diff options
Diffstat (limited to 'xen/arch/x86/mm/p2m-pt.c')
| -rw-r--r-- | xen/arch/x86/mm/p2m-pt.c | 44 |
1 files changed, 41 insertions, 3 deletions
diff --git a/xen/arch/x86/mm/p2m-pt.c b/xen/arch/x86/mm/p2m-pt.c index 41be7fbd61..5fa0d30ce7 100644 --- a/xen/arch/x86/mm/p2m-pt.c +++ b/xen/arch/x86/mm/p2m-pt.c @@ -122,17 +122,55 @@ static int write_p2m_entry(struct p2m_domain *p2m, unsigned long gfn, { struct domain *d = p2m->domain; const struct vcpu *v = current; - int rc = 0; if ( v->domain != d ) v = d->vcpu ? d->vcpu[0] : NULL; if ( likely(v && paging_mode_enabled(d) && paging_get_hostmode(v)) || p2m_is_nestedp2m(p2m) ) - rc = p2m->write_p2m_entry(p2m, gfn, p, new, level); + { + unsigned int oflags; + mfn_t omfn; + int rc; + + paging_lock(d); + + if ( p2m->write_p2m_entry_pre ) + p2m->write_p2m_entry_pre(d, gfn, p, new, level); + + oflags = l1e_get_flags(*p); + omfn = l1e_get_mfn(*p); + + rc = p2m_entry_modify(p2m, p2m_flags_to_type(l1e_get_flags(new)), + p2m_flags_to_type(oflags), l1e_get_mfn(new), + omfn, level); + if ( rc ) + { + paging_unlock(d); + return rc; + } + + safe_write_pte(p, new); + + if ( p2m->write_p2m_entry_post ) + p2m->write_p2m_entry_post(p2m, oflags); + + paging_unlock(d); + + if ( nestedhvm_enabled(d) && !p2m_is_nestedp2m(p2m) && + (oflags & _PAGE_PRESENT) && + !p2m_get_hostp2m(d)->defer_nested_flush && + /* + * We are replacing a valid entry so we need to flush nested p2ms, + * unless the only change is an increase in access rights. + */ + (!mfn_eq(omfn, l1e_get_mfn(new)) || + !perms_strictly_increased(oflags, l1e_get_flags(new))) ) + p2m_flush_nestedp2m(d); + } else safe_write_pte(p, new); - return rc; + return 0; } // Find the next level's P2M entry, checking for out-of-range gfn's... |