| Message ID | 20220311061123.1883189-11-Penny.Zheng@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Static shared memory on dom0less system | expand |
On Fri, 11 Mar 2022, Penny Zheng wrote: > From: Penny Zheng <penny.zheng@arm.com> > > If owner property is defined, then owner domain of a static shared memory > region is not the default dom_shared anymore, but a specific domain. > > This commit implements allocating static shared memory to a specific domain > when owner property is defined. > > Signed-off-by: Penny Zheng <penny.zheng@arm.com> > --- > xen/arch/arm/domain_build.c | 63 ++++++++++++++++++++++++++++--------- > 1 file changed, 48 insertions(+), 15 deletions(-) > > diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c > index d35f98ff9c..7ee4d33e0b 100644 > --- a/xen/arch/arm/domain_build.c > +++ b/xen/arch/arm/domain_build.c > @@ -872,6 +872,8 @@ static int __init process_shm(struct domain *d, > u32 shm_id; > u32 addr_cells, size_cells; > paddr_t gbase, pbase, psize; > + const char *role_str; > + bool owner_dom_shared = true; > > dt_for_each_child_node(node, shm_node) > { > @@ -899,6 +901,13 @@ static int __init process_shm(struct domain *d, > gbase = dt_read_number(cells, addr_cells); > > /* TODO: Consider owner domain is not the default dom_shared. */ We should remove this comment? > + /* > + * "role" property is optional and if it is defined explicitly, > + * so the owner domain is not the default "dom_shared" domain. > + */ > + if ( dt_property_read_string(shm_node, "role", &role_str) == 0 ) > + owner_dom_shared = false; > + > /* > * Per shared memory region could be shared between multiple domains. > * In case re-allocating the same shared memory region, we use bitmask > @@ -907,17 +916,38 @@ static int __init process_shm(struct domain *d, > */ > if ( !test_bit(shm_id, shm_mask) ) > { > - /* > - * Allocate statically shared pages to the default dom_shared. > - * Set up P2M, and dom_shared is a direct-map domain, > - * so GFN == PFN. > - */ > - ret = allocate_shared_memory(dom_shared, addr_cells, size_cells, > - pbase, psize, pbase); > - if ( ret ) > - return ret; > - > - set_bit(shm_id, shm_mask); > + if ( !owner_dom_shared ) > + { > + if ( strcmp(role_str, "owner") == 0 ) > + { > + /* > + * Allocate statically shared pages to a specific owner > + * domain. > + */ > + ret = allocate_shared_memory(d, shm_id, addr_cells, > + size_cells, pbase, psize, > + gbase); > + if ( ret ) > + return ret; > + > + set_bit(shm_id, shm_mask); > + } > + } > + else > + { > + /* > + * Allocate statically shared pages to the default dom_shared. > + * Set up P2M, and dom_shared is a direct-map domain, > + * so GFN == PFN. > + */ > + ret = allocate_shared_memory(dom_shared, shm_id, > + addr_cells, size_cells, pbase, > + psize, pbase); > + if ( ret ) > + return ret; > + > + set_bit(shm_id, shm_mask); > + } These two chunks are identical if not for dom_shared / d. Can we just do: if ( owner_dom_shared ) d = dom_shared; on top? Then we can implement this only once. > } > > /* > @@ -925,10 +955,13 @@ static int __init process_shm(struct domain *d, > * default dom_shared, so here we could just set up P2M foreign > * mapping for borrower domain immediately. > */ > - ret = guest_physmap_add_shm(dom_shared, d, PFN_DOWN(pbase), > - PFN_DOWN(gbase), PFN_DOWN(psize)); > - if ( ret ) > - return ret; > + if ( owner_dom_shared ) > + { > + ret = guest_physmap_add_shm(dom_shared, d, PFN_DOWN(pbase), > + PFN_DOWN(gbase), PFN_DOWN(psize)); > + if ( ret ) > + return ret; > + } What happens if the borrower is specified before the owner in device tree? I see the case is handle by the next patch. Maybe we can have at least a comment here or in the commit message. > > /* > * Record static shared memory region info for later setting > -- > 2.25.1 >
diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c index d35f98ff9c..7ee4d33e0b 100644 --- a/xen/arch/arm/domain_build.c +++ b/xen/arch/arm/domain_build.c @@ -872,6 +872,8 @@ static int __init process_shm(struct domain *d, u32 shm_id; u32 addr_cells, size_cells; paddr_t gbase, pbase, psize; + const char *role_str; + bool owner_dom_shared = true; dt_for_each_child_node(node, shm_node) { @@ -899,6 +901,13 @@ static int __init process_shm(struct domain *d, gbase = dt_read_number(cells, addr_cells); /* TODO: Consider owner domain is not the default dom_shared. */ + /* + * "role" property is optional and if it is defined explicitly, + * so the owner domain is not the default "dom_shared" domain. + */ + if ( dt_property_read_string(shm_node, "role", &role_str) == 0 ) + owner_dom_shared = false; + /* * Per shared memory region could be shared between multiple domains. * In case re-allocating the same shared memory region, we use bitmask @@ -907,17 +916,38 @@ static int __init process_shm(struct domain *d, */ if ( !test_bit(shm_id, shm_mask) ) { - /* - * Allocate statically shared pages to the default dom_shared. - * Set up P2M, and dom_shared is a direct-map domain, - * so GFN == PFN. - */ - ret = allocate_shared_memory(dom_shared, addr_cells, size_cells, - pbase, psize, pbase); - if ( ret ) - return ret; - - set_bit(shm_id, shm_mask); + if ( !owner_dom_shared ) + { + if ( strcmp(role_str, "owner") == 0 ) + { + /* + * Allocate statically shared pages to a specific owner + * domain. + */ + ret = allocate_shared_memory(d, shm_id, addr_cells, + size_cells, pbase, psize, + gbase); + if ( ret ) + return ret; + + set_bit(shm_id, shm_mask); + } + } + else + { + /* + * Allocate statically shared pages to the default dom_shared. + * Set up P2M, and dom_shared is a direct-map domain, + * so GFN == PFN. + */ + ret = allocate_shared_memory(dom_shared, shm_id, + addr_cells, size_cells, pbase, + psize, pbase); + if ( ret ) + return ret; + + set_bit(shm_id, shm_mask); + } } /* @@ -925,10 +955,13 @@ static int __init process_shm(struct domain *d, * default dom_shared, so here we could just set up P2M foreign * mapping for borrower domain immediately. */ - ret = guest_physmap_add_shm(dom_shared, d, PFN_DOWN(pbase), - PFN_DOWN(gbase), PFN_DOWN(psize)); - if ( ret ) - return ret; + if ( owner_dom_shared ) + { + ret = guest_physmap_add_shm(dom_shared, d, PFN_DOWN(pbase), + PFN_DOWN(gbase), PFN_DOWN(psize)); + if ( ret ) + return ret; + } /* * Record static shared memory region info for later setting