| Message ID | 5CF667B40200007800235145@prv1-mh.provo.novell.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | adjust special domain creation | expand |
On 04/06/2019 13:44, Jan Beulich wrote: > A couple of adjustments are needed to code checking for dom_cow, but > since there are pretty few it is probably better to adjust those than > to set up and keep around a never used domain. > > Signed-off-by: Jan Beulich <jbeulich@suse.com> Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Hi Jan, On 04/06/2019 13:44, Jan Beulich wrote: > A couple of adjustments are needed to code checking for dom_cow, but > since there are pretty few it is probably better to adjust those than > to set up and keep around a never used domain. > > Signed-off-by: Jan Beulich <jbeulich@suse.com> Acked-by: Julien Grall <julien.grall@arm.com> Cheers, > --- > v2: Use #if/#else. Split out emul-priv-op.c change. > --- > While for now this avoids creating the domain on Arm only, Tamas'es > patch switching to CONFIG_MEM_SHARING will make x86 leverage this too. > > --- a/xen/arch/x86/mm.c > +++ b/xen/arch/x86/mm.c > @@ -967,8 +967,8 @@ get_page_from_l1e( > return flip; > } > > - if ( unlikely( (real_pg_owner != pg_owner) && > - (real_pg_owner != dom_cow) ) ) > + if ( unlikely((real_pg_owner != pg_owner) && > + (!dom_cow || (real_pg_owner != dom_cow))) ) > { > /* > * Let privileged domains transfer the right to map their target > --- a/xen/arch/x86/mm/p2m.c > +++ b/xen/arch/x86/mm/p2m.c > @@ -568,7 +568,8 @@ struct page_info *p2m_get_page_from_gfn( > } > else if ( !get_page(page, p2m->domain) && > /* Page could be shared */ > - (!p2m_is_shared(*t) || !get_page(page, dom_cow)) ) > + (!dom_cow || !p2m_is_shared(*t) || > + !get_page(page, dom_cow)) ) > page = NULL; > } > p2m_read_unlock(p2m); > @@ -941,7 +942,8 @@ guest_physmap_add_entry(struct domain *d > /* Then, look for m->p mappings for this range and deal with them */ > for ( i = 0; i < (1UL << page_order); i++ ) > { > - if ( page_get_owner(mfn_to_page(mfn_add(mfn, i))) == dom_cow ) > + if ( dom_cow && > + page_get_owner(mfn_to_page(mfn_add(mfn, i))) == dom_cow ) > { > /* This is no way to add a shared page to your physmap! */ > gdprintk(XENLOG_ERR, "Adding shared mfn %lx directly to dom%d physmap not allowed.\n", > --- a/xen/common/domain.c > +++ b/xen/common/domain.c > @@ -74,7 +74,9 @@ integer_param("hardware_dom", hardware_d > /* Private domain structs for DOMID_XEN, DOMID_IO, etc. */ > struct domain *__read_mostly dom_xen; > struct domain *__read_mostly dom_io; > +#ifdef CONFIG_HAS_MEM_SHARING > struct domain *__read_mostly dom_cow; > +#endif > > struct vcpu *idle_vcpu[NR_CPUS] __read_mostly; > > @@ -547,6 +549,7 @@ void __init setup_special_domains(void) > if ( IS_ERR(dom_io) ) > panic("Failed to create d[IO]: %ld\n", PTR_ERR(dom_io)); > > +#ifdef CONFIG_HAS_MEM_SHARING > /* > * Initialise our COW domain. > * This domain owns sharable pages. > @@ -554,6 +557,7 @@ void __init setup_special_domains(void) > dom_cow = domain_create(DOMID_COW, NULL, false); > if ( IS_ERR(dom_cow) ) > panic("Failed to create d[COW]: %ld\n", PTR_ERR(dom_cow)); > +#endif > } > > void domain_update_node_affinity(struct domain *d) > --- a/xen/common/grant_table.c > +++ b/xen/common/grant_table.c > @@ -1095,7 +1095,7 @@ map_grant_ref( > host_map_created = true; > } > } > - else if ( owner == rd || owner == dom_cow ) > + else if ( owner == rd || (dom_cow && owner == dom_cow) ) > { > if ( (op->flags & GNTMAP_device_map) && !(op->flags & GNTMAP_readonly) ) > { > --- a/xen/include/xen/mm.h > +++ b/xen/include/xen/mm.h > @@ -643,7 +643,12 @@ static inline void filtered_flush_tlb_ma > } > > /* Private domain structs for DOMID_XEN, DOMID_IO, etc. */ > -extern struct domain *dom_xen, *dom_io, *dom_cow; > +extern struct domain *dom_xen, *dom_io; > +#ifdef CONFIG_HAS_MEM_SHARING > +extern struct domain *dom_cow; > +#else > +# define dom_cow NULL > +#endif > > enum XENSHARE_flags { > SHARE_rw, > > > >
--- a/xen/arch/x86/mm.c +++ b/xen/arch/x86/mm.c @@ -967,8 +967,8 @@ get_page_from_l1e( return flip; } - if ( unlikely( (real_pg_owner != pg_owner) && - (real_pg_owner != dom_cow) ) ) + if ( unlikely((real_pg_owner != pg_owner) && + (!dom_cow || (real_pg_owner != dom_cow))) ) { /* * Let privileged domains transfer the right to map their target --- a/xen/arch/x86/mm/p2m.c +++ b/xen/arch/x86/mm/p2m.c @@ -568,7 +568,8 @@ struct page_info *p2m_get_page_from_gfn( } else if ( !get_page(page, p2m->domain) && /* Page could be shared */ - (!p2m_is_shared(*t) || !get_page(page, dom_cow)) ) + (!dom_cow || !p2m_is_shared(*t) || + !get_page(page, dom_cow)) ) page = NULL; } p2m_read_unlock(p2m); @@ -941,7 +942,8 @@ guest_physmap_add_entry(struct domain *d /* Then, look for m->p mappings for this range and deal with them */ for ( i = 0; i < (1UL << page_order); i++ ) { - if ( page_get_owner(mfn_to_page(mfn_add(mfn, i))) == dom_cow ) + if ( dom_cow && + page_get_owner(mfn_to_page(mfn_add(mfn, i))) == dom_cow ) { /* This is no way to add a shared page to your physmap! */ gdprintk(XENLOG_ERR, "Adding shared mfn %lx directly to dom%d physmap not allowed.\n", --- a/xen/common/domain.c +++ b/xen/common/domain.c @@ -74,7 +74,9 @@ integer_param("hardware_dom", hardware_d /* Private domain structs for DOMID_XEN, DOMID_IO, etc. */ struct domain *__read_mostly dom_xen; struct domain *__read_mostly dom_io; +#ifdef CONFIG_HAS_MEM_SHARING struct domain *__read_mostly dom_cow; +#endif struct vcpu *idle_vcpu[NR_CPUS] __read_mostly; @@ -547,6 +549,7 @@ void __init setup_special_domains(void) if ( IS_ERR(dom_io) ) panic("Failed to create d[IO]: %ld\n", PTR_ERR(dom_io)); +#ifdef CONFIG_HAS_MEM_SHARING /* * Initialise our COW domain. * This domain owns sharable pages. @@ -554,6 +557,7 @@ void __init setup_special_domains(void) dom_cow = domain_create(DOMID_COW, NULL, false); if ( IS_ERR(dom_cow) ) panic("Failed to create d[COW]: %ld\n", PTR_ERR(dom_cow)); +#endif } void domain_update_node_affinity(struct domain *d) --- a/xen/common/grant_table.c +++ b/xen/common/grant_table.c @@ -1095,7 +1095,7 @@ map_grant_ref( host_map_created = true; } } - else if ( owner == rd || owner == dom_cow ) + else if ( owner == rd || (dom_cow && owner == dom_cow) ) { if ( (op->flags & GNTMAP_device_map) && !(op->flags & GNTMAP_readonly) ) { --- a/xen/include/xen/mm.h +++ b/xen/include/xen/mm.h @@ -643,7 +643,12 @@ static inline void filtered_flush_tlb_ma } /* Private domain structs for DOMID_XEN, DOMID_IO, etc. */ -extern struct domain *dom_xen, *dom_io, *dom_cow; +extern struct domain *dom_xen, *dom_io; +#ifdef CONFIG_HAS_MEM_SHARING +extern struct domain *dom_cow; +#else +# define dom_cow NULL +#endif enum XENSHARE_flags { SHARE_rw,
A couple of adjustments are needed to code checking for dom_cow, but since there are pretty few it is probably better to adjust those than to set up and keep around a never used domain. Signed-off-by: Jan Beulich <jbeulich@suse.com> --- v2: Use #if/#else. Split out emul-priv-op.c change. --- While for now this avoids creating the domain on Arm only, Tamas'es patch switching to CONFIG_MEM_SHARING will make x86 leverage this too.