Hi Penny,
On 07/06/2021 03:43, Penny Zheng wrote:
This commit checks `xen,static-mem` device tree property in /domUx node,
to determine whether domain is on Static Allocation, when constructing
domain during boot-up.
Right now, the implementation of allocate_static_memory is missing, and
will be introduced later. It just BUG() out at the moment.
And if the `memory` property and `xen,static-mem` are both set, it shall
be verified that if the memory size defined in both is consistent.
Signed-off-by: Penny Zheng <penny.zh...@arm.com>
---
changes v2:
- remove parsing procedure here
- check the consistency when `xen,static-mem` and `memory` are both defined
---
xen/arch/arm/domain_build.c | 37 +++++++++++++++++++++++++++++++------
1 file changed, 31 insertions(+), 6 deletions(-)
diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
index 282416e74d..4166d7993c 100644
--- a/xen/arch/arm/domain_build.c
+++ b/xen/arch/arm/domain_build.c
@@ -2424,23 +2424,47 @@ static int __init construct_domU(struct domain *d,
{
struct kernel_info kinfo = {};
int rc;
- u64 mem;
+ u64 mem, static_mem_size = 0;
+ const struct dt_property *prop;
+ bool static_mem = false;
+
+ d->max_pages = ~0U;
+ /*
+ * Guest RAM could be of static memory from static allocation,
+ * which will be specified through "xen,static-mem" phandle.
+ */
+ prop = dt_find_property(node, "xen,static-mem", NULL);
+ if ( prop )
+ {
+ static_mem = true;
+ /* static_mem_size = allocate_static_memory(...); */
+ BUG();
+ }
I would prefer if the static memory is allocated close to
allocate_memory() below. AFAICT, the reason you allocate here is because
you want to have the property "memory" optional.
However, I am not entirely convinced this is a good idea to make
optional. It would be easier for a reader to figure out from the
device-tree how much memory we give to the guest.
rc = dt_property_read_u64(node, "memory", &mem);
- if ( !rc )
+ if ( !static_mem && !rc )
{
printk("Error building DomU: cannot read \"memory\" property\n");
return -EINVAL;
+ } else if ( rc && static_mem )
+ {
+ if ( static_mem_size != mem * SZ_1K )
+ {
+ printk("Memory size in \"memory\" property isn't consistent with"
+ "the ones defined in \"xen,static-mem\".\n");
+ return -EINVAL;
+ }
} > - kinfo.unassigned_mem = (paddr_t)mem * SZ_1K;
+ kinfo.unassigned_mem = static_mem ? 0 : (paddr_t)mem * SZ_1K; >
- printk("*** LOADING DOMU cpus=%u memory=%"PRIx64"KB ***\n", d->max_vcpus,
mem);
+ printk("*** LOADING DOMU cpus=%u memory=%"PRIx64"KB ***\n",
+ d->max_vcpus,
+ static_mem ? static_mem_size : (kinfo.unassigned_mem) >> 10);
If we mandate the property "memory", then kinfo.unassigned_mem doesn't
need to be touched. Instead, you could simply check the
kinfo.unassigned_mem is equivalent to static_mem_size.
kinfo.vpl011 = dt_property_read_bool(node, "vpl011");
if ( vcpu_create(d, 0) == NULL )
return -ENOMEM;
- d->max_pages = ~0U;
kinfo.d = d;
@@ -2452,7 +2476,8 @@ static int __init construct_domU(struct domain *d,
/* type must be set before allocate memory */
d->arch.type = kinfo.type;
#endif
- allocate_memory(d, &kinfo);
+ if ( !static_mem )
+ allocate_memory(d, &kinfo);
rc = prepare_dtb_domU(d, &kinfo);
if ( rc < 0 )
Cheers,
--
Julien Grall
