> -----Original Message-----
> From: Julien Grall <[email protected]>
> Sent: Sunday, January 8, 2023 8:23 PM
> To: Penny Zheng <[email protected]>; [email protected]
> Cc: Wei Chen <[email protected]>; Stefano Stabellini
> <[email protected]>; Bertrand Marquis <[email protected]>;
> Volodymyr Babchuk <[email protected]>
> Subject: Re: [PATCH v1 05/13] xen/arm: allocate shared memory from heap
> when host address not provided
>
> Hi Penny,
>
Hi Julien,
> On 15/11/2022 02:52, Penny Zheng wrote:
> > when host address is not provided in "xen,shared-mem", we let Xen
> > allocate requested shared memory from heap, and once the shared
> memory
> > is allocated, it will be marked as static(PGC_static), which means
> > that it will be reserved as static memory, and will not go back to heap even
> on freeing.
>
> Please don't move pages from the {xen,dom}heap to the static heap. If you
> need to keep the pages for longer, then get an extra reference so they will
> not be released.
>
> >
> > Signed-off-by: Penny Zheng <[email protected]>
> > ---
> > xen/arch/arm/domain_build.c | 83
> ++++++++++++++++++++++++++++++++++++-
> > 1 file changed, 82 insertions(+), 1 deletion(-)
> >
> > +static int __init allocate_shared_memory(struct shm_membank
> *shm_membank,
> > + paddr_t psize) {
> > + struct meminfo *banks;
> > + int ret;
> > +
> > + BUG_ON(shm_membank->mem.banks.meminfo != NULL);
> > +
> > + banks = xmalloc_bytes(sizeof(struct meminfo));
>
> Where is this freed?
>
These kinds of info will be only used in boot-time, so maybe I shall
free them in init_done()?
Or just after process_shm() ?
> > + if ( banks == NULL )
> > + return -ENOMEM;
> > + shm_membank->mem.banks.meminfo = banks;
> > + memset(shm_membank->mem.banks.meminfo, 0, sizeof(struct
> > + meminfo));
> > +
> > + if ( !allocate_domheap_memory(NULL, psize, shm_membank-
> >mem.banks.meminfo) )
> > + return -EINVAL;
> > +
> > + ret = mark_shared_memory_static(shm_membank);
> > + if ( ret )
> > + return ret;
> > +
> > + return 0;
> > +}
> > +
> > static mfn_t __init acquire_shared_memory_bank(struct domain *d,
> > paddr_t pbase, paddr_t
> > psize)
> > {
> > @@ -975,7 +1041,7 @@ static int __init process_shm(struct domain *d,
> struct kernel_info *kinfo,
> > unsigned int i;
> > const char *role_str;
> > const char *shm_id;
> > - bool owner_dom_io = true;
> > + bool owner_dom_io = true, paddr_assigned = true;
> > struct shm_membank *shm_membank;
> >
> > if ( !dt_device_is_compatible(shm_node,
> > "xen,domain-shared-memory-v1") ) @@ -1035,6 +1101,21 @@ static int
> __init process_shm(struct domain *d, struct kernel_info *kinfo,
> > return -ENOENT;
> > }
> >
> > + /*
> > + * When host address is not provided in "xen,shared-mem",
> > + * we let Xen allocate requested memory from heap at first domain.
> > + */
> > + if ( !paddr_assigned && !shm_membank->mem.banks.meminfo )
> > + {
> > + ret = allocate_shared_memory(shm_membank, psize);
> > + if ( ret )
> > + {
> > + printk("%pd: failed to allocate shared memory
> bank(%"PRIpaddr"MB) from heap: %d\n",
> > + d, psize >> 20, ret);
> > + return ret;
> > + }
> > + }
> > +
> > /*
> > * DOMID_IO is a fake domain and is not described in the
> > Device-Tree.
> > * Therefore when the owner of the shared region is
> > DOMID_IO, we will
>
> Cheers,
>
> --
> Julien Grall
Cheers,
--
Penny Zheng
