Re: [PATCH v4 05/10] common/domain: allocate vmtrace_pt_buffer

[Julien Grall <julien@xen.org>]

Hi,

On 30/06/2020 13:33, Michał Leszczyński wrote:
> +static int vmtrace_alloc_buffers(struct vcpu *v)
> +{
> +    struct page_info *pg;
> +    uint64_t size = v->domain->vmtrace_pt_size;
> +
> +    if ( size < PAGE_SIZE || size > GB(4) || (size & (size - 1)) )
> +    {
> +        /*
> +         * We don't accept trace buffer size smaller than single page
> +         * and the upper bound is defined as 4GB in the specification.

This is common code, so what specification are you talking about?

I am guessing this is an Intel one, but I don't think Intel should 
dictate the common code implementation.

> +         * The buffer size must be also a power of 2.
> +         */
> +        return -EINVAL;
> +    }
> +
> +    pg = alloc_domheap_pages(v->domain, get_order_from_bytes(size),
> +                             MEMF_no_refcount);
> +
> +    if ( !pg )
> +        return -ENOMEM;
> +
> +    v->arch.vmtrace.pt_buf = pg;

v->arch.vmtrace.pt_buf is not defined on Arm. Please make sure common 
code build on all arch.

Cheers,

-- 
Julien Grall