender.com>
> 
> ---
> Changes since V1:
> 	- Remove "continue"
> 	- Add a new field in xen_hvm_altp2m_suppress_ve to store the
> continuation value
> 	- Have p2m_set_suppress_ve_multi() take
> xen_hvm_altp2m_suppress_ve as a param.
> ---
>   tools/libxc/include/xenctrl.h   |  3 ++
>   tools/libxc/xc_altp2m.c         | 25 ++++++++++++++
>   xen/arch/x86/hvm/hvm.c          | 20 ++++++++++--
>   xen/arch/x86/mm/p2m.c           | 58 +++++++++++++++++++++++++++++++++
>   xen/include/public/hvm/hvm_op.h |  5 ++-
>   xen/include/xen/mem_access.h    |  3 ++
>   6 files changed, 111 insertions(+), 3 deletions(-)
> 
> diff --git a/tools/libxc/include/xenctrl.h b/tools/libxc/include/xenctrl.h
> index f4431687b3..21b644f459 100644
> --- a/tools/libxc/include/xenctrl.h
> +++ b/tools/libxc/include/xenctrl.h
> @@ -1923,6 +1923,9 @@ int xc_altp2m_switch_to_view(xc_interface *handle, uint32_t domid,
>                                uint16_t view_id);
>   int xc_altp2m_set_suppress_ve(xc_interface *handle, uint32_t domid,
>                                 uint16_t view_id, xen_pfn_t gfn, bool sve);
> +int xc_altp2m_set_supress_ve_multi(xc_interface *handle, uint32_t domid,
> +                                   uint16_t view_id, xen_pfn_t start_gfn,
> +                                   uint32_t nr, bool sve);
>   int xc_altp2m_get_suppress_ve(xc_interface *handle, uint32_t domid,
>                                 uint16_t view_id, xen_pfn_t gfn, bool *sve);
>   int xc_altp2m_set_mem_access(xc_interface *handle, uint32_t domid,
> diff --git a/tools/libxc/xc_altp2m.c b/tools/libxc/xc_altp2m.c
> index 09dad0355e..6605d9abbe 100644
> --- a/tools/libxc/xc_altp2m.c
> +++ b/tools/libxc/xc_altp2m.c
> @@ -234,6 +234,31 @@ int xc_altp2m_set_suppress_ve(xc_interface *handle, uint32_t domid,
>       return rc;
>   }
>   
> +int xc_altp2m_set_supress_ve_multi(xc_interface *handle, uint32_t domid,
> +                                   uint16_t view_id, xen_pfn_t start_gfn,
> +                                   uint32_t nr, bool sve)
> +{
> +    int rc;
> +    DECLARE_HYPERCALL_BUFFER(xen_hvm_altp2m_op_t, arg);
> +
> +    arg = xc_hypercall_buffer_alloc(handle, arg, sizeof(*arg));
> +    if ( arg == NULL )
> +        return -1;
> +
> +    arg->version = HVMOP_ALTP2M_INTERFACE_VERSION;
> +    arg->cmd = HVMOP_altp2m_set_suppress_ve_multi;
> +    arg->domain = domid;
> +    arg->u.suppress_ve.view = view_id;
> +    arg->u.suppress_ve.gfn = start_gfn;
> +    arg->u.suppress_ve.suppress_ve = sve;
> +    arg->u.suppress_ve.nr = nr;
> +
> +    rc = xencall2(handle->xcall, __HYPERVISOR_hvm_op, HVMOP_altp2m,
> +                  HYPERCALL_BUFFER_AS_ARG(arg));
> +    xc_hypercall_buffer_free(handle, arg);
> +    return rc;
> +}
> +
>   int xc_altp2m_set_mem_access(xc_interface *handle, uint32_t domid,
>                                uint16_t view_id, xen_pfn_t gfn,
>                                xenmem_access_t access)
> diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
> index 06a7b40107..66ed8b8e3e 100644
> --- a/xen/arch/x86/hvm/hvm.c
> +++ b/xen/arch/x86/hvm/hvm.c
> @@ -4535,6 +4535,7 @@ static int do_altp2m_op(
>       case HVMOP_altp2m_destroy_p2m:
>       case HVMOP_altp2m_switch_p2m:
>       case HVMOP_altp2m_set_suppress_ve:
> +    case HVMOP_altp2m_set_suppress_ve_multi:
>       case HVMOP_altp2m_get_suppress_ve:
>       case HVMOP_altp2m_set_mem_access:
>       case HVMOP_altp2m_set_mem_access_multi:
> @@ -4681,7 +4682,7 @@ static int do_altp2m_op(
>           break;
>   
>       case HVMOP_altp2m_set_suppress_ve:
> -        if ( a.u.suppress_ve.pad1 || a.u.suppress_ve.pad2 )
> +        if ( a.u.suppress_ve.pad1 )
>               rc = -EINVAL;
>           else
>           {
> @@ -4693,8 +4694,23 @@ static int do_altp2m_op(
>           }
>           break;
>   
> +    case HVMOP_altp2m_set_suppress_ve_multi:
> +        if ( a.u.suppress_ve.pad1 || !a.u.suppress_ve.nr )
> +            rc = -EINVAL;
> +        else
> +        {
> +            rc = p2m_set_suppress_ve_multi(d, &a.u.suppress_ve);
> +
> +            if ( rc == -ERESTART )
> +                if ( __copy_field_to_guest(guest_handle_cast(arg,
> +                                           xen_hvm_altp2m_op_t),
> +                                           &a, u.suppress_ve.opaque) )
> +                    rc = -EFAULT;
> +        }
> +        break;
> +
>       case HVMOP_altp2m_get_suppress_ve:
> -        if ( a.u.suppress_ve.pad1 || a.u.suppress_ve.pad2 )
> +        if ( a.u.suppress_ve.pad1 )
>               rc = -EINVAL;
>           else
>           {
> diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c
> index e5e4349dea..9e1335065d 100644
> --- a/xen/arch/x86/mm/p2m.c
> +++ b/xen/arch/x86/mm/p2m.c
> @@ -3054,6 +3054,64 @@ out:
>       return rc;
>   }
>   
> +/*
> + * Set/clear the #VE suppress bit for multiple pages.  Only available on VMX.
> + */
> +int p2m_set_suppress_ve_multi(struct domain *d,
> +                              struct xen_hvm_altp2m_suppress_ve* sve)
> +{
> +    struct p2m_domain *host_p2m = p2m_get_hostp2m(d);
> +    struct p2m_domain *ap2m = NULL;
> +    struct p2m_domain *p2m;
> +    uint64_t start = sve->opaque ?: sve->gfn;
> +    int rc = 0;
> +
> +    if ( sve->view > 0 )
> +    {
> +        if ( sve->view >= MAX_ALTP2M ||
> +             d->arch.altp2m_eptp[sve->view] == mfn_x(INVALID_MFN) )
> +            return -EINVAL;
> +
> +        p2m = ap2m = d->arch.altp2m_p2m[sve->view];
> +    }
> +    else
> +        p2m = host_p2m;
> +
> +    p2m_lock(host_p2m);
> +
> +    if ( ap2m )
> +        p2m_lock(ap2m);
> +
> +
> +    while ( start < sve->nr )
> +    {
> +        p2m_access_t a;
> +        p2m_type_t t;
> +        mfn_t mfn;
> +
> +        if ( altp2m_get_effective_entry(p2m, _gfn(start), &mfn, &t, &a, AP2MGET_query) )
> +            a = p2m->default_access;
> +
> +        p2m->set_entry(p2m, _gfn(start), mfn, PAGE_ORDER_4K, t, a, sve->suppress_ve);
> +
> +        /* Check for continuation if it's not the last iteration. */
> +        if ( sve->nr > ++start && hypercall_preempt_check() )
> +        {
> +            rc = -ERESTART;
> +            break;
> +        }
> +    }
> +
> +    sve->opaque = start;
> +
> +    if ( ap2m )
> +        p2m_unlock(ap2m);
> +
> +    p2m_unlock(host_p2m);
> +
> +    return rc;
> +}
> +
>   int p2m_get_suppress_ve(struct domain *d, gfn_t gfn, bool *suppress_ve,
>                           unsigned int altp2m_idx)
>   {
> diff --git a/xen/include/public/hvm/hvm_op.h b/xen/include/public/hvm/hvm_op.h
> index 353f8034d9..9834ce0aea 100644
> --- a/xen/include/public/hvm/hvm_op.h
> +++ b/xen/include/public/hvm/hvm_op.h
> @@ -42,8 +42,9 @@ struct xen_hvm_altp2m_suppress_ve {
>       uint16_t view;
>       uint8_t suppress_ve; /* Boolean type. */
>       uint8_t pad1;
> -    uint32_t pad2;
> +    uint32_t nr;
>       uint64_t gfn;
> +    uint64_t opaque;
>   };
>   
>   #if __XEN_INTERFACE_VERSION__ < 0x00040900
> @@ -339,6 +340,8 @@ struct xen_hvm_altp2m_op {
>   #define HVMOP_altp2m_vcpu_disable_notify  13
>   /* Get the active vcpu p2m index */
>   #define HVMOP_altp2m_get_p2m_idx          14
> +/* Set the "Supress #VE" bit for a range of pages */
> +#define HVMOP_altp2m_set_suppress_ve_multi 15
>       domid_t domain;
>       uint16_t pad1;
>       uint32_t pad2;
> diff --git a/xen/include/xen/mem_access.h b/xen/include/xen/mem_access.h
> index e4d24502e0..ffecd2650e 100644
> --- a/xen/include/xen/mem_access.h
> +++ b/xen/include/xen/mem_access.h
> @@ -75,6 +75,9 @@ long p2m_set_mem_access_multi(struct domain *d,
>   int p2m_set_suppress_ve(struct domain *d, gfn_t gfn, bool suppress_ve,
>                           unsigned int altp2m_idx);
>   
> +int p2m_set_suppress_ve_multi(struct domain *d,
> +                              struct xen_hvm_altp2m_suppress_ve* suppress_ve);
> +
>   int p2m_get_suppress_ve(struct domain *d, gfn_t gfn, bool *suppress_ve,
>                           unsigned int altp2m_idx);
>   
> 
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel