On Sat, Jan 30, 2021 at 02:58:44AM +0000, Andrew Cooper wrote:
> From: Michał Leszczyński <michal.leszczyn...@cert.pl>
>
> To use vmtrace, buffers of a suitable size need allocating, and different
> tasks will want different sizes.
>
> Add a domain creation parameter, and audit it appropriately in the
> {arch_,}sanitise_domain_config() functions.
>
> For now, the x86 specific auditing is tuned to Processor Trace running in
> Single Output mode, which requires a single contiguous range of memory.
>
> The size is given an arbitrary limit of 64M which is expected to be enough for
> anticipated usecases, but not large enough to get into long-running-hypercall
> problems.
>
> Signed-off-by: Michał Leszczyński <michal.leszczyn...@cert.pl>
> Signed-off-by: Andrew Cooper <andrew.coop...@citrix.com>
Reviewed-by: Roger Pau Monné <roger....@citrix.com>
> diff --git a/xen/common/domain.c b/xen/common/domain.c
> index d1e94d88cf..491b32812e 100644
> --- a/xen/common/domain.c
> +++ b/xen/common/domain.c
> @@ -132,6 +132,71 @@ static void vcpu_info_reset(struct vcpu *v)
> v->vcpu_info_mfn = INVALID_MFN;
> }
>
> +static void vmtrace_free_buffer(struct vcpu *v)
> +{
> + const struct domain *d = v->domain;
> + struct page_info *pg = v->vmtrace.pg;
> + unsigned int i;
> +
> + if ( !pg )
> + return;
> +
> + v->vmtrace.pg = NULL;
> +
> + for ( i = 0; i < (d->vmtrace_size >> PAGE_SHIFT); i++ )
> + {
> + put_page_alloc_ref(&pg[i]);
> + put_page_and_type(&pg[i]);
> + }
> +}
> +
> +static int vmtrace_alloc_buffer(struct vcpu *v)
You might as well make this return true/false, as the error code is
ignored by the caller (at least in this patch).
Thanks, Roger.
